No camshaft end float (pics)
Turbo Mini Forums

I can’t move forward anywhere! I just finished posting my issue with the idler gear…still trying to figure out what to do with that… so I decided to work on the other side on the engine.

After installing the cam gear, I have no camshaft end float! I pulled the gear back off and measured the new camshaft triangular plate. It was .097” (2.46mm) thick versus the original .092” (2.34mm). The little shoulder on the gear appears to be ~.093” (2.36mm).

How can I take .005” (0.13mm) off the plate… I was thinking of glass and 4000 wet dry sand paper. Or do they sell shims… I can’t seem to find different thickness plates or shims….

Edited by Mikes1098 on 18th Oct, 2008.

Just measured a couple of used ones - about 093-094.

This implies the shoulder on the gear should be about 1.000 as your new one would then give minimum (but acceptable) clearance.

I have heard of people machining back the raised boss on the back of the gear instead of putting a new thrust plate in - possibly this has happened in your case ???

If so, you could make a shim (I doubt anyone sells them) BUT... if you try to thin down the thrust plate instead, make sure you thin down the steel side, not the bearing side.

EDIT - I'll repeat the last sentence "if you try to thin down the thrust plate instead, make sure you thin down the steel side, not the bearing side."

I've just seen posts on the other two "main" forums from someone in the States who was told on one forum that they have a bearing surface, didn't like the answer, so has posted on the other one trying to get someone to say different.

Maybe, just maybe, some copies you are getting in the USA aren't being made properly ???

They should have whitemetal on the side facing the cam and you shouldn't be able to put them on backwards as the three sides of the triangle are all different lengths.

Edited by Rod S on 12th Oct, 2008.

Schrödinger's cat - so which one am I ???

Wanted to update this post with what I found, just in case it will help someone else…

After Rod’s post, I looked at the gear much closer. I believe he was absolutely right when he said that people machine the gear instead of replacing the thrust plate (WHY someone would do this is beyond me). Measurements of the shoulder showed it to be ~.092” on one side and ~.095” on the other. They didn’t even machine it square! The face was clearly machined rougher than the original gear. Reinstalled the old plate to measure the original end float… turned out it only had .0005”! Explains why the plate had so much wear.

So I decided to just buy a new gear…which just arrived. The shoulder on the new was ~.101”…This gave me .004” of float.

To shed some light on the on the thrust plate material, I have uploaded pictures to help explain. The old thrust VERY clearly has two materials bonded together. The new does too but it is much tougher to see. However, the bolts holes force you to put it on right, as Rod stated. My guess is the dude just couldn’t spot the seam.

Thanks Sprocket - in fairness I had just been doing my own one a few days earlier so it was all fresh in my mind, and I had to ask the forum about another bit of it

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=248000

So Mike, don't forget to get the shims at the bottom right to match your new top gear, it ill be further out than your old one.

EDIT - and the gasket thickness behind the big steel plate can throw it out even further as the new gaskets can be a lot thicker than the originals.

Edited by Rod S on 18th Oct, 2008.

Schrödinger's cat - so which one am I ???

Yeah, I ordered a couple extra shims, figuring that I would have to get the crank gear out a bit.

Thanks!