Lateral Camshaft Movement 1.9 8V Photo Attached

[swervygerdy 0]

I recently purchased an engine from a forum member and have just tonight got it running.Its a 1.9 8v on carbs with a "hot" cam - the exact spec of which is unknown.

 

Anyways, I noticed that the cam moves laterally in the head. I removed the rocker cover and noticed a shim in place on the cam cap at the pulley end? See photo.

 

Is this common practise with uprated cams and could it be that the shim has been machined incorrectly and the cam can still move by it? Basically - how do I cure it? Its causing the t/belt to wander accross the pulley which is a concern! Also can anyone shed some light on the cam itself from the pics?

 

Cheers

 

Gerry

 

 

 

 

 

[welshpug 1,661]

That is standard on earlier heads, later heads rely on the flywheel end journal for location iirc.

 

The i.d marks will be under the pulley, looking at the chamfer it looks like a standard cam, though may be reground, look for catcam or piper or sportcam cast into the blank between the lobes, or pop that belt pulley off.

[swervygerdy 0]

Ok thanks Welshpug - so the lateral cam movement is nothing to be worried about?

[welshpug 1,661]

Depends how much it is.

[swervygerdy 0]

judging by the marks on the cam about 5mm max?

[nick205 12 5 Cars]

Cams always have some movement, but 5mm is surely way too much? At the very least its going to wear the cam belt unduly, I'd be worried about it coming off TBH.

[swervygerdy 0]

Yeah Nick, me too. So what's the cause and what's the cure!

[petert 588]

It still looks like to me that the shim is engaged. Have you unscrewed it and checked? When ever I regrind a cam, I have to reduce the diameter of that shoulder, so that it's less than the base circle of the first exhaust lobe. Otherwise, it will keep the bucket/valve open, riding the valve. Only 1mm or so is removed and there is still plenty of shoulder to retain the plate and control the thrust.

[hoodygoodwood 71 3 Cars]

Have just checked my Haynes manual and it says camshaft endfloat should be 0.07mm - 0.16mm . Looking at your photo closely it looks like a burr has been thrown up where the cam shoulder touches the location plate so it must be wearing here . If the endfloat is really 5mm your cam and location plate are scrap .Later type engines do not have the plate , the cam sits in a shoulder of the head casting iirc.

I would not run the engine again as the belt is likely to work its way off the pulley.

Interested to know what would have caused so much wear -- oil starvation ?

[Tom Fenton 1,542]

Looks to me like that location ring is riding on the cam follower as Peter describes. The outer face of it is shiny where it should be dull. Also look at the side of that cam lobe, as the fall ramp meets the diameter of the location ring there is a step on the cam lobe!

 

Remove cam and check for definite!

[petert 588]

I'd just make a new deeper plate if the engine is otherwise running ok. I suspect it's riding up over the shoulder, because the diameter is too small.

[Tom Fenton 1,542]

 

This was the bit I was looking at?

[Anthony 1,003]

Is that not just a reflection of the head casting Tom? Looks that way to me at a glance.

[swervygerdy 0]

Tom and Petert, you were right about the location ring riding on the cam follower, but that line on the cam lobe is just a reflection Tom.

 

Judging by the marks on the cam at the other cam caps, I think the cam is moving toward the distributor end at higher revs and then butting back against the shim causing the burr on the location ring as Petert noticed.

 

So.... I need to remove the cam, machine about 1mm of the diameter of the location ring and fit a thicker "shim"', is that the general consensus?

[hoodygoodwood 71 3 Cars]

If the slot in the cam is badly scored you will have to refinish it on a cylindrical grinder as well or it will knock out the new location plate . The plate might be hardened steel and is not going to be easy to make , you could get a 2nd plate and grind them both down in thickness until the 2 together fit the slot with the correct endfloat .If its a standard cam it might be easier to just get a new cam and plate .

[estland 3]

Didn't want to dig up old thread, but what's the tightening torque for camshaft thrust fork bolt?

[estland 3]

Haynes only gives data for TU engine and it's 16 nm.

Is it the same on XU engine?

[Tom Fenton 1,542]

I wouldn't think its critical. Put loctite on it and give it a firm hand tighten.