Is this too close? Alternator Mounting...

Sep 13, 2015
Catalina 22 Eugene
I've just installed the Balmar Serpentine kit....

And the belt they provided kinda had me put the alternator out quite a bit further. You can see I moved to a new hole in the alternator and its a good bit further out. Partially I'm quite happy about this extra reach as it gets the alternator away from the engine a bit. Which is also nice in that the temp sensor kinda rests on the coolant return line. At least that is the coolest coolant but still I wasn't too sure if that was going to cause issue...

So anyway what as me concerned is going out the other direction...

It pushes me out to where it touches this insulation material... I find that it touches the insulation material but it is not in contact with the wood behind it. I'm able to stick my finger in and compress the foam further yet and I can fit a finger between the alternator and the wall...

So what think people? Is there a potential issue with the alternator getting so hot that it melts this insulation stuff or? I should add that I'm planning on swapping my house bank out for Lithium here soon and so there may be some long run times for this alternator in the future. I can turn down the max allowed temp in the controller though I suppose if needed.
Feb 6, 1998
Canadian Sailcraft 36T Casco Bay, ME

Your primary means of alternator protection is Belt Load Manager. This should be at least level 3-4 for LiFePO4. Your alternator temp sensor is your back up insurance policy. Even at level 3-4 you may find alt temp protection kicking in. If this is the case drop Belt Load Manager one more level. We say this all the time but it bears repeating; No small fame alternator is rated for constant duty.

Getting the alt out away from the engine a bit is a good practice. You can simply cut some of the foam away to give a bit more cooling but as it is, it's ok. You may end up with a small hole in the insulation then black dust from the rubbing.

Please get some rubber insulated metal clamps on those battery cables and move them away from the front engine mount or any engine metal..
  • Like
Likes: heritage
Sep 20, 2014
Rob Legg RL24 Chain O'Lakes
The only thing I would worry about is rubbing through the foil and then getting foam all over. Those foam particles will combine with the engine grime and collect as a film of insulation all over the internal wiring inside the alternator. Once that happens, the alternator will not be able to cool properly. It maybe something you just keep an eye on and make sure you are not wearing through the foil. You may be able to add some extra wear layers of tape if it is rubbing.
Sep 13, 2015
Catalina 22 Eugene
Ok really glad to hear the responses and thank you RC for the reply. I'd thought about emailing you to ask that stuff but with all the comments on the website I figured I'd try my luck here first. Really appreciate the Belt Load Manager tips! I had fully read all your alternator mounting articles and was planning on doing the one tick per every few weeks ideas as I worked my way to figuring out what is going on. But right now I'm mostly in slowly refit mode and so it was going to take me a long time to get it figured. But that is ok its about the journey.

The thought about getting crap into the alternator is a real concern of mine as well. I've tested this setup with a 3/8" belt and started off using the wrong belt and it was eaten in about an hour. Took me a good while to clean the alternator up and get it all blown out before re-doing things with the serpentine kit.

Anyway all in good fun!

Battery is coming along nicely and once I get things a bit closer to figured out the new bank should go in... Here's progress so far: (the double top is to give the BMS a place to safely rest where it can still get airflow) But with my house bank load demands it should never get hot.
  • Like
Likes: jssailem
Jan 7, 2014
Beneteau 45F5 51551 Port Jefferson
You might want to screw in a couple of fender washers to compress the insulation and give you a little clearance just to avoid chafe. That looks like a universal m25, mine used to vibrate a lot.
Apr 22, 2011
Hunter 27 Pecan Grove, Oriental, NC
That is a nice diy battery box. What amp hour cells are those, and what bms are you thinking of using?
Sep 13, 2015
Catalina 22 Eugene
200Ah cells and I'm using the BMS that Overkill solar sells. Which is actually a chinese brand thing that you can get for a LOT less money on ALI express if you're willing to wait. But the guys at Overkill have done a good job to document things and to test units out to make sure you're not getting duds. So I went ahead and ordered through them. Got it in less time and it even came with a test report stating that it was within specifications. I then re-did the test and got nearly perfectly the exact same results. The cells I did purchase on Ali Express and waited for them as an effort to minimize cost. I've done 15 or so cycles on them and they have been performing as expected so far so I'm pretty happy.
  • Like
Likes: heritage