proper gear ratio

[xltier]

not sure if this is the right forumn but I got a 1987 221 starcraft islander that had a 3.0 4 cylinder with a 1.98 ratio outdrive.i now have a 4.3 v-6 in there and it overspeeds bad.what ratio should I run.i have a set of 1-65 gears I could put in.just wondering if that is to high.thanks

 

[alldodge]

A 1.65 would be better but you could increase prop pitch. What prop are you running now?

 

[xltier]

14 1/4 x19

 

[alldodge]

With a 19 you have room to change, can increase up to about 28 pitch. If you could find one to try maybe a 23 or even 21 could help dial it in

 

[xltier]

didn't know they went that high thanks.i was just offered a 1.65 leg to try.

 

[nola mike]

I bet you could make the 1.98 work. I have a spare 1.98 that I run with a 25p. My 1.84 runs with a 23p. You've got plenty of room propwise, as AllDodge says.

 

[xltier]

I see if I can find a 23 to try.

 

[Bondo]

Ayuh,...... I've got an ole '74 Islander, 4.3LX, 'bout a '94, 'n an Alpha 1 transom from 'bout '85,....

For years, I've been runnin' a 1.65:1 Alpha 1, with 20" of prop, 'bout 43mph at 4800 rpms,...

I put a 1.84:1 on it this year, but ain't had the time to play with a Torque-Shift prop to tune it to the ratio,....
I just slapped a 21" SSteel wheel on I had layin' 'round,...
No numbers, still loud, 'n much slower,....

 

[xltier]

gonna try a 1.65 this weekend.w/a 14.5x 19