Got a strange problem with the cam chain guide (front). The story is this: I pulled
the cylinder head off a spare engine to see if it was worth resurrecting. Found the
cam chain guide was broken: the part with 2 ***** that locks into 2 depressions in the
cylinder block had broken off the rest of the cam chain guide. (see dotted line on the
image). I assume it had been operating like that broken. Strange thing is that the
length of the cam chain guide from bottom of guide (where it lodges inside a pocket in
the crank case) to the ***** is longer than the same distance of the pocket to the
depressions, by about 3/8" - the ***** don't sit in the depressions (see other image).
So that if you installed the guide as is, and then screw the head down, the head bears
down on the ***** and breaks them off. It seems that either the cam chain guide is a
faulty manufacture (something is too long, or the bottom end of the guide doesn't sit
properly in the pocket).

So, can anyone please help me with some information: on a good cam chain guide (front)
can you measure and tell me what is the distance from the centre of the ***** to the
bottom of the guide? Then I should be able to figure out whether the ***** are in the
wrong place, or perhaps the bottom of the guide is too fat and not lodging in the
pocket correctly.

Thanks for your help!

[IMG]local://upfiles/20544/BBCA2969287E43BA80A6F6E19887D7A4.jpg[/IMG]

[IMG]local://upfiles/20544/01C57130247842FAA2FE3F913A54746B.gif[/IMG]

 

i'll go look at my spare tonight.

 

here is what it should look like. i think yours is kinda bent.

[IMG]local://upfiles/5094/96D59771A7A74EC589FC2183A4E96B39.jpg[/IMG]

[IMG]local://upfiles/5094/DDF7FC09CC774BC687CD2DDAD76E2FFD.jpg[/IMG]

 

here are the measurements.

i think if you just bent yours to the same shape, should fit. nevermind, forgot that part about yours being broken. looks like whoever had the engine before you just didn't care about it.

[IMG]local://upfiles/5094/242FE9D4D98C489B89E8893348A7827B.jpg[/IMG]

[IMG]local://upfiles/5094/DB32A1B93F774987BD8DAB3588AA9290.jpg[/IMG]

 

That's great, thanks. Can't figure out why the one out of my engine got straightened out.

[Edit: second thoughts: When I stripped the cylinder head, I forgot to remove the cam sprockets before loosening the camshaft holders, so the cam chain got tight because the valve springs were pushing up on the camshaft, lifting it up and tightening the chain.So I retightened the camholders andremoved the sprockets, then undid the cam holders. Maybe the cam chain got so tight that it straightened the guide? However, separately to this, one of the cam holders was cracked in the web that is also the oil way - before I started dismantling it. So maybe I damaged the guide, or someone else did?

Has anyone elseremoved the cam holders before undoing thecam sprocket andfound that it straightened the cam guide?]

Sorry 'bout the long narrative, but this really puzzles me.

 

Michigan 313, could you give me the measurements shown on the attached pic? That will help me bend my one back to the right dimensions. Thanks!

[IMG]local://upfiles/20544/673BC30BE66B4F14844CA70FE85CD42F.gif[/IMG]

 

i measured on a different angle.

overall length should be about 10.5 inches.

if you measure 2 inches from the end, at the intersection, the vertical measurement will be about 13/16 inch.



[IMG]local://upfiles/5094/291BD2BCE35449888247E3A31054E359.jpg[/IMG]

 

[sm=thanx.gif] I'll give that a go. I'm repairing the broken off piece with high temp cyanacrylate glue and carbon fibre - should hold.So now its just a matter of bending it back into shape.