I'm having a problem tuning my TR6, the motor is bored .030", the head is
about 3.375 thick (compression ratio 10.25:1) and has been modified to a
stage 2 configuration, the pistons have been shaved to all be the same
height and the block decked to 0 clearance, the engine has been balanced the
rods and flywheel have been lightened, I use stock pushrods with stock
rocker arms and spacers in place of springs, the cam is a D9 grind, the
distributor is a 22D that has 17 degrees stamped on the rotor and has a
Pertronix unit instead of points, it has a header that has long center
branches that go to a 2 1/2"collector & pipe and routed similarly to a stock
system with a 2 1/2" Flowmaster muffler, I'm running triple DCOE 40 carbs on
it.
I can't seem to get the car to rev over 5000 rpms at load! I'm running AV
101 fuel in it, I have a double ended fuel pump on it (not SU) and a
pressure regulator. I seem to be able to get consistent fuel pressure
between 3 1/2 and 4 1/2 psi.
I've tried rejetting the main jets, originally they were 120, and I've
gone to 130 & 140, I've played around with the air correctors going from 160
to 150 & 140. The venturi's are 30's. I've played with the timing and
advanced as far as I dare and it seemed to run the best when I had the
advance set at about 17 degrees at idle, about 32 or 33 degrees at 4000 rpm
(hard to tell the exact advance with my timing light).
The car runs good up to about 4800 rpm and then it starts to pop through the
exhaust, sounds like a misfire, and barely revs to about 5200 rpm's. This
rpm reading is done with the stock tach and could be reading wrong also, I
plan to find a high rpm test tach to verify my stock tach accuracy.
Any ideas? I keep getting stuck on the carbs, think they are running to
lean, but when I put in the 140 main jets, fuel was actually coming out the
stacks when I went WOT!
Charly Mitchel
----- Original Message -----
From: "Russ Moore" <rem9@sunlink.net>
To: "kas kastner" <kaskas@cox.net>; "Randy B. Williams"
<rwilliams@williamsoil.com>; <fot@autox.team.net>
Sent: Friday, May 16, 2003 3:19 PM
Subject: RE: Fuel starvation problem
> To add to the well stated points Kas makes, I have seen the foam in a fuel
> cell break down and give folks fits in trying to figure out their fuel
flow
> problems. With contamination, the pump will still build pressure when dead
> ended, yet the volume is significantly down, and is then exagerated under
a
> heavy load. Size of fuel line might also offer a restriction
>
> Another possibility, yet not so likely and definately off the topic of
fuel
> issues, is ignition. I have had all sorts of strange behaviors with top
end
> power, which I thought had to be fuel related, it turned out to be the
> ignition coil breaking down. Engine would act like it was running out of
> fuel at 6500rpm. Changed that out and the problem was instantly cured and
> the engine was clean up to 8000 again.
>
> Dwell angle can also cause some problems that can be mis diagnosed.
>
>
>
> Russ Moore
> Spitfire #49
>
>
> -----Original Message-----
> From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net]On
> Behalf Of kas kastner
> Sent: Friday, May 16, 2003 4:57 PM
> To: Randy B. Williams; fot@autox.team.net
> Subject: Re: Fuel starvation problem
>
>
> Several things. Number one is VOLUME at the carbs not just pressure.
Should
> have aa minimum of 15 gals per hour. Pinched hard tube of the fuel line,
> acumulation of dirt in a low section of the fuel line any or all could
give
> exactly your difficulty.Also have seen a piece of paper in the fuel tank
> (production tank) where it sank and closed off the supply tube. Obviously
> not likly with a fuel cell.
>
> Easy one next, needle and seat that have crud in them and not allowing
full
> fuel passage.
>
> Next, float level too low. (too easy to be the problem)
>
> The next one happened to me and was almost a mystery. The adjusting nuts
on
> the S.U. carbs slowly closing up from resonance of engine and leaning out
> the mixture. Okay for a few laps then then the top end just goes away
from
> lack of fuel. Put a wedge to stop the jet from moving up and the problem
> solved.
>
> ----- Original Message -----
> From: "Randy B. Williams" <rwilliams@williamsoil.com>
> To: <fot@autox.team.net>
> Sent: Friday, May 16, 2003 1:23 PM
> Subject: Fuel starvation problem
>
>
> > I recently purchased a TR3 from Richard Hardison and could sure use some
> help
> > to sort out what I believe to be a fuel supply problem. It appears as
> though
> > I am running out of fuel any time I have an extra long run at full
> throttle.
> > Richard was also having this problem, so he had his mechanice, Ed
Bernard,
> > install a second fuel pump. What could the problem be and what
> suggestions
> > can be offered to resolve it? The pressure after the regulator is only
> just
> > slightly over 2 pounds???? Randy Williams
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