heres some info from COMP CAMS
" Flat Tappet vs. Roller Tappet Lifters
theres far more than just the cam and lifters required to swap types of cams,
if your engines currently equipped with a flat tappet cam your almost sure to need a new
timing chain set
cam button
new push rods
obviously a new cam and roller lifters.
and its almost always in your best interest to add better valves springs, retainers,keeper rockers etc.
its also very common to need spring pockets cut, new spring shims etc.
roller cams allow less friction and better, more consistent and if properly set up more stable high rpm valve train control
a flat tappet hydraulic cam will function correctly if properly installed but compared to a decent roller cam it can easily cost you 30-40 plus hp in some applications
good hydraulic flat tappet cams and lifters are significantly less expensive at $170-$600 for name brand components vs $870-$1500 for a roller set up,obviously depending on components selected and changes required.
generally its best to purchase all the listed components in a cam installation kit (cam, lifters,valve springs, etc. ) from a single manufacturer as mixing parts, sources or brands,
allows the cam manufacturer to void the warranty, even if the parts in the kit they sell are either identical or inferior to,
the individually purchased components you individually sourced. keep in mind most manufacturers will have tested parts compatibility ,
so they are reasonably sure the components they sell in the kit will work, that can,t be always assumed,
with randomly matched parts even if those parts are good quality.
https://www.enginelabs.com/tech-stories/ferrea-helps-explains-valve-flow-dynamics/
CAST CAM CORES ARE NOT DESIGNED TO HANDLE OVER ABOUT 130lbs SEAT and 400lbs OPEN SPRING LOADS YOU NEED A BILLET CAM CORE FOR DURABILITY IF THOSE LIMITS ARE EXCEEDED
Isky claims that the Comp XE cams violate the 47.5% rule. The 47.5% rule applies to flat tappet cams for SBCs with 1.5 rockers but the concept is still the same for other configurations where the designs are "on the edge" or "over the edge" for lobe intensity. For 1.5 ratio SBCs, the duration at .050 must exceed 47.5% of the total valve lift or your asking valve train problems. For example, take a Comp Cams Magnum 280H, with 230 duration and, 480 lift...230/.480 = 47.9% which exceeds 47.5% therefore would not pose a threat to components. We do not regularly hear about the older, safer HE and Magnum designs rounding off lobes anywhere near as often as the XE cam designs. Unfortunately, some of the Comp Cams XE dual pattern lobes break this 47.5% rule on the intake side so they are likely to be problematic. The design has "steeper" ramps that are too quick for durability and reliability according to other cam manufacturers. They will wipe lobes in a heart beat especially if you have not followed the proper break-in procedure. Other designs are more forgiving during break-in and less likely to fail.
In nearly all circumstances, a good roller camshaft design will outperform its flat tappet counterpart. Among the benefits of roller cams are higher tappet velocity, more lift and more area, along with reduced valve train friction (often a 15+ hp increase) and higher engine rpm with little effect on low speed driveability and power.
Roller tappets are also reusable, which makes it possible to swap just the camshaft without the expense of new lifters. And finally, roller tappets are far less prone to wear, allowing higher spring loads, and they are more consistent with today’s oils.
The biggest advantage to building an engine with a flat tappet cam and lifters is the lower up-front cost. It can be significantly less expensive to use a flat tappet setup but should you decide to install a new camshaft, flat tappets are not reusable, roller lifters are more expensive. You will need new lifters as well.[/color]"
the answer depends on your goals, a good flat tappet cam and lifters usually costs $400-to under $240 some times under $159,
keep in mind the main reason solid lifter roller cams tend to have reputation for durability issues is the much higher valve spring pressures and stress levels used to allow solid roller cams to operate at high rpms, once you exceed about 6000 rpm valve train stress loads increase rapidly
keep in mind this is a small base circle cam with asymmetrical cam lobes you must use the .050 lift and duration numbers in calcs
https://www.summitracing.com/parts/...MIisTdgsuL3QIVlrjACh0EnAAjEAAYASAAEgKCTvD_BwE
http://www.enginebuildermag.com/2009/07/properly-matching-your-camshaft-and-distributor-gear/
http://garage.grumpysperformance.co...ts-needed-for-retrofit-roller-cam-swap.16456/
http://www.summitracing.com/parts/LUN-60104LK/
http://www.summitracing.com/parts/CRN-110692/
http://www.jesel.com/valvetrain/index.p ... rs/tie-bar
Read this link
http://www.superchevy.com/how-to/95258-hydraulic-roller-cams/
for name brand parts, off brands can be even cheaper
http://www.hotrod.com/techarticles/engi ... z2FeQk91VU
viewtopic.php?f=52&t=8582
viewtopic.php?f=55&t=58&p=36446#p36446
http://www.superchevy.com/how-to/148-0401-chevrolet-406-ci-engine-build/
http://www.hotrod.com/events/coverage/0611em-vortec-small-block/
http://www.superchevy.com/how-to/pr...t-tappet-cams-which-is-better-for-your-chevy/
most flat tappet cams use 110 lb-130 lb seat pressure springs ,
you can get by with the 140 lb-150 lb seat pressure springs in almost every application,
with a roller lifter cam, IF ITS A HEAT TREATED SURFACE HARDENED cam
but I would have suggested swapping to a billet cam by the time the seat pressure was much over 150 lbs
as the pressure on the lifter roller wheel increases so does the potential for having issues if you match a roller lifter and a soft cam lobe.
back in the late 1980s-early 1990s there are/were a few blocks made ,(mostly Mexican cast) that are not the newer roller lifter design
but yeah, most are the castings that have the longer taller lifter bores for roller lifters, even if the roller lifters were never installed
generally use of a cam with over about .530 lift with a spider flex plate retention system on the block and the OEM hydraulic lifters can lead to valve train failure at higher rpms
,and Ive seen it rather frequently with cams installed with stock heads and valve springs that had less than ,510 lift
http://garage.grumpysperformance.com/index.php?threads/small-base-circle-cams.3810/#post-72512
https://www.onallcylinders.com/2020...ith-roller-upgrade-for-small-block-chevy-350/
https://www.hotrod.com/articles/ccrp-0710-chevy-small-block/
http://www.superchevy.com/how-to/en...y-big-block-casting-changes-through-the-years
https://www.crower.com/media/pdf/RollerLifterGuide.pdf
http://www.superchevy.com/how-to/pr...at-tappet-cams-which-is-better-for-your-chevy
its NOT TYPICAL on the cheaper cams but its NOT hardly what you might call rare on cams that try to basically maximize results, and the current roller cam designs, because if you think about it the lobe is forced open as the roller rolls up and over the cam lobe but only spring pressure returns the valve most of the way to the cylinder head seat and they don,t want it to slam down and bounce so the lobe designs can be ground differently.An Asymmetrical cam has opening and closing ramps that are unlike and unequal. This profiles usually found on high performance cams and offers a high velocity opening and a lower velocity closing ramp in order to snap the valve open quickly and then set it back down more gently.
