Velvet drive 72C move to ZF or other transmissions

[sdowney717]

What is the velvet drive bolt pattern, is it an SAE number?

What about other transmissions swap in place of velvet drive?

Will a ZF directly bolt on where a Velvet drive was mounted?
Which ZF are common and reversible, meaning can flow power regardless of engine rotation?
Which ZF can use a 4 1/4 bolt 5 inch diameter pattern velvet drive male prop shaft coupler?
Looking for information to add to my mind's data base, and if ever changed engines, what trans would work. My current engines one is counter rotating, so would need a different transmission if I changed engine to a standard rotation.
Looking at a HP range as low as 250 to 350.

 

[Ski in NC]

There is generally an adapter plate between engine and trans. The pattern on the trans end is proprietary to the trans, the pattern on the engine end is whatever the engine is. Gas engines are proprietary, diesel generally conform to SAE standards. Plates can be bought for most applications.

ZF gears in that hp range can be run in either direction on output shaft. Have to look into specs to see if the coupling will work, probably would need to replace, but that is cheap.

Motor mounts would have to change as the ZF is not in line like the BW.

 

[sdowney717]

I found a coupler guide for what works with what.
http://catalog.buckalgonquin.com/Asset/Transmission-Guide.pdf

I have this split coupler
Item # 50500a1375, Transmission Couplers On Buck Algonquin

That prop coupler, 5 inch diameter, 4 1/4 bolt circle 7/16 bolts, works with a lot of various transmissions.
Of all those which is desirable, affordable but also common which can work outputting either rotation?
I figure someone has some of these. Ideas?

My 72C velvet drive has a 2.57 reduction, props are 22 by 20.
----------------------------------------------------------------------------------
For ZF
ZF88C, 45A, 63A, 63C, 63IV, 90ATS, 90TS,
110TS, IRM41A2, 50A2, 50V2, 50V3, 501,
50A2/K3, 50V2/3LD

Hurth
HS25A, HS45A, HS63IV, HSW630A, 630H,
630V, 880D, 450A2, 630D, 630A1, 630H1,
630V1, 90ATS, 90TS, 90VTS, 110TS,HBW630,
630A, 400, 450, 600, 630

Borg Warner
72C-1017, 1018, 1004, 1005, 1013, 1014, 2001

Newage
PRM 210/160

Twin Disc
5010A, 5011A

Volvo Penta
MS, MS3, MS4A, MV2

 

[SoWhat]

Bell housing between engine and transmission would probably be in $300 range. Output shaft flange in $200 range. Motor mounts estimate at $100 each. A new transmission might require a larger oil cooler. The existing hydraulic hoses might not reach the new oil cooler. And on and on. There are numerous combinations of engines and transmissions. I suspect finding the right parts wouldn't be the major problem.

 

[sdowney717]

My current mounts are 4 and only attach to the engine, transmission just bolts on as an appendage.

I would get a trans that fit my prop couplers, seems many trans will fit it ok.

Interesting that the bellhousings differ for various transmissions, not unexpected.
I wonder if some bellhousings work for multiple transmissions, meaning some trans have the same bolt pattern to engine.

 

[sdowney717]

http://www.fredwarner1.net/pdf/zf-marine-transmission-selection-guide.pdf

ZF transmission guide.
I assume a 'B/W' bell housing is a borg warner velvet drive bolt pattern.
So yes, they exist. Looks like a ZF 63C, ZF 88C, ZF 220A, etc... would attach.

"B/W = Borg Warner connection integrated with all casings except ZF 12, ZF 25, ZF
25 A, ZF 45-1"

 

[Edelweiss]

What about other transmissions swap in place of velvet drive?
Looking for information to add to my mind's data base, and if ever changed engines, what trans would work. My current engines one is counter rotating, so would need a different transmission if I changed engine to a standard rotation.
Looking at a HP range as low as 250 to 350.

The Velvet drive 72C was manufactured in both left or right hand models. If it's just a question of switching to a standard rotation engine, consider switching to the appropriate left or right 72C to keep the exchange simple.

Harbor Marine in Everett, Wa. has an extensive inventory of VD Transmissions or will rebuild yours to suit and ships worldwide.

https://www.harbormarine.net/

 

[FF]

It is usually way cheaper to rebuild than change to a different brand.

 

[Jeff F]

The Velvet drive 72C was manufactured in both left or right hand models. If it's just a question of switching to a standard rotation engine, consider switching to the appropriate left or right 72C to keep the exchange simple.

Harbor Marine in Everett, Wa. has an extensive inventory of VD Transmissions or will rebuild yours to suit and ships worldwide.

https://www.harbormarine.net/

I don't think that's exactly right. The 72C for a given reduction gear always maintains the same direction of shaft rotation relative to engine rotation. I have a 72C that was switched from a counter rotating Perkins to a standard rotation Cummins. In order to accomodate that change the oil pump was turned around, which is easy, and the RH prop was replaced with a LH. They may ask which way the transmission is going to turn when you order, but that's just to know which way to mount the oil pump, which has to be aligned with engine rotation.

 

[Edelweiss]

I don't think that's exactly right. The 72C for a given reduction gear always maintains the same direction of shaft rotation relative to engine rotation. I have a 72C that was switched from a counter rotating Perkins to a standard rotation Cummins. In order to accomodate that change the oil pump was turned around, which is easy, and the RH prop was replaced with a LH.

That is correct for some of the 72C models, those that are designed for both direction requires the pump to be indexed for left or right hand engine rotation. But some, I believe they're the inline like mine, are designated only for left or right and have the letter "A" after the ID number which designates "Clockwise rotation only". Running them in counter-clockwise would result in early transmission failure.

Best to check your model with a Velvet Drive service center

 

[sdowney717]

71C and 72C, they must turn same direction as engine rotation, else some bushing in them will burn up.
Sure you can switch to another engine with standard rotation, but then would have to change the prop since props are LH and RH, usually on a twin engine boat. And the old way of doing this was to use reverse and standard rotation engines, which is what I have.

My eventual goal, IF I was to change engines, is to keep props, shafts, couplers and only have to change engines and transmission, so was just exploring ideas.

Lots of transmissions use the couplers I have, enough that would not be a problem.

 

[Ski in NC]

Biggest problem with going from VD to ZF is that ZF input/output shafts are not in line like the VD, ZF output is below input. So back of engine must be raised a few inches. Also the ZF is considerably shorter, so you either need longer prop shafts or move the engine back on the mounts.

Almost all new engines available today spin the same way, and all new gears accept that input direction and output can be either direction. No muss no fuss.

Wierdness can be had when trying to regear engines that themselves are counter rotating. That was a common setup up to about 20yrs ago with Detroits, Perkins, etc. No longer common practice.

 

[sdowney717]

Biggest problem with going from VD to ZF is that ZF input/output shafts are not in line like the VD, ZF output is below input. So back of engine must be raised a few inches. Also the ZF is considerably shorter, so you either need longer prop shafts or move the engine back on the mounts.

Almost all new engines available today spin the same way, and all new gears accept that input direction and output can be either direction. No muss no fuss.

Wierdness can be had when trying to regear engines that themselves are counter rotating. That was a common setup up to about 20yrs ago with Detroits, Perkins, etc. No longer common practice.

Shorter trans is actually good, more room if I went from a V8 to straight 6.
My engine space has about a foot free in front of the v8 engine.

My one issue is height. Engines need to be low height, no turbos or manifolds perched high up top on an engine.