jslowss

i have a 88 four winns liberator has a 454 merc. found out the bearing on the driven gear went out and while im in it was wondering if i should stay with the 1.32 to 1 gear ratio or if theres another route i could go that wont take any top end out but give me a little more torque? this is all kind of new to me so any advice will help .. motor mainly stock and will be getting a m1 within the next year so if that changes anything?

DareDevil

its the lowest gear u can get, well they make a 1:25 but its not that much of a differents.

picklenjim

Comparing in terms of numbers that is a low number but in all actuallity the lower the number the higher the gear ratio. That seems to be geared actually high for a stock 454. It should be a 1.5 to 1 or more. A little more info is really needed. Is this a single engine? How big is the boat. What drive is it? Most important what is the maxium RPM the boat will turn now at WOT? What is the Horsepower? Also what pitch prop are you running? I my opinion I believe you most likely need a lower geared drive like a 1.5:1.

Just guessing I would think your boat is hard to get on plane and hard to idle around the docks.

jslowss

ya your right its stupid hard to get on plain..its not bad to dock or anything at all tho but its a 24ft four winns liberator has a single 330 hp 454 merc in it... cant remember what pitch on the prop i think 23 or 24 maybe but dont know..

jslowss

runs right at 4k rpm i believe.. its been about a year since ive had it on the water..and its just a alpha one gen 1

DareDevil

U def. need a 1:50 for that boat your rpm should be 4600-5000 !

picklenjim

I'm surprised that drive lasted this long with that high gear in it. They only put the alpha behind the big block for a very short period. Your prop is probably more like a 19 or 21 pitch. You may want to go to an even lower gear than a 1.5:1 to help preserve the drive. I believe you can also get 1.62:1 and 1.81:1 gears. This will give you more low end power and the motor will be able to turn more RPM's to keep your top end speed.
I don't know the story behind this boat but it never should of had a 1.32:1 gear drive on it. May want to double check on that gear ratio, I'm not so sure they even made a alpha with that high of a gear in it.

jslowss

good to hear because i can find a 1.50 to 1 ratio upper everywhere i have had the hardest time getting 1.32 to 1 parts or anything.. its the factory outdrive and gears my dad bought the boat new in 88 and i just bought it off them about a year ago.. big mistake.. we boat on the lake of the ozarks mainly and ill never own anything under 35 foot again..

wtfo

once propped right, the boat will be faster with a lower gear ratio on it (higher nyumerically). for the range you're running you might pick up as much as 3-4 mph for each step from 1.32, 1.47/1.5, 1.62/1.65, 1.81/1.84, and you won't be able to find good props in the range required for 1.98/2.00.

why? because more gear reduction (higher numerical gear ratio) means more torque at the propshaft and the ability to turn a higher pitch prop.

You ideallly want to prop to put you in the 27-29" pitch range I would imagine. BUT in terms of holding up, the 1.32 and 1.5 gear sets can be had in a heavy duty version (maybe all of the 1.32 gearsets - I should know, that's what i've got on my boat right now, but I don't...).

the 1.32 was an attempt to make the alpha drives live by lowering the torque on the lower gear set - the more mechanical reduction you have the more torque you have.... also the more prop you have, the more resistance it will have to being turned at low rpms and so the mroe strain it will put on the whole drive. It was a decent idea in theory, but the problem is that the entire drive is just not designed heavily enough to hold up to typical use under typical maintenence conditions in many boats with bigblock torque...

that's my understanding at present anyhow...

bottom line - go for a 1.5 ratio drive with the HD gear set in it...

wtfo

oops...