roller cam lobe designs are more complex than flat tapper cam lobes simply because the roller lifter allows much more precise valve open and timing events,
lobes on a roller cam,are generally asymmetrical, in the better roller cam lobe designs,
as its more important to open the valve fast, to maximize cylinder fill rates,
but reduce the valve seating/sealing, timing velocity, too prevent the valve bouncing off the seat as or after its closed,
this factor helps stabilize cylinder scavenging and valve train durability,
and stability but should not effect the software dyno results
RELATED
http://garage.grumpysperformance.co...d-high-spring-pressures-don-t-work-well.1489/
http://garage.grumpysperformance.com/index.php?threads/cam-wear-articles-you-need-to-read.282/
http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/
http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/
http://garage.grumpysperformance.com/index.php?threads/checking-piston-to-valve-clearances.399/
http://garage.grumpysperformance.co...-pushrods-and-check-info-you-might-need.5931/
http://www.superchevy.com/how-to/148-0307-converting-hydraulic-roller-cam
http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/
http://garage.grumpysperformance.com/index.php?threads/cam-bearing-install-tools-install-info.1479/
http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/
factory blocks with sheet steel lifter retention springs are NOT designed to exceed about .550 lift or 6000rpm
STOCK dog bone design hydraulic enclosed wheel roller lifters are generally designed for less than .550 lift and less than 6000rpm
the stock Chevy hydraulic roller lifters , dog bone and spider springs don,t always work reliably, ALL THE TIME with engines having over .500 lift or when spun over 6000rpm, its not all that rare for the lifter ,retainer to bend the retainer spring allowing the lifter to spin sideways, in the lifter bore, resulting in a destroyed cam, thats why Ive suggested BRAND NAME ,AFTERMARKET RETRO FIT CAM COMPONENTS BE USED
roller blocks have taller lifter bores, because roller lifters are taller, and a provision to bolt the lifter retainer spring, but they can be very easily used for the earlier flat tappet lifters if desired by simply removing the spider(SPRING RETAINER), keep in mind most roller blocks use one piece rear seals.
KEEP IN MIND that a good deal of the power in any engine combo will be the result of how efficiently you blend factors like,
EFFECTIVE COMPRESSION,vs fuel octane
CYLINDER HEAD FLOW rates vs displacement
and
EXHAUST scavenging efficiency.(cam timing)
theres a good deal of math involved, that can be used to accurately predict the results but there's also an ART and SKILL to tuning and engine assembly, and experience goes a long way there.
and yes a slight mis-match of components, not getting the clearances correct, or a few degrees of cam duration,plus or minus from what the engine needs, and a few cfm difference in intake or exhaust restriction,flow, a few extra fractions of an inch of valve lift, a better or worse multi angle valve job and your up or down 60-80 hp...
The answer to selecting the proper valve length in relation to the cam lift, and valve spring load rates, depends on the engine valve train geometry and the cylinder head design,
it differs from intake to exhaust on most engines also.
I've usually found longer valves are required if the valve lift exceeds about .630, but theres no rock solid rule, you need to do some research and call your machine shop and the cylinder head manufacture. the load rate also plays a significant part in that decision, thinner valve spring seats, is not always an option, as higher load rates require thicker castings for structural rigidity.
valve lift alone withing reasonable limits, has little to do with the need for longer valves, but as the lift increases the difference between the spring installed height and its spring bind or coil stack obviously changes.
if your standard valve spring has lets say a 1.70 installed height and a 1.20 coil bind or stack height you would generally be looking at .500 difference, subtract the .060 minimum clearance,
added to prevent binding issues for coil bind, that only leaves you .440 useful valve clearance.
now you can machine the heads in the valve spring seat area only minimally as the valve spring seats are over the coolant passages and generally ,
the manufacturers will tell you you can only machine the valve seat so far from the O.E.M. original location,
and in many cylinder heads you can't machine deeper without reducing the heads functional strength or causing problems.
if you can,t machine down into the valve spring seat, your other option is a longer valve stem, or if you just need about .040-.050 maybe you get by with off-set valve locks, or retainers, and longer push rods and valve lash caps.
but most machine shops would prefer the longer valves and longer push-rods to maintain the proper valve train geometry.
valves are generally available . .100,..200, .300 longer lengths for popular engines and you can certainly use a micrometer to measure similar valves from a different engine, if the proper length is not easily available.
be aware that theres both different valve stem diameters, valve lock location, valve lock designs, different intake and exhaust valve steels that you can,t interchange.
one of the old performance tricks some guys used to use on a BBC, engines with turbos, was to replace the 1.88 exhaust valves with 2.00 intake valves from a 430 lincoln engines that were made from exhaust steel.
keep in mind all that metallic trash, cycles through the oil pump BEFORE it reaches the oil filter
before as cast
example
http://garage.grumpysperformance.co...mmendation-from-erson-compared-w-crower.4530/
http://www.summitracing.com/parts/SUM-K1106/
notice the more aggressive cam lobe acceleration rate on the roller cam lobes
notice the stepped cam nose to fit retainer plate
a good hydraulic roller cam and lifters costs a good deal more
example
http://www.summitracing.com/parts/ISK-201282294/ cam $280
http://www.summitracing.com/parts/HRS-91164N/ lifters $297
http://www.superchevy.com/how-to/148-0307-converting-hydraulic-roller-cam
or more
http://www.summitracing.com/parts/LUN-60113/ cam $320
viewtopic.php?f=55&t=58&p=36446#p36446
http://www.summitracing.com/parts/CCA-885-16/ lifters $499
http://www.summitracing.com/parts/CRN-11532-16/ lifters $635
viewtopic.php?f=52&t=282&p=345#p345
having a REV-KIT that retains the lifters in their bores, to maintain oil pressure, even if the rocker comes loose or push rods breaks is a good idea
no mater what roller cam you select, youll need to get ,
the valve train geometry, clearances and spring load rates correct,
youll ideally want to get the quench distance in the .040-.042 range ,
port match the intake selected to the heads, and do all the other related checks and clearancing.
