Vintage race motor

Tar356 · 10-31-2005, 02:35 PM

Looking for some advice/opinions....

Like many, I really like the ST style cars, and I'm thinking about building one to vintage race.

I would like to build it as correct as possible, and I'm thinking about an engine based on the one of the earlier original recipes/variations of 66x85mm, twin plug, 46mm carbs etc.

Number one question is concerning the engine case. It would be nice to keep it somewhat period correct. Any problems using a circa 1970 case? I would anticipate somewhere around 230-240 hp.

Feel free to throw in your two cents!!

Thanks,

Todd

304065 · 10-31-2005, 03:14 PM

Todd,

Which sanctioning body or bodies?

The rules make ALL the difference in advising you what to do.

HSR? Klub Sport? SCCA? PCA? VSCDA?

Example: There's a 2.5 limit for HSR group 3K, but a 2.2 limit for PCA GT-5S, and if you built a 2.5 for HSR, you'd end up in GT-4, where the diaplacement limit for is 2.808. You'd be a sheep among the wolves with 11% less displacement I'd suspect. SCCA EP is 2.2 (84x66). SCCA GT2 is 2992 (70.4 x 95).

The best way to figure it all out is to find out who runs vintage at the closest tracks to you, and get a copy of the rule book and read it before you begin the buildup.

Tar356 · 10-31-2005, 03:40 PM

Hi John...

The car I have in mind will fit in well with either VARA or HSR-West...shouldn't be a problem from a "rules" point of view.

Not so worried about taking the chequered flag.....the authenticity is just as important for me.

Vintage911Racer · 11-01-2005, 06:37 AM

Using a mag case would be OK up to 250HP or so. Most guys now a days are running the aluminum case. Yes it is a little heavier, but I guess the main factor is durability and reliability.

If you did chose the mag case, the 7R case would be the best bet.
If you have any questions about VARA, I am the CP class rep and have been for 3 years. Shoot me an email and we can chat.

mark-at-vararacing.com

Good luck

Henry Schmidt · Henry Schmidt's Garage

Quote:

Originally posted by Tar356

Like many, I really like the ST style cars, and I'm thinking about building one to vintage race.

I would like to build it as correct as possible, and I'm thinking about an engine based on the one of the earlier original recipes/variations of 66x85mm, twin plug, 46mm carbs etc.

Number one question is concerning the engine case. It would be nice to keep it somewhat period correct. Any problems using a circa 1970 case? I would anticipate somewhere around 230-240 hp.

The original STs were 85, 86.7 and 87.5 mm bores. If authenticity is your goal perhaps we should talk. I might be able to get you a set of authentic ST pistons and cylinders.
As for the case, you can use almost any case with the correct prep work. Early aluminum case are the easiest, mag cases are the lightest and the 7R cases are the strongest. The key is knowing what your case needs in the way of prep work in order to get the best use of it.
If you really want authenticity look for a 72, 2.4 7R case.

Henry Schmidt · Henry Schmidt's Garage

Factory 85, 86.7 and 87.5

Henry Schmidt · Henry Schmidt's Garage

All three 85, 86.7 and 87.5

Plavan · Plavan's Garage

Todd- I sent you an email back. Give Mark or myself and email back. I have all the contact & information you need.
I also have access to NOS 86.7mm piston & cyl's

Turbo_pro · 11-07-2005, 05:06 PM

If you're thinking about building an engine for vintage racing, Henry @ Supertec is your guy. He is a master at the 2.0, 2.2 and 2.5 versions of the 911 engine. I have had two engines build by them and I couldn't be happier.
I've been thinking about one of his MFI 2.8 engines but as of now, I have no car to put it in.

side note:
Henry has some rough edges, but I want an great engine not a date.