Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
charleyf
Luke Skywalker
Offline
You could likely achieve the desired result by switching the needles in the present carbs.
Charley
-
Hi Guest!
You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
TR2/3/3A 1960 TR3A w/TR4 engine, fuel pump replacement
- Thread starter kodanja
- Start date
Share this page
Charley
I have heard there are hundreds of needle choices to do that. Probably complicated to narrow it down to what you want?
charleyf
Luke Skywalker
Offline
Not nearly as complicated as trying to get the best needle for a 2" SU on your car.
There are up to 14 measured positions on a needle. You just need to find the best combination for your use. Of course that would be by finding a needle chart and going from there. For example the normal needle for a TR3 is an SM. They call for a RH for a rich needle. I found a KD needle on a set of HS6's on a TR4 that was apparently raced.
Offline
I am sure if you have 87mm or larger the carbs would be fine.Boils down to air flow velocity at idle
getting too low on smaller engines. It worked on MGB motors as long as they were full race and you
didnt care about idle (cause of the cams)
IMHO an 86mm,mild cam motor, would NOT see any benefit. Also the splitter area in the manifold
on a Tr3 needs a lot of work and a bit of heliarc to work well. Look inside of a tr4a manifold and compare.
Mad dog
getting too low on smaller engines. It worked on MGB motors as long as they were full race and you
didnt care about idle (cause of the cams)
IMHO an 86mm,mild cam motor, would NOT see any benefit. Also the splitter area in the manifold
on a Tr3 needs a lot of work and a bit of heliarc to work well. Look inside of a tr4a manifold and compare.
Mad dog
Offline
I'll second this. TRF used to sell "better" pump rebuild kits... not sure who might carry the kits? A rebuild of the wear items could solve your problems.
Also TRF sold a "better" fuel pump made in Italy. I paid $200 for mine, vs $35 from Moss - and worth every penny. (My pump was (1) not original, and (2) beyond saving - thus the replacement.) Again, not sure who supplies these today? The A/C pumps were used on a bunch of cars, I'm sure there is another supplier??
WORD????