keep in mind scavenging the cylinders correctly requires a properly designed set of headers,
and open or at least very low flow restriction exhaust
http://garage.grumpysperformance.com/index.php?threads/engine-dyno-predictive-software.895/
http://garage.grumpysperformance.com/index.php?threads/building-custom-headers.961/
http://garage.grumpysperformance.com/index.php?threads/calculating-required-exhaust-pipe-size.11552/
http://garage.grumpysperformance.com/index.php?threads/calculating-header-design.185/
Tech Tip - 2008
Roller Lifters: Keep 'Em Rolling Longer
Most racers are aware of the advantages of Roller Lifters. For those who are not, a brief review is in order. Roller Cams & Lifters are employed today in all-out racing engines where valve lift/area requirements preclude the possibility of employing a flat tappet (solid lifter cam). Higher Lift requires higher valve spring loads (pressures) and flat tappet cams can only handle so much. Additionally, increased rates of lift (cam lobe velocity) above .007" per degree for example on an .842" diameter G.M. lifter, would cause the lobe to reach-out over the edge of the lifters' cam face. Consequently, with either too much spring or too high a lift rate, most racers know that extremely radical flat tappet cams will eventually self-destruct.
But, what about Roller Lifters? Are they as indestructible as many believe? How do we prolong the life of their roller bearings in today's modern race only engines? Roller lifters require special care and maintenance if they are to provide good service life. Here are the 4 most important factors you should consider to insure their success.
1. AVOID DRY "START UP": Roller Lifter Bearings are assembled with a "tacky" rust-preventing grease that is not intended for lubrication. Therefore, new lifters should have their roller bearings thoroughly washed in clean solvent or acetone to completely remove this assembly grease. After air drying, premium motor-oil (non-synthetic) such as Penzoil SAE 25W50 GTP Racing Oil (The best of the mineral based oils) or Amzoil "Red" Racing Oil (synthetic) should be used to pre-lube the bearings just before installation.
2. AVOID "OVERLOAD": Increased load always means reduced service life. Want 50% more thrust from a jet engine? Ask Rolls Royce or G.E. and they'll tell you to expect about ¼th the service life between overhauls. Similarly, employing drag race valve springs in the 900, 1000 to 1100 lb. Range will reduce the life of your roller bearings between rebuilds much the same as will employing high-impact roller cam profiles.
3. EMPLOY A REV KIT WHEN POSSIBLE: The primary advantage of Camfather Ed Isky's invention of the 1950's is that by pre-loading each Roller Lifter Bearing to its respective cam lobe, you eliminate needle roller bearing "skew". Skewing (the momentary mis-alignment of the bearings' needle rollers to their respective races) is provoked by the start-stop skidding action of the roller bearings each time the lash is taken-up. Eliminate it and you extend roller bearing life dramatically! Unfortunately, many engines such as the Big Block Chevy which could use one the most, don't lend themselves to such an installation because of the severe angularity of the pushrod coming out of the lifter.
4. EMPLOY LIFTERS WITH "PRESSURE-FED" OIL TO THE NEEDLE ROLLER BEARINGS: Hope is a good thing. But hoping oil will eventually find its way to your Roller Lifter bearings is not. Unfortunately, most roller lifters on the market do not pressure feed oil to the needle rollers, depending on the "splash & a little luck" system instead. In contrast, all Isky Roller Lifters feature pressure fed oil to their roller bearings. Isky's Top of the line "Red Zone" Series lifters feature an exclusive 3-Point "Multi-Port" oiling system to constantly bathe the needle rollers with cooling lubrication. Additionally, they feature our famous Marathon Roller bearing with the toughest shock absorbing heavy duty outer bearing race on the market for the highest possible load carrying capability and sustained Hi-Rpm Endurance. And, they're fully rebuildable, making them your best long-term value!
back to top
read thru this info, in the links below
http://www.idavette.net/hib/camcon.htm
http://www.chevyhiperformance.com/techa ... index.html
http://www.badasscars.com/index.cfm/pag ... prd100.htm
http://www.thirdgen.org/sbc-camshafts-primer
http://www.moparmusclemagazine.com/part ... index.html
viewtopic.php?f=70&t=1701&p=4159#p4159
http://www.chevyhiperformance.com/tech/ ... index.html
http://www.stockcarracing.com/techartic ... index.html
http://www.superchevy.com/how-to/148-0307-converting-hydraulic-roller-cam/
you should also keep in mind that a roller cam valve train with the same lift and duration as a flat tappet cam, can provide a good deal more port flow potential and resulting power, , how much more power is mostly the result of how much more port flow and volumetric efficiency you can get from the engine combo that the flat tappet cam will not be able top access because the valve opens longer per degree of rotation on the roller cam lobe and the lift and duration,the valve sees increases, roller cams have a far lower percentage of lobe wear and less friction, both tend to result in more usable horsepower.
now if your current flat tappet cam is providing most of the engines potential then the roller cam will only provide a mild improvement, but in most cases you can expect a 15hp-40 hp gain, (depending on displacement, port flow,exhaust scavenging etc,)over a similar flat tappet design with similar duration at .050 lift, but in many case the roller cams peak lift will be noticeably more.
within certain limits ,the larger the lifter diameter the faster the cam lobe acceleration ramp can be, chevy has a lifter diam. .842
ford uses a .874 diam, Chrysler .904 diam.
while all cam timing figures will vary this might help
but if your willing to pay for special cams and insert solid flat tappet lifters from the cam tunnel , or botton crank case side of the block while its inverted on the engine stand before the cam shaft is inserted holding them in the lifter bores, you can use mushroom base race lifters in a chevy, this allows you to gain the benefits of the larger chrysler lifter diameter while maintaining the stock lifter bore size, but its generally only done on race engines that see frequent maintence tear downs for inspection.
notice its right where the roller cams lobe design maximized the extra air flow potential that is the most effective flow area during the whole valve flow curve
and yes it frequently helps to match a roller cam to roller rockers as the reduced friction further helps the engines durability and ability to easily cope with faster valve train component acceleration, that tends to reduce heat and wear.
