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With it being a larger base circle cam how about rocker arm or push rod hitting rocker on stud maybe or push rod hole in heads not large enough
 

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Discussion Starter #23 (Edited)
Lifter wasnt the problem . Valve moves freely and I put a different spring on it .

Dont know where to go from here other than the cam .

Its the only other thing that was changed .

I think the black plug is a different issue . Maybe an injector . But Ill put a few miles on it and check the plugs again .

But Ill do a dynamic compression test next .

I couldnt see any damage to the cam lobes , but it was very hard to see from the valley .

These is not one speck of anything on the oil plug magnet , or in the filter .
 

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Discussion Starter #26 (Edited)
Maybe the fuel on the plug is not related .

I just cant help to think its rod to cam clearance . Dont know why .040 wouldnt be enough , but maybe I missed something because #2 rod was the only one I saw that was close . I thought it was usually two rods .

Under load , maybe its just enough to touch . But not enough to hear without load on the engine . I checked all the rollers on the lifters and they are fine . So if it is touching , its not enough to damage the cam .

I see no witness marks on the lobes from the valley , but its very hard to see .
 

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Seems odd you used it all the time you did with the old smaller base circle cam and shorter pushrods without any apparent problems. Now suddenly on a larger base cam you also needed longer pushrods too. Maybe you should go back and recheck your pushrod length to be sure. I'm not sure if it's the problem but something is off there.
 

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Discussion Starter #30 (Edited)
Seems odd you used it all the time you did with the old smaller base circle cam and shorter pushrods without any apparent problems. Now suddenly on a larger base cam you also needed longer pushrods too. Maybe you should go back and recheck your pushrod length to be sure. I'm not sure if it's the problem but something is off there.

Its a difference of .045 so its quite a bit I guess . But could it have contributed to a link bar failure . But it took 18,000 miles for the failure . And I ran the same pushrods for many years with the OEM style comp short travel lifters without issues .

Ill check everything again when I finally break down and pull the engine . Good thing is the push rods are made local and are quick to get .

Im probably going to order the cam on a small base circle before pulling the engine .

I know it seems like a lot of money for something that might not be the problem , but if Im pulling the engine , then see witness marks on the cam , it would suck not to have the cam ready to go .
 

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Discussion Starter #34
I guess just have to go over everything as I put it back together .

Also the #3 plug was black with just a few miles on it . Im going to send the injectors off to Eric Derr .

Oh , and all the push rods have oil coming through when priming so i assume the lifters are getting proper oil flow
 

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Discussion Starter #37
The lifter looks fine and runs smooth in the bores with no slop . I almost think its the cam itself . But I will go over everything again when I get the cam back . Heads are also coming off and getting a valve job , and springs checked .
Injectors are going out today also .

Dont know what else to do ........


looks like the lifter was moving sideways on that lobe
It sure looks like it wasn’t rolling. I have put 1,000 passes on a cam and it didn’t look that bad.
 
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