Converting Delco 28Si to external regulation

[evm1024]

Yes, That is pretty much it. Of course there are not the diode trio in this alternator so you have an extra set of 3 diodes. But the rest is fine.

[Thomasx]

Thanks!

I am converting an old Balmar with an internal D101HD regulator to external regulator, using the MC614H.
Just wanted to be sure I get it right

[rom]

Originally Posted by evm1024

In my other thread (alternator choices) I was convinced to use a bus alternator rather than an other choice. One of the real kickers for me was the cost of a Delco 28Si 200 amp OEM alternator (less than $400 including shipping). And that I have the room in my engine room.

I went ahead and bought one and it has arrived. They are big! and that is good. Even though this is a 200 amp alternator I expect to run it at a "reduced" output of around 120 amps but we will see.

I will be driving it with a K6 (6 ribbed) serpentine belt which the engine is already fitted with (see the thread for that as well). The engine is a Perkins 4.236

The first task is to convert the alternator over to external regulation. This is not a hard task but for those who do not want to do it I would steer you to Mainesail who offers a beefed up version of the 28Si with the conversion already done.

Here are some photos of the alternator and the internal regulator.

Many thanks evm1024, very useful information ! FWIW, I have bought the same 28SI from Energy parts in Belgium, 190 EUR inc. shipping to France, exc. VAT. First test yesterday on my yanmar 4JH4E: 190 A @ 1500 rpm ! (about 3700 rpm at the alternator). That is with the original regulator, I will do some more test and will install an external reg asap.

[evm1024]

Always happy to share my experience.

Regards

[rgleason]

Evm1024, this is the alternator I would like to install. I have searched on line for good dimensions for this unit. Usually there are only one or two dimensions.

Would you be able to provide better dimensions? I would like to make a full scale model of it to determine how to fit it on my 3ym30.

Thanks
Rick

[evm1024]

Originally Posted by rgleason

Evm1024, this is the alternator I would like to install. I have searched on line for good dimensions for this unit. Usually there are only one or two dimensions.

Would you be able to provide better dimensions? I would like to make a full scale model of it to determine how to fit it on my 3ym30.

Thanks
Rick

I have a lot of room around my engine so I had no problem. You likely have looked at the sales stuff and the pdf spec. Thise are the best that I could find as well.

Alternators by Model Family | Delco Remy

http://www.delcoremy.com/getmedia/90...12-14.pdf.aspx

You will note that the pdf specs the overall diameter of the alternator as 154 mm. That is right around 6".

So I would suspect that if you were to use a 6" dia can you might get a better idea of the fit.

Regards - PS if you need a specific measurement I could take a tape measure to my alt for you.

[rom]

I am reviving this excellent thead from evm1024 after some interest arose in another thread (http://www.cruisersforum.com/forums/...207549-21.html) and I am thinking here is a better place to discuss that matter. I also took the liberty to reuse one of evm's pictures, hopefully he wouldn't mind...


Long story short I have successfully installed a 28SI (200A@12V) on my starboard 4JH4E but I have not yet installed a remote voltage regulator.


Now, I could certainly afford a sterling or balmar VR but I believe there is a better alternative. First and foremost because my main goal is to be able to shut down the alternator, I am not really interested in multistage, belt manager etc ... The reason behind is that I have enough solar about 11 months a year to recharge my battery bank, but I don't want to discuss that here, off topic.


I have modified the port alternator (Hitachi 80A@12V, really 30 to 40A) for external regulation, and am successfully using a 20EUR automotive external VR which also allows me to start/shutdown the alt from the saloon. I am now seeing 70A plus, I don't really care if I burn it, I am going to change it for a 28SI as well.


Could I do the same at starboard with the 28SI ? Yes of course (this VR is powerful enough for that) and that is what I initially wanted to do. But I would be loosing the thermal protection that we find in sterling or balmar VR, AND in the internal 28SI VR !

Okay, long story short I want to keep using the bespoke delco VR but I just need to modify it so I can start/stop the alt. I am thinking I could cut the BAT+ connector of the VR and supply it with an external Pos cable, itself connected to a relay which I will be able to start/stop exactly like port side. Sorry that was a bit long ... So, what do you think ?

[evm1024]

No problem posting here. Glad to be of help/inspire others.

The internal regulator on the 28si is powerful and does have external voltage sense. It can be run in many cases just as it is.

I'll have to dig around to see what docs I have. And leave to others to answer your question. (who have more insight than I do)

[andyalford]

I'm curious why you are not seeking to get a higher current from the 28Si, given the size of your 700Ah LFP batteries - you could charge them a lot faster if you wanted. And I would have thought the 28Si would be completely up for doing that?

You mentioned a write-up about your Serpentine Belt, but I cannot find it with search. For my own installation, I am considering MaineSail's version of the 28Si with a higher ratio serpentine belt for my installation to get a higher current at low RPM and better cooling for the Alternator, assuming that the alternator is rated up to the highest rev, and the Regulator is going to control the output to ensure the alternator does not burn up.

