Just a heads up after reading this post a good friend of mine built an SBC recently not a race motor but a HP street motor and the Erson cam he installed just melted 3 lobes in the matter of less than 500 miles and I have seen many motors that he built with no issues so I'm not saying anything bad about them but check recent reviews he ended up getting a new block because of the metal particles all through his old one
My Cam Research for the Experts Eye
- Thread starter TXChevy
- Start date
as usual read the links and sub linked info
cast roller cams and high spring pressures don't generally work well
running a cast core roller cam on the street with significantly more than MINIMAL spring pressures for the intended application, IS JUST asking for valve train problems, but a balance must be maintained, if the valve spring is too weak and allows the cam lobe to throw or loft the lifter at...
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Links, links and more links!
I'm new here but getting lost in the links and sub links and their links is time well spent. I've recently replaced the blown 305 in my 85 K-10 with a mystery 383, I say that because I don't know it's history. It's an odd build and I would have liked to tear into it more before dropping it in my...
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down the rabbit hole with Alice
grumpy I've been reading info on this forum for a few years now. this forum is by far the most informative , (and at times confusing) Ive found. If you take the time to read the ENDLESS, links and sub links and endless SUB- SUB- LINKS , you can always find what your looking for, but its very...
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Thanks for this, it's always going to be a concern but there's so many factors especially with hydraulic tappet cams. I have found many pro and con on cam failures.
(1) THINK THINGS THROUGH CAREFULLY ,
WRITE DOWN A LIST OF COMPONENTS ,
MAKE DARN SURE THE LIST IS COMPATIBLE WITH,
and AT LEAST SEMI-REASONABLY PRICED WITHIN YOUR BUDGET.
FOR WHAT YOU INTEND TO BUILD AND RESEARCH THE RELATED MACHINE WORK,
RESEARCH CAREFULLY THE COMPONENT INSTALLATION AND INTENDED USE ,
AND POWER BAND THE PARTS WILL REQUIRE
AND FIND AN EXPERIENCED MENTOR.
#1 Rule. In the process I'm going back and forth to find that centerline of data and application, but that's ok. It helps to see what the boundaries are.
Here's an example of Straub cam recommended for the vintage 396/454, 1.7RR
When I use the calculator I get IVCA 73, DCR 8.0, SCR 10.69, CP 191.55
Looks like a lot of lift, I will ask more about this when I contact them. I really am not sure about the I/E ration of the mildly ported 427 heads other than to look at 2.06/1.72 valve sizing. Not sure that would be the right calc.
I wanted to respond yesterday, but the weather was good and it looked like it was my last chance this year to finish my project on the trailer. I'm polishing much of the aluminum and then spraying it with Cerakote CS-5100. It's a clear coat for polished aluminum. The sun was setting when I got around to spraying.
Keep in mind that I can easily change the LSA on ANY cam and then post the graph.
Glad you found the Snipping Tool useful. Under options you can turn on a border of any color, mine is red. The delay function is also nice when you need to open a menu first, then capture the menu so you can explain to something to grandma in an email.
Nice chart, I see you like Excel, like I do. You should upload it with an explanation about what it's for and how to use it.
Good, glad it helped !
What say you Grumpy, what was your reasoning behind this cam ???
12 seconds...... do I have to ??? How about 7 seconds ???
the erson cam was used as a rather random example of what was available,
in a hydraulic roller BBC cam vs a flat tappet, cam,
in roughly the duration range you are looking at,
to show the potential difference in lift & duration,
as I stated in the very next sentence..
when I mentioned that erson cam,
"(obviously only one of dozens of your options)
in a hydraulic roller BBC cam vs a flat tappet, cam,
in roughly the duration range you are looking at,
to show the potential difference in lift & duration,
as I stated in the very next sentence..
when I mentioned that erson cam,
"(obviously only one of dozens of your options)
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I hate to make such recommendations, I don't have tons of real world experience. I will
let Grumpy answer this one.
