B/W CR2 conversion to Twin Disc

[dafever]

I'm not sure if this question should be under "stability" or "diesel engines", I have twin Lehmans with Borg Warner CR2 transmissions and a slight seaping from one transmission. I'm told that it will run $2000 to $3000 to go thru the trans. and do factory updates and as much as $6000 if any problems are found and I will still have an obsolete, not very strong transmission.
For $4300 I can replace it with a conversion kit and Twin Disc transmission, which involves raising the engine(s) 2 1/2" (both should be raised to do the job correctly).
My concern's are what may be the effect on stability of a round bottom boat by raising almost 1 Ton (2 engines) 2 1/2" from the lowest point in the boat.
I also am concerned about the added stress on the stringers from the added 2 1/2" of leverage on the motor mounts from the engine torque when it is loaded.
Any input will be appreciated and if anyone has done this conversion I would like to hear from them.
Thanks
MV Dafever

[Frosty]

Wow all that work for a --slight seepage. Are you sure its not seeping from the breather, check the oil level very carefully.

You didnt say what size the boat is but with 2 Ford lehmans I would immagine that raising the engines by 2/5inches would not be a problem. Your fuel tanks would vary by that much!!

How you lifted them would be and you are right to be concerned at the 2/5 inches on the mounts. Lifting them on the thread alone I doubt would be possible to get that hieght and would not be the correct way. Its not so much torque as thrust.

The mounts themselves will need packing.

As far as the conversion itself,-- i havnt a clue, exept that all reverse ratios are not the same, as is forward ratio. a 2.5 :1 may just be 2.47:1 -- you might find yourelf coughing up for a pair of props as well.

I think I am right in saying BW are handed--L'R. Some other maufactures just run them in reverse. This results in reverse being a slightly less ratio. So you might end up with 2.5:1 port and 2.47:1 stbd.

I have 2x 630A ZF 2.5:1 and certainly have this engine balancing problem. Point to think about.

good luck and welcome to the forum

[FAST FRED]

Twin ford tractor conversions are very weak , seldome using over 3 gph,which is 50-55 hp each.

Moving these will not cause any problem from weight or torque.

12V71 might be a hassle to engineer , but not these.

FF

[dafever]

Thanks for the response: the seepeage is coming from the coupling at the splines, I caught it right away when the nylock nut loosened up and I have heard that letting it run with the nut loose spells death and destruction for a CR2.
The boat is a 44' DeFever and I had not thought about a different gear ratio in reverse, a question I will have to ask the manufacturer of the conversion kit. Thanks for the thought Jack.
Fred, the Ford Lehmans are the original engines with only 2100 HRS. on them and you are correct at 1800 RPM I burn about 2 gal. per hr. each at 1800 rpm, my thoughts were to put a 3"x3"x2 1/2" hi block on top of the 3" wide channel iron that is bolted to the stringer, drill through the block and use longer hardened bolts to go thru the motor mount, block and channel iron.
The exsisting motor mounts are now bolted directly to the channel iron.
dafever

[Frosty]

The seapage could be iether coming down the splines or the seal itself. The splines can be sealed with any kind of gunk and the sea replacement is easy.

The splines could wear to the point of failure but that would take a hell of a long time.

Theres 2 Lehmans 4 cylinder and 6