Converting Delco 28Si to external regulation

[BlueHeeler]

Originally Posted by 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!!

No worries. Glad to help.

[SweareDeep]

Originally Posted by 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.

I've been considering installing the Volvo Penta second alternator kit on my D2-75. However, I've been frustrated by the lack of detail available from V-P: it will be a tight fit in my engine compartment and I can't really tell if it's too tight without knowing the thickness of the spacer between the crankshaft pulley and the pulley supplied with the kit.

The kit (P/N 21384685) is around $1700 in the US, so if it can be found for €600 I'll buy it in euroland.

[BlueHeeler]

Originally Posted by SweareDeep

I've been considering installing the Volvo Penta second alternator kit on my D2-75. However, I've been frustrated by the lack of detail available from V-P: it will be a tight fit in my engine compartment and I can't really tell if it's too tight without knowing the thickness of the spacer between the crankshaft pulley and the pulley supplied with the kit.

The kit (P/N 21384685) is around $1700 in the US, so if it can be found for €600 I'll buy it in euroland.

Combined with bolt heads it extends my crank pulley approx 47.5mm on the D2-50. I think this is only about 10mm or less further forward than the front of the pulley on my coolant water pump and sea water pump. I was surprised how well it fit. The price I got for the kit was alongside the supply of the new engine. However I’m sure euro price is way cheaper than US$1700.

[SweareDeep]

Originally Posted by BlueHeeler

Combined with bolt heads it extends my crank pulley approx 47.5mm on the D2-50. I think this is only about 10mm or less further forward than the front of the pulley on my coolant water pump and sea water pump. I was surprised how well it fit. The price I got for the kit was alongside the supply of the new engine. However I’m sure euro price is way cheaper than US$1700.

That's very helpful indeed. Many thanks!

[BlueHeeler]

So I fired up the new d2-50 today with the DR 28SI mods finished and fitted on the Volvo Penta factory produced second alt mounting kit. Using the old external balmar MC614 and with battery SOC at about 82% the alternator kicked off at around 90 amps rapidly stabilizing at about 55amps at 1500 engine rpm. After about 20 min the alt was still cool enough to touch. The old motor was a Volvo md22 and had a large case balmar 94 series 210 amp fitted on top of the engine on a dodgy homemade mounting (fitted by previous owner). I tried to strengthen this mounting system several times after breaking various mounting points which seemed to just transfer stress to the next weak point every time. This was one reason on my decision to go with the factory mounting on the new engine. The factory mount is designed for the Volvo internal regulated 115 amp alternator which is significantly smaller than the delco remy 28SI.
Many thanks to evm1024 for showing me his detailed instructions on the regulator modification.

[FAST FRED]

If there is room the lowest cost 135A alt is a new unit from an OTR (18 wheeler) truck place. Large frame units.

Mostly Leece Neville units with no V reg , just the wire to install your own.

These are happy to run at their rating ,full time.

A pulley and a proper rotation direction fan are also needed.

If rewiring,, a rotary battery selector switch that includes a field disconnect is wise to install, it can save the alt diodes should someone disconnect the batts with the engine operating.

[sailingharry]

Originally Posted by BlueHeeler

So I fired up the new d2-50 today with the DR 28SI mods finished and fitted on the Volvo Penta factory produced second alt mounting kit.

I am so jealous! The clueless dolts at Yanmar motors haven't figured out that a factory built second alt mount would be an awesome accessory for a marine engine! So I'm left figuring out dodgy home built options (which I am pulling up nadda on so far....). LOL

[evm1024]

Originally Posted by BlueHeeler

So I fired up the new d2-50 today with the DR 28SI mods finished and fitted on the Volvo Penta factory produced second alt mounting kit. Using the old external balmar MC614 and with battery SOC at about 82% the alternator kicked off at around 90 amps rapidly stabilizing at about 55amps at 1500 engine rpm. After about 20 min the alt was still cool enough to touch. The old motor was a Volvo md22 and had a large case balmar 94 series 210 amp fitted on top of the engine on a dodgy homemade mounting (fitted by previous owner). I tried to strengthen this mounting system several times after breaking various mounting points which seemed to just transfer stress to the next weak point every time. This was one reason on my decision to go with the factory mounting on the new engine. The factory mount is designed for the Volvo internal regulated 115 amp alternator which is significantly smaller than the delco remy 28SI.
Many thanks to evm1024 for showing me his detailed instructions on the regulator modification.

Very nice install. My 28Si runs quite cool at 120 amps into LiFePO4. Happy to see others doing the mod.

[rom]

Originally Posted by sailingharry

I am so jealous! The clueless dolts at Yanmar motors haven't figured out that a factory built second alt mount would be an awesome accessory for a marine engine! So I'm left figuring out dodgy home built options (which I am pulling up nadda on so far....). LOL

https://www.yanmarshop.com/catalogue...generator-atta

[sailingharry]

Yes, someone else PM'd me that. Unfortunately,it's for the 4JH4 series. My 4JH2 is going to be a challenge to make it fit. The crank pulley is 3 bolts, mine is 4. Harder to fix, the mount on the back side seems to go where my injector pump sits.


