mercruiser 140

[wroberts840]

I got a 5.7L mercruiser and would like to replace my 3.0L mercruiser with it. How hard would that be to do?

 

[Bt Doctur]

Re: mercruiser 140

change the exaust pipe,change the gear ratio in the drive or replace the drive. correctly install new stringers to accept the V8 front mounts (structural fiberglass work), install larger gas tank, just to name a few.

 

[Kainon]

Re: mercruiser 140

What size boat? 18' you'd have some nice top speed and may sit a "little" low in the water. 19' is where the V8's usually start.

Is there an area on either side of the 140 where the 5.7 motor mounts cant bolt into ( stringers )

do you have the Y-pipe for the 5.7?

Do you have the outdrive for the 5.7, as the Gear Ratio is very far from the ratio for the 140, 1.98R for the 140, 1.50R for the 5.7L

Other than that, I would do a test fit of the engine cover, should be fine, but can be made from plywood and strapping.

 

[wroberts840]

Re: mercruiser 140

its a 17' boat might be too much power may sell it and find a v6

 

[Kainon]

Re: mercruiser 140

A V6 may be a better option, a little lighter and still decent power for a 17', you could do a BIG 4 too.. or an Inline 6.