Actually I already had this simulation done.
When I compared the Crower 01403 to your suggested specs, they weren't making
sense. If I began with Crower 01403 specs, then started making changes I was decreasing
the Duration @ 50 and increasing the advertised Duration. This provided a very different
looking curve.
BTW, This is where I input all my cam data. In the lower left corner there is the ramp rate.
This is an indication of how fast the cam is accelerating the lifter/valve off the seat and is
derived from advertised duration and duration @50 numbers. Most cams that I have used
in simulations for street engines fall between 2.6 to 3.05. The higher the number, the more
area under the curve, which is what makes for more performance. The perfect cam would
have square lobes if it could and we wouldn't be here talking about cams.
Below are your suggested specs. If I increased/decreased the intake by x, then I did the
same to the exhaust. I hopefully am not embarrassing you, I'm only going thru this for the
learning it might provide.
What I did end up doing was taking the Crower01403 specs and ONLY changing the LSA from
110° to 106°. What also happened by doing this, the cam would be ground with 0° advance.
Another words, it has a 106° LSA and a 106° ICL.
Exactly why I didn't put down the Erson brand I do know the man has built several engines over the years and I've known him for 40 years or so just a heads up is all your mileage may LOL
Agree with you, the internet can be useful but should be taken with a grain of salt.
Absolutely not! It's always in the details, the info you posted is of great help to see the differences and also the basis for those differences.
I'm glad you mentioned ramp rate. If I'm thinking of it right, we want to see a faster ramp rate to bring the curve up sooner, but that starts to move the lifter requirement to a roller? Related to the info Grumpy posted about a flat lifter "digging" into the lobe as the ramp becomes more severe. So this reinforces the decision to use roller rather than flat tappet.
So this tells me that you can't simply list what may be "ideal" specs and go buy a cam without some sort of empirical comparison? Looking at those curves it looks like the specs I listed would be far from the best application to my particular setup - is this right?
It also looks like the Crower cams are yielding results in the right direction? Tq peaks at around 3500 rpm, hp peaks at about 4800 rpm (I had considered 6k rpm as max rpm to keep piston speed no more than 4000 ft/min). But it looks like from about 2800-4000 rpm the car's more dependent on torque as the hp is fairly low.
I'm just putting my thoughts down for verification to see if I'm looking at the broader picture right.
I hate to ask but I am interested to see what the Straub cam would look like. It's got a boatload of lift that maybe the heads can't use (looking at the I/E ratio) but I'd be very curious to see where it lands on the simulations.
Here's an example of Straub cam recommended for the vintage 396/454, 1.7RR
Other than that, I'll be contacting some cam mfg and waiting to see if my block comes home from the machine shop. Thank you again.
Yes, the faster you open the valve the better.... period !! [ Remember the square cam lobe ]
Well, not exactly the flat lifter can actually lift the valve faster in the beginning ( good
for stock classes ), but then the roller takes over and passes the flat lifter. Wish I could
say exactly when this happened, but that would depend on several factors. Maybe you
have noticed that there are mods to make the Chevy lifter bigger in diameter from a .842
inch to a xxx inch diameter. The bigger the lifter dia the faster the lifter acceleration
physically possible before the edge of the lifter diggs into the lobe and destroys your
dreams. This is assuming you don't change the camshaft base circle diameter.
I'm betting all my money on Grumpy, that he has a couple of dozen links associated with
lifter diameter.
Below you can begin to see the physical constraints of the two sizes, camshaft and lifter.
Two cams with identical specs ..... Adv Dur, @50 Dur, Intake Lift, Exhaust Lift, LSA and ICA
can be most definitely different.
Harvey Crane came up with what he called Hydraulic Intensity. Which is ....
