Update on first engine rebuild...

Well I finally got that damed cam nut off! I removed all the rockers and placed them in the proper order and recorded the information. Pulled the chain housing and removed the last of the head nuts. So far, so good.
Good news #1: I removed the cam housing and the heads to find that the stud broke off with plenty of room to work with (on the intake side).
Good news #2: Cylinders say Mahle so i'm assuming that they are Nickasil (correct me if i'm wrong). The hone is shiny and I think I can even still see the factory criss cross hone marks.
Bad news #1: One of the valves on in the middle of the bank has a small pie shaped break in it and the piston shows a mark. This break must have happened some time ago because it looks "erroded". There doesn't appear to be dammage to the cylinder but i'll have an expert check it out.

Well thats pretty much it for now, I'll check out the other side this weekend.

Does anyone know if the stock pistons are supposed to be just a basic round top or if they are supposed to have a bump or non uniform curvature like mine do? Thanks fellas. Wish me luck!!

Adam Roseneck

Adam, thanks for the updates. You might want to add the year and model of your car to your 'signature' as it often makes a difference to us. I've never had my pistons out, but it seems to be I;ve seen pictures and besides, my compression ratio is 9.3:1, so they are surely domed pistons. The engine is basically a "hemi."

------------------
'83 SC

Here we go, hooked it up and chaged my signature. Hey, anyone have any 98mm pistons with about a 9.5:1 compression???


Adam Roseneck



------------------
1978 911SC 3.0
roseneck@cyberbeach.net

Adam, Sounds like maybe a burned valve.

------------------
Robert Stoll
83 SC
83 944

One of the frequently mentioned piston upgrades (you're likely to hear more on this from Warren) are J&E pistons. You may very well be able to use your old cylinders and the J&E sets are not too spendy, I believe. Relatively speaking.

------------------
'83 SC

Adam:
Just because your cylinders say Mahle on them, don't trust that they are Nikasil. You might want to check your engine number with whatever records to see if it came with Nikasil cylinders. Mahle & K&S make Nikasil cylinders. Another way to check is to take a small magnet & see if it sticks to the inside of the cylinders. Nikasil cylinders are magnetic on the inside, but not strongly. Alusil cylinders, etc. aren't magnetic. If you go with JE pistons, you will need to use Nikasil cylinders, because the alloys of the JE pistons & Alusil cylinders are too similar. Some people might say you can get by having the inside of your Alusil cylinders "Nikasiled", but I think the best road is to buy a set of Nikasil cylinders. If you discover yours are already Nikasil, you've lucked out. My 2 cents.

------------------
Marv Evans
'72 911E