Question about 2.7l heads

[DspWest]

Hi
I have 2 different casting number heads that come from a 2.7L engine...
i have 911.104.342.0R and 911.104.345.0R and the last one have an edge or groove in angle in the combustion chamber and the other have not. And i was not able to find here where thoses two head come from.

My question is... Can i rebuild and install them in my engine...what this groove purpose ?
Thank

[DspWest]

[75 911s]

I can't answer your question but maybe I can add to the conversation and bump the thread. This list says the .342 head should be a 2.7 air injector head, but all your heads have the non air injector casting, including the .342 casting number...

Did you take this motor apart? was that cylinder different for the grooved head?

[targa72e]

The heads without the bevel should be 2.4 heads. The bevel is needed on 2.7 engines because of the larger bore. Bevel keeps piston from hitting the head. You can have the bevel machined on the ones that do not have them to use on a 2.7. You would need to make sure the ports are the same size if mixing.

john

[DspWest]

Thanks for the anwser...and do you know the difference between 345.0R stamped k1819t and K1?
Thanks

[Walt Fricke]

You can tell from John's chart. For '74-5 Porsche offered a lower powered 911 (listed as "911) while the more powerful (but same displacement but listed as 911S) was a bit more expensive. The non-S had smaller ports and a less aggressive camshaft. Silly attempt at market differentiation, as the cost differentials to Porsche for the motor components, at least, had to be 0 marks. The chart lists both.

[75 911s]

So is John's chart missing the 73.5 2.4 CIS heads that the OP has then? 911.104.342.OR Because that casting number says 75 with air injector ports?

[DspWest]

Can someone tell me the difference and meaning of the K1819t and K1, K2? Thanks

[Walt Fricke]

K1 would be the Euro heads for the years indicated. The K1819t is the small port non-S model.

[DspWest]

Thanks you very much for this informations Walt Fricke!😊