Your problem is one I fought last year only to find that my mechanical timing
was off by about 24 degrees. (I won't comment how I did that in the first place)
Your setup is similar to my TR250 (webers/60 over/header/etc.), We proved it by
using the Bentley Book method of checking the cam timing to the crank by
setting the 11 & 12 valves to 120 thousands and getting them to the point of
rock (one opening one closing at the same gauge measure) at that point you
should be at TDC. After resetting the cam timing it ran fantastic, climbing
right thru 6000 RPM
--
Ed Major
'58 TR3A, '68 TR250
ejmajor@attbi.com
> 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
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