How do i prepare a holley for boost?

[Anonymous]

I know EFI is better but Carbs are cheap.
I want to know how to prepare a Holley for boost. Ive heard a 650DP is best to use.
If using a carb what else needs to done? It will be a blowthrough setup. Does my dizzy need to be regraphed or changed? What fuel pump and regulater should i use?
Dont tell me to go EFI, it will be too expensive, Its for a 351 cleveland not a 250 xflow.
Its not a six but i thought you guys could help me anyway as there is an aussie 6 in the shed.

Thanks guys
Dan

 

[George]

Hi Dan,

The best way to prepare a holley it is to thow it in the bin :!:

Anyway..
It you are going blow through then you need to do a few things to get it to work. The easiest way to set it up would be buy or fabricate a box to house the complete carby with holes only for the fuel line and accelerator cable in it. You will also need a rising rate fuel reg to compensate for boost. you will need to fully seal the box.

To reliably modify the holley for boost without boxing it requires alot more work. You need to take into account that all the internals of the carb will be pressurised including the fuel bowls. Q. Will the gaskets around the fuel bowls handle 15PSI reliably for a year? You will also need to modify the shafts to stop leaks. Plus many more little mods that I dont know about!
The funny thing is that a properly modified holley for boost actally cost close to a couple of grand making it more expensive that EFI.
George Hadad sell's modified holley's for some ridiculus price.

For best results you should regraph the dissy. Boost retard is also a good idea..I have been told 1 Deg retard for every 1 PSI is a good starting point.

Good luck..

 

[Anonymous]

Ohh a couple of grand! that blows my budget out of the water.
I was hoping to have the whole thing running with boost for that much. It wasnt going to be the most optimal setup but it would have been running.
For $2500 i can buy the whole kit to add EFI to the engine. Maybe this turbo project will be an extra long term thing.

Oh well thanks for the advice.
Dan

 

[addo]

You can do it for less, but need to know what you're doing. Even then, there will be appreciable compromises. A good tunable EFI rig will see you better placed to take advantage of forced induction later in time.

Regards, Adam.