[Fot] Fwd: GT6 carb issues

[malaboge at aol.com]

Gas guzzlin?friends,

One of the big issues on many cars that I have found is a fuel system that just doesn't deliver when really needed.? A fuel pressure gauge that reads as close to the carbs as possible will quickly tell the story.? Too many motors are running lean at sustained RPM's.? Every motor that I've dynoed has been overjetted with the RB needles. I'm here at sea level,?and the RB's have way too high a F/A ratio on my motors.? When in doubt (better rich than lean) I've used them until I could actually tune the motor and then it always put out more poop with leaner needles (currently running in the 190 HP range).
You say that the float level is at 3/16.? If that is a static measured distance ala factory style measured settings, my limited experience has been that NO static float level is relevant to real world float levels.? In situ inspection of float levels in the jet is the only relevant setting.Basically run the fuel level as high in the jet as is possible without "slosh" out of the jets in corners.? This will take some tuning on your part, but is easy to do?to make both fuel levels the same in each carb.? The other issue is foaming of the fuel and once again leaning out.? Use a 45 DCOE soft mount to mount the SU's to help alleviate this.

HS-6's are great carbs and can deliver way more than your 2 liter motor should require

Feelin fuelish here ...
????????????????????????????? Nick in Nor Cal





On the carb question, in a TR-4 with the HS-6's, we ended up with a 
.104 jet (drilled out), and RB or RC needles.  Those are the richest 
needles, and we drilled out the jet on top of it.  I think in the end 
we had custom needles that were like the RB at low end and the RC at high end.

Dunno how that transfers to the GT-6, tho.

- Tony D


<big snip>

>One more question.. I have 175 SU's on the GT... at about 4000 rpm 
>it's leaning out, like hanging there, if I let off the gas a bit it 
>will catch up.
>The carbs were built by Joe Curto with these specs...
>HS 1 3/4
>metering RF
>Float level 3/16
>Idle screw 1 turn In
>Mixture Nut 1 1/2 turns out
>Jet 1oo
>I emailed Joe once asking if I could purchase some needles that 
>would let the car run a little richer, I think that is what I need 
>but don't know for sure...
>Probably the wrong weekend for a query, but I know all of us aren't 
>at the Glen, although I got a really nice tee shirt from the event!
>
>Kindest regards,
>Bobby Whitehead
>#53 CVAR Triumph GT6+
>_______________________________________________
>http://www.team.net/donate.html
>
>Fot mailing list
>Fot at autox.team.net
>http://autox.team.net/mailman/listinfo/fot


_______________________________________________
http://www.team.net/donate.html

Fot mailing list
Fot at autox.team.net
http://autox.team.net/mailman/listinfo/fot


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/fot/attachments/20080909/ddadcf6b/attachment-0003.htm>