Transmission Recommendation Sought

I am reconsidering the equipment list on a possible build. This is a planing lobsterboat hull and I want to price gasoline power. I'd estimate about 800 annual hours participating in the NW Atlantic cod and tuna hook fisheries. The MFI 8.1 Crusader (385 hp) provides this for transmission options: "Compatible with all available marine transmissions". I do know that the Velvet Drive 72C and the ZF Hurth 630A are among the options (I'm estimating the reduction at 1.5:1). Obviously I'm interested in reliability so I thought that I'd seek out recommendations for these or any others on this forum - any opinions as to the better marine transmission?

 

Twin Disc.

 

Also twin disc here. 13,000 hrs at present. serviceing a 220hp diesel. no problems.

 

Twin Disc. 10-1 at least, in terms of reliability.

They have been made for decades so check "Boats and Harbors" for a quality rebuilt ,or a low time takeout.

FF

 

I give up! E-mailed the closest TD distributor and got no response. Called corporate headquarters in Racine and was transferred to their Rick Lund - left a voicemail message. Lund returned the call and I explained the application and he said that he'd get back to me shortly. Well, four more voicemail messages left for Lund over the next several days went unanswered.

I e-mailed ZF headquarters and got a near immediate response and after a telephone conversation later in the day, had the information that I needed. Guess which manufacturer I'm going with!

 

I e-mailed ZF headquarters and got a near immediate response and after a telephone conversation later in the day, had the information that I needed. Guess which manufacturer I'm going with!

Before you jump off that bridge call a local ZF dealer and ask about parts avilibility and prices. On many items ZF has to have them flown over (at your cost) , after the factort makes it.

In other words there is almost NO stock, of parts in the USA or Europe , except for the barest minimum.

A used or rebuilt Twin Disc will last far longer , but do not expect the factory to respond to a request to find what is in local dealer inventory for you.


Again, www.boats-and-harbors.com/classified ,,,, find a dealer from the dozens that will help with the fitting on your engine.


$$$$ 2k should get a good TD rebuilt , $$$10K? at ZF ,,, your choice

 

Plenty of used Twin Discs around. I notice that the local marine engine shop strips off the twin disc , then sends the old tired diesel off to the scrap yard.

 

I have reservations about ZF too (going back to their early, aluminum case issues) and that's why I've gone to this forum for advice. ZF's customer service fell over themselves getting me the application data that I sought. TD, on the other hand, seemed not to care either way.

My question is pretty simple: What reduction gear do you have in your line that will handle roughly 400 hp at rpms that could reach 5000? So far, I can't beat that information out of Twin Disc!

 

Velvet Drive is a good workhorse. A rebuild kit is quite inexpensive too.

 

but a stock one is not great at 5000 ( huge internal drag)
bam marine at www.go-fast.com
can make a stocker work, are we talking commercial or pleasure here?

 

Light commercial is probably the best description. About five hours of fast cruise to the continental shelf and then trolling for the bulk of the day and then the return trip home.

 

well 72's were standard install on Mercruisers (in the old days)up to 460hp and they ran to 5200rpm and would do that all day on a pleasure craft.
You can buy them new again these days