1975 2.7S rebuild

[nimskov]

I bought this damaged 2.7S engine type 911/44 to use while I rebuild the original engine in my car. But before I rebuild my own, I gotta make this one work.

I'm just gonna make it work, so its a basic repair, no tuning or too many "while I'm in there" projects on this engine...

Problem: Cam tensioner in left side failed - thx for your help in identifying tensioner type in a prev. post.

Result:
- Cylinder 3 exploded piston disintegrated
- Cylinder head 3 deadish
- Connecting 3 rod bent
- Intake valves made contact with pistons in cylinders 1-2, no obvious damage

Solutions I figured out myself:
- Bought replacement cylinder head on ebay, otw now
- Splitting case to clean out p&c debris and check for further damage
- Case has allready Case Savers installed, so thats good.

Once I get all the gunk off, I'll pick upp case, crank, rods, cylinders & pistons, heads and rocker boxes and head to a local expert to have it all checked and meassured.

Questions (I'm sure more will follow later on):
On the cylinders in left bank, the stamps are 90ZN2 W4. Cylinder walls are magnetic, so its Nicasil - nice.
The W4 is the height group, right?
If I find a cylinder from a different height group, is it possible to make it work by machining this or the other cylinders or by shimming the base? Or do I need the correct height group?

Connecting rod is marked on one side: 911.103.105.0R and on the other side: 36L 31597
As far as I can read on the forum, theres no way to determine weight group from the markings?
So if I'm gonna weigh the old rod, is it with wrist pin bearing, without crank bearing and inluding bolts?

I'm gonna ditch the nozzels for the air induction in the exhaust ports. Anywhere to get some plugs for the holes, or do I need to machine them myself?

[Flat6pac]

the plugs are 10mm fine thread
The other valves that touched the pistons are probably bent.
The deck height is either a 5 or 6 stamped in a triangle on top of the cylinder where the 0/1/or 2 is stamped for bore size.
Its usually easier to buy a set of 6 rods than try to find a match for the one you need.
You need to describe the cylinder you need. Deck height and size and nikisil. 2.7 just because they are Mahle doesnt mean they are nikisil.
Bruce

[nimskov]

Originally Posted by Flat6pac

the plugs are 10mm fine thread
The other valves that touched the pistons are probably bent.
The deck height is either a 5 or 6 stamped in a triangle on top of the cylinder where the 0/1/or 2 is stamped for bore size.
Its usually easier to buy a set of 6 rods than try to find a match for the one you need.
You need to describe the cylinder you need. Deck height and size and nikisil. 2.7 just because they are Mahle doesnt mean they are nikisil.
Bruce

Bruce,
Thanks for your reply.

I'll check all valves, gotta check the valve guides anyway.

I cannot find the triangle with the deck height...? No stamps on top of cylinder it seems... You mean the top as beeing the end facing the cylinder head?

Since the cylinder walls are magnetic, I thought it was nickasil?

[Flat6pac]

It is nikisil
the part of the cylinder near the case should have the number stamped in place along with the triangle for the deck height.
Mahle in the 2.7 made the both nikisil and alucil.
Bruce

[nimskov]

I found the cylinder deck height - its a 6.

So I need a 90mm Nick cylinder with deck height 6 and a matching piston.

Regarding the cylinder heads, is the stamp within a triangle also the height group here?

[Flat6pac]

No, the heads match with the 6 letters and numbers in a small oval on the face such as
(k1819W). Its usually on the opposite corner from the 911 part number.
Bruce

[nimskov]

Ok, thx. I'm fine with cylinder heads then.

[fred cook]

With the cylinder head combustion chamber up, fill the combution chamber with some anti-freeze coolant. If the intake or exhaust ports become moist or wet, then you have a valve leak. If they stay dry, then the valves are closing properly. If I was doing the repair, I would go ahead and have the valves done. It would add to the value of the engine once you are thru with it and want to sell it. Just a thought.

[nimskov]

Fred
That sounds as good advice, thanks. I'll take valves out, check for bent valve stems and make sure valve guides are not worn.