twin disc mg 5061

29chawk

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got a cat 3208 with a twin disc mg5061 2:1 ratio pushing a 24'' prop. would this transmission work on a cummins 6bt? looking to swap out the cat, boats a 28' x10' commercial lobster style hull.
 

traditions

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It will work if the bell housings are the same.I had a 260 b with a 506 gear on it that came of a cat,and it had a spacer ring under the drive gear to make it fit.The starter on the cat sticks out the back,so ther ewill be a hole where the starter was.Whenever installing a gear on a engine always make sure you have recommened end play in the crankshaft.If you bind the crank it will wipe out the main bearings.The HP should be close if you are going 3208 natural for a 210 b.The weight will be much less for sure.
 

BillD

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got a cat 3208 with a twin disc mg5061 2:1 ratio pushing a 24'' prop. would this transmission work on a cummins 6bt? looking to swap out the cat, boats a 28' x10' commercial lobster style hull.

Here ya go 29chawk,

boatdiesel forum....if you have a marine diesel....best $25/yr you can spend!!!!

Response #1 from: Tony Athens [email]
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Date: August 24, 2012 - 08:08 AM 99% yes you can use the gear and the coupling drive to it.. BUT, you will have to cut off the starter ring that is part on the housing on the 506.. It will leave a small vent hole in the adapter, but just ignore it.. No harm, no foul..

Tony
 

29chawk

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Thanks Bill, yeah ive been thinking about geting a membership there guess its well worth it. Thats good news does a 2:1 spinning a 24'' wheel on a 6bt around 300hp sound like a good combo? Im starting to look for a good running take out.
 

BillD

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Thanks Bill, yeah ive been thinking about geting a membership there guess its well worth it. Thats good news does a 2:1 spinning a 24'' wheel on a 6bt around 300hp sound like a good combo? Im starting to look for a good running take out.

You are asking the wrong guy, but "sounds about right".

I spoke with a guy who is rehabbing a 33 DE with maybe a 6BTA 315/330.

He's considering a 1.75 gear with a 22" wheel.

Lots of guys here will have excellent experience with hp/gears/props in a DE hull
 

traditions

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Make sure to measure the holes in your bell housing.Some 3208's used a SAE #3 housing,and I would guess the B would be a #2.You may be able to change housings on the B easily if they dont match.
 

BillD

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Make sure to measure the holes in your bell housing.Some 3208's used a SAE #3 housing,and I would guess the B would be a #2.You may be able to change housings on the B easily if they dont match.



All of the Cummins mid-range marine engines ( Bs & Cs) have always come SAE#3 bell housings.. Never was a #2 available from the factory on a B marine engine.

Cummins never even offered any other option until the release of the
6CTA 8.3 255 around 2001. This was a really nice low HP, high torque 1800 RPM commercial marine engine that you could get SAE #1, #2 or #3 housing as a factory option.. But that engine is gone now.

Cummins B & Cs come with an SAE #3 w/ SAE 11.5 flywheel. No other option.


But just an FYI.With some dealer support one could easily covert a B or C series Cummins to a different bell housing or flywheel by ordering the parts for the same base engine used in other markets ( Industrial, Argriculture, etc etc) ..


As I always say, the B is a great engine and will be around for decades because of its simple but rugged design, easy support for the product and because parts are cheap and readily available from multiple places.
 

captainlarry84

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ZF

I think in the long run you will be happier by also changing the gear to a ZF 220 A. It is lighter and all you need. In addition the Cummins is a little taller that the 3208 so on install with the 506 and inline six you may have some clearance problem.
If you can swing the 24 blade stay with the 2:0. You will gain nothing by swing a 22 blade faster other than more wear on the shaft & bearing.
 

29chawk

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Thanks, Cap. yeah makes sense i put this project off for a few weeks but im about to start back at it here soon. Im going to try and trade in the 3208t and gear for cummins b series probally take a chance with a rto. cant afford a recon. have any idea how a 300hp 6bt would compare to 3208t 325hp?
 

captainlarry84

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You will pick up about 1.5 knots due to the weight savings of the Cummins & ZF gear. Plus you will turn the same wheel.
 
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