Reply With QuoteGenerally it is marked on the side of it (when it's removed) or if you're not sure just take a drill bit drop it down the top and measure it.
Does anyone know if there is a way to tell what size the needle and seat is in a Holly carb?
Generally it is marked on the side of it (when it's removed) or if you're not sure just take a drill bit drop it down the top and measure it.
Originally posted by BradP:
Does anyone know if there is a way to tell what size the needle and seat is in a Holly carb?
I dont know if I am doing this right but here goes. The only needle and seat in a holley carb is the ones that control the float level. Unlike Carter and Q-jet Holleys only use jets. I do know that Holley offers a high flow needle and seat usually used on alky carbs but I dont know how they rate them. The jets are rated by thousands. So if you unscrew the jet and it has a 62 than the dia. of the orffice would be .062 and a 75 would be a .075 and so on. Hope this helps you.
The jets do have sizes on them but the needle and seat doesn't. The drill bit is the only way I have heard of to size them. Thanks for the tip
Most N&S assembly's are marked on the side of the cage. Holley offers .097", .110" and .120" for gas, while other companies like Barry Grant offer larger sizes. Do not run alcohol N&S on gas, they will not seal properly. The .110" is the most common size in a performance carburetor.
On the jet is stamped a set of #s Like 89 or 90 or 82. This is your size of Jet http://free.***boat.net/ubb/biggrin.gif http://free.***boat.net/ubb/biggrin.gif
The needle and seat have no #'s but the drill sizing worked. I have 120's George @ Clay Smith recommends 130's minimum with my setup (496 w/871). The only reference book I can find with info on carbs with a blower is "Street Supercharging" it has some great tips but I was wondering if anyone knows where I can get literature on marine supercharging.
Also the tuning tips in the book I have recommends changing the accelerator discharge nozzles (squirters) to eliminate off idle stumble. He only mentions up to 750's I have 830's and don't want to keep buying nozzles until I "stumble" on the right one, .034's are recommended for the 750's I have .031's. Any tips?
Hey BradP,
I don't think there is a way to figure it out other than trial and error, but I'm running a 37 squirter in mine 468 BBC,800dp but at 12.99 ea I can see where you want to hit it right the first couple of tries$$$$$. Just my .02, good luck
Originally posted by Clutch:
Hey BradP,
I don't think there is a way to figure it out other than trial and error, but I'm running a 37 squirter in mine 468 BBC,800dp but at 12.99 ea I can see where you want to hit it right the first couple of tries$$$$$. Just my .02, good luck
What carbs are you running? I also have the 30cc accelerator pumps, do you have 50's?
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