Jack, Thanks for the input. It looks like I will stay away from the 2 in.
carbs, and either get some unmodified carbs, go back to my H6 carbs, or try
one more time at the HS6's. I had since gotten some good info on fuel flow
testing that another lister had done with modified HS6 carbs. Any advice on
keepng the H6 carbs leaking from the float bowl/jet connection? it always
seemed that no matter what I did, I would get a leak. Also I know that you
could not run Weber's in SCCA racing, but have you tried any On any TR3/4
race engines? Most of the people that I race aginst have Webers on their
Volvos, MGBs, and 240Zs. I'm thinking that I may need to make the jump to
the Webers just to stay up front. Joe (B)
----- Original Message -----
From: Jack Wheeler <jwheeler@seidata.com>
To: 'jaboruch' <jaboruch@netzero.net>
Cc: 'FOT' <fot@autox.team.net>
Sent: Tuesday, May 23, 2000 6:16 AM
Subject: RE: TR3/4 carbs
> Joe, I used the 1 3/4" H6 SU carbs, even though in the last few years I
> raced, the 2" SU's were legal. Hardy Prentice told me that he and Joe
> Huffaker spent many hours on the dyno getting the 2" carbs to work
properly
> (and then, didn't gain a whole lot of horsepower). Since I didn't have
the
> resources to invest in that much dyno time, and the 1 3/4" carbs always
> worked well on my car, I stuck with the smaller carbs.
>
> I used unmodified carb bodies and pistons. I did not use any oil in the
> dashpots, and in fact, removed the dampers and springs from the dashpots.
> This is the only way I could get the pistons to go all the way up into
the
> dashpots. I used the RB needles and 34 degrees of ignition timing. We
set
> the jet adjustments on the dyno using exhaust temperatures. Started rich,
> then kept leaning them out until the exhaust temps got up to about 1400
> degrees, then richened them back up just a tad. Also, if you use 34
> degrees of advance, you need to use very good fuel, and make sure your
> timing marks, pointer and timing light are very accurate!
>
> I used 4 lbs. of fuel pressure, measured at the fuel manifold on the
> firewall. From the manifold, I had separate fuel lines for each carb.
> Once we got everything set on the dyno, I measured the distance from the
> fuel bridge to the top of the jet in each carb with a dial caliper. When
I
> rebuilt the carbs, I would go back to this same setting. I almost never
> had any trouble with the carbs - rebuilt them about every other year.
>
> Good Luck!
> -----Original Message-----
> From: jaboruch [SMTP:jaboruch@netzero.net]
> Sent: Tuesday, May 23, 2000 12:08 AM
> To: Jack Wheeler
> Subject: TR3/4 carbs
>
> Jack, a while back, there was a thread on the FOT list about SU's, and you
> said that you had the best results with unmodified carbs. Unfortunately
my
> modified HS6 carbs have me pulling my hair out. They are pretty much to
> what David Vizard recommended in his BLS A series book. The car has no
top
> end. When I get over 6000 Rpm's the oxygen sensor goes lean, and exhaust
> temps go to 1400 deg., and power drops significantly.
>
> You noted that carbs out of the box worked the best for you. When you
were
> racing were you using 1 3/4 in. carbs, of 2 in.? I have had some people
> tell me with similar sized engines that 2 in. carb have worked great for
> them, and others have had problems. I wouldn't mind a set of 45 webers,
> but they are not in the budget right now. Any suggestions you may have
> would be appreciated.
>
> We coresponded a few months ago about vented front discs. I was able to
> fit rotors from a v6 Honda Accord to my hubs, along with Wilwood Superlite
> calipers. They work great. Regards, Joe
> << File: ATT00000.htm >>
>
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