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Tips
Tips

Sloppy cam?

Tabcon

Jedi Warrior
Offline
I was trying to degree the camshaft today, what fun, and I noticed an abnormal amount of end play in it. Way, to much end play to be more specific, about .075".

I remember that when I dismantled the engine, the distributor/oil pump shaft was wobbly as was the cam. I didn't worry about it at the time because I was replacing the cam and the geared shaft as well. Then I realized that I decided to use the original cam instead of the Newman cam I had bought a while back. I had the original cam reground by Integral cams to a Stage 2 which I thought would work better with the build.

I have not tried installing the new Newman cam to see if this solves the sloppy end play yet, but I will most likely try this tomorrow to see if this corrects the problem.

If it does not correct the loose end play, what are my options?
Do they make bushing of some sort to place between the front of the cam and the cam bearing to take up the slack?

It's funny that the factory manual advises you to check the end play, but it doesn't address how to fix it if it's off.
 
Tab,

The usual culprit on a TR6 when the cam end play is sloppy is the front retainer plate. They get a groove worn in them that can almost look natural, if you don't know that it's supposed to be perfectly flat against the cam.
 
Is the front retainer plate the same as the front engine plate? If so and that was worn down, wouldn't it place more pressure on the front of the cam by being closer to the cam?
 
On the TR4 (which is different than the TR6), the cam is retained by the front cam bearing being trapped between a flange on the cam and the timing chain sprocket. For too much clearance, normally you just replace the bearing; but it's possible that either the sprocket or the cam is worn (and needs to be replaced).
 
Tabcon said:
Is the front retainer plate the same as the front engine plate? If so and that was worn down, wouldn't it place more pressure on the front of the cam by being closer to the cam?

No its not the same. The cam locating plate is number 61 in the diagram.
Internal Engine
 
Oh, okay. I don't have one of those on my engine.

The the front cam bearing and the sprocket are both new. I'm going to try the other camshaft and see what it does.
 
Of course, it's also possible that your new cam bearing was not made right ... there is a similar situation inside the gearbox and both of the new bearings I bought were about 0.1" too short. Fortunately, the original wasn't too badly worn.
 
That could be a big possibility with the way parts are made for the TR's now.
Doesn't seem to be much, if any quality control. Just have them made by the lowest bidder in some third world country by school children...lol.
I still have the original, so I'll check it against that one.
 
Romanh,
Tab has a tr4, that is a picture of a tr6 engine not the tr4.
Tab, look at the moss site for the tr4.
https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=36459

If item 20 does not keep the cam in place, you will need to machine the back face to tighten it up. What is supposed to happen is that is should be too tight so you can shim it forward to get your .003" clearance.
Could it be that your engine mount plate has too thick of a gasket or too much sealer?
Rob
 
Oops, my bad, I had forgotten to tighten down the distributor pedestal and the gears were not engaged. What can I say? It was late and I was tired...so shut up! :nonono:
 
trfourtune said:
Romanh,
Tab has a tr4, that is a picture of a tr6 engine not the tr4.
Tab, look at the moss site for the tr4.
https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=36459

If item 20 does not keep the cam in place, you will need to machine the back face to tighten it up. What is supposed to happen is that is should be too tight so you can shim it forward to get your .003" clearance.
Could it be that your engine mount plate has too thick of a gasket or too much sealer?
Rob

Sorry about that.
I should have looked a bit closer. Old eyes! :whistle:
 
Tabcon said:
Oops, my bad, I had forgotten to tighten down the distributor pedestal and the gears were not engaged. What can I say? It was late and I was tired...so shut up! :nonono:

Did you shim it properly before tightening down???
 
Ah yes, the old shim the pedestal trick. Shown on my engine build page. Proper clearance is necessary here as well.

A lot of guys wonder what those funny thing gaskets are for that won't fit the water outlet.

TR6 Engine Assembly

newengine 415 (Medium).jpg
 
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