merc # 2 drive packages

[jay dezman]

i'm considering taking a ride to look at a boat with twin #2's with 350 chevy's.<br /><br />what i curious about is....<br /><br />purportedly they are counter rotating. (i seem to recall that availability)<br /><br />did mercury do this with counter rotating engines or do it in the transmission?<br /><br />second question....<br /><br />i know it (the #2) was a large heavy duty unit. was/is there a terminal speed before blowout?<br /><br />third question.....<br /><br />can just the legs(s) be changed to the trs units (to allow the potential for higher speed) or do you have to swap the transom plate also?

 

[jay dezman]

Re: merc # 2 drive packages

I guess i should clarify a bit....<br /><br />i'm talking about the large, heavy duty drive that uses the separate transmission between the engine and drive.....maybe the II drive!

 

[Laddies]

Re: merc # 2 drive packages

Jay, first all stern drive engines are counter rotating (LH) as they use automotive cams. If your talking about prop rotation the units could be ran either way. I think it would require repair of the transom for TRS units and installion of a transmission on the rear of the engine. The II units were designed as a heavy duty work unit and not for speed, but we had a customer with a Keith Black 327 that was 50+MPH

 

[Laddies]

Re: merc # 2 drive packages

I was talking about the old II unit--Bob

 

[jay dezman]

Re: merc # 2 drive packages

the more i think about this maybe the identity of the drive is the "TR II".... the big (huge) heavy duty drive with the separate transmission inside the boat, between the engine and drive<br /><br />what i am after, information wise is:<br /><br />in order to achieve counter rotation at the propellers did mercruiser<br /><br />A. run both engines with the same rotation and have the transmissions provide the opposite rotation to the propeller or<br /><br />B. run the engines with opposite rotations and hence opposite propeller rotations.

 

[Haut Medoc]

Re: merc # 2 drive packages

There are both LH & RH rotation engines

 

[jay dezman]

Re: merc # 2 drive packages

so its "B." then? that each engine rotates in opposite directions and that the transmissions are straight thru?

 

[marinemech1]

Re: merc # 2 drive packages

the rotation of the drive was/is determined by the position of the gear in the lower drive. either ahead or behind the pinion gear<br />switching to tr"s" is easy but expensive.<br />just empty every bank account you have and buy lower gearcases that are trs also you will need to shim drive shaft tapered roller bearing