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Tue Dec 12, 2006 6:36 pm

Can 356A,B heads be interchanged with a 912 engine?

Wed Dec 13, 2006 4:40 pm

Hello Eczar1,
Yes 356 A or B Heads will fit on a 912 Engine.
Do you have "Super or Normal" 356 Heads? 912 Manifolds have pretty big runners. If your 356 heads are "Normal" you will have to "Match Port" the 356 Heads to the 912 Manifolds. Not to mention Valve size.
The 912 Heads have a different Combustion Chamber Angle and you could run into interference( not enough Clearance) between the 912 ( does the Engine have a Big Bore Kit?) Pistons and the 356 Combustion Chamber. Normal A Heads with a Big Bore Kit will be the most problematic. BTW, this info is from Harry Pellow and not from my experience. I am more familiar with the "Smaller" 356 Engines; but that is another story.
912 Rescue posts pretty often......try a PM. He may be answering your question as I "Hunt and Peck"!
912s also have a different Rockers and Rocker stand(alright about the same as "C" "SC" 356), you could run into Rocker Geometry problems with the "A" cast iron rocker stand.
Hey Eczar1, it's possible. But, do you really want to put 356 Heads on your 912 Engine?
Good Luck,
Al

Wed Dec 13, 2006 5:41 pm

Ok, Sounds like I may run into some problems trying to do it.
Reason I'm asking is I have a set of rebuilt "A" heads.
I can's find anyone here in Nashville to rebuild the 912 heads.
Would try to rebuild them myself, but I sure would hate to ruin them putting in new valve guides.

Thanks, any suggestions?

Thu Dec 14, 2006 1:23 pm

I always thought NO..

Only Super 90 are close because of the valve size's

If you fit the A or B heads then the car will be underpowered.. due to the sizes of the inlet and out valves being smaller

I could be wrong but I don;t think so..

Always leaning..

8)

Thu Dec 14, 2006 3:16 pm

356uk wrote: I always thought NO..

Only Super 90 are close because of the valve size's

If you fit the A or B heads then the car will be underpowered.. due to the sizes of the inlet and out valves being smaller

I could be wrong but I don;t think so..

Always leaning..

8)

I think you're correct there..................what would be the point? You probably would not have near as much power.

Thu Dec 14, 2006 5:06 pm

Actually a Super 90 head swap would cost you about 6 hp according to a guy I know who has done it. Any other 356 head would be a serious drop in power.

Sun Dec 17, 2006 2:13 pm

beside engine size your heads and carbs are what will make your engine run. You can't assume that because your engine is in a 912 it's a 912 engine, first arm yourself with a little knowledge. check your engine number with the 356 and 912 registrys. Remember that someone may have done the same thing you are trying to do only 20 years ago, with an engine. normal cheaper then super cheaper then s90 cheaper then SC.

Next what type of carbs are on the engine, if webers, they have been changd and you no longer have porsche manifolds. etc. Knowledge is POWER. If the heads arn't right the engine will not make HP, get the heads rebuilt, at the least. Join the registry or just use the information, buy a couple of books. Your car has been waiting for you for 40 years give yourself a little time and do it right. Don't go backwards if you can avoid it you wont be happy with something making 20% less horsepower then you were expecting.

Good Luck
Gerald