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TR2/3/3A TR3 Dash Pots

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GBRandy

GBRandy

Jedi Knight
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So what is the story with these TR3 dashpots? I have never seen them so short.

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I am used to seeing this:

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Those are ZS carbs, rather than SU, likely from a TR4. Never standard on a TR3, but same bolt pattern so easy to convert. They use a rubber diaphragm instead of the precision piston.
 
GBRandy said:
I would think the SU carbs would be better. No?
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Debateable, IMO. The ZS carbs supposedly flow a bit better (for the same throat size), and eliminate the common leakage points on the original SU H6 carbs (jet & float bowl seals). The shorter bodies may also ease problems with clearance to the inner fender when using paper element air filters or the TR4A "bunch of bananas" intake manifold. But there aren't nearly as many different needles available for tuning, and the diaphragms can be troublesome.
 
My choice for 'upgrade' carbs are SU HS6, which offer all the advantages and none of the disadvantages of the ZS carbs, IMO.

That is, provided I don't go to port injection instead
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Check the engine number stamped on the block down and to the rear of the coil. If the engine number is within about 400 numbers of the Comm. No. (VIN) TS number, then you have the original engine for that TR. If the number is nowhere near the VIN number, your engine may have come out of a TR4, in which case, this might explain why your TR has the carbs from a TR4.
 
Quite possible that the old worn out SUs were just swapped for a pair of ZSes that sombodies buddy had layin around for cheap... stuff like that happened all the time..
No biggie, but I also prefer the SUs over the ZSes. I just find them easier to set up. and I think they look better.
 
GBR,
If that's the 'engine bay black paint' you were talking about seeing in the other thread it looks like tar undercoating (bottom of bonnet) probably covering rust. Black paint I wouldn't worry about (if the price is right) but beware the undercoating anywhere.
As in all old cars it's easier and cheaper to repair mechanical issues than to redo a body/frame.
 
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