TOPIC:

stocktoy wrote: Just a thought here, before you pull head again did you set the valve clearance starting from the correct side of the engine. I know years back the first time I set the clearances I started from the wrong side of the engine and had similar results.

What do you mean? Clearance is clearance isn't it? Doesn't matter where you start surely. I checked all of them when I did the last correction...

I'll check again when I have the cover off, before I pull the head, but please can you explain?

Cheers

Paul

I think he's suggesting: if you set the crank position for checking the 1st cylinder but then checked the clearance for #6 then that would cause problems - although I don't see how you could check #6 at that point since the cams would obviously be in the wrong position.

Nothing to do with the current problem but I would suggest the method of checking valves as per the service manual is goofy. Easiest to set #1 to TDC (#1 cam lobes facing away from each other), check valves, then rotate #2 to TDC, check valves. then rotate #3 to TDC, check valves etc. etc. etc.

Right, well, I checked each valve when the lobe was facing 'up', meaning the valve was as closed as it can be. It was not in any particular sequence, but I did start from T at the case split line and turned the engine forward from there and then as each lobe faced up, measured.

But obviously I b*ggered it up when I got the cam timing wrong and the valves interfered with each other, which may have caused damage. We'll see when the head comes off, but as said, I will check the clearances again, following the procedure described in the manual - just to be sure.

Paul

Ok, took the oil out (clean, so I did something right), took off the head cover and measured the valves again. All perfectly within spec.

So next thing is to take the head off again and have a look.

I'll report back when I'm done.

Paul

McBoney wrote: ... measured the valves again. All perfectly within spec....

In my personal experience that is weird. If a valve is bent, it's usually really bent. Enough that it would have too much clearance at the lifter.

Are you sure both cams are properly timed?

Frank make's a good point here I might just stop a go and buy a leak down tester before going any further. (before pulling the head) You will need an air compressor to go with the leak down tester and not a big one. Something like 2 cubic feet per minute would be more than ample.

The compression numbers are lower than they should be considering that you also did the rings. #3 and #4 being at zero suggests something significant. Even the best cylinder at 95 is a concern. Up around 120 or 130 on a completely fresh ring and valve job would be expected.
I have to ask since I've seen this before. Did you by chance happen to change the schrader valve in your compression tester for a schrader valve from a tire valve? The schrader valves in compression testers are designed with a much lighter spring than a tire valve and can throw off compression reading by 30 to 50 psi

Just for verification see this Schrader valve /compression tool repair