Cummins 6BT vs 6BTA

I am contemplating a marinization of a Cummins 12 valve 5.9. I want to be in the 220-250 HP range. I am looking for input from all on whether or not I'll need the aftercooler based on the power level I am looking for. Also any input from anyone who has completed such a marinization on the B series motors would also be appreciated.

 

Be aware the blocks and fuel pumps on truck takeouts are not the same as the Marine version.

Not a big deal on a 3GPH 50 hp "trawler", would be a concern on a 10-12GPH go fast boat.

 

Thanks Fred!
Do you know any specifics with regards to the pump? I know that the trucks used either the P-700 or the VE pump.
As far as the blocks are concerned; do you think that it would be a concern at that relatively low power level?
There are 12v Ram pickups putting down close to 1000 hp with those engines. Ideally I'd love to get my hands on a Cummins 220B diamond series Recon motor however that's not my style or in my budget

 

I believe a search of this site should give the basic info between the marine and truck engines.

Remember boats require power for long hours on end , not just for a 5 mile hill, or a 1/4 mile drag.

Unless you are at really low power requirements , probably under 100hp , 5GPH , I would look to the marine units.

 

Thanks again!

I searched prior to posting as I was unable to locate specifics. There are some older posts that recommended some distributors of conversion hardware however they appear to no longer in business. I think I'd be willing to give it a chance for my application as the Cummins truck motor is likely more robust than the gas 454 that's in there. The current 454 gas motor is a 4 bolt main truck block based on the casting. I have not heard of any examples of the 5.9 blocks failing at anything under 300 HP. Basically I'm looking to create my own CMD 220B non aftercooled, low boost.

 

Spend $25 and join ,


Boatdiesel.com. The independent site for technical information and ...
boatdiesel.com/

Better $25 than a big mistake.

Go to the "Boats and Harbor" site for new short or long blocks , and other parts.

 

I appreciate you help and advice!

Boatdiesel.com is an absolute wealth of information!

 

Boatdiesel is a great site for people who have bought their marine engines straight from the manufacturer (Cummins etc) - big bucks !

If you think it worthwhile to investigate how much power you can get from a 12-valve Cummins - which may be dependent on year of manufacture - then the following link should interest you, as this business is owned by an engineer who spent 30-years working at the Cummins plant:

http://tstproducts.com/cummins-1.aspx

The later (1994 onwards) 12 - valve 6BTA can be fitted with marine injectors for a whooping power increase !

Obviously, you will need to marinise the engine, fit a water-cooled exhaust mainfold or dry-stack exhaust, a sea-water pump, build and fit engine supports and mounts, etc etc....

Cheers !

 

My cummins pulls 170 ton okay. Bit slow off the mark though. Sorry to get off topic but can you cummins fans tell if the signature truck engine comes in a marine version. I know the k19,s we used to use were also marine engines.

 

Good information, Thanks.
The nice thing about these motors is the availability of the marine manifolds, heat exchangers, marine turbos etc... A lot of the components are available aftermarket which should add to the value. I know the CMD Diamond Series B220 is a 210 hp non after cooled engine. I am going to want something in the 225-250 hp range. Is there any rule of thumb to calculating the safe hp output with and without an after cooler?

 

After-coolers do two things:

1. On cooling the compressed air-charge exiting from the turbo, its density increases, meaning more mass / unit volume; should the the injection púmp be adjusted for delivering more fuel, an enhanced power output is perfectly feasible;

2. A greater temperature margin is afforded for the combustion in the cylinder, before limiting exhaust gas temperature (EGT) - that can damage the engine - is attained; say a non-after-cooled air-charge is typically 170 º C and an after-cooled charge is say, 100 º C, then you´ve gained 70 ºC and your engine is in safer hands !

As for safe output, it will depend also on mechanical / thermal constraints on piston-tops, cylinder heads, valve gear, con-rods and bearings, main journal bearings, coolant circuit efficiency and cooling of the lubricating oil.

Your best bet is to contact an outfit like TST that has heaps of experience on enhancing power in Cummins engines.

The other alternative is to pose your questions on Dieselpower magazine (published monthly) and see what they have to say.