Holley Carb 600 vs 650 Differences and Which One is Better | Holley Carb Secrets |Holley Carb Tuning

Holley 600 vs 650 CFM carb how are they different and which one is better. Today I am diving into the two most popular carbs for your carbureted engines. My stock carb ls currently has a 650 holley carb and I just love it. Tuning holley carbs are fairly easy to tune once you understand all the holley carb secrets that the old timers keep to themselves. Which carb should you get? Watch the video and find out!

[@NewEngland462]

I took a 1850 drilled it for 4 corner idle. Cathedral bowls and hands down the best meetering carburetor i ever had. Afr is actually perfect. Cruise. Everywhere

[@NightWrencher]

I'm glad to hear it! I personally really like the 1850s. Even the 4160 versions are small and compact but still have a lot of potential

[@oscarantonionagaya7556]

Hello, excellent video, I have a carburetor like that, my engine is a slightly modified 350 but I bought an 850 cfm too much for this engine that I have to change to make it a 650 cfm

[@NightWrencher]

you're better off getting a different carb. Theres no easy way to get a 650 onto an 850 baseplate so the only reusable parts of the 850 are the metering blocks and bowls. You can machine a 650 main body onto an 850 by the way. Its not uncommon to see that done to 750s.

[@chevyrellstraightdropracin0603]

Nice content keep it comin

[@NightWrencher]

Thanks a ton man, good to see you!

[@eddieb1408]

Can you put 850 metering blocks on a 650 dp main body and not run rich

[@NightWrencher]

It all depends on the engine its going on. If the engine wants a lot of fuel, it will be ok, but if its a mild or stock engine, the PVCRs are going to be too big

[@erik041982]

Guys that take stuff apart and throw all the partsl in a pile know what they are talking about.

[@aservclive]

Can you pass me that 70 main jet on the bench

[@NightWrencher]

Lol you need a 70?

[@porterpowerrotary7619]

Can u tune a 600 to be allittle lower?

[@NightWrencher]

What do you mean? Like take away CFM?

[@porterpowerrotary7619]

@@NightWrencher ya I have a rotary that has a Holly 460 cfm an I wanted to make a 600 into like a 500 550

[@NightWrencher]

@@porterpowerrotary7619 CFM is figured by the size of the venturis, throttle blades and booster type. Most carbs are measured using straight leg boosters. Downleg boosters increase CFM by about 20 or 30 due to their position in the bore. Annular boosters decrease CFM by about 25 due to the size of the booster blocking air, but also increases fuel atomization and promotes better mix. You can send your 600 main body to get annular boosters installed and thatll bring it down to 550-575. Hope that helps

[@NightWrencher]

www.hotrod.com/articles/carburetor-showdown/

[@RossWood-sl5oj]

not sure but push in annular? restrictors were available to reduce primary flow.

[@joe-hp4nk]

Your junk bench is a little cluttered.

[@NightWrencher]

Juuuuuuuuuuuuust a little bit

[@Inthefoxhole]

Those are the ones who know what they are talking about.