Gear ratio 1:50 vs 1:36

[Chrish]

My Z33 will have 454s at about 400-450hp each. What would be the better gear?
Cheers!

[MOP]

the 1.50 is used by most, but it has been said many times the a slower turning prop is more efficiant. This should draw a few good responses!

[Donzigo]

When the Z-33 was first introduced, the Aloha drive was the only thing available until the Bravo came on the market in 1988 or so. The alphas were paired with the 454s and came with a 1:30 to 1 ratio. I had one of these. Most of them have long since failed and been replaced with the 1:50 to 1 gears. The Bravos were equiped from day one with the 1:50 to 1 ration. I can't imagine why you would want to use the 1:30 to 1 ration gear. The 1:30 to 1 won't work, unless you are super careful not to overstress the outdrive.

In short: "Don't do it"

[MOP]

I agree 100% with Donzigo on Alphas but I am not sure about Bravos, looking at the the drives offered bu Merc the highest rated Bravo offers 1:24. I have read posts on ratios, many high perf boats run 1:36/1:24, many do because they run out of prop selection. Some say the uppers last longer due to more gear surface contact, I would get more input from big HP guys before buying gears. I think there is more to this and worth digging deeper.

http://www.go-fast.com/mercruiser_bravo_sterndrives.htm

[Chrish]

There are a pair of 1:36 Bravos on ebay. Sounds like I should stick w/ the 1:50!
Thanx for the input.

[MOP]

I posted the question on another board, the replies said though the 1:36 wre stronger they cost you in performance. The 1:50 appears to be your best bet on a heavy boat.

Phil

[Pismo]

More torque at the prop with a 1.5

[BlownCrewCab]

For his 400-450 hp the 1.50 is a better chioce. It'll accelerate faster and have good top end with 27-30" props. 1.36's will hamper acceleration and be harder to get top end with that power. It may have a really decent cruise rpm and cruise speed, top end will suffer. most boats that run 1.36's have huge motors and are built for speed.