I cracked open the valve covers to find a very neglected engine. For starters the timing mark on the exhaust side cam shaft isn't vertical at TDC front and rear?? Could I correct this or does it indicate a huge problem?

EDIT: Photobucket is down but it is about 7-8° off vertical.

I also found that 6 of the shims had be ground down with precision that could only be matched by an epileptic with a strobe light. The biggest issue with the clearances is that one of them has <0.05mm but the shim (at its biggest point) is 1.74mm and if I remember correctly the smallest shim is supposed to be 1.8mm. What would cause this and how would I go about fixing it?

OK - so, with the timing cover off and the marks lined up correctly - you looking at them side on.

> the little tell tales are not where they are supposed to be? You sure that the crank timing mark is bob on? I would expect that if it was out then the pistons and valves would have made very good friends.

secondary >> Your shims are ground down?! So, some bellend has taken the hardened coating off them and tried to slim them down. LOL.. You need to get your good shims, take some measurements using them and then get hold of some proper shims.

The clearances do shrink over time - the valv and the seat take a smack and the valve regresses in the head.

0.05 is pretty tight! Valve will be close to the piston by at least 0.07 more than it should be when the piston starts to rise back up the bore... I am very surprised this engine is not fucked.

Can all be sorted though mate. No worries.

How many miles / k's on it?

It's possible it's been run with too little oil which has caused valve-train wear.. how do the cam-lobes look? Any marks on them?

And the shims need changing as the valves repeatedly closing wear the head down so the shims need making smaller in most cases.

Sounds as though it's been neglected.. or done a lot of miles or both.

Hopefully you can get it running sweet again.

I'm sure I've done everything correctly, I have read the guide on here (all 14 pages) and I have Haynes. I line up the crank timing mark (T1 or T2) and the camshafts marks on the inlet valves are then vertical as they should be but the exhaust ones are off as shown here:



With regards to the ground down shims, yes this idiot removed a lot more than the coating. When I said <0.05mm that was less than 0.05 as my feeler gauge doesn't go any lower. The cams were noisy before but the engine sounded good, can't be that bad.

The questions remain, can I realign the exhaust side camshaft and if the shim needed is less than 1.8mm what are the options?

The lobes looked fine but I will double check. So if the head has been warn down to the point where a shim smaller than 1.8mm is needed then do I need a new head? Not gonna happen.

There are sellers on ebay that have shims down to 1.2mm

Phil

That cam's a tooth out by the looks of it.

Yes you can take unbolt the camshaft retainer caps and move it into the correct position to match the other-one.

Is it the inlet cam? Some people use to do that on older Kawasaki's to alter the intake duration but never seen it done on a Honda before.

You can get smaller shims just be wary of over-all head wear.. if it were me i'd be wanting to remove the heads and check the condition of the valves and valve-seats if the engine looked that bad.. but that will involve two new head-gaskets.

You have cleared that up nicely. Both the front and rear exhaust side cams are the ones that are offset so maybe it wasn't intentional?? I would think it is best to correct it as it would surely throw the timing out wildly, what do you think?

Although the 6 shims were ground down there is only one that will need a shim less than 1.8mm, probably about 1.55 (really hard to be sure when none of my good shims are less than 2mm and seeing as the current shim is uneven I wont get an accurate measurement). Things are looking up , thanks.