Mark's 951

HELP!! I have a 2.8L 944 turbo stroker that was built by a local shop. I spun a rod bearing and am now starting the process of rebuilding - again. I want to verify which crankshaft they used in this engine. I have found the casting number on the rear counter weight. The casting number is 944.103.6 R. I also found stampings on the front counter weight. One stamping is 944-11. The other stamping is E836655. There are also some symbols stamped on the counter weight in the front. One looks like a triangle with a reversed capital D inside it. Another is a circle with an M inside it. Can anyone direct me to a source to find out what this crankshaft is?

gruhsy

What size pistons?
78.9mm stroke plus 106mm pistons is a 2.8L
Which means it would be a stock 2.5 crank.

I have 3 cranks sitting in my house right now and can check when I get home.
one 944 crank
one 2.5L turbo crank
one offset grind 2.5L crank

Mark's 951

It appears that the casting numbers for the 2.5L cranks have more digits. The 3.0L cranks appear to have the shorter casting numbers. The 3.0L cranks that I have seen for sale also show similar stamping on the front counter weights. I appreciate anyone checking on cranks they have access to. It would be nice to get a list of the casting numbers Porsche used on the M44 engine series crankshafts.

Thank you all for your help.

blade7

There's an old thread I started on here with pictures of 2.5 and 3.0 cranks showing the different big end offset.

gruhsy

Sorry I will have to check tonight. Ended up working until late yesterday.

alex_cristocea

The one on the bottom it's 3L, the one on the top it's 2.5 and it has stamped 944-11. So I think you have a 2.5 L crank.

gruhsy

944201509 is stamped on the offset grind crank from an 86 2.5L turbo going into the 2.85 in my basement right now.

Will have to dig out the other cranks shortly.

......And same number on my stock 2.5L crank from my 87 turbo

gruhsy

This is stamped on the other side of the 87 turbo crank.

M 9

E406869

.

alex_cristocea

I'am sorry. I was wrong. I figured out these evening when I put the 944-11 crank in the 2.5 block with 2.5 pistons and , at the TDC, the pistons would come out 4.4 mm.
So the 944-11 it's the S2 crank and the 944201509 it's the 2.5 L crank.