Mark Grasser at MGDC has a belt kit that follows this concept. I think you have to buy his Alternator with a fancy remote rectifier small frame alternator, which is nearly $3k. This is fine for light-weight racing boats with an unlimited budget, but I have lots of space in the engine room and less money(!)


UPDATE> I think I found answers to my questions here
http://www.cruisersforum.com/forums/...209089-35.html
Post #515 duplicated here, in case others are looking....

Originally Posted by rgleason

evm1024

My engine area is quite narrow, but I think raising the alternator several inches will help.


Perfect, this what I would like to do.
1. Alternator Choices, SI28 or 200A J-180mount we build here, the CMI-ED200-ER,
2. Converting Delco 28Si to external regulation
3. Who makes TAD and Serpentine Belt? (Uses a K6 Belt)


SW Diesel is in Boston!
TAD serpentine kits


Serpentine Kits CVF


I have another place that will custom make the crankshaft pulley.

[evm1024]

Yup, you found the serpentine belt writeup in #3 in the list (above).

Motivations for both converting my28Si to external and the serpentine belt install were to keep costs down.

My 28Si pulley was sourced from Mainesail and do recommend his 28Si based alt for those who do not want to DIY their own.

Yes, the 28Si is designed to run "near" full output and can handle more than I am asking it to do. My thought is that the alt max output (200 A) and my wiring (2/0) are a near match in terms of ABYC engine room ampacity so we are good there. Then I did some back of the napkin calcs for the alt running at "low" RPM in a hot tropical engine room and decided to derate the alt output to 120 amps or so. This was designed to keep the alt within a conservative temp envelope. Also, I expect to be pushing in significant solar when we start cruising and our current cruising profile typically has 4 hours of motoring every 3 day or so. We are not full time cruisers yet.

[rgleason]

Evm1024
Just saw your offer, still have not done anything about the alt. $800-1k seems a lot to pay for a good 160 to 200 ah alt that will be derated, so the 28si is very appealing. I need about 100ah-130ah/day and would like to use 200-300ah of battery (lithium or carbon) at a .3 to .35 charge rate. If I were able to charge at 100-130ah I would be very happy. I sense the 28si would work well if I can fit it. Your thoughts about this?

My main problem with fitting is the depth, because the 3ym30 has a heat exchanger that comes pretty close to the back end of the existing small case alt, so I need some good measurements for the depth of the alternator and the location of the front and back location and thickness of the support brackets, so I can really draw it up in the engine, and the make a cardboard mockup.

I do have some room off to the port side to mount the alt out further, but not enough to get the alt completely out there beyond that heat exchanger.

Also there are bolt holes in the 3ym30 flywheel pulley that might allow me to mount a 5.5" serpentine on the face and thus gain some depth by mounting the alternator further forward in the boat, away from the exchanger. The raw h20 pump and system water pump would remain driven by their evisting pulleys and there would be a dedicated serpentine belt for the 28si. What do you think?

"Regards - PS if you need a specific measurement I could take a tape measure to my alt for you."

[sailingharry]

Originally Posted by rgleason

Also there are bolt holes in the 3ym30 flywheel pulley that might allow me to mount a 5.5" serpentine on the face and thus gain some depth by mounting the alternator further forward in the boat, away from the exchanger. The raw h20 pump and system water pump would remain driven by their evisting pulleys and there would be a dedicated serpentine belt for the 28si. What do you think?

Your thought of mounting a serpentine belt on the FRONT of the flywheel pulley mirrors my thoughts on my 4JH2E.

The question I've not been able to solve is WHERE to get a pulley?


Any luck sourcing one?


Harry

[Q Xopa]

Originally Posted by sailingharry

Your thought of mounting a serpentine belt on the FRONT of the flywheel pulley mirrors my thoughts on my 4JH2E.

The question I've not been able to solve is WHERE to get a pulley?


Any luck sourcing one?


Harry

I got some machined up. My machine shop guy can knock em up no problems. I'd be pretty sure most reasonable machine shop guys can.

If you need any other help let me know.

[BlueHeeler]

I am in the process of fitting this alternator to my new Volvo D2-50 using the Volvo factory supplied 2nd alternator kit. The kit includes mounting bracket, tensioner bracket, K5 polyvee crank pulley with spacer, all bolts wiring harness and a belt. It’s designed for the 115 amp Volvo alternator but I’ve gone with a DR 28SI instead and am in the process of modifying to external balmar regulator following Evm1024‘s method. I’ve used a K8 alt pulley (2.5” dia approx) that I added to the order with alternator. The belt lines up nice about two grooves back from the end. I had to grind a little bit of metal off the j180 bracket webs to allow the alternator to sit down far enough and also bought a slightly bigger k5 belt - the Volvo belt is a 1054 and I changed it to a 1060. This 28SI drawing may be of help to those trying to figure out if this alt fits for them. The alt kit cost about €600 and the 28SI was a bit over €200 including K8 pulley.

[sailingharry]

Blue Heeler, this is GOLD! I've been looking and looking for more detailed dimensions of the 28SI, and can only find a side view with limited dimensions. With this, I can put together a cardboard mockup and see how it fits!


Thanks so very much!!