mm u engine

rpllr · Aug 4, 2014

can someone tell me the best combinations for building a u mm engine, I know about the 4.81 pistons but what rods and stroke do you use with them. Also know you can use 800 blocks with machining the crankcase but also unsure of what rods and heads you can use with those blocks, would like to use 4232 heads but not sure they fit 800 blocks. Also wondering who makes the big intake manifolds for them? thanks for the help

MikeJM · Aug 4, 2014

The common combo around here is 4.8125 bore with an offset ground G crank with U rods to make 6.1875 stroke. Makes 450 cubic inches on a budget.

MDHJR · Aug 5, 2014

The best bang for the buck is 5.25 bore with a 6 inch crank 520 cubes about a 135 HP can use the 4232 heads

rpllr · Aug 5, 2014

Is the 5.25 bore a stock 800 block? And I assume you just use g crank
Thanks

bp4455 · Aug 5, 2014

stock 800 jugs are 5.319 bore. however they arent legal some places. check local rules

jd plowboy · Aug 6, 2014

you can do some machine work to the case and to hd800 jugs and with a standard 5.319 bore or overbore to 5.5 and use custom pistons. with the standard bore it is 530 cubes and with 5.5 it is 570. i had a 570 cube and it made over 150 horses and pulled strong. a 530 would be a good combo also.

6pack · Aug 6, 2014

(quoted from post at 18:16:28 08/05/14) Is the 5.25 bore a stock 800 block? And I assume you just use g crank
Thanks

I have a fresh 665 cube (5.5x7) I would sell
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BGomez · Aug 7, 2014

What's the HP on that 450 cub motor

mm u engine

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