Problems, problems, problems......
I do appreciate your advice though. Thanks!
I do appreciate your advice though. Thanks!
Pete is right and I stated in a previous post that you will see a ~1.78 installed height on your valve springs. As much as I respect Pete, I'm going to say I don't think the valve springs are your problem.
Pete is right and I stated in a previous post that you will see a ~1.78 installed height on your valve springs. As much as I respect Pete, I'm going to say I don't think the valve springs are your problem.
They may not be. But if he continues to run the motor with the spring pressures I think he has, the lifter will be junk soon (if they are not already). Continued pounding will break the cam (if it is cast iron) or dent the crap out of it if it is a steel one.
The Best of Corvette for Corvette Enthusiasts
If I had just half of his know how with my reckless spending I would have a REALLY FAST car. Good Luck Mike !! The reward for all your hardwork is near





My installed height is 1.8 with Rev Tech extra long valves, cut heads and GMPP lifter with OEM length pushrods.
I wish I was there to help, as I am OCD when it comes to troubleshooting.
Last edited by steve40th; Oct 29, 2009 at 10:37 PM.
My installed height is 1.8 with Rev Tech extra long valves, cut heads and GMPP lifter with OEM length pushrods.
I wish I was there to help, as I am OCD when it comes to troubleshooting.
hmm, ya know Iw as thinking, the 200+ cylinder pressure was high enough that the cam could be in there advanced a lot. Hopefully it is not 1 tooth off but I would degree it and so where it is.
What timing chain is on there?
They are probably around 1.780 on a stock unmolested head and that would give them 155-160 lbs or so. Usually not enough to have problems. If the lifters were collapsing due to the pressure, I would think you would have TONS of valve trane noise.
The cams timing events would work with stock heads or ported heads. Bore, stroke, intake manifold runner length, etc are what dictates that. The ported heads just allow more HP/TQ to be made at every RPM over stock heads. I have had a few people make 330-350 RWHP with that cam and stock heads. I'll look and see If I have a dyno graph.
The "cam" has been correct on every one I have ever degreed. "Degreeing" a cam is when you make sure that the cam is in the proper location in relation to the pistons movement. The cam, upper gear, bottom gear and crank are all factors. If the cam ends up being off, it will be one of these things causing it (assuming that the cam is not 1 tooth off).
I doubt the cam is the problem and the timing chain/gears are usually the problem. Only way to know is to place a degree wheel on it. I would tear the front of the engine off and look at the timing chain again. Make sure the dots are aligned first off and if so, use a degree wheel to see where the cam is currently at. There is a MUCH greater chance of something wrong in this area instead of the springs.
You might consider just getting a GM "replacement" chain, reusing the stock gears and reinstalling the sensor on the timing cover instead of the dbl roller chain.
I guess.
In my mind, the fact that the car is not making the power is insignificant. You can find it, and correct it. But to see a pro talk around those spring pressures is not wise.
Excessive pressure will bust **** up quick.
My thought since the beginning of your troubles is to prevent a broken motor first, then worry about the power being down.
Last edited by Pete K; Oct 30, 2009 at 07:54 AM.
Do you have an on line catalog? Now that I am living back in Pa, I have my garage back, and can do some stuff in it. I am looking to build up the tool collection. Could you shoot me a link? If a printed catalog is available, maybe I can get one?
Thanks,
PK
PS: 406 currently being built. I am like a kid at christmas.
I was just wondering what the main differences were between your cam install and mine.? I think they were real close with most of the same parts being used. I know I have a different cam. I believe I also used a different length for my pushrods. I used LS7 lifters instead of reusing the stock one's. I saw you mentioned the timing chain. Did you also go with the Coyles timing chain and EWP? I did not choose to degree the cam either. It's been about 8 months now and so far everything has been running great.
Last edited by rickneworleansla; Oct 30, 2009 at 12:40 PM.





You will find the problem, and you have awesome friends helping you out here. Drink a beer, make a plan and execute it with the advice you get from here.
If you were local Id suggest coming over and we could verify the cam timing with a degree wheel
http://www.tavia.com/free_degree_wheel.html
http://www.summitracing.com/parts/TFS-90000/
http://www.summitracing.com/parts/PRO-66787/
http://www.summitracing.com/parts/CCA-4796/
http://forum.grumpysperformance.com/....php?f=52&t=90
http://forum.grumpysperformance.com/...php?f=52&t=181
http://forum.grumpysperformance.com/...php?f=52&t=727
the three most obvious were that the spring clearances, valve train geometry and load rates were not verified, to be exactly correct and the cam was not degreed in, so your guessing, if those factors are correct and I don,t see any reference to the IGNITION timing, or exhaust back pressure being verified , the 210-225 psi compression test readings tend to indicate a cam thats advanced
when you get into stuff like this you CAN,T GUESS , you need to KNOW the answers
and you CAN,T be 100% sure the marks on the timing gears used to line up the cam index to the crank are exactly correct,
step one
is degree in the cam (use the sub-links in the linked info above)
step two
verify the valve train clearances and geometry
step three
verify your fuel pressure , the exhaust back pressure,you ignition timing on the dyno, and get that info on a real time print out
"The cam is a LE 226/230 .565/.565 111 lsa"
that timing places the intake valve fully closed at about 50 degrees after BDC, so your effective stroke once the valve closes is about 3.0",making your effective compression with that cam timing closer to a 145psi-160psi compression reading
http://www.iskycams.com/ART/techinfo/ncrank1.pdf
http://www.crower.com/misc/valve_timing_chart.html
Last edited by grumpyvette; Oct 31, 2009 at 01:37 PM.





Last edited by Weav's Vet; Oct 31, 2009 at 02:09 PM.