[ He also came up with Snap, Crackle and Pop, but that's another math story ]
HI = Advertised Duration - Duration @50
Therefore, Crower 01403
287 - 229 = 58° of HI
What if I keep keep the (Seat Timing or Adv Timing) IVO at 287° per spec, but change the
IVO @50 from 229° (Ramp Rate = 2.75) to IVO @50 to 265° (Ramp Rate = 5.84). .... Yes you
will need to read this several times possibly.
Below are the two Cam Managers Profiles. First is the Crower 01403/LSA-106 (Sim05a)
that you have seen above and then the experimental Crower 01403/LSA-106 with the
new IVO @50 of 265° (Ramp Rate =5.84).
Hydraulic Intensity went from 58° (Above) to
287° - 265° = 22° (Below)
That's not a problem, but it will be late tomorrow or maybe Tuesday! Like I said, I love this kind of numbers !!!
Everyone here has taken time to help me - whatever your schedule or availability is, that works for me.
That's something looking at the change in the cam HI, its like there's no meet-and-greet at the ramp base, just hit it and go. Is that one of the factors in increasing base circle in "race" cams?
While I continue going thru Grumpy's links I will also do some research on HR lifter noise. Trying to sift into current info. Example: I see a lot of comments about noise on Morel, and not so much on Howards. But then I'm trying to figure out who actually makes what lifter....
The Erson cam I talked about was hands on eye witness now what happened is a mystery weather or not maybe it got through without heat treating or a few bad springs or a million other things that could go wrong and if every cam they made did this I would thing that they would have been out of business long ago just a tip to proceed with caution
Thanks, I agree with that. The Erson in my engine looked great after many years. I did look at them, based on a link Grumpy had sent but I only found the one cam in a hydraulic roller version.
I sifted through the 23 cams I had "narrowed" lol and came up with these 4 (compared with my original Erson cam). They are all shown at 0 degree installation. In trying to consider the factors that have been laid out, I like the Clay Smith Cam.
I sifted through the 23 cams I had "narrowed" lol and came up with these 4 (compared with my original Erson cam). They are all shown at 0 degree installation. In trying to consider the factors that have been laid out, I like the Clay Smith Cam.
lack of oil pressure feeding the lifter and volume can result in noise,
if you adjust a lifter preload too tight or allow it to lose contact with the cam lobe due to lack of valve spring pressure keeping it in direct contact with the cam lobe as inertial loads, at higher rpms, exceed the valve spring resistance the lifter will both wear faster and eventually fail, and this can cause noise.
incorrect valve train geometry and lack of proper clearances is also a common source of valve train noise
related threads and sub links
if you adjust a lifter preload too tight or allow it to lose contact with the cam lobe due to lack of valve spring pressure keeping it in direct contact with the cam lobe as inertial loads, at higher rpms, exceed the valve spring resistance the lifter will both wear faster and eventually fail, and this can cause noise.
incorrect valve train geometry and lack of proper clearances is also a common source of valve train noise
related threads and sub links
sellecting valve springs, and setting up the valve train
How do you determine the spring pressure needed to keep the valves under control for a given lift, duration, and max rpm. It might take you several hours to read thru all the links and sub links but its time very well spent as it could save your engine from destruction and save you thousands of...
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valve train clearances and problems
you might want to read thru these links and sub links it will help you avoid costly mistakes http://www.summitracing.com/parts/pro-66830/overview/ https://www.harborfreight.com/multipositional-magnetic-base-with-fine-adjustment-5645.html...
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correctly adjusting valves
this is an area that causes many newer guys problems ,a slight clicking noise at idle in any hydraulic or solid lifter valve train is usually the result of clearances in the valve train, obviously you should have, some clearance, to allow oil flow thru the lifters to provide lubrication on...
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rocker/push rod wear issues
Put vortec heads on my L98 and ordered 1417 1.52 Roller Rockers and 7808 Pushrods from CompCams. Installed screw in rocker studs with guide tool before assembly of the engine. Checked valve geometry and the roller left a mark right on the center of the valve like its supposed to. Oil pressure...
