How to check cam thrust face to lifter clearance.

[Justa6MB]

I have a 210-215 Comp hydraulic roller cam and I want to ensure the lifters aren't contacting the adjacent cam thrust faces. The question is should I just use feeler guages through the holes in the block? I assume there doesn't need to be much clearance?
Thanks
D

 

[ek02]

If you have a spring loaded stock or roller button on a cast cam, no checking needed. If you have a shimmed roller button, you need to check fore and aft movement on one of the lobes with a dial indicator. Recommended end play is .005-.010".

 

[BEATAV8]

Put the cam in the block. Put a pair of lifters in their bores and carefully turn the cam. If an adjacent lobe is going to touch you will feel it and see it as you turn the cam.

 

[BEATAV8]

Exhibit A:

 

[Justa6MB]

Yes I previously saw Exibit A and that is partially the reason why I'm wanting to check I put the engine together about 3 years ago and I decided to pull it apart this winter to check a few things. I was hoping to not pull the front cover off though just intake and heads etc. Wouldn't the lifters show signs if there was any contact with the adjacent cam lobes?

 

[ek02]

I guess I did not understand your question. Now I see what you are trying to check. If that photo is of the back end of the block, that engine could have a broken spring on the button letting the cam slide forward. The post that photo came from also mentioned some Comp cams with lobes that were made too wide. I would think if the lobe to lifter clearance is the same on both sides of the rollers, you don't have a problem.

 

[BEATAV8]

Yes I previously saw Exibit A and that is partially the reason why I'm wanting to check I put the engine together about 3 years ago and I decided to pull it apart this winter to check a few things. I was hoping to not pull the front cover off though just intake and heads etc. Wouldn't the lifters show signs if there was any contact with the adjacent cam lobes?

Yes there would be some evidence, depending upon severity of the interference. Exhibit A was found because the adjacent lifter would actually jump when it's neighboring lobe hit it. Could feel the cam bind when it hit.

 

[BEATAV8]

Now I see what you are trying to check. If that photo is of the back end of the block, that engine could have a broken spring on the button letting the cam slide forward.

this issue was identified during assembly. cyl 5. the camshaft thrust face was too thick. fortunate that I caught it! motor has been running beautifully for a few years now.

 

[Justa6MB]

Ok thanks, I'll pull the lifters and inspect.

 

[forzfed]

Darren, how is everything looking so far?

 

[Justa6MB]

Hey Nick, well I just pulled the intake so far but everything looks good. This weekend I'll pull the heads and check out the lifters. I've been looking for high rpm false knock so I want to check the valve train, valve spring pressures, and heads and pistons while I'm at it. And what the heck - we got a long winter ahead of us

 

[BEATAV8]

With the 215/220 cam I have had good results with the PAC1201 valve springs. The 215/220 has ~.513/.530 lift. I was running 125lb on the seat and 345lb over the nose, that was not enough. High RPM false knock all the time. Stepping up to 147lb on the seat and ~408lb over the nose took care of that issue. still using the 853 lifter too.

 

[Justa6MB]

I'm supposed to have K750 springs on there now. The 210/215 cam has .517” lift and I'm running 853's also. I was talking to Tom at Champion last summer and he said they should be 135-140 lbs on the seat and 380-400 at lift. He sent me some shims to try but we'll see what the spring pressures are first. I also got a tip from one guy who said 1 of his pistons was hitting his head and would cause high rpm knock.