Is my engine a 2.7?

[Mbremith]

Hoping someone might be able to help me confirm (or otherwise) that my engine is a 2.7.

Came with a project car, I don't have it running yet. It is a 2.4T case but I am told has been built up as a 2.7 (running webers). Is in a 74S that was imported from the U.S. a few years back (ex Porsche Club San Fran according to sticker on back window).

Cylinders aren't ferrous. Is there a number or something I can check without pulling the whole thing apart?

[Chuck Miller]

Mitchell,

I'd let the experts weigh in, but if I'm not mistaken, '74 type 2.7 Alusil cylinders (and the 2.7 RS Nikasil cylinders) had/has 11 cooling fins as apposed to the 15 fins a 2.4 has...

That would be the first thing I'd look for....

Chuck

[Jon B]

Hoping someone might be able to help me confirm (or otherwise) that my engine is a 2.7... It is a 2.4T case... Cylinders aren't ferrous.

If the alloy cylinder fins have a split down the center, on top & bottom, then the cylinders are Biral and not 90mm.

Jon B.
Vista, CA

[Mbremith]

Pic from below - so 90mm (2.7 assuming rest is stock?)

[sithot]

My '74 has Nikasil cylinders. When the engine was rebuilt they showed no wear. Alusils showed up a bit later. Cost cutting. They're not known for good wear qualities.

[Richy]

Back to the original question , those look like 90 mm 2.7 cylinders .

[Mbremith]

Thanks everyone, I thought it was a 2.7 but this has helped confirm.

[Jon B]

Pic from below - so 90mm (2.7 assuming rest is stock?)

The cylinders do appear to be Nikasil, but Mahle re-made the smaller sizes in Nikasil as well, so they could be newer 84mm cylinders.
If they were Biral cylinders with split alloy fins, then they would definitely not be 90mm.

Jon B.
Vista, CA

[Jon B]

The cylinder heads have plugs in the exhaust ports, so are '75 or later heads.

Jon B.

[Mbremith]

is that a reversal of an "anti smog" measure?