Cummins 6BT

[classictrade2]

I have the opprotunity to pick up a Cummins 6BT engine. Will this engine fit in my 1977 23' inboard Seacraft without to much trouble? I know the Yanmar is the motor of choice, but the Cummins is what I have to work with.

[ct9amr]

This will be too big and heavy for a 23ft.
At best you are looking at a 4BT for that size boat.

[Fr. Frank]

The Cummins 6BT weighs over 1100 lbs with the flywheel and marine transmission and produces 160 hp normally aspirated and 250 hp with "factory" turbocharging in a Dodge truck, but can easily be made to produce 600 hp with supercharging and reprogramming.

The Cummins 4BT weighs about 850 lbs. with flywheel and trans, and produces 140 hp normally aspirated, 210 hp with
"factory" turbo, and with aftermarket supercharging and chip reprogramming can easily be made to produce 450 hp.

The Yanmar 6LP weighs 930 lbs with flywheel and trans, and produces 260 hp normally aspirated, 315 hp with factory turbo, and can be "factory" supercharged to 470 hp without reprogramming. (I've read claims of 650 hp, but I personally believe that's exaggeration for bragging rights.)

The Volvo D4 weighs 1230 lbs with flywheel and trans, and produces from 180 to 300 hp. The D6 weighs in at 1440 lbs, and produces OEM rated 330 to 550 hp.

The Steyr 6H weighs only 730 lbs dry, and produces 260 to 290 hp. Unfortunately, it's the most expensive of the lot.

[lost2a6]

If the Cummins does weigh in around 1100 lbs with gear then I believe that you'll be fine being that the engine is in the center of the boat. My big block chevy with outdrive weighs around that and it's in the very stern.

[workinpr0gress]

A 4bt can be made into a real powerhouse without affecting reliability

[classictrade2]

Thanks for your comments. I just have access to two 6BT's and was hoping I could make it work. The 351 Ford engine I now run is getting tired and I am considering all angles before repowering the boat.

[riprunner]

I have 2 370B Cummins on order right now for a 32 Blackfin, I wouldn't even consider trying to shoe-horn one into my inboard Seacraft. That Steyr sounds very interesting though!

[Old'sCool]

I believe someone here on CSC repowered with a Steyr.

[77SceptreOB]

I believe someone here on CSC repowered with a Steyr.

Check out the thread " Tom's 23 inboard "Recurve". beautiful boat w/ a STEYR. Good link to pictures too.

[Snookerd]

I have done research on the Steyr AND what the original Volvo weight in my 23SF. The weight for the originally installed volvo diesel in a 23 was around 1100 lbs. The Steyr is a great German motor with a very small dealer network. It is the superior motor. I was quoted 11-12K for a decent used motor and 23K+ on a new one. I have a friend with a 27 Ocean Master with that Steyr in it.