is the L79 cam, still a good choice??

[grumpyvette]

duntov 30 30 cam replacement

"hey grumpy? I want to build something similar to the old 302 Z28 engine with a 327 fuelie engine I just picked up that has 11:1 pistons and fuelie heads from a old semi wrecked corvette thats been in storage for 40 plus years, naturally Ill tear it down and put in new rings and bearings ETC.but I was wondering about that old dontov cam? any tips?

old school fuelie and z28 cams

buying out dated fuelie heads with todays increased tech aftermarket heads available if max performance is your goal is a bad joke, as you can easily put $1200 into machine work and porting and not come close to some of the better current aluminum aftermarket head flow levels

these were great heads back in the 1960s but current design and testing technology has far surpassed that flow and power level nearly 60 years after they were originally used.

http://sallee-chevrolet.com/Cylinder_Heads/Vortec.html

http://www.superchevy.com/how-to/en...-1003-classic-chevy-small-block-dyno-testing/

Standard 302 (30-30) cam, P/N 3849346
Casting #3849347
254 duration @ .050" (intake & exhaust)
.485" lift (with 1.5 rockers)
114 deg. lobe separation
Exhaust Max lift @ 116 deg. BTDC
Intake Max lift @ 112 deg. ATDC

First Design Off-Road cam, P/N 3927140
Casting #3927141
Intake 257 duration @ .050" (333 advertised)
Exh. 269 duration @ .050" (346 advertised)
Lift: .493" intake, .512" exhaust
Intake Max lift @ 108 deg. ATDC
Exhaust Max lift @ 116 deg. BTDC

2nd Design Off-Road cam, P/N 3965754
Casting #3965751
Intake 248 duration (324 advertised)
Exh. 267 duration (334 advertised)
Lift: .512" intake, .535" exhaust

a cam will open the valves , and in large part control how far they open and how long and where in the rpm range, but its the heads and intake and headers that have the most effect on air flow rates,
the best cam in the world won,t do much if those components are not well matched to the displacement and compression and drive train gearing.
FUELIE HEADS

DART HEADS

CHEVY 882 smogger heads

VORTEC HEADS

rhs heads

we would need a good deal more info,to give you a good idea what would be about ideal.. but just a bit of info you might find of interest, the old Z28 302 engines tended to run really well with the crane 114681 flat tappet solid lifter cam if they had 3.90-4.11 rear gears and a muncie trans. Id point out that the old FUELIE cam, your referring to is a nearly 60 year old flat tappet design and as in most 60 year old designs, theres been significant improvements in related technology in that time making the older design far from current or nearly as effective as some newer designs.
yes even back in the 1980s crane and crower had much more efficient flat tappet cam designs
Id also point out that computers have made the design of the newer roller cam designs far more efficient than that older flat tappet lifter cam design.


that cam swap back in the day made the cars noticeable more responsive, but that was when SUNOCO 260 was 40 cents a gallon also

your best plan would be to make a real detailed list of all your engine and drive train info and call at least 7 cam companys


http://www.cranecams.com/product/cart.p ... il&p=24424

http://www.cranecams.com/product/cart.p ... il&p=23891

read these links, it will save you time and money

http://forum.grumpysperformance.com/viewtopic.php?f=44&t=4463&p=11732&hilit=crossram#p11732

http://www.camaros.org/302valves.shtml

viewtopic.php?f=52&t=82

viewtopic.php?f=52&t=181

viewtopic.php?f=44&t=2099&p=17024&hilit=fuelie+heads#p17024

viewtopic.php?f=44&t=4463&p=11732&hilit=crossram#p11732

viewtopic.php?f=55&t=3431&p=9088&hilit=crossram#p9088

 

[Big_G]

Re: duntov 30 30 cam replacement

I'm currently rebuilding a '64 'Vette with an original 327/365. The solid lifter cam is wiped. One thing I have found so far during diagnostics is 2 of the intake valve seat pressures were only 50 lbs. (These were not on the wiped lobe) The other 14 were about 80. Chevy spec. is 80 lbs seat. Any comments on that, Grumpy? I will lash them using the above procedure you listed. Thanks.

 

[grumpyvette]

Re: duntov 30 30 cam replacement

your valve springs obviously need replacement or the installed height was incorrectly set up.
even 80 lbs of seat pressure is very low, most engines require 100lb-120lb valve spring ,seat load rates,
if the springs are original, they are 47 plus years old and way past the point they should be replaced


these links might help

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=1005&p=15534&hilit=spring+shims#p15534

viewtopic.php?f=44&t=4949&p=13698&hilit=broken+studs+rocker#p13698

viewtopic.php?f=52&t=401&p=17237&hilit=rocker+studs#p17237

viewtopic.php?f=52&t=2746&p=7513&hilit=rocker+studs#p7513

 

[Big_G]

Re: duntov 30 30 cam replacement

your valve springs obviously need replacement or the installed height was incorrectly set up.
even 80 lbs of seat pressure is very low, most engines require 100lb-120lb spring seat load rates
if the springs are original they are 47 plus years old and way past the point they should be replaced


FWIW, this engine has about 3-5000 miles since a rebuild, done in 1998. It has pretty much been a garage queen, sat for maybe 15 years without starting. The customer recently started driving it (last year). Chevy spec. calls out 80 lbs. on the seat. Obviously, something was not set up right. I am gonna be cautious on assembly, as I don't want to wipe the cam. This has happened once on this engine already in the past.

