Having serpentine pulleys fabricated for alternator upgrade?

[mrybas]

Hi,
I have a Nanni 3.21 and would like to upgrade the stock alternator. The existing alternator uses a 3/8” V-belt.
I haven’t found anyone that makes a serpentine pulley kit for the Nanni 3.21.
Can anyone recommend how to get serpentine pulleys fabricated? I guess my best bet is to take the existing v-pulleys to a machine shop and see if they can fabricate serpentine pulleys?

[Sailmonkey]

What engine is the 3.21?

I purchased pulleys from Beta for our Phasor p3-28-05 because it’s the same engine as a beta 30.

[mrybas]

Originally Posted by Sailmonkey

What engine is the 3.21?

I purchased pulleys from Beta for our Phasor p3-28-05 because it’s the same engine as a beta 30.

The Nanni 3.21 is based off of a Kubota D-722. I tried contacting Beta Marine,as they use the same/similar block, but they said they didn’t have anything that would work for the 3.21.

[mrybas]

Originally Posted by Sailmonkey

What engine is the 3.21?

I purchased pulleys from Beta for our Phasor p3-28-05 because it’s the same engine as a beta 30.

I just called Beta again and talked to someone different. He said they block may or may not be the same even though both the Nanni 3.21 and Beta 20 are based of the Kubota D-722. The marinizing/plumbing for the raw water on the Beta is certainly easier for the larger K-6 Serpentine pulleys.

[Sailmonkey]

I’d be tempted to remote mount the fuel filter, then turn the water pump">raw water pump 00 degrees to accommodate the pulleys. I remote mounted our fuel filter years ago, it’s been a positive change!

[mrybas]

Originally Posted by Sailmonkey

I’d be tempted to remote mount the fuel filter, then turn the raw water pump 00 degrees to accommodate the pulleys. I remote mounted our fuel filter years ago, it’s been a positive change!

Yeah, that’s what I was thinking too.

Hopefully Beta will sell me their serpentine pulleys and they will fit on my Nanni without too much hassle.

[rbk]

If anything make sure the shafts on the beta are slightly smaller than your Nani and you can have them turned out to fit your shafts by any machine shop for fairly cheap. Better than having some fabricated from scratch.

[Nemesis33]

Originally Posted by mrybas

Hi,
I have a Nanni 3.21 and would like to upgrade the stock alternator. The existing alternator uses a 3/8” V-belt.
I haven’t found anyone that makes a serpentine pulley kit for the Nanni 3.21.
Can anyone recommend how to get serpentine pulleys fabricated? I guess my best bet is to take the existing v-pulleys to a machine shop and see if they can fabricate serpentine pulleys?Attachment 209485

Try these guys: https://electromaax.com/

[Locquatious]

See markgrasser.com An advantage of his pulleys is that you can use belts that are sold in regular auto stores.

[Nemesis33]

Originally Posted by Locquatious

See markgrasser.com An advantage of his pulleys is that you can use belts that are sold in regular auto stores.

Same with Ekectromaax. I have theirs on my Nanni 3.30. They use a stock Gates automotive belt.

[bcboomer]

I had a machine shop make serpentine pulleys for my crankshaft and water pump.
They are sleeved over the old ones and I was able to change the ratio so I could speed up the alternator and get more power at low rpm.
My engine is a Westerbeke marinized Mitsubishi but the principal is the same.
The pic is sideways but you get the idea.
That is a brushless 200 amp alternator that has worked really well.
I saved a bunch of money over buying off the shelf.

[mrybas]

Originally Posted by bcboomer

I had a machine shop make serpentine pulleys for my crankshaft and water pump.

They are sleeved over the old ones and I was able to change the ratio so I could speed up the alternator and get more power at low rpm.

My engine is a Westerbeke marinized Mitsubishi but the principal is the same.

The pic is sideways but you get the idea.

That is a brushless 200 amp alternator that has worked really well.

I saved a bunch of money over buying off the shelf.

Is the idea to make the crank and water pump pulleys as large as possible? Is there limit or downside to increasing the diameter of the water pump and crank pulley?

How much did the machine shop charge? Did you bring the serpentine belt/ serpentine pulley to them and ask them to sleeve over the existing pulleys?

[mrybas]

Originally Posted by Locquatious

See markgrasser.com An advantage of his pulleys is that you can use belts that are sold in regular auto stores.

I sent my existing v-pulleys to Mark. He said he could fabricate new pulleys in a couple weeks time. Two weeks later, and he hadn’t done the drawings yet. The pulleys are being shipped back to me.

[bcboomer]

Originally Posted by mrybas

Is the idea to make the crank and water pump pulleys as large as possible? Is there limit or downside to increasing the diameter of the water pump and crank pulley?

How much did the machine shop charge? Did you bring the serpentine belt/ serpentine pulley to them and ask them to sleeve over the existing pulleys?

The alternator pulley came with the alternator so that was a fixed size. I calculated the size I wanted the crank pulley to be, then the water pump size that maintained the same ratio as the old pulleys.
I took the old pulleys and a new serpentine belt to a little machine shop and he machined the new pulleys to bolt onto the old ones.
The existing alternator mount wasn't quite right for the new alternator and the machine shop skimmed a little off the mount and a little off the alternator to make it line up. Perfect match, no stress on the belt. I then went back to the auto parts store and bought a belt that was the correct length.
I don't remember exactly how much he charged but it was around $300 CAD.
The alternator was $320 CAD, so I saved a fair bit compared to the usual sources.

[RaymondR]

Might be easier to just put a second alternator on.