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Re: Carbs for Vintage Racing TR250

To: Chuck Arnold <chuck.arnold@oracle.com>
Subject: Re: Carbs for Vintage Racing TR250
From: Jeff_Durant@amat.com
Date: Wed, 19 Jan 2005 17:21:51 -0800
Chuck, 

I'll go along with Charly's comments concerning the TR4 Strombergs.  My 
TR6 runs a late (TR6) intake (similar to the TR4A's)
and TRA 175CD's.  The porous floats on early Strombergs will sink 
instantly if old!  I got around this by modifying later Stromberg 
floats to fit  the early float bowls.  Another mod I did was to increase 
the float bowl capacity by adding a 1/4 spacer cut to match and
run larger (Jag) float needle/seats.  Better fueling capacity.  The 
metering needles are SU and the throats cleaned up a bit. 

I've found the low end excellent, the carbs extremely reliable and simple 
to tune.  I've run webers, but besides a little loss on top end, 
put the Stombergs back on.  Like that low end pull.

Jeff D.







Chuck Arnold <chuck.arnold@oracle.com>
Sent by: owner-fot@Autox.Team.Net
01/19/2005 05:50 PM
Please respond to Chuck Arnold
 
        To:     FOT <fot@Autox.Team.Net>
        cc: 
        Subject:        Carbs for Vintage Racing TR250
 


I have been communicating with Joe Alexander regarding induction for my 
some-time to be TR250  vintage race car.  I asked what would be 
preferred -- 2 SUs or 2  Strombergs.
Here is his reply [maybe from a digest mode]
"So the order of choice is 1 - late SU's, 2 - early SU's, 3 - Stroms

Now the reason that nobody with a vintage TR6 uses any of the above is 
that the stock intake manifold absolutely kills intake flow. It is just 
awful. That's the reason everybody running TR6's use Webers. TR6 intake 
ports are very restrictive, and putting the stock manifold on it kills it.

If  Webers not a choice, I'd get the Richard Good three carb manifold 
without the Stroms he sells and put SU's on in their place. A few 
purists might wince, but nobody in a club like VSCDA would care. Just an 
opinion, but I think a TR6 with two carbs on a stock manifold would be 
beaten by every TR4 on the track. But if the owner can't afford Webers, 
go with it".

Unfortunately, SOVERN, the vintage group whom I will be racing under 
requires the car to be setup to the 1969 SCCA regulations.  According to 
their site, this means 1.75  Strombergs or SUs [no mention of PI, though 
Kas  has related to me that that was the only  way the factory raced 
them]. 

So, to the collected group:
What carbs give me the most gas?  Is there anything [visibly legal] that 
can be done to improve the intake manifold's flow?

Thanks,
Chuck

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