 

[grumpyvette]

Re: duntov 30 30 cam replacement

I have a line on a set of 461 corvette heads, just missing rocker arms.
Would these have the 1.5 or 1.6 stamped steel arms? non rollers?
or best to just put a set of rollers on the heads? what else do these need?

3782461....64-66...327......Camel hump,no accessory holes,160/62cc port volumes,62cc chamber

these are 45 year old cylinder heads, if your sure you want to use those heads,they
are one of the common FUELIE heads. many had pressed in rocker studs , the first thing ID suggest is having a machine shop machine the heads and install screw in rocker studs, elongate the push rod slots and install push rod guide plates and better valve springs that have clearance for a .600 lift, check the valve guides and install new seals and have a valve job done.
but I generally just sell or donate fuelie heads , the aftermarket has far superior heads even the VORTEC HEADS flow better in stock form

HERES A SET OF LONG SLOT STAMPED ROCKERS 1.5:1 ratio that will work if your trying to minimize costs
http://www.summitracing.com/parts/lun-85025/overview/


READ thru these threads and sub links
viewtopic.php?f=52&t=9811&p=37235&hilit=vortec+heads#p37235

viewtopic.php?f=52&t=401&hilit=vortec+heads

viewtopic.php?f=52&t=2746&p=7144&hilit=pressed+studs#p7144

viewtopic.php?f=32&t=5521&p=29720&hilit=vortec+heads#p29720

viewtopic.php?f=52&t=3613&p=9521&hilit=pressed+studs#p9521

viewtopic.php?f=52&t=181&p=9294&hilit=pressed+studs#p9294

viewtopic.php?f=52&t=266&p=35948&hilit=215cc+vortec#p35948

viewtopic.php?f=52&t=3124&p=9141&hilit=pressed+studs#p9141

 

[grumpyvette]

I'm kind of stuck at the moment...... helping a buddy build a motor for his 83 c10. He ordered all his parts and I sold him a fresh set of 461 heads that I was hanging onto for a future project. But anyway what we have is a .30 over 4bolt 350 that's going together with with the 461 heads a EB rpm intake 650 cfm holly and a new set of headers. I got looking at the spec sheet for the cam and noticed the 221 duration and 447 lift and the higher rpm rang...... talked to him and he told me it was a copy of the old Chevy 350hp 327 cam aka l79 cam. So I start doing research and found out that it love high compression around 11.1 well the motor were building should be around 9.1. I guess long store short am I going to be pissing up a rope if I use this cam with the lower compression and if it well work what rpm rang is he looking at is he going to need a stall converter and should I still set the timing around 10 degrees 750 rpm's with the bigger cubic inch block?....!!! Any help would be great!! Thanks in advance

RELATED THREADS
viewtopic.php?f=44&t=6548&p=20798&hilit=dontov#p20798

viewtopic.php?f=44&t=2099&p=17024&hilit=dontov#p17024

heres that cam
pn #3863151 Hyd. 221/221 .447"/.447" 11.0:1 114 327/350HP L-79
heres cranes improved version

your forgetting that back in the late 1960s-early 70s we had decent high test leaded fuel,and you generally can,t run a true 11:1 compression with that cam on todays fuel and with a 114 lsa this cam was not ideally set up for power and lobe ramp design was by todays standards rather poor, and most sbc head had less than 160cc port sizes requiring a bit more duration to compensate for restrictive flow, even today's vortec heads, (WHICH ARE FAR FROM THE BEST AVAILABLE) far out flow most early "FUELIE HEADS"

a much more modern cam lobe design with a bit more lift and a bit less duration like a crane
114142 generally provides better results in todays lower compression engines, especially if matched to 1.6:1 ratio rocker (provided you upgrade to matching valve springs and check clearances) yes the old technology still works but its not nearly as good as efficient as the better modern designs, yes you can install that older design and have decent performance, but your giving up significant improvements made over the last 50 plus years since it was designed.
Id suggest you call CRANE,CROWER,ISKY ,ERSON and get some suggestions, but I generally use that crane grind in engines similar to what your describing as long as its a manual trans drive train.
especially when used with 1.6:1 ratio rockers the newer crane version below generally provides more power over the whole rpm range, in my and several other of my friends experience, so much so, its become almost a standard selection for semi mild 383 sbc builds, with manual transmissions and about 10:1 compression

