Going from Volvo 1:66 drive to 1:79

[corv75]

I have a 2001 Regal 2860 with twin volvo SX-M outdrives. They are currently 1:66 and wonder what would happen if I goto 1:79 ratio? Engines are 4.3 with 205 hp. Has anyone ever ran 1:66 on one side and 1:79 on other?

 

[bruceb58]

Re: Going from Volvo 1:66 drive to 1:79

Bad idea. Let's not even go into the fact that you would have to have a different sized prop on both drives. You would never be able to sync them up and you would have to carry two different size spare props.

 

[corv75]

Re: Going from Volvo 1:66 drive to 1:79

Thought it would be unwise to run two different ratios wonder if anyone had tried it. I still would like to know effect of going to 1:79 ratio though. I can get a new one very cheap and then pick up the second one used. So would I lose hole shot and top end or would my rpms go to high and need to repop. or all of above. Thanks for response's this great information site.

 

[havasuboatman]

Re: Going from Volvo 1:66 drive to 1:79

The effect would be props spinning at two different speeds when the engine rpms are equal. One engine would be doing more work than the other, and your boat would always veer slightly to the side with the lower ratio.
This is just not something you should do.
Switching both drives to a higher gear ratio can have very detrimental effects on performance and fuel efficiency.
Unless your boat is hitting the rev limiters with the existing gear ratio (or it's over reving) you will lose both hole shot and top end.

 

[Bondo]

Re: Going from Volvo 1:66 drive to 1:79

I still would like to know effect of going to 1:79 ratio though.

Ayuh,... Imagine that what you have now is High Gear, in a 3sp. transmission,...
Goin' to the 1.79 would be like being stuck in 2nd gear....

 

[corv75]

Re: Going from Volvo 1:66 drive to 1:79

Thanks gentlman I appreciate the info. Just have to wait for that good deal on right drives.

 

[havasuboatman]

Re: Going from Volvo 1:66 drive to 1:79

Wise man!

 

[Maclin]

Re: Going from Volvo 1:66 drive to 1:79

What exactly is your boat doing that you are wanting to "fix"?

 

[corv75]

Re: Going from Volvo 1:66 drive to 1:79

Boat was a bank repo and the outdrives have bad bad corrision. I was told to run them till they fail so I am looking for units in advance so I have them on hand when one does go. Ran 100 hours last summer and gave me no problem so I have time to look. love volvos. they must be bullet proof.

 

[cr2k]

Re: Going from Volvo 1:66 drive to 1:79

If you like going in circles it would be kwel!