The following equation mathematically defines the available flow area for any given valve diameter and lift value:
Area = valve diameter x 0.98 x 3.14 x valve lift
Where 3.14 = pi (π)
For a typical 2.02-inch intake valve at .500-inch lift, it calculates as follows:
Area = 2.02 x 0.98 x 3.14 x 0.500 = 3.107 square inches, thus it makes a great deal of sense to push the valve lift a bit over .500, and have an intake port that is at least 3.2 square inches in cross sectional area, if you want to maximize flow on a 2.02" intake valve
http://garage.grumpysperformance.co...-the-extra-cost-vs-a-flat-tappet-design.3802/
the slight bevel on the cam lobe and the slight convex surface on the lifter base in combination with the lobe center-line being slightly offset from the blocks lifter bore results in the lifter rotating in its bores as the lobe rotates under the lifter base
but even roller cams can wipe out lobes if the valve train components or valve train lubrication,and geometry is not set up correctly
a quality hardened cam with proper lube won,t wear like this first two picture's, but notice the lifter stayed on track
hardened cam lobes and high quality hardened roller lifter wheels have very low rotational friction,
and as long as the valve train stays in its designed limitations and the inertial loads don,t over come the valve springs ability to maintain constant lifter to lobe contact,
and theres a constant bath of cooling oil flowing over the contact areas,
rates of lifter to lobe contact and wear are minimal or basically non-existent over any reasonable time frame
drilling the pass side oil passage plug with a 1/32" bit so oil constantly sprays on the timing gears, and cam retainer plate areas helps extend chain and gear life.
Comparing Cam Lobes – The roller camshaft (on the left) has steeper opening and closing ramps which allows for more time at max lift.
example
heres two similar hydraulic performance cams
heres a flat tappet with 246 duration and .500 lift
http://www.cranecams.com/product/cart.p ... il&p=23763
heres a hydraulic roller with the same 246 intake duration with a .558 lift
http://www.cranecams.com/product/cart.p ... il&p=24185
BTW if your thinking about getting those stamped steel, roller tip rockers , DON,T!!, they have a tendency to fail, and they don,t handle high spring pressures well, and they don,t reduce friction much so they are basically a (FEEL AND LOOK GOOD" part that doesn,t do much constructively[/color]
Because, easily 90% PLUS of the friction in the valve train is NOT on the contact between rocker arm tip and the valve stem, so swapping to a roller tip on a rocker provides negligible benefits in friction reduction.
you can buy decent quality full roller rockers, for well under $250-$300
and roller tip rockers commonly cost 1/2 or more of that making the full rollers a much better option
the required stall has little to do with the type of lifter your using, its need, to be used, or changed is determined by the rpm range of the cam you select and your car weight,the cars automatic transmission first gear ratio, tire diameter and rear gear ratio.
a mild roller cam would work with a stock stall converter just as a mild flat tappet lifter cam will.
the whole idea of swapping to a higher stall speed torque converter is to allow the engine UNDER LOAD to jump in rpm up into the engines most efficient power range or the most effective part of the torque curve.
http://garage.grumpysperformance.co...electing-a-torque-converter-stall-speed.1715/
http://garage.grumpysperformance.co...hing-the-drive-train-to-the-engine-combo.741/
http://garage.grumpysperformance.com/index.php?threads/more-converter-stall-speed.12964/
http://garage.grumpysperformance.co...mbers-or-a-good-street-combo-your-after.5078/
http://garage.grumpysperformance.co...d-high-spring-pressures-don-t-work-well.1489/
http://garage.grumpysperformance.com/index.php?threads/matching-parts-and-a-logical-plan.7722/
http://garage.grumpysperformance.co...gine-to-match-the-cam-specs.11764/#post-55651
It is when they stop spinning that the camshaft and lifters fail and become a lathe.
" Flat Tappet vs. Roller Tappet Lifters
theres far more than just the cam and lifters required to swap types of cams,
if your engines currently equipped with a flat tappet cam your almost sure to need a new
timing chain set
cam button
new push rods
obviously a new cam and roller lifters.
and its almost always in your best interest to add better valves springs, retainers,keeper rockers etc.
its also very common to need spring pockets cut, new spring shims etc.
roller cams allow less friction and better, more consistent and if properly set up more stable high rpm valve train control
a flat tappet hydraulic cam will function correctly if properly installed but compared to a decent roller cam it can easily cost you 30-40 plus hp in some applications
good hydraulic flat tappet cams and lifters are significantly less expensive at $170-$600 for name brand components vs $870-$1500 for a roller set up,obviously depending on components selected and changes required.
generally its best to purchase all the listed components in a cam installation kit (cam, lifters,valve springs, etc. ) from a single manufacturer as mixing parts, sources or brands,
allows the cam manufacturer to void the warranty, even if the parts in the kit they sell are either identical or inferior to,
the individually purchased components you individually sourced. keep in mind most manufacturers will have tested parts compatibility ,
so they are reasonably sure the components they sell in the kit will work, that can,t be always assumed,
with randomly matched parts even if those parts are good quality.
https://www.enginelabs.com/tech-stories/ferrea-helps-explains-valve-flow-dynamics/
CAST CAM CORES ARE NOT DESIGNED TO HANDLE OVER ABOUT 130lbs SEAT and 400lbs OPEN SPRING LOADS YOU NEED A BILLET CAM CORE FOR DURABILITY IF THOSE LIMITS ARE EXCEEDED
Isky claims that the Comp XE cams violate the 47.5% rule. The 47.5% rule applies to flat tappet cams for SBCs with 1.5 rockers but the concept is still the same for other configurations where the designs are "on the edge" or "over the edge" for lobe intensity. For 1.5 ratio SBCs, the duration at .050 must exceed 47.5% of the total valve lift or your asking valve train problems. For example, take a Comp Cams Magnum 280H, with 230 duration and, 480 lift...230/.480 = 47.9% which exceeds 47.5% therefore would not pose a threat to components. We do not regularly hear about the older, safer HE and Magnum designs rounding off lobes anywhere near as often as the XE cam designs. Unfortunately, some of the Comp Cams XE dual pattern lobes break this 47.5% rule on the intake side so they are likely to be problematic. The design has "steeper" ramps that are too quick for durability and reliability according to other cam manufacturers. They will wipe lobes in a heart beat especially if you have not followed the proper break-in procedure. Other designs are more forgiving during break-in and less likely to fail.