READING THE LINKS IS NOT A WASTE OF EFFORT HERE!

viewtopic.php?f=52&t=181

viewtopic.php?f=52&t=82

viewtopic.php?f=52&t=528

viewtopic.php?f=44&t=6548&p=38933&hilit=+l98+fuelie+corvette#p38933

viewtopic.php?f=32&t=5521&p=29720&hilit=+l98+fuelie+corvette#p29720

viewtopic.php?f=52&t=133&p=163&hilit=stock+chevy+cams#p163

viewtopic.php?f=52&t=10268&p=41364#p41364

 

[grumpyvette]

I got asked a similar question about the old ZL1 3959180 cam,
darn that question brought back a ton of memories!
3959180 Mechanical Flat Tappet
This mechanical flat tappet is a ZL-1 and LS-7 mechanical lifter competition cam, good in 427-454. (Use spring P/N 3916164.) The duration at lash point in degrees (intake/exhaust) is 327/333; duration at .050" tappet lift (intake/exhaust) is 262/273; and maximum lift with 1.7:1 rocker ratio (intake/exhaust) is 580/620. Valve lash is .024/.026 and lobe centerline is 110 degrees.
again, 50 year old technology, that still kicks ass, if its used in a combo with parts that match the application, !
but again its not quite as effective as the more modern design versions or todays roller cams, after all we learned a great deal in the last 50 years about what does and does not work, and about how computer designed cam lobe acceleration ramps can be used to provide a more stable valve train.
back in the 1970s this was the hot ticket if you were building a 454-496 bbc on a tight budget
(back in the 1970s bare open chamber heads cost under $100 each and that kick butt cam with lifters was under $110 ) and if you were building a 12.5:1 compression big block with a manual transmission, and something like 4.11:1 rear gears in a stripped nova or camaro that weighed under 3000 lbs, matched to a set of open chamber rectangular port heads and a proper port job, long tube headers , the correct valve springs , an 850 holley on a good dual plane intake and once your clearances and valve spring load rates were correct,a set of 1.7:1 roller rockers, a good vertex ignition, and 550 plus hp was easily surpassed
the new versions part number crane # 131141

CRANE CAMS HAS A WHOLE CATALOG DEVOTED TO IMPROVED VERSIONS OF THE OLDER MUSCLE CAR CAMS
http://www.cranecams.com/uploads/catalog/pp0811a.pdf


Ive used this 2nd design L88 cam in old school high compression big block build with good results several times
http://www.cranecams.com/product/cart.p ... il&p=24440

 

[grumpyvette]

heres a few more old school chevy cams that were both cheap and popular, and links to related info
http://garage.grumpysperformance.com/index.php?threads/how-fast-were-the-old-muscle-cars.1938/

http://garage.grumpysperformance.com/index.php?threads/decent-cam-supply-sources.155/

http://garage.grumpysperformance.co...g-a-better-cam-to-a-zz3-350-sbc.182/#post-216

http://garage.grumpysperformance.com/index.php?threads/the-cross-ram-intake.623/#post-834

http://garage.grumpysperformance.co...s-and-a-few-similar-aftermarket.133/#post-163



Standard 302 (30-30) cam, P/N 3849346
Casting #3849347
254 duration @ .050" (intake & exhaust)
.485" lift (with 1.5 rockers)
114 deg. lobe separation
Exhaust Max lift @ 116 deg. BTDC
Intake Max lift @ 112 deg. ATDC

First Design Off-Road cam, P/N 3927140
Casting #3927141
Intake 257 duration @ .050" (333 advertised)
Exh. 269 duration @ .050" (346 advertised)
Lift: .493" intake, .512" exhaust
Intake Max lift @ 108 deg. ATDC
Exhaust Max lift @ 116 deg. BTDC

2nd Design Off-Road cam, P/N 3965754
Casting #3965751
Intake 248 duration (324 advertised)
Exh. 267 duration (334 advertised)
Lift: .512" intake, .535" exhaust

 

[bob]

http://www.camaros.org/crossram.shtml

 

[Grumpy]

How far can I flat mill my old big valve -291's, 66 cc chamber heads?

Same with angle milling them?

I want to install a 50 cc chamber head is all.

Should I just install either 1.94" or 2.02" intakes and 1.60" exhaust valves in my old -601 heads, open them up and then flat mill them back down to 50 cc's?

Money is always tight or I would buy new heads so this is why I ask.

