Looking for Aftercooler for Cummins 6CTA

OCEANA · 03-25-2023, 07:16 PM

Mine is all pitted right up to the o-ring sealing surfaces so time to replace. Bundle fails the pressure soap test as well.

Cummins and SMX are way out on these and I want to get the boat operational again. I have good caps and can get the bundle, but the housing is elusive. I am hoping someone has one languishing on a shelf or wrecked engine somewhere....

Comodave · 03-25-2023, 09:28 PM

Good luck! I have one on emergency order with Cummins and they predict about 100 days as of a week ago. I guess supply chain problems. However in Cummins defense in the last week or so I have placed 2 different orders with them both coincidentally on Friday at 4PM. I received each order in 1 day on Saturday with free shipping.

lwarden · 03-25-2023, 09:50 PM

If you can’t wait a good machine shop could cut a bore in the housing and bond in an aluminum sleeve. Not ideal but I would think it would last a couple years or at least until the next service or you can get a new one. Bond the sleeve in with JB weld or other suitable epoxy with a few thousands gap.

Arc · 03-25-2023, 09:53 PM

If you can get the bundle , you could have the housing welded up. Then cut back down to size. It’s not that difficult to have done. It’s the same as boring a cylinder

Comodave · 03-26-2023, 01:33 AM

I think they had the core available, not absolutely sure. Call 800-CUMMINS.

OCEANA · 03-26-2023, 10:25 AM

I think I can get the bundle, not sure about welding since we don't know the exact metal used? I don't have a lot of knowledge about welding, esp repair vs fabrication

Lepke · 03-26-2023, 01:38 PM

There are probably after market after coolers available. In the past, with commercial sized engines, I found it usually cheaper to have heat exchangers and other parts custom built than pay the OEM price.

tpbrady · 03-26-2023, 01:46 PM

Depending on your use why not bypass it? 99% of my operations are without any boost, so the input air temperature and output temperature are not much different and a lot of the time it is cold enough the air heater doesn’t shut off (that’s why I pulled the fuse on it). I talked with my diesel guy and he didn’t think it was a bad idea and wouldn’t hesitate to do it as long as you kept out of the turbo. I always keep that in the back of my mind if that happens to my aftercooler while waiting for a replacement.

With your Hinckley that probably means running at hull speed, but gets you on the water until you get a replacement. I run my 6CTA at 1200-1400 rpm which gets me 7-8 knots. The only time I get into the turbo is to verify the cooling system is working correctly.

Tom

OCEANA · 03-26-2023, 02:05 PM

I would be happy to consider aftermarket if I could find one. Most outfits make HX, and oil trans coolers, but not AC

SMX is developing one, but having trouble with the quality of the castings..

OCEANA · 03-26-2023, 02:07 PM

Quote:

Originally Posted by tpbrady

Depending on your use why not bypass it? 99% of my operations are without any boost, so the input air temperature and output temperature are not much different and a lot of the time it is cold enough the air heater doesn’t shut off (that’s why I pulled the fuse on it). I talked with my diesel guy and he didn’t think it was a bad idea and wouldn’t hesitate to do it as long as you kept out of the turbo. I always keep that in the back of my mind if that happens to my aftercooler while waiting for a replacement.

With your Hinckley that probably means running at hull speed, but gets you on the water until you get a replacement. I run my 6CTA at 1200-1400 rpm which gets me 7-8 knots. The only time I get into the turbo is to verify the cooling system is working correctly.

Tom

Not a terrible idea at all, but I moved to this boat specifically so that I can get 10-12 knots when I want it...

Lepke · 03-26-2023, 09:07 PM

I don't know Cummins well, but there are new and used aftercoolers on ebay.

Check www.alibaba.com
Many Cummins parts and some complete engines are made in China. Probably why the long wait.

sunchaser · 03-27-2023, 04:39 AM

Quote:

Originally Posted by OCEANA

Not a terrible idea at all, but I moved to this boat specifically so that I can get 10-12 knots when I want it...

I had to bypass an after cooler a few tears ago for about one month. The 6C after cooler adds about 15% of the last HP as turbo boost climbs above 15 psi or so.

By keeping your boost low, monitor the EGTs and shoot each cylinder exhaust with an IR gun you should be easily able to keep the one engine running ok. Especially with the other engine as a template for comparison. Consult with SBar for the rationale of AC bypass as a check.

What are your thoughts as to the reasons for pitting and corrosion on the housing? A possibility is the PO doing an in place acid cleaning. Arcs idea on welding the housing is another SBar check, maybe they've done it before.

OCEANA · 03-27-2023, 09:12 AM

Quote:

Originally Posted by sunchaser

I had to bypass an after cooler a few tears ago for about one month. The 6C after cooler adds about 15% of the last HP as turbo boost climbs above 15 psi or so.

By keeping your boost low, monitor the EGTs and shoot each cylinder exhaust with an IR gun you should be easily able to keep the one engine running ok. Especially with the other engine as a template for comparison. Consult with SBar for the rationale of AC bypass as a check.

What are your thoughts as to the reasons for pitting and corrosion on the housing? A possibility is the PO doing an in place acid cleaning. Arcs idea on welding the housing is another SBar check, maybe they've done it before.

Well, I only have the one engine. The pitting and corrosion I suspect is from lack of maintenance and attention from the PO on a 25 year old AC. It is possible it was over zealously cleaned at some point. In the records there was some corrosion reference of the AC and HX about 10 years ago. I have fixed it for the future in two ways, first I disassemble and relube (with Tony's ALCO metal lube) AC/HX every two years, not a terrible job once you pull them out. Second, I put SBMARs SMX freshwater flush caps on the groco strainers. This is new for me, so I am very interested to see how it works over time.

I will ask SBMAR about the welding option, but they didn't mention during my last call to them.

Thx

Hornloaded · 03-31-2023, 04:08 PM

Quote:

Originally Posted by OCEANA

I put SBMARs SMX freshwater flush caps on the groco strainers. This is new for me, so I am very interested to see how it works over time.

I'm lucky, Tony and SBMAR are my neighbors. I added fresh water flush to both my Diamond 450's three years ago. They still look new inside. Just changing zincs at this point. I flush EVERY time I run the engines.

OCEANA · 04-17-2023, 02:19 PM

Quote:

Originally Posted by Hornloaded

I'm lucky, Tony and SBMAR are my neighbors. I added fresh water flush to both my Diamond 450's three years ago. They still look new inside. Just changing zincs at this point. I flush EVERY time I run the engines.

This is great to hear. Do you just connect a FW hose and run it for a few minutes? I heard caution might be needed with pressurized water, so I was considering a gravity feed of about 5 gallons FW after each use.