4 replies to this topic

[tampaguy]

Happy Holidays to all and may the new year bring everyone prosperity and Good Health ! I am interested in knowing of any interesting stories surrounding the use of GMC 270's in early race cars ? I have heard that the maestro Mr. Fangio used one in his first car he raced in Argentina. I have a 1950 270 I would like to turbocharge and install in a 49 Chevy Coupe

[maoricar]

You are correct, this WAS frequently used in several forms of racing, in many different countries.

It was comparatively speaking, quite a powerful and cheap power plant, popular in racing hydroplanes too. The head in particular, had well shaped combustion chambers, as near hemispherical as you could want, although valve sizes were quite small; it was a truck motor and built for low rpm torque and it certainly had that !

With a modest amount of headwork, a decent cam, intake and headers, it was fairly easy to obtain over 220 rear wheel horsepower. In the day ( 40's and 50's ) there were several manufacturers of speed equipment for the 270 and 300 GMC engines--Wayne comes to mind but there were several others.

There always seemed to be a lot of core shift in those 270 blocks and heads and they had a nasty habit of dropping the center main webs at anything much over 4500rpm.

I'd keep the boost low. The 270 has only a 4 main bearing crank, and not very sturdy intermediate main bearing webs. Strong-backs might help, but not a whole lot.
Having said all that, it still is one great engine, for its time; with open headers it makes a thunderous growl that it unmistakeable.

[Terry Walker]

1962 Australian Grand Prix, Caversham, Western Australia. Bruce Mclaren in the works Cooper Climax roars past the front engined TS Spl, driven by E D Edwards. The TS, at the end of its front-line career, was powered by a GMC six. It is still racing, in the Historic category, today. It was originally built locally using a flathead Dodge 6, and a beam front axle, in the early 1950s, upgraded a few years later to the GMC and independent front end.

So: a GMC six has contested an International Grand Prix!

[Ray Bell]

Ray Wamsley had some of these in the Alfa Tipo B that originally came to Australia for Jack Saywell...

After losing the original Alfa engine when it was shipped back to Italy just before the start of WW2, the car sat around for years before Bill Murray put a 4.3 Alvis into it. The car was a real handful, losing all its balance with this engine for some reason.

Ray Wamsley bought it and ran with the Alvis several times, but it was an unreliable beast as well as a difficult car to drive. He used GMC trucks in his business and put together a race engine from one of his spares. He found it transformed the car's handling as well as giving it good power.

Later he fitted a Corvette engine and it went better still...

Ray is still around if you want to ask him direct questions about those engines. They are, as I understand it, basically a slightly larger Chevrolet ohv 6 with the luxury of pressure-fed main and big end bearings.

You will also find a lot of information (and people with whom you can correspond...) on the www.inliners.org bulletin board.

[tampaguy]

Ray-Terry,
Thanks so much for the info, now that i know of the GP history of this engine I am going to proceed with the rebuild. I am still interested in hearing about the Fangio connection to this motor..........Happy Holidays to all