Is this cam too big???

[onebadazzsrt]

I bought this off of a member and he said to use 1.6rr with this cam-comp cam custom grind .566 lift intake and ex. duration@ .050 232 intake 232 exhaust.

onece I installed my FMS 1.6 roller rockers on my gt40p heads it seems like it's hitting the valves a hair when I crank it by hand. If this is the case what cam should I use I've been getting screwd left and right on this build, by ordering a set of crane roller rockers and haveing the stud mount kit back orderd and then 2 weeks later they go out of business.

[sleeeper88]

Did you check your ptv clearence? If you are running a stock piston or even a speed pro i think you will have the pistons and valves kissing each other with that much duration @ 50.

[onebadazzsrt]

no because I took the guys word, so it looks like I'll be buying another cam. When I called comp to find out what springs to use I told them my exact setup and that said I would be fine as well. Is there a difference in gt40 and 40p's

[sleeeper88]

You should always check the ptv clearence even if you go to a smaller cam. I have seen some very tight clearence issues even with small cams. I learned the hard way years ago, i lost a engine because i never checked the ptv. If you do it right you will have a nice piece of mind.

[onebadazzsrt]

well now I have to find a good cam to go with my 1.6's

[slo895.0]

Originally Posted by onebadazzsrt

no because I took the guys word, so it looks like I'll be buying another cam. When I called comp to find out what springs to use I told them my exact setup and that said I would be fine as well. Is there a difference in gt40 and 40p's

well the guy didnt lie to you. there are no 2 engines that are exactly alike. so this cam could have cleared in his engine and not yours.

[93mustank]

Cant wait to see your next thread

[onebadazzsrt]

Give me a break this is my first V-8 I'm building, ask me almost alnything about 2.3t or subaru boxer and I'll answer it. I'm getting out of the 4's and into the 8's.

[93mustank]

Would you take someones word if they said a 2.3 subaru motor will handle 30 psi stock???????

[csgoody]

If its hitting your pistons its to big.

[onebadazzsrt]

people come on here to talk and have questions answerd not to deal with smart asses.

[dan89lx]

How do you know it's hitting your pistons? Lay down some clay (pretty thin) over the intake and exhaust reliefs of one piston. Torque your head down with the same gasket thickness you'll be using when you button up the engine for good. Set up an intake and exhaust rocker. Rotate the engine until both valves on that cylinder have completely opened and closed. Pull head off and check.

You want a minimum of .080" on the intake and .100" on the exhaust.

I use a fixed lifter for this procedure that basically acts like a lifter that's pumped up with oil. The plunger is set about .050 down from the top.

It depends on the cam's valve timing, but you have a good chance of being ok with a small valve head like you have.

Don't worry about people being Jerks here, they just don't have social skills and look for ways they can put others down. Be like success, and ignore them.

Good Luck.
-Dan

[Trey LePark]

You don't have to pull the heads to check. Just use the drop valve method. Set up a dial indicator at the tip of the number one valve stem (intake or exhasut, you'll have to do them both) and zero it out. Put a degree wheel on the crank and bring the piston up to 20° before TDC. Remove the valve spring and see how far the valve drops. Then turn the crank to 10° before, TDC, 10° after and then 20° after. Now you have your clearances.

[shortthrow50]

Either that, you can get super light springs. Some hillbilly gave them to me a few months ago. I don't know where he got them

[Modular]

Originally Posted by dan89lx

Don't worry about people being Jerks here, they just don't have social skills and look for ways they can put others down. Be like success, and ignore them.

Good Luck.
-Dan

Agreed.

[onebadazzsrt]

Well it's not hitting the valves I checked the clearence and it's fine, the problem is either in the trans or trans sheild is hitting the flywheel, I'll have a look and see whats going on tonight. Thanks for the help guys.

[Michael Yount]

"I checked the clearence and it's fine"

How did you check it and what were the clearances (the measured dimension preferably in inches) on the intake and exhaust? If you used clay, did you take the lifter apart and turn it into a 'solid' before taking measurements?

