Converting Delco 28Si to external regulation

[rgleason]

Thank you Q xopa. That is a very nice HD install!

I think you've answered my question as 1/2" clearance is to little for good airflow, even if the manifold is involved for just 20-25% of the back of the alternator.

I think I'll have to plan on mounting the alternator 1" further forward in the boat and have a 1" spacer between the pto and new pulley.

Or perhaps build a taller mounting bracket to lift the alternator higher and away from the manifold.

[Q Xopa]

Originally Posted by rgleason

Thank you Q xopa. That is a very nice HD install!

I think you've answered my question as 1/2" clearance is to little for good airflow, even if the manifold is involved for just 20-25% of the back of the alternator.

I think I'll have to plan on mounting the alternator 1" further forward in the boat and have a 1" spacer between the pto and new pulley.

Or perhaps build a taller mounting bracket to lift the alternator higher and away from the manifold.

Yes it takes a bit of messing around with. Most people dont want to tackle this but it is really not that difficult. I find it preversly sstisfying.

Yes sounds like you could just add an extra little spacer link to get it where you want it.

Depending on how fussy you are you could just drill and bolt or weld, or make a new one.

Yes that is what I am chasing at the moment. As you can see from the pic attached my pulleys need a bit of aligning.
Ive measured for my belt lengths and theyre coming.

Ive also measured how far back and forth everything is in relation to each other, with a straight edge.

Now just making up some spacers. Maybe some longer bolts. I reckon its worth turning up some nice wide spacers with the right size holes etc.

Cobbling this together with washers has it all flooping around. Its worth the effort to keep everything nice and solid.This is relatively the easy part.

[rgleason]

Nice photo of the pulleys. I need to just get hands on with it I think.

Since I am considering and have shown direct from pto pulley to alt pulley, and I now need to move the alt further forward for more back clearance from the manfold, an idea by A24 might help to provide a higher alt rpm and permit adjustment of belt tension as well.

Between the flywheel an alt insert a double pulley on a common shaft with a bearing. The inside pulley would be 2" and accept the belt from the pto flywheel. The outside pulley would be 3" to 3.5" and go to the alt pulley, thus increasing rpm and moving the alt forward. This middle pulley would have an adjustible plate for belt tension.

I need to draw this better.

[Mexbungalows]

As a retired alternator design engineer may I offer a suggestion? A serpentine belt tensioner may offer an option that allows an alternator to be hard mounted against the engine eliminating the need for space for arc tensioning. Any automobile salvage yard can be a worthwhile source. Replace the used bearing with a quality bearing like an NTN LUA.
I am not a boat owner but I have built draggers and crabbers to 130' and revamped many cruising salboats to 85' in length. However make no mistake, I am not only over-the hill, but have crossed the bottom on the other side. My boarding and debarking days are long gone.
One option not mentioned is the hairpin stator design alternator which offers higher power to size and weight than a conventional wind. The ND offers 100+ amperes cold in a package the size of a 60 ampere older alternator. In my off grid and bus application I have a 400 ampere 28 volt Niehoff powered by an NTC Cummins engine, and a Delco 50DN air-cooled alternator powered by a 2-cylinder air cooled Lombardini engine. Both have external rectifiers. The rectifiers are plating industry 1275 amp (each) 1600 PIV units. They require 4/0 cable. Unless a vessel can handle Brontosaurus size components these units are not viable. They do feed 1,650 A/H Rolls & Surrette twinned 2-volt cells a total of 24-cells. Again, 28-volts.

[rgleason]

Thanks mex bungalows. Will consider that but my real problem is air flow clearance between the manifold and aft end of the alt.

[Cdn]

Originally Posted by 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....

Anyone know if Mainesail is still selling these? Can not find them on the web store on the site.

[evm1024]

Originally Posted by Cdn

Anyone know if Mainesail is still selling these? Can not find them on the web store on the site.

You can ask him. Here is the link for the alternator:

https://shop.marinehowto.com/product...uty-alternator

[Cdn]

Disregard the above post. I found them. Didn’t realize it was large case. Anyone know if there is any off the shelf kits so I can install two of them on a 4JH80?