Still, worth considering.


Note, when I asked my local (but large) yanmar shop, they didn't even suggest this.

[Q Xopa]

Originally Posted by sailingharry

Yes, someone else PM'd me that. Unfortunately,it's for the 4JH4 series. My 4JH2 is going to be a challenge to make it fit. The crank pulley is 3 bolts, mine is 4. Harder to fix, the mount on the back side seems to go where my injector pump sits.


Still, worth considering.


Note, when I asked my local (but large) yanmar shop, they didn't even suggest this.

Yes the Yanmar guys I have dealt with have seemed to not know or care much about the product range. I guess this is an all too common attitude these days unfortunately.

The Yanmar mount listed above looks similar to my Yanmar mount but not exactly the same. That one has the pivot at the top and adjuster at the bottom. Mine is the other way around.

I can see that they are picking up on the same 4 bolt holes in the block to anchor the mount.

But either way Im sure makes little difference. Perhaps on mine it might be easier to get to the top of the motor to make belt adjustments than down the side of the motor.

We have a lot of details to go on. For starters we know that and where they can be fit.

If you like I can get an pretty accurate measurement on mine where my lower Alternator pivot mount point is positioned in relation that lower RHS front of the block.

If you can see what reasonably solid anchor points, ie bolts holding a cover plate or something similar or empty bolt holes in that area. Even if you dont have space between the injection pump to fit nuts it still is most likely to be doable with a little creative construction. It shouldnt be that difficult. The Standard Alternator LHS mount is only secured at one point by a M10 (on that diag above where it says 'Fig 2') as opposed to this Optional RHS mount which is secured by 4 bolts M8.

If you can get a pic of that lower RHS front area of your motor, I'll be happy to have a look and most likely come up with some ideas for you.

As for 4 bolts instead of 3. My machinist can whip these pullies up pretty easily. Some he has made for me he simply gets others I have given him and he makes hubs to suit mine he screws in place. All done in a lathe so its all concentric.

Im confident we can get something going and happy to help if you can get us some more details.

This stuff isnt an off the shelf option, but it also isnt actually that difficult.

[wsmurdoch]

The picture of the alternator mounting kit on page 9 has three bolts... http://dan.mackboring.com/CMFiles/Do...iesCatalog.pdf Maybe they have more bits than they have catalogued.

I had a MACK 456 (3MH35F) pulley turned down to a smaller v-groove diameter to drive a refrigeration compressor. My other option was to use an adaptor that I bought for a standard 5/8" bore v-belt pulley. It is just a piece of 1/4" plate that bolts to the forward face of the standard engine pulley with a 2" long piece of 5/8" keyed shaft welded into a hole in its center. Any hardware store pulley would fit it.

Bill

[rgleason]

I like this idea.

It is just a piece of 1/4" plate that bolts to the forward face of the standard engine pulley with a 2" long piece of 5/8" keyed shaft welded into a hole in its center. Any hardware store pulley would fit it.

I've used BlueHeeler's post #29 with the 28SI diagram with dimensions to check my drawing for a Yanmar 3YM30 with a Delco SI28 Alternator with a four hole serpentine pulley secured to the face of the standard flywheel pulley. The original drawing appears to be pretty accurate. The back clearance is about 1/2" from the back of the alternator case to the manifold.

I see how clear the back of the alternator is in BlueHeeler's Post #35 and it makes be concerned that 1/2" is not enough clearance for good airflow, and the terminal bolts may also become a problem.

Are there any thoughts or suggestions about this?

I suppose I could put 1" thick or 1 1/2" thick spacer between the original flywheel pulley and the new serpentine pulley to make more room at the back of the alternator. Any thoughts about that?

[rgleason]

Does anyone know if conversion of SI28 alt to external regulation and diodes will give me more room at the back?

Approximately how much?

[Q Xopa]

Originally Posted by rgleason

Does anyone know if conversion of SI28 alt to external regulation and diodes will give me more room at the back?

Approximately how much?

Im not currently near my boat at the moment.

Im guessing space is tight so this isnt the response you want.

But off the top of my head, and (pic of my installation Im working on), attached, I would say no.

Firstly the black plastic rear cover is the most rear point, except the terminals.

So the terminals are the most rear points, although obviously not all of the back area.

Even with the back plastic cover off, from memory the internal voltage regulator is still within the bounds of the case. So no extra clearance to be gained removing the Internal Voltage Regulator.

It also depends on exactly how you 'remove' the internal Regulator. Most Ive seen, like 'evm1024's #1 post on this thread (very nicely done IMO, thanks), remove the original regulator and put another board to mount the connection studs etc. Definnately worth having another look at his initial posts.