brad-cam

I tried search and came up dry so I'll ask it again...

What are the differences between the 944 NA and 951 engine blocks ?

brad-cam

Bump...anyone ?

flyguy

one has a turbo on it.

duh!!!!

(I'm just being a jackasss... first post in a LONG while - hope someone answers)

brad-cam

Zero10

Difference?.... Still haven't found one...

I'm using an N/A block for my NA/turbo buildup.

The blocks themselves are identical.

hosrom_951

The NA block doesn't have the hole in the upper balance shaft cover for the turbocharger oil feed line.

brad-cam

Ah, right, I remember there being a difference with the balance shaft covers. I think that was difference I was thinking of. Anything else ?

KuHL 951

Supposedly the oil passages in the "early" N/A blocks were smaller than the turbo also. This hasn't prevented them being used in a turbo application though. Besides the oil tap for the turbo weren't the bearing shells for the balance shafts mounted differently also. They do look different in PET, I'm pretty sure the shaft covers won't interchange with the later blocks.

Chris White

Shaft covers are not interchangeable between any engines – they are align bored to each specific engine (and then stamped with that engines ID number)

The Series I and Series II engines have different sizes oil main galleys. (Series II are bigger and, in theory, better).

After a certain point in the series II production (a good guess is late 86) the NA blocks had all the needed parts to supply oil to the turbo – they just have to have the upper balance shaft cover tapped for the fitting.

The most important difference – the NA blocks are generally in much better shape!!

Chris White

Magown

I am using a block out of an 86 NA. It has the turbo oil line connection already in the balance shaft cover and the oil return in the pan.

Campeck

the na block doesnt have threads for the knock sensors.

Chris White

All of the 86 and later blocks have threads for the knock sensors, two actually!

Chris White

Campeck

oh....hmm. nvm then.


edit. are you completely positive. arent the knock sensors on the driver side up near the head. next to the water temp sensor?
i have an 86 block in the garage and i dont see any.

Campeck

see.

special tool

Campeck - probably be a good idea for you to reread what Chris wrote in his penultimate post.