[rom]

Originally Posted by Cdn

Disregard the above post. I found them. Didn’t realize it was large case. Anyone know if there is any off the shelf kits so I can install two of them on a 4JH80?

Yes, from yanmar:
https://www.yanmarshop.com/catalogue...g-47-generator
https://www.yanmarshop.com/catalogue...or-kitoptional

[Cdn]

Originally Posted by rom

Yes, from yanmar:
https://www.yanmarshop.com/catalogue...g-47-generator
https://www.yanmarshop.com/catalogue...or-kitoptional

Thanks Rom. These fittings will hold the Relco 28si? I was under the impression that this alternator was larger than the stock alternator..

[rom]

Originally Posted by Cdn

Thanks Rom. These fittings will hold the Relco 28si? I was under the impression that this alternator was larger than the stock alternator..

My engines are 4JH4E and I can't tell for the optional second alternator as I only have one per engine. I replaced my hitachis with 28SI which are indeed much larger ! looking back it was much easier than I thought it would be, and rather inexpensive. I spent a lot of time on that project though, so if your time is more valuable than mine you may ask someone to do it for you. A local shop made the spacer and modified the tensioner, I found the rights bolts quite easily, the 6PK belt that"s right for me is 1250mm.

[Q Xopa]

Mine is a 4JH4-TE. I have the Yanmar optional extra mount bracket on the RHS. I have fitted a 28si in the original position, LHS, and on the optional additional, (ie RHS).

I'm not familiar enough with the differences with the 4JH motors. But I assume they'd be pretty close and are likely to fit.

I agree with ROM that it has taken me some time and messing around. Having said that it has been actually relatively easier than I expected. And certainly quite inexpensive.

I got 8 groove pullies machined up.

I then measured and ordered the correct length belts.

I spent some time playing around with the pulley alignments and as ROM says got my machine shop to make some nice solid spacers. You could use washers, but IMHO, get a much nicer, more solid setup with nice tight solid spacers. This is what keeps the belt alignments true. So worth the effort.

I also agree that the adjuster brackets took a bit of playing with, mixing bits to get a setup I am happy with.

I will be back at the boat tomorrow and try and get some pics of my setup for you.

I'm nearly done with it, and will compile a bit more of an organized list of the parts that I've used. I'd assume they would be close to what you would need.

I'm happy to help you with any other details you might want. Bolt lengths, belt lengths, spacers made etc. But even better, if your interested, I can point you in the right direction to measure yours so yours will be exactly right for your motor.

All I use is a measure tape, straight edge and a digital vernier caliper (maybe $20 at your local tool shop).

[Q Xopa]

It was too dark last night, but got some pics for you today. They are pretty much in place ok save a few washers I ran short of.

2 x 28si's 24V, 110A, on my 4JH4-TE.

I put the Gates 8 rib belt Part numbers in the pics of the belts that fit my install (obviously might be different for yours).

The crank pullies are about as big as I could squeeze on the front of my motor. Then I got the smallest alternator pullies available to have them spinning as fast as I could. I went with bigger Water pump pulley to keep that speed about the same with the bigger crank pullies.

All in all it was a bit of chasing around but in the end not that difficult. Any one up for some DIY it was a fun project.

Not that you can buy a comprable 'off the shelf' kit, (that I'm aware of), and I looked. But anything similar was very generous numbers. Without a proper add up, just off the top of my head, I'm into this somewhere in the $1,500-2,000 range.

Any other details you want just let me know.

Cheers.

[Cdn]

That’s looks great!

Why did you go with 24v vs 12v. Is their an advantage to 24v?

What size is your bank?

What amps are you getting while running?

[Q Xopa]

24V is half the Amps, therefore half the heat losses (in rough terms). So great for high current devices like Inverters and Windlasses. More commonly done for bigger boats.

I'm mid refit at the moment and havent quite got to my batteries yet. I'm pretty sure about LFPs but still deciding on exactly which ones and how big etc. I am leaving this to last, but have done everything else in preparation- programmable chargers, heavy wiring and bus bars etc.