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nzjetboating.com Forums => Engines => Tech Library => Fuel System and tanks => Topic started by: Matthewf/Norbert/TuiDog on July 10, 2021, 17:22:27 PM

Title: Holley Carby Size - P76 4.4l Advice please
Post by: Matthewf/Norbert/TuiDog on July 10, 2021, 17:22:27 PM
Hello I've been asked by a mate and forum member sans pc for the following info..

He is restoring his fathers old jet boat which has a P76


He has a 4 barrel inlet manifold and a 650 CFM Holley not yet fitted..seems way too big to tune to me.


Please advise what Holley best suits and any jet sizes?
Title: Re: Holley Carby Size - P76 4.4l Advice please
Post by: Nigel on July 10, 2021, 19:12:23 PM
mine had a 2 barrel 350 holley, 650 way to over carbed
Title: Re: Holley Carby Size - P76 4.4l Advice please
Post by: Jimmy Jet on July 10, 2021, 22:47:28 PM
The Holley website has a great carb size calculator. You can input lots of variables, I'm picking a 390-450cfm 4 barrel will be close but even a 350 2 barrel could be it. Lots of people go too big.
Title: Re: Holley Carby Size - P76 4.4l Advice please
Post by: Warwick Marflitt on July 14, 2021, 16:47:49 PM
Try one of these two Holley pages.

https://www.holley.com/retailer/carbselector/

Or maybe use a Carter carb off a 245 or 265 valiant
Title: Re: Holley Carby Size - P76 4.4l Advice please
Post by: Hacky on July 17, 2021, 21:25:50 PM
A 350 is big enough unless heaps of work has been done to the engine and is pulling BIG revs. I have had much better results over the years with Carter carbs which is now Edlebrock. The Carter / Edelbrock are much more tuneable. If they made one around 350 cfm I would be considering that. I just don't know if they make a carb that small. 
Title: Re: Holley Carby Size - P76 4.4l Advice please
Post by: Hacky on July 17, 2021, 21:37:33 PM
It looks like the smallest after market carb edelbrock make is 500cfm
Title: Re: Holley Carby Size - P76 4.4l Advice please
Post by: Jimmy Jet on July 17, 2021, 23:53:35 PM
I have a Quickfuel 450 on my 1uzfe. Started it for the first time today. Float levels were perfect and it idled amazingly out of the box. Seriously impressed, highly recommend.
Title: Re: Holley Carby Size - P76 4.4l Advice please
Post by: bbs 540 on August 24, 2021, 19:51:33 PM
390 would work well as you have small primary and would give you good throttle response and starting and the sec will only work when engine requires it. The smaller four barrels are getting expensive compared to your common as 600 vac/sec, which is too big for you. I run the 390's on my twins and they go really well.