81'/78'-79' motor parts id help

[NoEardGoat]

The car is a European 1981 911sc Coupe

I am in the middle of a 3.0 rebuild (see My new (old) 1981 911sc Project car ) and need some help figuring out what parts I have.

Engine: 930/10

Smog system: air/smog pump and air lines tapped into exhaust on head. This is typical of the 78-79 smog system not the 81 smog system which uses an O2 sensor. Possible part of a conversion done to smog when imported to CA.

Heads: 930.104.329.3R, Y, 4-81, 5, K1926d 35mm exhaust ports and 39mm intake ports. Typical of 78-79 head configuration. But I think the "4-81" is the manf. date, no?

Intake Manifolds: 81/4, 39mm ID

Pistons: Mahle- 95L70 ++ C021. Swirled Dome CIS shape Weight w/pins and clips: +/- 680g. Which I believe are 1981 euro 9.8:1 pistons, but I am not sure?

Cylinders: Mahle- 95ZN1W3

Trans is an 82'.

My speculation is that I have an 81' Euro engine case, either 9.3:1 US or 9.8:1 Euro or 78-79 pistons and cylinders (not sure at all), 81' euro heads with larger intake ports and tapped for smog line or 78-79 heads, 81' CIS intake with larger ports or 78-79 CIS intake, jerry rigged smog system added to pass CA smog.

Sorry for the overload of info, but what do you think I have?

[MBEngineering]

HI the engine you have is a correct with all the parts fitted as you have found them , as the engine is a EURO spec engine type No' 930/10 at 204 BHP and 9.8:1 CR engine No' should start 631 ****, the heads are correct for the year, the auxiliary air injection is correct for the year, and the pistons and cylinders, as all the DATE stamps you have given are correct for a 81 engine not a 78-79.

regards mike

[NoEardGoat]

Thanks for the reply!

Do you think the smog equip was OE? or do you think the heads were tapped and all the pump things added when brought to California?

And the large intake ports, are they OE for euro 81'?

[MBEngineering]

HI the 'smog equip' would be STD on the EURO engine and the air injectors in the heads, we usually remove the pump and pipe work off the engine and pull the injectors out of the heads and plug the holes, as we have not got the 'smog' regs you have yet, I can see that we will be re-fitting the pump and pipes back on in the next few years, the port size is std as i have just checked again with heads I have hear, 39 IN/ 35 EX. the heads I have are 1983 and still have the injector hole. we usually junk the 'smog' equip as it shortens the life of the exhaust valve guides with the extra heat.

regards mike

[NoEardGoat]

Thanks Mike,

I have been listening to my local parts guy and he has been thinking they are 78'-79'. But I am glad I talked to a much better source for European model info, someone actually in Europe!

Thanks again,
Emerson