In nearly all circumstances, a good roller camshaft design will outperform its flat tappet counterpart. Among the benefits of roller cams are higher tappet velocity, more lift and more area, along with reduced valve train friction (often a 15+ hp increase) and higher engine rpm with little effect on low speed driveability and power.
Roller tappets are also reusable, which makes it possible to swap just the camshaft without the expense of new lifters. And finally, roller tappets are far less prone to wear, allowing higher spring loads, and they are more consistent with today’s oils.
The biggest advantage to building an engine with a flat tappet cam and lifters is the lower up-front cost. It can be significantly less expensive to use a flat tappet setup but should you decide to install a new camshaft, flat tappets are not reusable, roller lifters are more expensive. You will need new lifters as well.[/color]"
the answer depends on your goals, a good flat tappet cam and lifters usually costs $400-to under $240 some times under $159,
keep in mind the main reason solid lifter roller cams tend to have reputation for durability issues is the much higher valve spring pressures and stress levels used to allow solid roller cams to operate at high rpms, once you exceed about 6000 rpm valve train stress loads increase rapidly
keep in mind this is a small base circle cam with asymmetrical cam lobes you must use the .050 lift and duration numbers in calcs
https://www.summitracing.com/parts/...MIisTdgsuL3QIVlrjACh0EnAAjEAAYASAAEgKCTvD_BwE
http://www.enginebuildermag.com/2009/07/properly-matching-your-camshaft-and-distributor-gear/
http://garage.grumpysperformance.co...ts-needed-for-retrofit-roller-cam-swap.16456/
exampleMouseFink said:The Cadillac CTS-V lifters, GM-88958689 (box of 16 - $296.36 msrp) will not withstand bone crusing valve spring spressure for long. The Cadillac CTS-V lifters are lighter weight and are no stronger than standard Chevrolet LS-7 lifters, GM-12499225 (box of 16 - $139.76 msrp) or GM-17122490 (box of 8), AC Delco HL-224 hydraulic roller lifters. If you use standard or aftermarket SS valves and valve train components with more than 130 - 150 lb. seat pressure and 330 -360 lb. open pressure, you are better off using hydraulic roller lifters that can withstand that much pressure, such as Comp Cams 875 Reduced Travel or Comp Cams 15850 Short Travel hydraulic roller lifters with restricted oiling.
If your ordering any cam, be very sure you explain what year block and what cylinder heads will be used as there are differences in the cams. between early and later SBC, block s and the cams they require,and on big blocks theres similar issues, a mark VI cam is different from a MARK IV cam
The Chevrolet LS and Cadillac CTS-V lifters are designed to be used with less than 100 lb. seat pressure and 300 lb. open pressure. That is because instead of bone crushing valve spring pressure, the Chevrolet LS and Cadillac CTS-V engines use titanium locks and retainers with sodium filled and titanium valves. Those lifters also have restricted oiling for moderate load beehive valve springs. Those type valve springs have progressive pressure and do not need to be flooded with oil for cooling. The Chevrolet Z06 and Cadillac CTS-V engines are supercharged and don't need to be be spun up to the stratosphere to make over 500 HP.BTW...You don't have to specify "LS7 lifters" anymore. You can just call them "Chevrolet roller lifters" because GM uses the GM-12499225 (AC Delco HL-124) roller lifters as service replacements in all 1991-2013 V8 engines, except the Cadillac CTS-VR engines.
http://www.summitracing.com/parts/LUN-60104LK/
http://www.summitracing.com/parts/CRN-110692/
http://www.jesel.com/valvetrain/index.p ... rs/tie-bar
Read this link
http://www.superchevy.com/how-to/95258-hydraulic-roller-cams/
for name brand parts, off brands can be even cheaper
http://www.hotrod.com/techarticles/engi ... z2FeQk91VU
viewtopic.php?f=52&t=8582
viewtopic.php?f=55&t=58&p=36446#p36446
http://www.superchevy.com/how-to/148-0401-chevrolet-406-ci-engine-build/
http://www.hotrod.com/events/coverage/0611em-vortec-small-block/
http://www.superchevy.com/how-to/pr...t-tappet-cams-which-is-better-for-your-chevy/
most flat tappet cams use 110 lb-130 lb seat pressure springs ,
you can get by with the 140 lb-150 lb seat pressure springs in almost every application,
with a roller lifter cam, IF ITS A HEAT TREATED SURFACE HARDENED cam
but I would have suggested swapping to a billet cam by the time the seat pressure was much over 150 lbs
as the pressure on the lifter roller wheel increases so does the potential for having issues if you match a roller lifter and a soft cam lobe.
back in the late 1980s-early 1990s there are/were a few blocks made ,(mostly Mexican cast) that are not the newer roller lifter design
but yeah, most are the castings that have the longer taller lifter bores for roller lifters, even if the roller lifters were never installed
generally use of a cam with over about .530 lift with a spider flex plate retention system on the block and the OEM hydraulic lifters can lead to valve train failure at higher rpms
,and Ive seen it rather frequently with cams installed with stock heads and valve springs that had less than ,510 lift
http://garage.grumpysperformance.com/index.php?threads/small-base-circle-cams.3810/#post-72512
https://www.onallcylinders.com/2020...ith-roller-upgrade-for-small-block-chevy-350/
https://www.hotrod.com/articles/ccrp-0710-chevy-small-block/
http://www.superchevy.com/how-to/en...y-big-block-casting-changes-through-the-years
https://www.crower.com/media/pdf/RollerLifterGuide.pdf
http://www.superchevy.com/how-to/pr...at-tappet-cams-which-is-better-for-your-chevy
its NOT TYPICAL on the cheaper cams but its NOT hardly what you might call rare on cams that try to basically maximize results, and the current roller cam designs, because if you think about it the lobe is forced open as the roller rolls up and over the cam lobe but only spring pressure returns the valve most of the way to the cylinder head seat and they don,t want it to slam down and bounce so the lobe designs can be ground differently.An Asymmetrical cam has opening and closing ramps that are unlike and unequal. This profiles usually found on high performance cams and offers a high velocity opening and a lower velocity closing ramp in order to snap the valve open quickly and then set it back down more gently.
