speaking of SBC blocks

October 31, 2019, 08:17 AM

Mike Rietow

quote:
Originally posted by ts393c:
Just curious on peoples thoughts. But when you talk about cranks and blocks. Witch is better. Small journal mains or large journal mains. I can see pros and cons both way. Smaller less rotating weight. Larger should be stronger.

A practical approach to take when considering overlap is if a Top Fuel engine has large journals and a pro stock engine small, with large and small being relative. Crank deflection at high rpm is determined more according to application. Some of these aftermarket blocks you sacrifice strength of the cap 400 sbc mains. So there's another variable. Overlap depends on what you're building.

This message has been edited. Last edited by: Mike Rietow,

October 31, 2019, 10:01 AM

ts393c

quote:
Originally posted by Mike Rietow:
quote:
Originally posted by ts393c:
Just curious on peoples thoughts. But when you talk about cranks and blocks. Witch is better. Small journal mains or large journal mains. I can see pros and cons both way. Smaller less rotating weight. Larger should be stronger.

A practical approach to take when considering overlap is if a Top Fuel engine has large journals and a pro stock engine small, with large and small being relative. Crank deflection at high rpm is determined more according to application. Some of these aftermarket blocks you sacrifice strength of the cap 400 sbc mains. So there's another variable. Overlap depends on what you're building.

That's a good point. Never thought about it that way. Small journal on both rod and mains could make the crank weak. Depending on stroke of course.

November 06, 2019, 09:15 AM

Mike Rietow

This is a run of the mill Motown I did for a guy. Made several laps in the 5 twenty's and teens at 3,000 lbs with 350 - 400 hp on a plate system 23 sbc Brodix 227 T1 700 lift camshaft. Bracket racing at around 700 hp I can't see this block not being plenty durable if funding is an issue. 5 teens at 3,000 lbs is well over 1,000 hp.