Thanks in advance for any comments.

pdq67

Im placing this here because matching the heads used too the selected cam duration and lift, and engine displacement, is critical to getting good results,yes I'm all too well aware that moneys darn hard to come by, but I'm also pointing out that theres far more effective choices than re-machining and adding larger valves too 30-60 year old cylinder head designs and the cost required to upgrade them significantly!
THINK THINGS THROUGH!
short answer, any time your thinking about spending cash on major components, just step back and think things through carefully, what will it cost and what can you reasonably expect to gain from the money spent?
will the new parts match and work well with the other components?
will the combo work with my cars drive train gearing?
will it work with the octane fuel I will use?
can I get replacement parts in a few years?
can I spend a bit more and get significantly improved performance for the extra cash outlay?
601 heads, or any of the old small valve OEM fuelie heads are by todays standards, are at best door stops, that would be a total waste of financial effort, to upgrade simply because by the time they were modified enough with port work and bigger valves, to even come close to the flow rate of aftermarket heads the cost will be very prohibitive, getting the heads that were designed to produce decent low and mid rpm torque on a 305 to flow even as well as mildly reworked vortec heads is unlikely

Start adding up what you will potentially have in a set of basic 305 heads if you were to start throwing cash at them in the basic hope of improving them

Heads from junkyard
Having them hot-tanked
Having them re-surfaced
buying new valves
having larger hardened seats installed
getting a multi angle valve job
getting the heads machined for larger valve springs
Having the valves ground
New Springs
New Retainers
New locks
Tapping them for screw in studs if you are running much spring pressure
New guides if they are worn out
Regrind the valves for a 30 degree back cut
Multiple Carbide burrs for porting
Multiple drum rolls for polishing
example
http://www.steveschmidtracing.com/machine-shop
Machine Shop - Labor Prices
Head Work
V-8 Valve Grind (Pr) $120.00
Pro Sportsman Valve Grind & Blend (Pr) $250.00
Competition Valve Grind (Pr) $350.00
Grind Valves (Set) $ 40.00
Back-Cut Valves (Set) $ 20.00
Surface Heads (up to .020) (Ea) $ 25.00
O-Ring Heads (.041 wire) (Pr) $120.00
Cut Heads for Loc-Wire (Pr) $120.00
Cut for Teflon Seals (Pr) $ 32.00
Cut for Large Springs (Pr) $ 32.00
Mill & CC Heads (Pr) $100.00
Clean Assemble Set Spring Height $ 80.00
Cut for Seats (1st seat) $ 30.00
Cut for Add'l Seats (2-7) (Per Head) $ 20.00
Hone Guides (Ea) $ 2.00
Install Guides (Ea) $ 5.00
Mill Int. or Ex. Side (Per Surface) $ 5.00
Angle Mill Head Correct Int. Side & Ream Head Bolt Holes $200.00
Clean Heads (Ea) $ 20.00
Custom Machine Work (Hr) $ 60.00

fact! it will be much more cost effective to sell those heads and buy a decent aftermarket head design, that will significantly out flow the ported 601 heads, plus have alot more features


yeah I know not 1/4 of the guys will read through the linked info, but that group is far more likely to have a fast car later as a result


http://www.summitracing.com/parts/tfs-30310002/media/chartsandguides

http://garage.grumpysperformance.co...u-buy-bare-or-assembled-heads.534/#post-27236

http://garage.grumpysperformance.com/index.php?threads/milling-heads-and-intakes.2988/#post-9055

http://www.hotrod.com/how-to/engine/ccrp-1209-eight-budget-sbc-head-shootout/

http://www.stockcarracing.com/techarticles/scrp_0801_budget_racing_engine/

http://www.superchevy.com/how-to/engines-drivetrain/sucp-0705-budget-chevy-cylinder-heads/

http://www.superchevy.com/how-to/en...e=cxrecs&cx_navSource=related-bottom#cxrecs_s

http://garage.grumpysperformance.co...ed-up-fuelie-heads-for-cheap.2099/#post-50526

http://garage.grumpysperformance.com/index.php?threads/unleaded-fuel.11498/#post-52990

http://www.ws6transam.org/ported.html

http://www.strokerengine.com/SBCHeadsFlow.html

http://garage.grumpysperformance.co...olishing-combustion-chambers.2630/#post-48319

http://garage.grumpysperformance.co...at-angles-and-air-flow.8460/page-2#post-32923

http://garage.grumpysperformance.com/index.php?threads/whats-a-valve-job-cost.8596/

http://garage.grumpysperformance.co...-old-heads-in-the-scrap-bin.10728/#post-46832

http://garage.grumpysperformance.co...king-piston-to-valve-clearances.399/#post-488

http://garage.grumpysperformance.co...g-vortec-heads-and-other-heads.401/#post-7853

http://garage.grumpysperformance.co...u-buy-bare-or-assembled-heads.534/#post-27236

http://garage.grumpysperformance.com/index.php?threads/sellecting-cylinder-heads.796/

http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/