roller cam lobe designs are more complex than flat tapper cam lobes simply because the roller lifter allows much more precise valve open and timing events,
lobes on a roller cam,are generally asymmetrical, in the better roller cam lobe designs,
as its more important to open the valve fast, to maximize cylinder fill rates,
but reduce the valve seating/sealing, timing velocity, too prevent the valve bouncing off the seat as or after its closed,
this factor helps stabilize cylinder scavenging and valve train durability,
and stability but should not effect the software dyno results
RELATED
http://garage.grumpysperformance.co...d-high-spring-pressures-don-t-work-well.1489/
http://garage.grumpysperformance.com/index.php?threads/cam-wear-articles-you-need-to-read.282/
http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/
http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/
http://garage.grumpysperformance.com/index.php?threads/checking-piston-to-valve-clearances.399/
http://garage.grumpysperformance.co...-pushrods-and-check-info-you-might-need.5931/
http://www.superchevy.com/how-to/148-0307-converting-hydraulic-roller-cam
http://garage.grumpysperformance.com/index.php?threads/rocker-push-rod-wear-issues.9815/
http://garage.grumpysperformance.com/index.php?threads/cam-bearing-install-tools-install-info.1479/
http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/
factory blocks with sheet steel lifter retention springs are NOT designed to exceed about .550 lift or 6000rpm
STOCK dog bone design hydraulic enclosed wheel roller lifters are generally designed for less than .550 lift and less than 6000rpm
the stock Chevy hydraulic roller lifters , dog bone and spider springs don,t always work reliably, ALL THE TIME with engines having over .500 lift or when spun over 6000rpm, its not all that rare for the lifter ,retainer to bend the retainer spring allowing the lifter to spin sideways, in the lifter bore, resulting in a destroyed cam, thats why Ive suggested BRAND NAME ,AFTERMARKET RETRO FIT CAM COMPONENTS BE USED
Solid Roller Cams.. What you need to know for running them on the street!
Unity Motorsports dive into the basics of running Solid Roller Camshafts on the street... What you need to know from the basics of when its best to go from t...
www.youtube.com
roller blocks have taller lifter bores, because roller lifters are taller, and a provision to bolt the lifter retainer spring, but they can be very easily used for the earlier flat tappet lifters if desired by simply removing the spider(SPRING RETAINER), keep in mind most roller blocks use one piece rear seals.
KEEP IN MIND that a good deal of the power in any engine combo will be the result of how efficiently you blend factors like,
EFFECTIVE COMPRESSION,vs fuel octane
CYLINDER HEAD FLOW rates vs displacement
and
EXHAUST scavenging efficiency.(cam timing)
theres a good deal of math involved, that can be used to accurately predict the results but there's also an ART and SKILL to tuning and engine assembly, and experience goes a long way there.
and yes a slight mis-match of components, not getting the clearances correct, or a few degrees of cam duration,plus or minus from what the engine needs, and a few cfm difference in intake or exhaust restriction,flow, a few extra fractions of an inch of valve lift, a better or worse multi angle valve job and your up or down 60-80 hp...
The answer to selecting the proper valve length in relation to the cam lift, and valve spring load rates, depends on the engine valve train geometry and the cylinder head design,
it differs from intake to exhaust on most engines also.
I've usually found longer valves are required if the valve lift exceeds about .630, but theres no rock solid rule, you need to do some research and call your machine shop and the cylinder head manufacture. the load rate also plays a significant part in that decision, thinner valve spring seats, is not always an option, as higher load rates require thicker castings for structural rigidity.
valve lift alone withing reasonable limits, has little to do with the need for longer valves, but as the lift increases the difference between the spring installed height and its spring bind or coil stack obviously changes.
if your standard valve spring has lets say a 1.70 installed height and a 1.20 coil bind or stack height you would generally be looking at .500 difference, subtract the .060 minimum clearance,
added to prevent binding issues for coil bind, that only leaves you .440 useful valve clearance.
now you can machine the heads in the valve spring seat area only minimally as the valve spring seats are over the coolant passages and generally ,
the manufacturers will tell you you can only machine the valve seat so far from the O.E.M. original location,
and in many cylinder heads you can't machine deeper without reducing the heads functional strength or causing problems.
if you can,t machine down into the valve spring seat, your other option is a longer valve stem, or if you just need about .040-.050 maybe you get by with off-set valve locks, or retainers, and longer push rods and valve lash caps.
but most machine shops would prefer the longer valves and longer push-rods to maintain the proper valve train geometry.
valves are generally available . .100,..200, .300 longer lengths for popular engines and you can certainly use a micrometer to measure similar valves from a different engine, if the proper length is not easily available.
be aware that theres both different valve stem diameters, valve lock location, valve lock designs, different intake and exhaust valve steels that you can,t interchange.
one of the old performance tricks some guys used to use on a BBC, engines with turbos, was to replace the 1.88 exhaust valves with 2.00 intake valves from a 430 lincoln engines that were made from exhaust steel.
keep in mind all that metallic trash, cycles through the oil pump BEFORE it reaches the oil filter
before as cast
example
http://garage.grumpysperformance.co...mmendation-from-erson-compared-w-crower.4530/
http://www.summitracing.com/parts/SUM-K1106/
notice the more aggressive cam lobe acceleration rate on the roller cam lobes
notice the stepped cam nose to fit retainer plate
a good hydraulic roller cam and lifters costs a good deal more
example
http://www.summitracing.com/parts/ISK-201282294/ cam $280
http://www.summitracing.com/parts/HRS-91164N/ lifters $297
http://www.superchevy.com/how-to/148-0307-converting-hydraulic-roller-cam
or more
http://www.summitracing.com/parts/LUN-60113/ cam $320
viewtopic.php?f=55&t=58&p=36446#p36446
http://www.summitracing.com/parts/CCA-885-16/ lifters $499
http://www.summitracing.com/parts/CRN-11532-16/ lifters $635
viewtopic.php?f=52&t=282&p=345#p345
having a REV-KIT that retains the lifters in their bores, to maintain oil pressure, even if the rocker comes loose or push rods breaks is a good idea
no mater what roller cam you select, youll need to get ,
the valve train geometry, clearances and spring load rates correct,
youll ideally want to get the quench distance in the .040-.042 range ,
port match the intake selected to the heads, and do all the other related checks and clearancing.