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I've recently run across descriptions of the passenger side front galley plug getting a .030 air bleed hole drilled into it. It seemed to be something GM did as a fix for initial lifter clatter? My block has threaded plugs but no drilled hole, everything was always quiet. So would this be useful using HR lifters?
if you don't have oil supply issues currently, Id skip the added cam oil supply air bleed hole,
its designed to allow trapped air in the lifter gallery oil supply passages to rapidly exit the block
and its critical it rather small, and only in the pass side oil gallery plug.
read this thread
its designed to allow trapped air in the lifter gallery oil supply passages to rapidly exit the block
and its critical it rather small, and only in the pass side oil gallery plug.
read this thread
oil system mods that help
heres a short list REMEMBER the object or goal in building and maintaining the lubrication system is too maintain a 100% dependable pressurized cooling flow of lubricant to the bearings, rockers ,valves etc. your most important tool, is your ability to think about how things are supposed to...
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Using Rare Earth Magnets
Using rare earth magnets on/in your oil pan, drain plug, etc.. Do you do it? Or at least when breaking in a motor? You can get them for free if you have any old computer hard drives laying around. I split and opened up a total of 14 older apple hard drives that I had down in the basement, took...
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Yes I saw that info. Do you think it may be worth adding if I'm going to HR lifter from the HFT lifters ?
BTW if your building a big block chevy engine, Big blocks have a tendency to trap air in the front of the oil passages feeding the lifters, which causes a rocker tap on start up. Because of this, there is a recessed Allen head oil galley plug behind the timing gear on the drivers side that has a hole drilled into it. This hole bleeds off air trapped in the front of the oil galley, and it also lubricates the back of the timing gear. This was a stock-from-the-factory modification to the oil galley, on some bbc engines.
removal of the drilled oil passage plug with a solid galley plug (a BAD idea) or if a piece of trash or silicone in the oil passage that managed to block this galley plug,will usually result in lifter noise and lack of oil flow for a few minutes that can cause wear on the cam and lifters. its suggested one of the plugs get drilled ,drill the lifter gallery plug with a #72-1/32" drill to prevent this
BTW if your building a big block chevy engine, Big blocks have a tendency to trap air in the front of the oil passages feeding the lifters, which causes a rocker tap on start up. Because of this, there is a recessed Allen head oil galley plug behind the timing gear on the drivers side that has a hole drilled into it. This hole bleeds off air trapped in the front of the oil galley, and it also lubricates the back of the timing gear. This was a stock-from-the-factory modification to the oil galley, on some bbc engines.
removal of the drilled oil passage plug with a solid galley plug (a BAD idea) or if a piece of trash or silicone in the oil passage that managed to block this galley plug,will usually result in lifter noise and lack of oil flow for a few minutes that can cause wear on the cam and lifters. its suggested one of the plugs get drilled ,drill the lifter gallery plug with a #72-1/32" drill to prevent this
like I stated, its a solution to a minor issue, with lack of oil reaching the lifters during the first 10-15 seconds of engine start up,
you have not said you have, that issue, so there's zero reason to include it unless your curing that issue,
now it sure won,t hurt anything to do it either,
so its your choice, personally I do it on every engine I build,
but its not something thats considered mandatory
many guys do that mod to SBC as well as BBC as they feel the extra oil flow ,
directed to the back of the upper timing gear and timing chain aids durability
you have not said you have, that issue, so there's zero reason to include it unless your curing that issue,
now it sure won,t hurt anything to do it either,
so its your choice, personally I do it on every engine I build,
but its not something thats considered mandatory
many guys do that mod to SBC as well as BBC as they feel the extra oil flow ,
directed to the back of the upper timing gear and timing chain aids durability
Using Rare Earth Magnets
Using rare earth magnets on/in your oil pan, drain plug, etc.. Do you do it? Or at least when breaking in a motor? You can get them for free if you have any old computer hard drives laying around. I split and opened up a total of 14 older apple hard drives that I had down in the basement, took...
garage.grumpysperformance.com
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