# Camshaft endplay, bad thrustplate?



## ibarbuckle (Feb 24, 2014)

Finished the short block for my '69, and moving into building up the long block, I have run into a problem. 

Put in the cam and timing gear, I find the end play is out of spec. Pontiac calls for 4-7 thous., I keep getting 12-13. So I pulled everything apart and the aftermarket thrustplate I recently bought from Ames is ~0.008 thinner than the plate that came off of the engine. Has anybody else had this problem? Is there any other reason that cam could be shifting around in the block? 

Always possible I have done something stupid, too. Doesn't seem like there is much to go wrong in this situation, though.


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## PontiacJim (Dec 29, 2012)

I found this on another forum which might help?

"Cam endplay should be .003" to .007".

"The endplay is determined by the thrust plate thickness, as that gets sandwiched between the cam and the upper timing gear.

If your looking at the endplay w/o the upper timing gear on there, then your not seeing things they way they should be.

Also, the cam "snout" needs to be pulled past the face of the upper cam gear to properly set the actual endplay. This is acheived via the "step" that is on the fuel pump eccentric, it allows the snout of the cam to be pulled past the face of the cam gear."


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## Cory (Mar 2, 2014)

Defiantly check the eccentric. I once seen it installed "catty wampums" over the nose causing so much end play that it made the base timing erratic by 15 degrees. 

To much cam thrust will change ignition timing (not mechanical) cause of the 45 degree distributor gear.


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## ibarbuckle (Feb 24, 2014)

Thank you gentlemen.


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## ibarbuckle (Feb 24, 2014)

Update:

The repo I bought was definitely too thin. Got one from a different supplier and everything is good.

For posterity, this is what I ended up with:










Nitemare thrustplate


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## PontiacJim (Dec 29, 2012)

ibarbuckle said:


> Update:
> 
> The repo I bought was definitely too thin. Got one from a different supplier and everything is good.
> 
> ...


Thanks for the update. Checking the cam endplay is something I never have checked, let alone knew it was to be checked. I also have always installed the factory thrustplate.

I guess it seems with most all aftermarket, non-factory manufactured parts, the part may look like original until you take some measurements or try and fit/install the part. I have run into the same thing, but if you can't get it "factory new" or don't want to pay NOS prices, then you buy what you can and hope for the best -even if it takes some fitting to make it work. And that's why we are hot-rodders!:thumbsup:


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## Raleigh251 (Apr 13, 2019)

There is a guy that makes a Pontiac Cam trust plate with roller Torrington bearings. These are great for all cams but are a must for roller cams. His name is Scott Sims he does the work for $285 his contact info: 812-350-8637 or [email protected]. Or you could pick up a cheap stock one for $50.

Raleigh251


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## PontiacJim (Dec 29, 2012)

Raleigh251 said:


> There is a guy that makes a Pontiac Cam trust plate with roller Torrington bearings. These are great for all cams but are a must for roller cams. His name is Scott Sims he does the work for $285 his contact info: 812-350-8637 or [email protected]. Or you could pick up a cheap stock one for $50.
> 
> Raleigh251


Thanks for the reference. However, I am curious why you said this is a must for a roller cam. I have never used a roller cam, but others here do/have. So why is this a must and what will happen to a roller cam if you do not use one and go with a stock type thrust plate? :thumbsup:


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