Alternator Mounting on Perkins 4-108

[bobfnbw]

Wanted to upgrade the 100 amp alternator on our engine when its rebuilt soon. Currently has balmar 100 amp with 1 3/8" belt. Since I will be using around 400 amp hours of TPPL Sears/Oddessy batteries with high acceptance rates, and may increase it to 600-800 amphrs in the future, would like to charge as fast as possible, hence a larger alternator.
I looked at balmar, electrodyne and leese neville. All are acceptable, but the balmar is my least choice based on others recomendations.
This leese looks promising
Brushless Alternators , 160 amp and 185 amp, 12 volt, are universal replacements | Prestolite News
But I wonder how to mount is. Currently I have 1 2" mount plus adjusting arm. This is either a 4" mount or a pad mount.
I could use the balmar mount Balmar Charging System Accessories but am not sure how to mount it in the engine room.
Anyone have this mount or seen it installed? How is it done? I plan on puttnig in a serpentine belt for this, should be fine with the 160 amps.

Thanks Bob

[James S]

This is CharlieJ using JamesS account...
You are limited to 100 amps on a 1/2" belt...increasing above the 100 amps will require two 1/2" belts. Your serpentine belt removes the consideration that, as a general rule of thumb, each 25 amps requires one horsepower. Thus a 185 amp alternator will require about 7+ horsepower. This is a heck of a side load on the water pump bearings.

You may have to consider a power take off of the crankshaft.

Best regards,
Charlie
The devil is in the details...

[slacker]

I have had good luck with Powerline alternators. 40% less $$$ than Balmars and very reliable. We have been happy with the 100 amp unit using a 1/2" belt.

At one time I was thinking of using a larger alternator and purchased a serpentine belt kit. TAD says that they are good for up to 200 amp alternators. My plans changed (honda generator) and would be happy to sell it. PM me if you are interested.

[hellosailor]

"serpentine belt kit. "
Serpentine just means it isn't a plain loop. USUALLY a serpentine belt is also a RIBBED BELT and that can take higher hp loads than a single v-belt, but so far you guys are simply confusing the issues. And modern serpentine ribbed belts often have an automatic tensioning device on them, which is nice until that also seizes up.

A 160hp alternator will not be drive by a single v-belt, and v-belts are almost impossible to find in auto parts stores because they've been obsolete for so long--except in odd applications like old boats. Changing from a v-belt to a ribbed belt could mean sending out a flywheel to the machine shop though.

[Redcoat]

You are going to cook everything if you have to motor for 10 hrs if you can't shut the regulator off.For a 400- 800 ah battery bank you only need 105 amps.Wire it directly to the bank and find the happy amp setting,

[slacker]

The serpentine belt kit for the 4-108 is a ribbed belt. Here is the link TAD for Serpentine Pulley Kits, Perkins 4.107 Pulley Kit, Perkins 4.108 Pulley Kit, Westerbeke 40 Pulley Kit

[hellosailor]

Nice retro kit! Kinda hate to push the "enquire" button to find out what it costs, but it is nice that someone out there is offering them at all.

[bobfnbw]

Thanks all for the responses.
Since I have to rebuild the engine, all new bearings, etc will be going in.
The serpentine belt is a good choice for this, If I go with it.
I do have some questions about loading a 4-108 with that much load.
I plan on using a gas generator honda or something like it so I could forgo the high amp alternator but would like to charge the oddessy batteries fast as they can take it.

[Davey1000]

I'd just like to give my ten cents worth on this topic. Allegedly there were two types of Perkins 4.108 engines built and allegedly the US models are different from the UK models. According to "Captain Bligh" the Ocean Cruising Club reckon that the basic Perkins 4.108 just had a single belt drive to its basic alternator. Allegedly the de-luxe Perkins 4.108 had a double belt driving an alternator rated at 90 amps or more. One fly in the ointment is that most replacement water pumps only have a single groove pulley but the de-luxe engine needs a double groove pulley on the water pump. In Europe the double belt set-up is so rare that it seems that no parts suppliers have ever heard of it. AFAIK one has to go to Foley Marine.

As to poly-vee belts, personally I don't like them at all as I have snapped quite a few on different cars. They usually fail when one is making a three point turn. (Its the power draw from the PAS pump that does it)

[Davey1000]

Originally Posted by hellosailor

"serpentine belt kit. "
Serpentine just means it isn't a plain loop. USUALLY a serpentine belt is also a RIBBED BELT and that can take higher hp loads than a single v-belt, but so far you guys are simply confusing the issues. And modern serpentine ribbed belts often have an automatic tensioning device on them, which is nice until that also seizes up.

A 160hp alternator will not be drive by a single v-belt, and v-belts are almost impossible to find in auto parts stores because they've been obsolete for so long--except in odd applications like old boats. Changing from a v-belt to a ribbed belt could mean sending out a flywheel to the machine shop though.

You NEVER go to auto-parts stores if you have any sense, you go to an Industrial Drive specialists such as Medway Power Transmissions. The local spot-lamp shop and boom-box seller just will not have what you need although they might have a good stock of furry-dice!

Medway Power Transmission Products | www.medwaypowertransmission.co.uk