CUMMINS 6BTA REPOWER AUTOMOTIVE

[andyvinkus]

I have a 1937 retired Canadian Fish Tug.  Currently powered by a Perkins 6.354 N/A.  The tug is keel cooled with dry exhaust.  I’ve purchased a 1993 Cummins 6BTA CPA 1579, with low miles/hours that I’m looking to repower with.  For the most part this conversion should be straight forward with already having dry exhaust and the keel cooler.  Where I’m hung up, is on the aftercooler.  Is the aftercooler required if I’m plumbed to outdoor air?  If the aftercooler is needed, do I need to run an additional cooling circuit for it?  The motor did not come with the aftercooler and I’m wondering if anyone has expertise in this area.  

Topic

[Tony Athens]

Original aftercooler on the engine was air to air or coolant cooled?  Some good pics on the engine would answer that for me..

Original engine rating was? (HP & RPM?)   

What are you expecting to gain over the Perkins you have now?   

Any good 6BT 5.9 with a good working turbo,  set up right can make  up to about 150HP in the 2400 RPM range without an aftercooler at cruise,  using about 8 GPH of you want to run that hard… 

[pwrobert]

A second thought

Possibly your keel cooler wouldn’t have the captivity for the extra heat from the extra HP. Also the water intake requirement would need addressing most likely. 

[pwrobert]

Yes in short you can.  But why.  Only reason I see to take off an otherwise good aftercooler is to avoid the preventive maintenance.  I’ve had normally aspirated, turboed and now turbo aftercolled engines over the years.  Aftercoolers don’t add any more weight over a turboed engine and the extra HP is “free” power and fuel efficiency when needed.

Back in the day I was looking for a way to add an aftercooler to my old Detroits but never did..  My Cummins 6BTA 370 have one and taking it off would be a huge HP hit.  If all you do is trawl there is still a savings when loaded and pushed on occasions.

All the 5.9L engines weigh the same, have the same footprint.  I’m not saying there are not personal mods that people can make – I put on different than stock thermostats, took off the fuel cooler, added Tony’s enviro kit for starters.  I guess it depends on what you want to accomplish and are willing to give up.

My boat had 8.2L 200 HP engines and now has 5.9L 355 HP engines and I took away 1500 puonds.  End of the day I go faster, better miles per gallon and gallons per hour.  Mostly thanks to the aftercoller even though I gave up almost 2L in displacement per engine.

That’s what I love about boating – we each have our own and can do with them what we want.  I’ve had mine 30 years and more than one of my “experiments” have bitten me back and I had to go back to prior setup.  But the tinkering is half the enjoyment.

[andyvinkus]

Bta

Thanks for the feedback. I don’t think I was clear.  The engine is originally a 6BTA (aftercooled).  I was questioning if I can get away without installing an aftercooler on an engine that is an aftercooled model.  

[pwrobert]

More differences

There is more to a 5.9L engine than just the bolted on accessories that make up the different HP models.  Putting an after cooler on an earlier engine will not make it a 6BTA.  As far as having cooler outside air it is always nice for general cooling of the engine room and such but the heat that the after cooler is there to work on is from the heat generated from compressing normal atmospheric air pressure to the higher a nd more dense air going into the cylinders.  That heat has little to do whith whatever the outside air temp is and more to do with the amount of compression the Turbo is producing.

My understanding is that the Cummins Diamond 370’s have different pistons, rings, fuel pump settings and more.  Bolting on an aftercooler to an engine not intended for it will run but I’m not sure of it’s longevity and will likely fall short of the sought after 355 HP that a “realDiamond 370” produces.

 

 

[Author]

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