keep in mind scavenging the cylinders correctly requires a properly designed set of headers,
and open or at least very low flow restriction exhaust
http://garage.grumpysperformance.com/index.php?threads/engine-dyno-predictive-software.895/
http://garage.grumpysperformance.com/index.php?threads/building-custom-headers.961/
http://garage.grumpysperformance.com/index.php?threads/calculating-required-exhaust-pipe-size.11552/
http://garage.grumpysperformance.com/index.php?threads/calculating-header-design.185/
Tech Tip - 2008
Roller Lifters: Keep 'Em Rolling Longer
Most racers are aware of the advantages of Roller Lifters. For those who are not, a brief review is in order. Roller Cams & Lifters are employed today in all-out racing engines where valve lift/area requirements preclude the possibility of employing a flat tappet (solid lifter cam). Higher Lift requires higher valve spring loads (pressures) and flat tappet cams can only handle so much. Additionally, increased rates of lift (cam lobe velocity) above .007" per degree for example on an .842" diameter G.M. lifter, would cause the lobe to reach-out over the edge of the lifters' cam face. Consequently, with either too much spring or too high a lift rate, most racers know that extremely radical flat tappet cams will eventually self-destruct.
But, what about Roller Lifters? Are they as indestructible as many believe? How do we prolong the life of their roller bearings in today's modern race only engines? Roller lifters require special care and maintenance if they are to provide good service life. Here are the 4 most important factors you should consider to insure their success.
1. AVOID DRY "START UP": Roller Lifter Bearings are assembled with a "tacky" rust-preventing grease that is not intended for lubrication. Therefore, new lifters should have their roller bearings thoroughly washed in clean solvent or acetone to completely remove this assembly grease. After air drying, premium motor-oil (non-synthetic) such as Penzoil SAE 25W50 GTP Racing Oil (The best of the mineral based oils) or Amzoil "Red" Racing Oil (synthetic) should be used to pre-lube the bearings just before installation.
2. AVOID "OVERLOAD": Increased load always means reduced service life. Want 50% more thrust from a jet engine? Ask Rolls Royce or G.E. and they'll tell you to expect about ¼th the service life between overhauls. Similarly, employing drag race valve springs in the 900, 1000 to 1100 lb. Range will reduce the life of your roller bearings between rebuilds much the same as will employing high-impact roller cam profiles.
3. EMPLOY A REV KIT WHEN POSSIBLE: The primary advantage of Camfather Ed Isky's invention of the 1950's is that by pre-loading each Roller Lifter Bearing to its respective cam lobe, you eliminate needle roller bearing "skew". Skewing (the momentary mis-alignment of the bearings' needle rollers to their respective races) is provoked by the start-stop skidding action of the roller bearings each time the lash is taken-up. Eliminate it and you extend roller bearing life dramatically! Unfortunately, many engines such as the Big Block Chevy which could use one the most, don't lend themselves to such an installation because of the severe angularity of the pushrod coming out of the lifter.
4. EMPLOY LIFTERS WITH "PRESSURE-FED" OIL TO THE NEEDLE ROLLER BEARINGS: Hope is a good thing. But hoping oil will eventually find its way to your Roller Lifter bearings is not. Unfortunately, most roller lifters on the market do not pressure feed oil to the needle rollers, depending on the "splash & a little luck" system instead. In contrast, all Isky Roller Lifters feature pressure fed oil to their roller bearings. Isky's Top of the line "Red Zone" Series lifters feature an exclusive 3-Point "Multi-Port" oiling system to constantly bathe the needle rollers with cooling lubrication. Additionally, they feature our famous Marathon Roller bearing with the toughest shock absorbing heavy duty outer bearing race on the market for the highest possible load carrying capability and sustained Hi-Rpm Endurance. And, they're fully rebuildable, making them your best long-term value!
back to top
read thru this info, in the links below
http://www.idavette.net/hib/camcon.htm
http://www.chevyhiperformance.com/techa ... index.html
http://www.badasscars.com/index.cfm/pag ... prd100.htm
http://www.thirdgen.org/sbc-camshafts-primer
http://www.moparmusclemagazine.com/part ... index.html
viewtopic.php?f=70&t=1701&p=4159#p4159
http://www.chevyhiperformance.com/tech/ ... index.html
http://www.stockcarracing.com/techartic ... index.html
http://www.superchevy.com/how-to/148-0307-converting-hydraulic-roller-cam/
you should also keep in mind that a roller cam valve train with the same lift and duration as a flat tappet cam, can provide a good deal more port flow potential and resulting power, , how much more power is mostly the result of how much more port flow and volumetric efficiency you can get from the engine combo that the flat tappet cam will not be able top access because the valve opens longer per degree of rotation on the roller cam lobe and the lift and duration,the valve sees increases, roller cams have a far lower percentage of lobe wear and less friction, both tend to result in more usable horsepower.
now if your current flat tappet cam is providing most of the engines potential then the roller cam will only provide a mild improvement, but in most cases you can expect a 15hp-40 hp gain, (depending on displacement, port flow,exhaust scavenging etc,)over a similar flat tappet design with similar duration at .050 lift, but in many case the roller cams peak lift will be noticeably more.
within certain limits ,the larger the lifter diameter the faster the cam lobe acceleration ramp can be, chevy has a lifter diam. .842
ford uses a .874 diam, Chrysler .904 diam.
while all cam timing figures will vary this might help
but if your willing to pay for special cams and insert solid flat tappet lifters from the cam tunnel , or botton crank case side of the block while its inverted on the engine stand before the cam shaft is inserted holding them in the lifter bores, you can use mushroom base race lifters in a chevy, this allows you to gain the benefits of the larger chrysler lifter diameter while maintaining the stock lifter bore size, but its generally only done on race engines that see frequent maintence tear downs for inspection.
