4.25 stroke small block. Experience?

Anyone have the good, bad or ugly with a 4.25” crank in a small block??

Seems like ALOT of crank in a small space.

Any excessive side loading anyone have an opinion on?

Bloomer, you out there somewhere???

Thanks in advance.

Moparbilly’s IMM built small block mill was a 4.25 piece. Couple of drag weeks, nos assisted quarter passes, drove it around metro Phoenix... pretty stout well thought out combo.

*my bad.... I believe that was a 4.125 stroke in moparbilly’s

I did a 427 inch SB once using a 4.125 crank with small journal chevy rods. Things were very close. The windage tray had to be modified, we tried several different oil pickup tubes before finding one that worked, etc. Hughes might still sell their stroker kit with the 4.180 stroke and Honda journals. That combo might clear things a little better. I'm not so sure I'd try the 4.250 combo unless I had a lot of time and patience.

Was it Ron Silva that built a 501 cube smallblock, posted here? Google Silvaliant

I got 2 4.25"/2.0" cranks, a 340 & 360. the 340 is supposed to be in a deep skirt A8 alum dry sump block. As we all know, both Rome and A8's aren't built in a day.

I use a Rod Bloomer 4.250 crank in my old x block. Its worked well. I dont use a standard style pick up.Thats where a big problem is. I have a Kevco pan with arear pick up.It cleared everything with minimal work. On my Molnar 4.125 crank it helped to cut the front and rear counter weight about .300. Using comp star rods and JE pistons it balanced very easy. The 4.250 x 4.125 x block has been 5.66 at about 121. I dont spin it very high, I shiift it about 65-6600

If this web site werent so difficult some older members might stop in more often. I havent been here in quite some time.

Thanks all! I have access to a 4.25" crank motor, in an R3 block (with the Bloomer kit) and by biggest concern was excess side loading of the cylinder walls. So I text Bloomer Saturday and he responds. Not only did he respond, but he was on a break during a bow hunting trip. Now, THAT is service after the sale!

you mind sharing what he had to say? interested in this stuff also....Thanks!

Michael

You're right Billy's was a 4.125 stroke. I still have a copy of the receipt with the specs that Billy posted on here once. I believe Streetwise did a 4.25 stroke on the relatively cheap though.

Just that in a nutshell, the excess side loading deal is all talk. His piston called for a .003 piston to wall clearance to minimize piston rock to further help the situation. He claims many 4.25" crank combos in service with thousands of runs/miles, with no issues that he has been aware of.

I must say again, Bloomer was great about my questions. We left our conversation with him wishing me luck if I bought this motor and if I had any more questions to reach out to him. Class guy! .

has been 5.66 at about 121.

Thanks a lot!

Michael