Thanks Yak,

I found that one - but I'm missing the tolerance (if there is one) for the width / thickness of the first camshaft bearing tower.

I can't find it in the FSM - in chapter 05-220 "Removal and installation of camshaft" they call it the "camshaft bearing cranking end". It is part 11 in the figure on the last page (page 11) of the chapter...

Haynes also doesn't specify it - despite a surprisingly OK chapter on the engine - well I say OK, OK compared with the rest of that pathetic book!

I'm off to see the engine shop next week. So hopefully he'll have the specifications.

Sorry. I misunderstood which spec you were looking for.

Along the same lines of inspecting the alignment rings in the towers, the camshaft bearings and "bearing crank end" all have dowel pins (cylindrical pins - #16 in the assembly pic in 05-220). Have you done the same sort of inspection on the bearings that you did on the rocker towers? All holes round, good snug fit, pins/dowels in good shape?

Another thought: are you checking alignment too early in the rebuild? (Excuse my ignorance here, I've never rebuilt a head/camshaft). I presume you haven't installed the sprocket. With the "compensating washer" and the sprocket (and chain, maybe?) installed, would that push the camshaft in the direction you need it to move for better alignment?

I'm basing the question on the supposition that bearing #1 may be "too thin" so the camshaft might be a bit "too far forward."

Hi Yak,

I did go through the process of checking the bearing holes in the camshaft towers and all the rest of it - I've been following the process in the FSM. Everything looked hunky dory but I've not been able to find the required thickness of the first tower. This is a problem because as you say once the sprocket is fitted (with the washer that also has the timing mark notch - 2.75mm thick by the way) that determines the position of the camshaft.

The only way to alter the position of the camshaft is to change the position or thickness of that first camshaft tower. All of the other cam lobe positions depend on this point.

(I've already checked the relative cam lobe positions of my new cam with the old one).

Update - conflicting advice!
 

I took off the camshaft and the front crankshaft bearing tower and cycled off to see the engine builder today =>

Please note - I am in Holland - so you do cycle!

He said that he had seen the problem with the rocker arms not aligning exactly under the cam lobes loads of times before.

He also said - "well what can you do? It won't cause any trouble. Don't worry - get on with it!"

I asked about the possibility of adding in a spacer between the lip on the camshaft and the first bearing tower and he said that would be tricky because you then are likely to mess up the axial clearance.

He looked at my bearing tower and said it was in perfect condition. He was also impressed with the new camshaft. He said there wasn't anything to be done about the camshaft journals slightly protruding from the bearing towers.

Apparently there isn't a quoted dimension for the thickness of the bearing tower - everything is deemed to be in limits or not when you measure the axial clearance of the camshaft when fitted.

Err so it is - last call for anymore advice

Thanking you all in advance...

I would have given the same advice if I thought you would have taken it. Even in a perfect situation, the cam width and the follower face are not going to be exactly the same, so a slight mis-alignment shouldn't be an issue. If only half the lobe was on the follower, that would be a completely different situation, however.

Thank you very much for the reply.

The only reason why I'm posting these problems on a forum is that I am looking for other people's opinions. I work on the principle that I collect all the advice I get and then make a decision.

Please don't feel that your efforts have been in vain if I decide not to take your advice - everyone's input is greatly appreciated, but I need to take overall responsibility for fixing the problem.

I know that it seems daunting to add a comment to a thread when some posts seem so outspoken - there is nothing worse than when technical threads turn into cyber punch ups - I understand that it is a risk that you take when you add advice but please don't let it stop you. Ideally if someone disagrees it shouldn't be taken as a personal insult, but I have seen cases when that is difficult.

What are you going to do if you leave it how it is? in a few hundred k miles you will have rockers & cam lobes that have un-worn high ridges on the edges. I guess you could then get the engine rebuilder to grind them down.

Yeah it is pants - I'm still deciding. After butchering the short axle shaft / spindle for the rocker arms - trying to get it to fit over cylinders 4 and 5 (WHICH IS WRONG!!!! <= added for others!) - I've got another one on order.

When I get that I'll be back fiddling again.

Perhaps I should turn this thread into a pole:-

Should I grind metal and add spacers for better fitting rocker arms?

OR

Should I leave it alone?

Update - my final solution!!!
 

Well it has been a long time but I've now got my ducks all nicely lined up.

I took the rocker arm towers (all five of them) to a machine shop and got them to mill off 0.5mm off of the back surface of the tower where the rear most rocker arms sit.

You can see this surface here in the picture below.

http://www.peachparts.com/shopforum/...1&d=1299679234

I then got hold of some 0.3mm and 0.2mm steel shims so that I could "add metal" to the other side of the rocker arm towers and position the forwards / front rockers.

http://www.peachparts.com/shopforum/...1&d=1299679385

If you didn't know the shims were there - I think most mechanics would miss them:-

http://www.peachparts.com/shopforum/...1&d=1299679458

I'm now one happy bunny. The rocker arms sit nicely under the cam lobes - I can now (finally) adjust the valves!

Small print:-

This is not an authorised modification - so if you don't see shims between your rocker arms and the rocker arm towers; that is OK, that is how it is meant to be!

I'll keep you all posted on how I get on with this.