Jump to content


Group C2 /Imsa engines

  • Please log in to reply
4 replies to this topic

#1 doc knutsen

doc knutsen
  • Member

  • 515 posts
  • Joined: May 03

Posted 13 November 2013 - 17:01

We are considering getting our C2 car, which has lain dormant since an Interserie round at Donington Park in 1995, back where it belongs, ie racing again.  It ran with an 1800 BDT engine (and an 420R for a few races) back in the day, but the BDT was a temperamental beast, especially when using the Motronic 1.2 management system. Anyway, that engine suffered a major melt-down at Mondello Park in a BOSS round, so a revival of the C2 car will require a new engine.  To that end, I have been considering fitting a Yank V6, either the Chevy or Buick engines that were extensively used in period. Does anybody have any experience with these engines? Any good or not so good points about them? The Chevy could be built with an aluminium alloy block, does anybody know the weight of these engines?  Horsepower and torque figures? I would like to think that these engines would be much closer to "plug and play" than the BDT, but I would dearly love some advice on people's experiences with these engines.


#2 ray b

ray b
  • Member

  • 2,635 posts
  • Joined: January 01

Posted 13 November 2013 - 18:07




the buick 3.8 v6 redone as a alloy race motor for indy


the 3.8 was used in GTP2 imsa in both chevy and buick flavors

but they were two different motors [ at least in street trim]

the chevy based on the 4.3v6 by way of the mouse v8

and the buick by way of their v8


the buick was a heavy cast iron lump redone as the menard for indy cars in alloy

I am unsure if the menard version was used in GTP2 or C2 without the turbo

and with high boost fast but not a finisher very often


buick later did the 3800 in 3 versions mark I II III but not the same as the older 3.8/menard

#3 Rudernst

  • Member

  • 111 posts
  • Joined: September 11

Posted 13 November 2013 - 19:04

You dont mention which car You are talking about...


I might be stating the obvious, buuut:

its called "Historic Racing",

so can only fit a particular type of engine to Your car,

that was used in that type of car (but not Your chassis) in period.

otherwise You wont get an HTP and wont be allowed to race


if in doubt, check with Historic Group C, Bob Berridge


quite apart from that_

You need to ask Yourself if it is wise to spend a lot of money to change your car very much away from its period configuration.

that can increase competiveness and value, possibly more in the short term

or it can do the opposite


Id personally try to stay close to period.....

but i dont know enough about the problems about running your little turbo 4s.


aaand, last but not least

You need to look at the regulations and scoring System of Historic Group C.

IMSA cars are wellcome but not exactly favored, at least to my knowledge


aaaand: dont forget:

Historic Group is now more of a sprint compared to period

races are much much shorter

reliability is less of an issue now

races are more a sprint

less emphasis on fuel economy more on outright speed



#4 doc knutsen

doc knutsen
  • Member

  • 515 posts
  • Joined: May 03

Posted 14 November 2013 - 22:09

Yes, I am aware of the points you make, which is why I mentioned "period correct" engines. The car in question is the Cheek C288, which I designed and built myself, so converting to a different power unit is not too much of a problem, certainly not cost-wise: Consider the price of building a new BDT with all the turbo bits and pieces,compared to the price of a pushrod V6. Also, we will probably run mainly in Scandinavia, where the circuits are short and twisty, thus making a reasonable torque curve more important than ultimate top-end power. Before deciding, I would like some information from people with some experience with the US pushrod V6 engines, which is why I ventured out on the Forum with my request. Of course, I would not mind being given a DFV... :)

#5 Bob Riebe

Bob Riebe
  • Member

  • 1,818 posts
  • Joined: January 05

Posted 14 November 2013 - 22:58

Maybe you could use one of the BOP V-8s.


They have parts supply on your side of the pond.