Since if there's anything I know, it's History, here goes.....
Prior to the widespread use of computers, very few mushroom cams were made. The earlier designers had enough trouble making cams follow their normal lifters, much less an extra-wide one.
By the mid-70's, NASCAR racers had learned enough to know that the Chrysler .904" tappets allowed more aggressive lift curves than the .842"-.874" tappets. NASCAR's compromise?---Let everyone use a Mushroom lifter. Chevrolet went to .960", and NASCAR settled on that, even though Chrysler had some 1.000" ones. Those were used in drag racing.
In 1978 I designed the Comp Cams' 310/318 mushroom cam, 268/276 at .050, .390"/.410" lobe lift. In 1980 Buddy Baker won the 1980 Daytona 500 with this cam, and it is still the fastest Daytona 500 ever run. NASCAR went to restrictor plates, and then to .874" max tappet diameter.
Cams with flat-bottom lifters, either hydraulic, solid, or mushroom, are design-limited by velocity. Here are the max safe velocities(more or less) for the various lifter diameters:
.842" .00705"/°
.874" .00733"/°
.904" .00759"/°
.960" .00808"/°
There ARE tricks around these numbers, but not all cam designers know them, or else how to use them right.....
Cams with rolller lifters, either hydraulic or solid rollers, are design-limited by acceleration and base circle diameter. A peak acceleration rate that may be un-makable for a .900" base circle may be usable for a 1.100" base circle.
There are obviously tricks around these limitations, also. The hard part is knowing the tricks, not the basic theory, and when and how to use the tricks....
You and I are probably calling different things 'aggressive', but basically, yes, mushroom tappet cams are more aggressive, even older ones.
The thing is, whatever you can do to a .842" tappet, you can also do to a .960", only the lifter is moving about 15% faster. That is a whole lot faster in cam design.
If you're not careful, you can move the intake valve faster than the air can follow the intake valve/piston. Then the engine is always overcammed---I have done this in NASCAR, and I have had to slow the cam down---dealing with .874" tappets!
My famous 288R roller cam would require a 1.155"(VW-size!) mushroon tappet if I cut it out as a flat tappet cam, as it is over .0094"/° at max velocity.
UDHarold
notice its right where the roller cams lobe design maximized the extra air flow potential that is the most effective flow area during the whole valve flow curve
and yes it frequently helps to match a roller cam to roller rockers as the reduced friction further helps the engines durability and ability to easily cope with faster valve train component acceleration, that tends to reduce heat and wear.
The following equation mathematically defines the available flow area for any given valve diameter and lift value:
Area = valve diameter x 0.98 x 3.14 x valve lift
Where 3.14 = pi (π)
For a typical 2.02-inch intake valve at .500-inch lift, it calculates as follows:
Area = 2.02 x 0.98 x 3.14 x 0.500 = 3.107 square inches, thus it makes a great deal of sense to push the valve lift a bit over .500, and have an intake port that is at least 3.2 square inches in cross sectional area, if you want to maximize flow on a 2.02" intake valve
http://garage.grumpysperformance.co...-the-extra-cost-vs-a-flat-tappet-design.3802/
the slight bevel on the cam lobe and the slight convex surface on the lifter base in combination with the lobe center-line being slightly offset from the blocks lifter bore results in the lifter rotating in its bores as the lobe rotates under the lifter base
but even roller cams can wipe out lobes if the valve train components or valve train lubrication,and geometry is not set up correctly
a quality hardened cam with proper lube won,t wear like this first two picture's, but notice the lifter stayed on track
hardened cam lobes and high quality hardened roller lifter wheels have very low rotational friction,
and as long as the valve train stays in its designed limitations and the inertial loads don,t over come the valve springs ability to maintain constant lifter to lobe contact,
and theres a constant bath of cooling oil flowing over the contact areas,
rates of lifter to lobe contact and wear are minimal or basically non-existent over any reasonable time frame
drilling the pass side oil passage plug with a 1/32" bit so oil constantly sprays on the timing gears, and cam retainer plate areas helps extend chain and gear life.
Comparing Cam Lobes – The roller camshaft (on the left) has steeper opening and closing ramps which allows for more time at max lift.
example
heres two similar hydraulic performance cams
heres a flat tappet with 246 duration and .500 lift
http://www.cranecams.com/product/cart.p ... il&p=23763
heres a hydraulic roller with the same 246 intake duration with a .558 lift
http://www.cranecams.com/product/cart.p ... il&p=24185
BTW if your thinking about getting those stamped steel, roller tip rockers , DON,T!!, they have a tendency to fail, and they don,t handle high spring pressures well, and they don,t reduce friction much so they are basically a (FEEL AND LOOK GOOD" part that doesn,t do much constructively[/color]
Because, easily 90% PLUS of the friction in the valve train is NOT on the contact between rocker arm tip and the valve stem, so swapping to a roller tip on a rocker provides negligible benefits in friction reduction.
you can buy decent quality full roller rockers, for well under $250-$300
and roller tip rockers commonly cost 1/2 or more of that making the full rollers a much better option
the required stall has little to do with the type of lifter your using, its need, to be used, or changed is determined by the rpm range of the cam you select and your car weight,the cars automatic transmission first gear ratio, tire diameter and rear gear ratio.
a mild roller cam would work with a stock stall converter just as a mild flat tappet lifter cam will.
the whole idea of swapping to a higher stall speed torque converter is to allow the engine UNDER LOAD to jump in rpm up into the engines most efficient power range or the most effective part of the torque curve.
http://garage.grumpysperformance.co...electing-a-torque-converter-stall-speed.1715/
http://garage.grumpysperformance.co...hing-the-drive-train-to-the-engine-combo.741/
http://garage.grumpysperformance.com/index.php?threads/more-converter-stall-speed.12964/
http://garage.grumpysperformance.co...mbers-or-a-good-street-combo-your-after.5078/
http://garage.grumpysperformance.co...d-high-spring-pressures-don-t-work-well.1489/
http://garage.grumpysperformance.com/index.php?threads/matching-parts-and-a-logical-plan.7722/
http://garage.grumpysperformance.co...gine-to-match-the-cam-specs.11764/#post-55651
It is when they stop spinning that the camshaft and lifters fail and become a lathe.
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