Blower prep carbs

[74duster]

I know there are companies that will prep your carbs for forced induction. What I don't know is what do they do to them? Can I modify a pair at home, or is there something magic that has to be done at a shop?
The setup would be two carbs on an 8v71 on a 8.5 cr 440.
Any advice would be appreciated.

 

[bOb shingler]

you might try and find a book titled "street supercharging". there's good info in it to read about the carbs.

 

[ramcharger]

The most important thing that's done is reference the power valve to manifold vacuum rather than referencing directly above the blower. This can be done yourself if you're handy or Holley offers metering blocks with this modification already done.

Another thing is to richen those carbs way up. If you're too lean you'll melt a piston.

 

[bOb shingler]

i'm kinda thinking that the manifold only has boost in it but there still is vacuum on top of the blower. a blow thru set-up may be different.

 

[cuhemida]

if your near Pa try Nickerson in Bristol Pa one of the best blower carb guys in the country or talk to fstfish66 about them

 

[ramcharger]

i'm kinda thinking that the manifold only has boost in it but there still is vacuum on top of the blower. a blow thru set-up may be different.

There is always vacuum under the carbs on a roots style set-up and that will prevent the power valves from opening. Yep, a blow through set up will be different.