When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm trying to find out about this carb, Holley double pumper 4778-8.
What I've found is that it is a 700 cfm and the higher number on the end means bigger jets but I can't find any with the -8 on the end.
Any idea of what the jet sizes may be on this, or if it is a 700?
I'm trying to find out about this carb, Holley double pumper 4778-8.
What I've found is that it is a 700 cfm and the higher number on the end means bigger jets but I can't find any with the -8 on the end.
Any idea of what the jet sizes may be on this, or if it is a 700?
The -8 on the end is a series number and it has nothing to do with jet sizes. And by the way, double pumpers aren't intended for street use. They're made specifically for drag and track racing where 4000+ rpm is constant.
Holleys are best! You prob have #72 primary jets and #78 or 80's in the secondaries. I think that size DP is perfect for a 350 engine as long as you're using a stick trans. Like the previous poster, they're not so good with an auto trans. more suited for racing.(sometimes)
Holleys are best! You prob have #72 primary jets and #78 or 80's in the secondaries. I think that size DP is perfect for a 350 engine as long as you're using a stick trans. Like the previous poster, they're not so good with an auto trans. more suited for racing.(sometimes)
People buy carburetors that are made specifically for track racing and then put them on street engines. In track racing where 4000+ rpm is constant the vacuum secondary carburetors would be the wrong choice just as double pumper carburetors are the wrong choice for street engines where rpms vary from 550 to 5500 rpm. Once these double pumper carburetors get put onto street engines the owners have no end of tuning problems because of their poor choice.
carb question
)
