Anybody upgraded the alternator on a Cummins 5.9?

Particularly the QSB common rail engine as it appears to be crowded in the alternator area. I'm wondering what you found that fit. I'm looking at 160 - 200 amp externally regulated. Large frame would be best as it will last longer at those outputs, but it might be a tight squeeze.

Talk to these guys, they are expert at fitting alternators onto about anything.

ZRD - High Output and Dual Alternators

Hadn't seem that site, but their replacement (1st) alternators have quite modest output. There is no room on this boat for a second alternator which seems to be more what they concentrate on.

DDW, what will you be using as a regulator for the high output alternator? I would suggest being very careful about using a Balmar product as some of their gear can create electrical problems with the Cummins. You will know right away because the engine will run badly.

I upgraded the old Delco on my QSB-5.9 (2005) to the newer 165 amp Delco 24SI. You have to change the bracket and a couple of bolts, but it's a pretty easy swap. Let me know if you need the part numbers.

Dave, I read that on another thread somewhere, but the cause was never resolved and it sounded like it was a singular situation. Do you know of multiple instances? I would like to use the Balmar, it seems to be the best one. I've got two on the other boat.

Timeoff, thanks, that's part of what I wanted to know. It looked like you could swap the bracket from the 2" spool to the 4" J-180 which opens up the choices a bit.

DDW: I have 2 x Cummins 370hp and Balmar everything EXCEPT alternators, where Leece Neville is by far my favourite. No problems at all.


Check out the sbmar.com site: they sell a special bracket designed for 5.9's to take larger alts. They also have a terrific Forum and you can post engine-specific queries and photos (they like photos!) there and get commentary from one of the best Cummins shops in the business.

10+ years ago I upgraded my small frame to a large frame J-180 mount.

Great solution. I bought the mount from cummins directly. Back then it was around $40.

Changed the belt and used a generic NAPA tensioner arm and it has been working flawlessly ever since. Runs substantially cooler than the small frame unit ever did.

I run a 200A Alternator along with a Balmar ARS-5 regulator. My motor is vintage 1996 so don't have the fancy electronics which the OP references.


good luck

The 24 on a QSB, is a direct bolt up. No changes. I have a 160 amp, that was installed 2 seasons ago. Pluses, charges higher at lower RPM, also has fan front and rear, so cooling is better. You can buy a replacement for OEM at most auto shops for less than 200 bucks. I purchased one to get by, while in Alaska, until I received the 24 which was over 400 dollars. Keep the auto parts one for spare, original was toast. Check SBAR marine in California for details.

DDW said:

Dave, I read that on another thread somewhere, but the cause was never resolved and it sounded like it was a singular situation. Do you know of multiple instances? I would like to use the Balmar, it seems to be the best one. I've got two on the other boat.

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The PO of my boat had issues with both a single stage Balmar regulator and I had problems with a Balmar Duo-charger. 2009 build QSB 5.9.

Best advice would be to check with Seaboard Marine and ask them. Sbmar.com. They will be able to give you the definitive answer and sell you what you need.

DDW said:

Timeoff, thanks, that's part of what I wanted to know. It looked like you could swap the bracket from the 2" spool to the 4" J-180 which opens up the choices a bit.

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Yes some of those engines can fit a J180 but J180's are all over the map in actual frame size. If you can get the 4" J180 mount for that engine the alt below may be of interest.. CMI-ED200-ER




.

The 24 and newer (J180) bracket would swap on, but it isn't externally regulated, and I'd be skeptical of its ability to produce 160 A continuously. Most of the Delco and other automotive sourced alternators were designed to keep a starting battery charged, which is very light duty compared to what we ask them to do.

It's the size of the large frame J180 alternators that I'm concerned about. On the QSB (as compared to the mechanical version), there are hoses and pipes and brackets that surround the alternator, limiting the space available. Most of the aftermarket alternators are not available off the shelf to hold up to your engine, they need to be ordered in, then sent back which gets time consuming and costly.

I will talk to SB, but would like to know as much as possible before I do that.

Timeoff said:

I upgraded the old Delco on my QSB-5.9 (2005) to the newer 165 amp Delco 24SI. You have to change the bracket and a couple of bolts, but it's a pretty easy swap. Let me know if you need the part numbers.

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HI, Like part numbers, particularly of bracket, pulley and belt if you still have them around. In Aussie and Cummins not very helpful. Thanks

The early QSB engines where equipped with a Delco 19Si alternator, which has a 2” foot solid. Around 2007 or 2008 they changed to a 22si alternator with the 4” split foot, also known as the J180 mount. All large frame alternators like the Balmar 95 are J180. Even in the early years, the 22si with a J180 mount was offered as an option by Cummins, so the parts exist and are a bolt in replacement. The two parts needed are the alternator base pn 3969163 and the support arm 3971982. Skip the Cummins bolt, pn 3903105 and nut 3903210. These are just a 12mm bolt but unthreaded for the portion that bears on the alternator, an ordinary grade 8 1/2" x 6" bolt works and fits better for far less. These parts will cost a bit under $200 as they say Cummins on them . These are shown as not available by Cummins distribution, but can be special ordered by having the dealer call the factory.

I was able to fit a 28si, 160A. This was converted to external regulation using a Balmar 614. It will actually only do about 120A continuous, after it is derated with temperature.

QSB Alternator upgrade

Many thanks for the info. It was exactly what I was looking for and found supplier in US with parts off the shelf. Upgrading to the J180 later type has to be a better proposition than continuing to chase the 19SI type that are only available as an aftermarket if you can find them m here. Interestingly, the genuine 28SI is nearly half the price of a knock-off 19SI here locally. Previously (on another boat) had a big frame Leece-Neville 'school bus' brushless alternators and they were bullet proof and would produce full rated amps all day. Can't see any way of squeezing them in amongst all the stuff on the side of the QSB. Many Thanks.

Squeezing a big frame in might be the problem. The 28 Si fits with about 4 mm clearance on both sides. On the other hand, if you have the QSB with the optional remote oil filter, and the filter lines are in the way, it is possible (I was assured) to simply remove the remote mount, lines and adapter and fit the filter to the original mount. This eliminates the oil lines which wrap the alternator, (on my boat) improves access to the filter, and (again I am told) increases your oil pressure by a couple of psi.

An interesting approach I hadn't thought of. For now, if I can get a 28SI on and get something in 100+ amps continuous, I will be happy. We are in tropics with lots of refrigeration and a/c so a fair bit of gen set running when not travelling or a/c on and charger does a good job on bringing batteries back up. Local support for smarts or parts is pretty skinny so don't get too adventurous.