Minimum Engine Spacing
 

I have an old cig with the drive spacing at 25 1/4". I curious if anyone knows if a pair of small blocks would fit. They would replace a pair if I-6's. Thanks for any help.

Are you measuring prop shaft center to prop shaft center or distance between the transom plates?

Big blocks work on 36" centers in side-by-side applications. Small blocks will work on slightly less, but you may be limiting your exhaust choices.

Staggered engines usually end up on 18" centers and a short stagger about 22" centers.

From your post I suspect you're talking about an old 28' Cigarette that had the Chevy 250 cu.in. 6 cylinder engines with Alpha drives. Yes?

Close, it's a 24' and it has 6 cyl 165hp engines. I measured the distance between the transom plates.

Measure from prop shaft to prop shaft.

Easier yet is to measure grease fitting to grease fitting in the top of the outer transom plates, if so equipped.

25 1/4 was the distance between grease fittings.

32 is usually standard small-block spacing. With Merc manifolds, you have a couple inches. With Crusaders, they just about touch.

I know you can atleast go 31" centers ( propshaft ) on small blocks with Gil manifolds. You may even be able to squeeze another inch or so.

I have a buddy that has an older 28 cig. small block boat with stock exhaust & although I am not sure what the centers are I know that the manifolds are all but touching. so some of the guys in the cig. section should be able to tell what the tightests you can go is. I would post your question in there also if you havn't already..

32 inch centers with twin 280 TRS packages in a 24 race boat.

This is the exact same hull you have with a 24 Cigarette.


www.bananaboatco.com

Measured my small block setup in the scarab. Propshaft measurement was 31" . Measured @ the dimple in the top of the gimbal ring and it was 31" , thought I had the drives toed but I guess not . Measured between the transoms , 19" . I can barely get my hand between the stock merc manifolds. Alpha transom / drive setup.