Questions about top end rebuild 3.2
 

Hi there, I am putting together my brothers 3.2, it was taken down to cylinders to change the dreaded valve guides. Heads were carbonized and excessive smoke on startup plus cyl 6 fouling plugs. Bottom end and cylinders seem fine so we decided to keep it to head rebuilds.

We'll be starting putting the engine together tomorrow, from what I've read (Waynes book and the workshop manual) I understand we have two important measurements, the cam timing (1.25 mm overlap at TDC in this engine) and the sprocket offsets.
(of course alot of wrenching an torques, but this sure aint the first engine, just the first 911 engine..) :rolleyes:

The third measurement is valve to piston during 720 degrees revolution, but putting together with all the same components (heads restored, machined though) I cannot see any reason to do this. All heads go back to respective cylinders and we did not flycut as all surfaces were smooth.

So, in short,.. i'll skip the piston to valve measurements, recommended or not?

Thanks for any input.

You didn't remove the cylinders, so the base gaskets are the same.... and your heads won't be surfaced THAT severely, and stock Ps and Cs have gobs of clearance.... so, I don't think there's much to gain by the clearance check. Having said that, it's not a big deal, so do it on 1 and 6 just to do it and you'll sleep better.

JB

But if you didnt change out the bottom row of head studs there is a good chance that the nuts with the broken studs will be laying under the exhaust valve cover.
They dont retorque well
Bruce

Ditto what Flat6pac said. Change the bottom row of studs to steel, the dilavars will fail. I did a rebuild on my engine due to two broken studs and valves needed refreshing. 88,000 miles and stored winters, so never saw bad weather or salt.

Thanks everyone, I just checked and it has the original dilavar studs, based on all recommendation they have to go.. I have two options as we are on a tight schedule (planned to finish this weekend)

1) order new steel studs

2) reuse 12 steel studs from a 1977 2.7 engine I tore down, if so I was planning on using the upper bolts and test one of the other bolts from the 2.7 to 130% of the correct torque..

What you think, option 2 too risky?

Option 2 is as good as it gets, you already own them

Definitely option 2. :cool: