Difference between 356 C and SC engines

Whippet · 11-07-2007, 02:27 PM

Hi!

What exactlty is the difference between the C and SC engines, except for the compression ratio? What makes up the relative big difference in hp? Are there any other differences to the cars themselves?
Is it therefore quite easy these days to upgrade a C to SC spec?

Thank you kindly, I appreciate the info.

Whippet

preston_brown · preston_brown's Garage

The cam is different too. That's about it.

-- Preston

Les Paul · Les Paul's Garage

Wasn't the C the old S 75hp and the SC the old S-90 90hp?

Whippet · 11-07-2007, 09:47 PM

Quote:

Originally Posted by preston_brown

The cam is different too. That's about it.

-- Preston

So a slightly different cam and higher compression accounts for 15 hp? Are the carbs the same? So one can then easily modify a C to be SC spec I guess.

Thanks for the feedback!

id10t · 11-08-2007, 04:33 AM

Very common to rebuild a C to SC or 912 specs....

356racing · 11-08-2007, 08:29 AM

Off the top of my head... Different carbs, intakes, heads, crank, and pistons but you can update everything to SC/912 specs pretty easily.

Dann Smith · 11-08-2007, 10:53 AM

I think the carbs in the C are 32's and in the SC they are 40's

Whippet · 11-08-2007, 10:55 AM

Quote:

Originally Posted by 356racing

Off the top of my head... Different carbs, intakes, heads, crank, and pistons but you can update everything to SC/912 specs pretty easily.

Aha, thank you. I thought there was a little more to it. I would like to keep things as original and standard as possible. I wouldn't want to go big bore etc. - but taking a C to SC spec seems to still be within the realms of "originality".

Dann Smith · 11-08-2007, 11:02 AM

I'm having 67' 912 engine done right now. Big bore kit, and Webber 44's. I think we're going to put the old 40's on e-bay. They were OK but they have to be rebuilt- throat air leakage- normal stuff for these old carbs.
As previous threads have stated, the SC is basically a 912 spec.
Good luck.

C. Clark · C. Clark's Garage

44's are to big for a 912, or so I've observed; other in the 912 registry have tried 44's with poor results, tuning problems, idle trouble, etc.
Chas.
356
912
911

Dann Smith · 11-08-2007, 12:07 PM

That's what I thought too. I was put in touch with this guy, a mechanical engineer for Mack Trucks. He's in charge of mechanical design fabrication. He told me he's done it before. Worked on alot of 356's and 921's. He really seems to know his stuff, so we're giving it a shot. He's using the same cam but fabricated manifolds and other modifications. I'll let you know how it works out.
He's going to put this engine in my C, while he rebuilds the C engine.

teleski42 · 11-09-2007, 05:01 AM

Dana, Chas. is right. Also make sure the 40's are mated with the correct manifolds as sometimes the 44 manifolds are used by mistake with the 40's. The linkage to the throttle arms my need some work too to get full throttle. I made these errors with a 912 so I speak from bad experience. Jim

preston_brown · preston_brown's Garage

Just to clarify the carbs:

Original C's came with Zenith 32 NDIX's, and the SC's came with Solex 40PII-4's. And yes, the intake manifolds are of course different.

Webers or Dellortos are a common upgrade for either engine. Dellortos on a C cam can give a nice bit of extra grunt.