A few high-performance Cosworth Vega questions...

Moderator: Moderators

A few high-performance Cosworth Vega questions...

Postby MBellRacing » Sun Apr 02, 2017 7:10 pm

Hey there everybody,

I am thinking about building up a fun Cossy Vega as a daily. I race cars professionally, and have an affinity to rare, short-run, performance cars, especially when they tick quite a few "first" boxes for a manufacturer. I have a long history with GM and feel the Cosworth Vega is a really interesting car with which to feed my obsession. I do not like to keep things original, nor do I like to kill off a car's charm. I feel that, while keeping the skeleton intact, any improvement with modern enhancements is exactly that: an enhancement. I'm not talk about swapping in an SBC, as that would no longer make this car a Cosworth. That said, I understand there are quite a few shortcomings with the GM-supplied motor that really hurt the reputation and the real-world performance of the Vega.

I LOVE (love, love...) high revving, peppy, barky 4-bangers. My first race car was an E30 M3 that we swapped in an "Evo 3" 2.5L version of the S14 into. 9000rpm and 250rwhp was epic to drive and even more enjoyable to listen to. My brother still has his old E30 M3, which I drove around Charlotte yesterday. I miss it, but do not miss BMW at all. I would love to build something somewhat similar out of, what I call, GM's E30 M3. I am still, however, petrified of the block splitting issue, but am never one to shy away from an engineering challenge. What are options, short of finding some of the 50 original reinforced racing blocks, to make sure this engine could handle 250hp+ without turning into a pair of motorcycle engines? The ones I can think of:

-Machine the block for steel top hat sleeves.
-Gusset between cylinders 2 and 3 as well as between the motor mount face and the block with aluminum.
-Ensure absolute balance of the bottom end.

Is there anything I could do that I'm missing? Will the later Dura-Built blocks fit under the Cossy head? Do they offer any real advantage over the early blocks?

Finally, a drivetrain question, though in regard to the engine: I saw something, somewhere on this forum, about a T5 transmission fitment. The search function won't let me find the thread I was looking for, now that I'm logged in, for some reason. I am a big fan of the T5 and the aftermarket that has followed it. I feel that a close ratio and a tall 5th (0.80-0.63:1) would suit this application well. What are the options for fitting one to the Vega motor, and which fitment works (GM, Ford, Ford WC...)? Does someone make an adapter or bellhousing that make it all work?

Any advice on this would be well appreciated. I am very into the idea of owning one of these awkward parts of GM history, but want to do my homework first! Thanks!

-Matt Bell
Posts: 1
Joined: Sun Apr 02, 2017 10:14 am

Re: A few high-performance Cosworth Vega questions...

Postby HI WINDING MONZA » Sun Apr 02, 2017 7:50 pm

You might want to talk to Dick ( hammerdown7 ) I' m sure he can answer your questions. I hear you on GM 4 cylinders,drag raced a 151 Pontiac in my Monza for many years before it was popular like today. That's how I got the " Hi Winding " nickname. :th:

Doug in P.R. 8)
My Old Cadillac Powered Monza Still Lives...........now on its 5th owner!..........Somewhere ?

The 90's just keep rollin' along........
1990 Chevrolet Silverado Regular Cab Long Bed 350 TBI V8 700R4 108k miles
1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 148k miles
User avatar
Posts: 3050
Joined: Thu Jun 29, 2006 7:37 pm
Location: Salinas, Puerto Rico

Re: A few high-performance Cosworth Vega questions...

Postby Greybeard » Wed Apr 12, 2017 2:29 pm

Pro Motion Performance Powertrain remans t5s with a gforce case that has Saginaw/Muncie bolt patterns, and a choice of shifter placements.
1937 Chev 2dr sedan
1966 Chevy El Camino (daily driver w/300K miles)
1966 Chevy V8 Corvair https://greybeard.shutterfly.com
1972 Vega GT
1985 Corvette
1999 Safari Sahara 30' with Cat 330
1999 Jeep Cherokee 'toad'
Next: 1964 289 slabside Cobra, LS525 power
User avatar
Posts: 79
Joined: Mon Dec 08, 2014 4:48 am
Location: Sequim, Washington

Re: A few high-performance Cosworth Vega questions...

Postby hammerdown7 » Wed Apr 12, 2017 5:28 pm

Matt, Just found your posting. I'll get back to answer your questions when I have more time in the next couple of days. Sorry for the delay but I rarely look at the engine section on here, that's why I'm so late in responding.

User avatar
Posts: 3553
Joined: Mon Jun 26, 2006 7:53 pm
Location: Clawson, MI

1976 Chevrolet Vega Cosworth

Re: A few high-performance Cosworth Vega questions...

Postby hammerdown7 » Fri Apr 14, 2017 10:54 am


I have a couple questions for you. Would you be using the car on the street only or also doing some track days. The problem with a high revving street engine using parts that are typically available for the Cosworth Vega is the lack of low end torque. The engine of the USAC style midget team I was a part of normally ran from 6500 to 9000rpms. There is an interesting story on how the Dick Myers midget ended up making external bracing because of my loaned stock block to finish the racing season many years ago.

What we have found as a more satisfying street engine was to either use a stock Vega 2.3L crank or billet crank which greatly increases the low end torque, the stock crank can handle 7000rpms without any problems and there are several configured that way today. Different combinations of cam profiles, compression ratios and Weber carbs have been estimated to give 220 to 230hp.

There are a number of ways you can go with the car depending on how you plan to use it.

There are two owners that currently have 2.0L turbo configurations, one using the stock EFI system for drag racing and one using a custom EFI system for all around street use. Both of these are using the stock block without any special additional reinforcement. I know the street car has seen over 20lbs of boost, has been driven very hard frequently including some drag racing without any problems in over 6000 miles.

The drag car is in Ohio and the street car is in California. Mark Schwartz of Campbell Auto Restorations Center in Campbell, CA is the builder and owner of the street car.

According to Google you live in San Mateo, you are less than an hour from Campbell. Give Mark a call, tell him Dick Baumhauer suggested that he should take you for a ride in his CV.

I'll try to answer any questions you have.

User avatar
Posts: 3553
Joined: Mon Jun 26, 2006 7:53 pm
Location: Clawson, MI

1976 Chevrolet Vega Cosworth

Return to Engine Tech

Who is online

Users browsing this forum: Bing [Bot] and 1 guest