Pboden

Have a -78 928 with no engine number on the block. It is stamped ATR. When a bought it, the seller said it was a refurbished engine from Porsche and that its not supposed to have a matching number.
The seller also said it is a 4,7ltr engine, but since the car did not come with any papers, I have no way to confirm this- maybe other than on a dyno or even measure the pistons.

Is there a alternative way to measure wheter I have a the 4,5 or 4,7 ltr engine ?

Thanks

Ducman82

hmmmm. good question. being a euro car, i would say 4.7...

Pboden

Its actually an US modell. Imported to Norway from Houston I beleive.

Ducman82

hmmmmm. well, id say 4.5 if it was done state side. then again, short of taking the engine apart... not going to be easy to figure it out.

James Bailey

Makes no difference really.....if it was a 4.7 block odds are it is all the original 4.5 heads camshafts and intake. So NOT a 300 HP Euro S .

STRIKEMASTER

Pull the plug on #1 cylinder at TDC and fill the combustion chamber with oil, turn #1 to BDC and fill it again to the same mark. The amount of additional oil is the displacemant for one cylinder, X8 for the engine desplacement. A ballpark measurment, for sure, but it may give you some idea of the engine size. Don't forget to suck out the oil before you start the car...LOL

Hilton

ATR is the stamping for a factory replacement block. My '87 has one too.

One possible way to identify which engine is the pistons - if you can get a good shot of the top of them with a small USB camera or endoscope, the size of the dish, valve reliefs etc. may give some information on which pistons are actually in there (coupled with the experience of someone like Erkka).

James Bailey

Again it makes little difference...if it is a 4474 cc or a 4664 cc ..... it is what it is... and not an S