RPM Change

[DANNY]

Taking into account that ALL things are the same: motor, car, driver, tires, gears, ect...

What kind of RPM changes would you see going from a 4412 2bbl to a 750 4bbl?

[50j]

Depends on what is limiting the usable rpm. It should be the carb with a 2bbl, but you have to consider valve springs, cam, heads, manifold, etc. etc.

[MQueen]

Thats a hard one to answer. If this was one of my cars and lets say we are talking about a 3/8 track I would change the gear about 2-3 points higher. I would guess 500-700 rpm if it was a stock 4412

[boogityk5]

It's been a few years since I went through it myself just in the opposite direction. Went from a 750 double pump to a willys stage 1 350, best i can remember dropped 300-400 rpm with everything else remaining the same.

[MM90]

It's been a few years since I went through it myself just in the opposite direction. Went from a 750 double pump to a willys stage 1 350, best i can remember dropped 300-400 rpm with everything else remaining the same.

I used my stock car engine in my mod last year. Changed the intake and headers, and maybe gained anywhere from 500-800 RPM, used the same gear ratio at the same track. Got a new cam and different intake for the engine this year, so should gain maybe a couple hundred more RPM.

[DANNY]

Sounds like I'm going to need a gear change, been running 7.33 (track is paper clip 1/4 mile) on the 2bbl. I ran a 7.00 before with a 4bbl with less power and we had dirt bozz tires. Now we are on G-60's. My goal is to be 7000-7400. On the 2bbl I didnt hit the 7000 mark much most about 6500-6800, thats where im up in the air lol