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TVR 2500M Triple Weber 40 DCOEs
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Only if the bottom cover plate gasket lets go...
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True, but then the fuel wouldnāt come out of the velocity stacks.
Anyway - had the car out for a run around the neighborhoodā¦. stayed at low RPM.
I have an airflow āsynchrometerā, getting the following at 900 RPM Idle speed.
1: 2.5 kg/h
2: 3.0 kg/h
3: 8.0 kg/h
4: 8.0 kg/h
5: 3.0 kg/h
6: 2.5 kg/h
My reading seems to indicate the two center carburetors are too high, normal range is 1.0 - 2.5 kg/h.
I think this means the throttle plates are open a bit?
Advice on where to start my adjustment?
The Redline guidelines say (step 1) say: āall air bypass screws should be set in the closed positionāā¦. On my carbs, I believe there are hard white plastic caps covering them, and they are non-adjustable?
Thanks -
Rocky
Anyway - had the car out for a run around the neighborhoodā¦. stayed at low RPM.
I have an airflow āsynchrometerā, getting the following at 900 RPM Idle speed.
1: 2.5 kg/h
2: 3.0 kg/h
3: 8.0 kg/h
4: 8.0 kg/h
5: 3.0 kg/h
6: 2.5 kg/h
My reading seems to indicate the two center carburetors are too high, normal range is 1.0 - 2.5 kg/h.
I think this means the throttle plates are open a bit?
Advice on where to start my adjustment?
The Redline guidelines say (step 1) say: āall air bypass screws should be set in the closed positionāā¦. On my carbs, I believe there are hard white plastic caps covering them, and they are non-adjustable?
Thanks -
Rocky
Tybalt
Jedi Warrior
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And I too think that throttle sync is a good guess as the first thing to check. I couldn't remember how you had the linkage set up so I took a look at it this morning (it was too late last night when I saw your post for me to trust my judgement) in one of your pictures. I would go to that turnbuckle link on the middle carb and adjust it. I can't help but feel it is holding the throttle plates open just a bit more than the other two.
As for the air bypass screws, they are indeed the ones under those little plastic caps and they are adjustable, but save that for after you try tweaking that middle carb turnbuckle link.
As for the air bypass screws, they are indeed the ones under those little plastic caps and they are adjustable, but save that for after you try tweaking that middle carb turnbuckle link.
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Tybalt said:
Adjusting the turnbuckle: Can't see the throttle stop/idle adjustment screw on the middle carb but be sure it has no way to interfere with the trurnbuckle adjustment, i.e: keeping the t-shaft from being able to close down the blades further w/turnbuckle.
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Well - none of the linkage is attached.
I pulled the middle (offending) carb, and adjusted the throttle plates as carefully as I could for full closure. Still the same readings.
Switched the front & middle carbsā¦. problem moved up front.
I need a flow bench. I might make one with my shop vac. More work to do this week!
Rocky
I pulled the middle (offending) carb, and adjusted the throttle plates as carefully as I could for full closure. Still the same readings.
Switched the front & middle carbsā¦. problem moved up front.
I need a flow bench. I might make one with my shop vac. More work to do this week!
Rocky
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hmmm... that both barrels are the same rules out likelihood of bent shaft or plates not seated (since you went back and realigned).
Another thought: is the internal return spring keeping enough tension on the shaft at full closure? Could it somehow have been 'stretched'?
After seeing that air corrector jet in place of a main, my suspicions are raised that it could be possible.
Another thought: is the internal return spring keeping enough tension on the shaft at full closure? Could it somehow have been 'stretched'?
After seeing that air corrector jet in place of a main, my suspicions are raised that it could be possible.
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Unless you can see some sort of evidence there's wear at the closure point of the blades to the throats, that two-and-a-bit degrees different angle won't mean much. The plates may be subject to the problem but not the cause, IMO.
Your flow-meter indicated that both barrels are drawing equally, the problem "moved" with that carb, so you've isolated it to that. Something mechanical on that carb is restricting the shaft movement or allowing more volume. It may well BE the bypass screws. But swap out that spring first.
Your flow-meter indicated that both barrels are drawing equally, the problem "moved" with that carb, so you've isolated it to that. Something mechanical on that carb is restricting the shaft movement or allowing more volume. It may well BE the bypass screws. But swap out that spring first.
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Only way I know is to upload to YouTube first, then provide a link. Maybe someone else knows a different way.