Pete K

And you thought all you were going to get was bloody knuckles

Weav's Vet

repertoire of mechanical knowledge is growing!Slowly,but growing.........

94vettelover2

Everyone on this subject I'm sure knows more than I ,but you previously said you weren't so sure on cam install position.For me if I'm not 100%,I go back & check.That would eliminate any doubts.If it is off,you would be so pissed & wasted all that money but learned alot of things along the way(experience).Thats how I learned(hard way).

Weav's Vet

I really feel like I'd have some kind of backfiring or something of the like if the cam was off a tooth but maybe that's wrong also. It appears as though I'm going to have to recheck everything to get this corrected so it only makes sense to me to start wth the easiest of parts I changed. To me that's the springs as Pete has mentioned. They are some heavy duty dudes. If that doesn't do it I'll move down to the opti. If that checks out I'll attack the cam. If I can't use the springs I have on now on some new heads down the road I can sell them and at least get some of my money back. Sound logical? I hope so.

I do appreciate your advice though. Thanks!

Pete K

The reason I suspect them, is because most chevy heads I run across are somewhere near 1.78 installed height. I have never set up springs on an LT-1 casting, but if it is about 1.78, pressures will be about 20 pounds higher than what is on the label.

STL94LT1

I remember reading a thread by a forum member that installed a Hot Cam and the car ran decent, but not like it really should. After months of driving the car he pulled the timing cover, and the timing gears were a tooth off.

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 K

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.

STL94LT1

Pete, I hope your wrong, but I have a feeling you may not be. There are alot of guys running Patriot Extreme springs on stock heads/valves/lifters. But, they haven't been out for long enough to see any long term effects of the spring pressures.

JD'S WHITE 93

I've learned the hard way nothing is ever as simple as others make it seem. I hope you get it sorted and if you need a cam degreeing kit I can help you out there. I would trust Pete's advice though as he REALLY knows his stuff, so much so I tried hiring him in part so I could get him closer to me and all my big ideas 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

steve40th

I am going to throw a little lesson learned I had on springs. I ran Comp Cams 941's(very stiff single springs with high seat pressure, not to be installed at 1.75 as JEGS sells it as it has tooo much spring pressure, 130 at 1.75 and 454 lbs/in and 358 at 1.25 RACE SPRING ONLY). Holy Heck were they stiff. I was told they were the spring I needed for my cam, a Hot Cam. The head porter told me this. I ended up bending a valve, as a result of a broken spring at idle, and broke three more over time. I then went with 981's and what a frickin' difference. Springs to make a difference.
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.

Weav's Vet

What's a round trip ticket to NC cost form Hawaii?

Weav's Vet

I may just put I back to stock or it can sit out in the yard and rot! This is from LE.

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.

Pete K

If the closed pressure at 1.800 is 155 pounds, and you compress the spring an additional .020, he thinks it will still be 155 pounds?
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.

JD'S WHITE 93

Hang in there Mike, the bright side is since you've already had it apart once it will go much quicker and easier the second time around IF you end up having to go that route. I got your price on the degree kit check your PM box buddy.

Pete K

JD,
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.

rickneworleansla

Hey Weav,

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.

steve40th

1000 bucks, unless I fly a MAC. My wife just came back from where I will retire, Charleston and if it wasnt for having a gazillion miles, she would not have gone.
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.

grumpyvette

ok having read thru this, thread its rather obvious that several rather critical factors were NOT VERIFIED during the cam installation, you can,t GUESS!, you need to VERIFY what your working with.
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

steve40th

Wow Grumpyvette, lots data to confuse him even more. My cam is 230/236 544/555 112+2, and with 11.1 compression ratio on my 396 LT1 my compression reading were 190-195.

Weav's Vet

Steve....I asked him to take a look at the thread. Looks like I'll be tearing it back down.