Perkins 4-108 Alternators

[Tomek-N41]

Hallo every body, I have problem with a alternator, what type belongs
to Perkins 4108 and what amp. Please help me

[GordMay]

Perkins usedmany different altrernators, including AC-Delco, over the years.
The 4-108 was usually fitted with a 55 Amp Alternator.

See Also ➥ perkins alternators, perkins engine parts alternators, perkins parts, perkins engine parts, diesel engine and parts, engine parts, diesel engine parts

As detailed below, the Alt' was a Delco "10SI"

[Tomek-N41]

Hallo Gord, thanks for the information's, I tried four different alternators by delco ( gmc-chevy 1978-1986 the same bracket ) and then I found out thad my electric wiring is screwed up by "electrician" from Mariner place on Alameda. So far cost me
~ $1500-. to rewire the Newport 41s, also I have to by pas electronic regulator (very complicated with lots of functions) be-cos was making the alter.. working 17.5 volt &
drying the battery, so I thing to used only the internal alter.. regulator, different electrician told me that I burned tachometer by connecting wrong to alter.. I am frustrated. Sorry for not responding long time, on top I was sick to my stomach, ahoy Tomek N41s

[Tomek-N41]

Originally Posted by Tomek-N41

Hallo Gord, thanks for the information's, I tried four different alternators by delco ( gmc-chevy 1978-1986 the same bracket ) and then I found out thad my electric wiring is screwed up by "electrician" from Mariner place on Alameda. So far cost me
~ $1500-. to rewire the Newport 41s, also I have to by pas electronic regulator (very complicated with lots of functions) be-cos was making the alter.. working 17.5 volt &
drying the battery, so I thing to used only the internal alter.. regulator, different electrician told me that I burned tachometer by connecting wrong to alter.. I am frustrated. Sorry for not responding long time, on top I was sick to my stomach, ahoy Tomek N41s

[CSY Man]

I have problem with a alternator, what type belongs
to Perkins 4108 and what amp. Please help me

Help is on the way..

Got a Proline 150 amp alternator attached to my Perkins 4-108.
Using a Proline 3 stage voltage regulator and a Proline isolator.

The system is bullet proof, had no problems in 11 years of use except adjusting belt and servicing alternator with new bearings. etc.

Tried to Google Proline just now, but can't find 'em.
They may have changed name or be out of business.

Balmar is also good, but seems to be twice the price...

[Sharkman]

We had a Motorola 55 amp on our old 4.108 which I believe was standard on the later models.

When it quit we replaced it with a Leece-Neville of around 100 amp, but had problems, and in the end fitted a Balmar 110 amp which is still working fine with the new owner. It took a little playing around with different pulley sizes to get the best out of it, and it was hard on belts, but worked very well. It was also a simple direct fit replacement.

[btrayfors]

Tomek N41,

Sorry you're so frustrated, but you need to step back and take a look at your entire DC system, not just the alternator.

The type and sizing of an alternator depends not so much on the engine, but rather on the type and size of your house battery bank. What came originally on the Perkins 4-108 may be almost totally irrelevant.

I have a 4-108 on my boat, too. I have a house bank consisting of six Trojan T-105 flooded lead acid batteries, totaling 675AH capacity. Ideally, I'd want an alternator with about 25% of that capacity, or 170 amps. My setup, however, is smaller but has worked well for over 10 years.

It consists of a Balmar 100 amp alternator with a Balmar MC-612 external regulator. An external regulator is mandatory if you want to take advantage of the amperage capacity of your alternator. The MC-612 is one of the best regulators on the market. And, since they've now come out with a new model which can handle two alternators, the original regulator is available at big discounts and is an excellent buy for those who don't plan to fit two alternators (check eBay).

One limitation of the 4-108 in fitting a larger alternator is the belt type and size. The stock Perkins uses a 1/2" belt, and it's on the same power train as the water pump">raw water pump. Most owners have found that 100-120 amp alternators are about the largest you can fit with this configuration. A larger alternator would mean you'd have to fit another pulley, mount, etc.

So....assuming your boat has a house battery bank typical of a 40-footer, you'd probably want to fit a 100 amp alternator with an external regulator in order to have the best charging system you could without doing major surgery on the engine.

One final note: the above pertains mostly to flooded and gelled battery types. AGMs are a whole different thing. Because AGMs can accept huge charging currents, they can also tax your alternator to the point of burning it out....unless you take pains to ensure that current is limited and temperatures are monitored. The MC-612 and other similar regulators can do this, by monitoring alternator temperature and by de-rating the alternator's output to any value you choose.

Bill

[DeepFrz]

I have no experience with PennTex but have seen others recommend their alternators on this forum. They took over another heavy duty alternator manufacturer (Proline?). Their product looks pretty good.

PennTex Industries, Inc.

[CSY Man]

I said Pro Line alternator above, but I meant to say Powerline:

Hehr Power Systems: Electrical Products Manufacturer

[svusha]

I have an adverc battery management system running 2nos. 60 amp lucas 127 alternators. so far its been fit and forget. If I had to change something it would be to exchange the single V type belts to serpentine types and pulleys of course.
Adverc Battery Management - Adverc Systems