[SOLD] Comp Cams Thumpr camshaft

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604

604

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I have a new comp cams thumper cam I would like to trade for a smaller cam or sell.
http://www.summitracing.com/parts/CCA-CL20-600-4/

I installed this cam in my 318 and did not have the needed valve clearance with factory no valve relief pistons. So I am needing to go to a smaller cam. Would trade it for a cam that is a little smaller (new) or sell the cam with out lifters for $125??? I could use the lifters with another cam. Located in northern KY.
 
With a thick head gasket, not torqued down. The intake clearance was only .06 The exhaust was fine. Recommended min clearance on the intake is .1
 
................so ur pistons are flush with the top of the block, or are they down in the hole a certain amount.......how thick is the head gasket......u can get away with .080 or alittle less on the intake side......whats the ex clearance...........kim.......
 
Pistons are down in the bore. Stock, and stock hight for a 71. Do not remember the exhaust clearance but it was plenty. I would have to go out and mike the head gasket. It is thick, and I will be using thin gaskets on this engine to get the compression up a little. Was just checking with normal gaskets to see what the ballpark was on the clearance. There is just no way this cam will work with this engine. If I do not part with it I may just set it aside for a future project.
 
...............I think something is amiss, i've run the mopar 484 cam without a problem with tin head gaskets back in the day[.025 compressed thickness]...had miles of clearance on stock 70-71 318s.......i am at a loss now as u should have no problem with that cam............can u tell us how u are coming up with ur calculations.......kim...
 
Clay on the piston, and checking with a dial caliper. Must be the timing of the cam. The cam card says the intake opens 36' before TDC. Maybe that is the problem? I to have run the 484 cam and never had a problem.
 
No to degreing, and using stock 273 rockers and comp cam push rods. per there instructions I am checking clearances with a set of solid lifters ( hydraulic lifters made into solids by me just for checking cams)I have been asking around and it sounds like it as all about cam timing. The timing is weird on these cams to make them sound bigger than they are.
 
I think something is wrong too, I had a .475 lift cam in a bone stock bottom end and heads and had a ton of clearance, IMO if you put anything "smaller" in your engine you are going to regret it, I have that cam in my Stroker and love it, that cam makes great bottom end, I would recheck everything, have you talked to comp cams?? you can give this guy a call he is very knowledgable. Andy Stroud 901-795-2400 ext.559
 
604 said:
No to degreing, and using stock 273 rockers and comp cam push rods. per there instructions I am checking clearances with a set of solid lifters ( hydraulic lifters made into solids by me just for checking cams)I have been asking around and it sounds like it as all about cam timing. The timing is weird on these cams to make them sound bigger than they are.
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I would degree the cam and then recheck. If that cam is installed straight up you could be off up to 7 degrees making all the differance you need.
 
I will try to give them a call. I do not have the tools to degree a cam, nor do I know how. I have never degreed a cam in my life. I did recheck the clearance with a set of small valve commando heads, and it is just big enough clearance with those heads. But barley. And it looks like the intake valve opens way early. We are talking way before TDC. I think this is why it is so darn close. The intake is darn near 1/3 open before the piston is all the way up. I sure do not get it. I am starting to wonder if the cam was ground wrong.
 
604 said:
I will try to give them a call. I do not have the tools to degree a cam, nor do I know how. I have never degreed a cam in my life. I did recheck the clearance with a set of small valve commando heads, and it is just big enough clearance with those heads. But barley. And it looks like the intake valve opens way early. We are talking way before TDC. I think this is why it is so darn close. The intake is darn near 1/3 open before the piston is all the way up. I sure do not get it. I am starting to wonder if the cam was ground wrong.
Click to expand...
That dont sound rite. Intake valve should not be opening while piston is still headed to TDC. You would be forcing air up into the intake. Interesting. Mabe its a defect and they ground the keyway slot in the wrong place. Find someone w/ a degree wheel localy that can help you check it out and that will tell you what is what.
 
That is what I think. I think it is a bad cam. Or the Comp cams timing chain is off. Some thing is not made right. I need to get a degree kit. Just one more thing I have yet to get. Wish I new some one locally I could pay to check it out. I am going to give Com a call again tomorrow.
 
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