Cam end play question

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Badart

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I am in the process of rebuilding my 73 318 and last night I was installing my new comp XE cam and noticed that I have a ton of end play (maybe 1/4"). When I pulled the factory cam out there were no bronze thrust washers installed. How much cam end play is acceptable? Where can I get some thrust washers for a mopar? This is the first small block mopar that I have rebuilt. I am a Chebby convert who has seen the light. Thanks
 
Ok I have found that spec is .002-.010 My thrust plate is flat in the back and I can see where the old cam was rubbing on it. Is my thrust plate worn that much? Should I try and find some brass thrust bearings?
 
No. You don't need brass washers between the cam and thrust plate. How about a picture of what you have? Is the thrust plate worn more than a couple of thousandths? If so, just replace it. When you checked the end play, did you have the cam sprocket bolted on the end of the cam?
 
lilcuda said:
No. You don't need brass washers between the cam and thrust plate. How about a picture of what you have? Is the thrust plate worn more than a couple of thousandths? If so, just replace it. When you checked the end play, did you have the cam sprocket bolted on the end of the cam?
Click to expand...

No the cam sprocket was not bolted to the cam when I checked the end play. Why would this matter? Is the thrust plate supposed to be flat on the cam side of it, or should it have material there? The back side of mine is flat.
I am at work right now so I can't take a picture.
 
Badart said:
No the cam sprocket was not bolted to the cam when I checked the end play. Why would this matter? Is the thrust plate supposed to be flat on the cam side of it, or should it have material there? The back side of mine is flat.
I am at work right now so I can't take a picture.
Click to expand...

The thrust plate is between the cam and sprocket, when the sprocket is tight that keeps it in place.
 
lilcuda said:
Babyblue66 is correct. The thrust plate is sandwiched in between the cam nose and the cam sprocket...
Click to expand...

Uh, no, that would be the cupped snout washer, which aids in retaining the pump eccentric in alignment on the keyway.
The thrust plate is the large plate with 4 bolt holes that the front journal of the cam rides near.

Typically these wear a minimal amount over an engine's lifetime, so unless it's severely scored or gouged up, it's hardly the end of the world to put it back in.

If the clearance is objectionable to you, about the only way to adjust it is to 1)Replace the plate with a new one.
2)Have the shoulder that the back of the timing gear seats against, on the cam, machined a few thousandths to correct it.

Personally, it's not really worth worrying about.

Mark.
 
Mark Nixon said:
Uh, no, that would be the cupped snout washer, which aids in retaining the pump eccentric in alignment on the keyway.
The thrust plate is the large plate with 4 bolt holes that the front journal of the cam rides near.

Typically these wear a minimal amount over an engine's lifetime, so unless it's severely scored or gouged up, it's hardly the end of the world to put it back in.

If the clearance is objectionable to you, about the only way to adjust it is to 1)Replace the plate with a new one.
2)Have the shoulder that the back of the timing gear seats against, on the cam, machined a few thousandths to correct it.

Personally, it's not really worth worrying about.

Mark.
Click to expand...

OK. Maybe I didn't type that quite right. I was NOT referring to the cupped washer that holds the whole assembly together. The thrust plate is just that - a plate. If you confuse a washer with a thrust plate, you shouldn't be working inside an engine in the first place.

What you missed in the conversation was the fact the he didn't have the cam sprocket installed when he checked the end play, so he was measuring the travel between pulling the cam forward against the back of the plate and pushing it back against the rear cam plug, hence the 1/4" of play he mentioned.
 
All is good. Thanks for the help. I tightened the cam chain sprocket and it put the end play in spec. I feel silly.
 
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