Large port SC heads
 

Question for the gurus

Are large port 39mm/35mm SC heads (86mm stud spacing ) available without air injection ports ?

From which specific engine models ?

930/??

Which head assy number / casting numbers should I be looking for ?

Thanks in advance

John

The large ports were used through 83 euro on the 930/10 engines and the ROW, rest of the world production. I believe the air injection was used on all euro 78-83
If you want big ports without air injection use Carrera heads and PMO insulators to get the correct height of the intakes.
Bruce

All the SCs used air pumps.

To get large port heads w/o the injection ports you want '76 or '77 Carrera 3.0 heads

Thanks Bruce & Bill - your responses are much appreciated

Bruce - I assume you are referring to 3.2 Carrera (1984-89) (40mm/38mm) with the shorter intake requiring the plastic spacer??

Bill - the 2.7's of that era (circa 75-77) had 80mm stud spacing (I think ???) - does the 1976-77 Carrera 3.0 (39mm/35mm) have 80mm (per 2.7) or 86mm (per 3.0SC) head stud spacing ?? Is this type 930/02 ?

Apologies for all the questions !!

Thanks and regards

John

Yes I was refering to the Carrera heads and spacers
The 76/77 Carrera was a different case, aluminum, with 3.0 spacing on the head bolts, definitely the predecessor of the SC
Bruce

Thanks again Bruce
John

John,

Are you looking for valve size or port size or just something without the air injection ports? My 80SC 930/07 had the large valves the later head stud spacing and 35mm exhaust ports with NO air injection ports. The intake ports were the smaller 34mm CIS ones but can be enlarged. I took mine out to 37mm because I was looking for torque not high rpm.

Just a thought.

Thanks Dave - It's stock large ports without air injection that interest me - I'd prefer to steer clear of custom porting at this stage.
John