390 camshaft no end-play

[Katz427]

The camshaft has no end-play and the only thing I can think of is that the plug at the back of the block is in backaswards. The motor was rebuilt but .... I think they missed this one. I did not install engine but I am the one who has to pull it back out! Damn ..more work!

[blykins]

Are you installing a new cam, or just checking things out on a new motor?

I often have zero end play on new builds.  It's a function of timing sets and new camshaft thrust plates.  Not abnormal at all to have to surface the thrust plates to gain clearance.

With that being said, the cam plug could indeed  be in backwards, but I'm just saying there are other causes.

[Katz427]

Thanks Brent. I bought the car with a rebuilt and it just did not seem "right". I thought the cam timing was off a tooth the way it acted. Checked and found everything lined up but the chain was not replaced and sloppy so I pulled the gear off and no fore-aft movement at all. The cam turns but is right against the thrust plate.

[Yellow Truck]

On my build (my first and only) we didn't have any cam end play and had to take the cam out and drive out the cam plug a little with a hammer and a piece of pipe. This is where I made a poor decision. I should have realized it was installed backwards - I had read the instructions that the cam bearing is the only plug in the block to be installed convex. I didn't notice that the machine shop that had assembled the bottom end had put it in wrong.

Just before I put the engine in the truck I pulled the plug and installed a new one the right way around.

[My427stang]

If it is too tight with the gear off, it has to be either the rear plug or a failed cam bearing, it should slide backwards.

What Brent was talking about is zero play with the gear ON, that would be a retainer plate or timing gear issue

[Katz427]

Thanks for replies , much appreciated. Time to pull the engine! Maybe best to check it all over. I found the exhaust valve lifters about .030 off of bottomed out, way to much preload. But that is just new push rods They did spend money on nice Le mans valve covers for this engine!