[onebadazzsrt]

yes I used clay and it's not paper thin like some have stated but there is a little room to breath, The heads were never fully bolted to the block just enough to turn them over and check and install the FMS roller rockers.

[kim]

With or without gaskets? Figure heads on stock deck, then when you add the average gasket you have between .043 and .054 additional clearance. But, from what it sounds like, the "room" to breath, is probably .020 at most. So your right on the inside of acceptable clearance if you plan to run a thicker crushed value head gasket.

Im not an advocate of thick head gaskets, when I have no idea where the piston sits in the bore, IM REALLY against recomending a thicker head gasket, as many times a low compression 9-1 engine, will have all sorts of fuel requirements/knocking issues, simply because the engine was built with no quench.

[onebadazzsrt]

I had the head sitting on a felpro headgasket with bolts at about 10lbs 1 in each corner and 1 in the center of the head. I didn't break out the micrometer but I would say it's about .020 giving the .560 lift that I have. I haven't got a chance to look at the tranny to figure out why it's wanting to lock into place after almost a complete turn of the crank with the heads off.

[slo895.0]

did you also install a spec clutch while doing all of this? if so its most likely the pressure plate hitting the bell housing. that is a common spec problem

[Michael Yount]

"I didn't break out the micrometer but I would say it's about .020 ...."

You don't know what your clearance is. The lifter must be turned solid. The gasket has to be a 'crushed' thickness. And the .020" clearance isn't anywhere near enough - besides that, you didn't measure it - you GUESSED at it. You're looking for at least .080"-.100" on the intake, and .100"-.125" on the exhaust. You have to section the clay and measure it with calipers. And you keep referencing peak lift -- peak lift has absolutely nothing to do with p to v clearance because the pistons are way down the cylinders when the valves are open to peak. I think you need to get a friend that knows what they're doing to assist you with this one.

And all of that to say -- it sounds like this isn't even the issue that's causing the problem.

[mustang86super]

[QUOTE=Michael Yount;8785069]"I didn't break out the micrometer but I would say it's about .020 ...."

You don't know what your clearance is. The lifter must be turned solid. The gasket has to be a 'crushed' thickness. And the .020" clearance isn't anywhere near enough - besides that, you didn't measure it - you GUESSED at it. You're looking for at least .080"-.100" on the intake, and .100"-.125" on the exhaust. You have to section the clay and measure it with calipers.

+1

[onebadazzsrt]

Originally Posted by slo895.0

did you also install a spec clutch while doing all of this? if so its most likely the pressure plate hitting the bell housing. that is a common spec problem

It's an e-clutchmaster stg.2 with 13lb flywheel, I'm going to check the bell housing today to see if there's any rubbing going on. And my stepdad is a hot-rod chevy guy he is going to double check everything to make sure it's OK.

[Michael Yount]

"And my stepdad is a hot-rod chevy guy he is going to double check everything to make sure it's OK."

"I've got a bad feeling about this." --- Han Solo

[malmsten]

Originally Posted by onebadazzsrt

And my stepdad is a hot-rod chevy guy he is going to double check everything to make sure it's OK.

http://www.youtube.com/watch?v=DwWIUeaSdx8

Hopefully not this guy.

[onebadazzsrt]

I thought we were adults on this web-site, I'm done with this thread. And FWIW his camaro that he races has over 1200HP and runs 8's so I think he knows what he's doing.

[kim]

Have him take the stereo box out of the car... and maybe put some slicks on it... turn the AC off when he's racing. A dedicated drag car with 1200hp, is either one HEAVY pig... or one poorly driven car.

[I8URICE]

usually the springs in those heads can't hold a stock cam.. there extremely weak... i can't believe the comp guys would feed you bull like that.. their usually pretty good.. i bought the matching springs to my cam so I wouldn't be guessing.. comps aren't that bad,, i paid $90 for the springs..

[I8URICE]

Originally Posted by malmsten

http://www.youtube.com/watch?v=DwWIUeaSdx8

Hopefully not this guy.

that is friggen hilarous!!!!!!!!