Should I aim for the higher end of the tolerance?

whats going on with 3B intake? Measured .006…
how can 3A 4A 5B get larger from the initial factory setting?
1977 pre He 45000km European delivery

Intake Exhaust

1A .012 .012
2A .011 .014
3A .016 .014
4A .016 .011
5A .011 .013
6A .010 .010

1B .013 .012
2B .011 .013
3B .006 .012 ! Is that .006 a problem?
4B .010 .011
5B .017 .010
6B .012 .012

 

Could receeding Valve seats cause this increase?

 

I think that would tighten clearances; but an eroding valve stem would cause it, as would an eroding tappet shim or cam lobe.

 

Should I leave them alone or remove cam and tweak them all a bit ? I’d hate for the tensioner to break..i ll of course use a hook and wing nut to slowly stretch it but still.. do they always break ? Even if it doesn’t break, it seems like stretching it to the max (lock) might create small cracks weakening it.. maybe I can simply put tension on it but not max stretch. Just enough to take over from the spring to remove my cam shaft.. almost equal tension.

 

Quite right Greg. I was working upside down! Thanks. Appreciate your correction!

 

Jeff
I would leave everything alone!

 

I tend to agree.

As Jeff and I have emailed each other on this, and updating a Forums Post is one of standards, I will "copy/paste" my replies to Jeff.

1) To remove the camshafts, that Godforsaken Plastic Tensioner needs to be "played with", and they break, age is now against them. Left alone, they be fine. Last 1 I needed, 20 years ago, $675 AUS, so now, who knows.

The chanced of wedging it so it does not spring fully out is something I have seen, once, but never done.

To so that "thing' the front of the engine comes off.

If the car is going to be a quiet hobby type of thing, leave it alone. If the use is robust and hard, do them. The labour to do a few suspect is not much less than doing them all, and that damn tensioner is still teasing you.


I had the heads off all mine when I did them, as that tensioner was broken on all of them, or cracked at least. The chain just had that odd feel to it when flexed with the finger down the B bank side. Rotating that engine backwards is the main cause of that breakage, and I reckon that was the case with 3 of my 4.2( )Worth a try with the rod. I reckon a pry bar or similar down the gap, and "push" the blade back as you wind that nut, that will take the strain off the lower pivot of the plastic, which is the part that snaps as you pull up. That is what the guy here with the wedge shaped broom handle down there was doing. I was at work and could not hang around to find the results.

YES those 035 Injectors are the correct ones. The system is Bosch, with Lucas stickers, oh boy, and Benz used the same Injectors in odd models using the D Jetronic system, same yaers as these Jags roughly.

Make of this what you will, and ask away if confusion is bothering anyone.