Builds Isuzu 4HE1TC into FJ62

[astr]

Thanks for the starter info. All rear-mounted starters are ccw. I looked into a direct-drive starter and they only seem to be available in 24 volt. I thought maybe one of those could be rewound to run on 12Volts. I checked with a couple of starter shops and the answer I got was that it could be done but not recommended because at 12 volts the current would double and the brushes and solenoid contacts wouldn't handle it.

 

[vsa911]

I don't think I explained what I was drawing up very well. I'm not planning on doing anything internally to the 24 volt starter. The easiest route is probably going to be to use two batteries (as most diesel pickups do anyway) and run them in series to the starter with a series/parallel switch so it has it's own 24 volt circuit when starting while the rest of the Cherokee keeps its 12 volt system once the starter is disengaged. This may require a larger alternator, but I doubt it since most NPRs utilize two batteries, anyway. I'm not positive, but I imagine the stock alternator is around 130 amps. Delco Remy made a parallel switch for GM (I assume for CUCVs), and there are probably many others out there for marine applications. A lot of older marine diesels used 24 volt starting systems while the rest of the boat was 12 volt. The Delco part is D2-6032N.

Another option for the 24 volt starter will be to use a transformer. Anything over 1000 watts can get expensive (and 1000w isn't nearly large enough for the starter), so the ideal solution in this case would be to use a 24 volt alternator and starter, and then run the rest of the system through a transformer (24v to 12v). I imagine this is a pretty common topic in forums dedicated to CUCVs.

Honestly, I think I'm going to re-work the front housing so I can clock the original starter down as far as possible and go from there. A lot of different solutions will work, but this one will require the fewest changes from the stock wiring. If anyone wants to play with some parts without buying a whole starter the front housing from a Wilson starter is 54-29-2048. Of course, it may be just as cheap to buy a used starter off ebay.

 

[Dougal]

Thanks for the starter info. All rear-mounted starters are ccw. I looked into a direct-drive starter and they only seem to be available in 24 volt. I thought maybe one of those could be rewound to run on 12Volts. I checked with a couple of starter shops and the answer I got was that it could be done but not recommended because at 12 volts the current would double and the brushes and solenoid contacts wouldn't handle it.

I've been putting 300-500 amps through my starter for a long time now. They seem to handle it okay.
500 amps is when it needed cleaned out, just over 300 amps normally.

 

[astr]

I don't think I explained what I was drawing up very well. I'm not planning on doing anything internally to the 24 volt starter. The easiest route is probably going to be to use two batteries (as most diesel pickups do anyway) and run them in series to the starter with a series/parallel switch so it has it's own 24 volt circuit when starting while the rest of the Cherokee keeps its 12 volt system once the starter is disengaged. This may require a larger alternator, but I doubt it since most NPRs utilize two batteries, anyway. I'm not positive, but I imagine the stock alternator is around 130 amps. Delco Remy made a parallel switch for GM (I assume for CUCVs), and there are probably many others out there for marine applications. A lot of older marine diesels used 24 volt starting systems while the rest of the boat was 12 volt. The Delco part is D2-6032N.

Another option for the 24 volt starter will be to use a transformer. Anything over 1000 watts can get expensive (and 1000w isn't nearly large enough for the starter), so the ideal solution in this case would be to use a 24 volt alternator and starter, and then run the rest of the system through a transformer (24v to 12v). I imagine this is a pretty common topic in forums dedicated to CUCVs.

Honestly, I think I'm going to re-work the front housing so I can clock the original starter down as far as possible and go from there. A lot of different solutions will work, but this one will require the fewest changes from the stock wiring. If anyone wants to play with some parts without buying a whole starter the front housing from a Wilson starter is 54-29-2048. Of course, it may be just as cheap to buy a used starter off ebay.

If you are going to use a 24 volt starter, two batteries, and a series/parallel switch then you only need a 12 volt alternator. The only time the batteries are in series to produce 24 volts is during starting and then the alternator isn't charging anyway. During normal running, the batteries are in parallel so a 12 volt alternator is what you need. The standard Isuzu alternator on an NPR is rated at 80 amps (4HE1) and the NPR's come with two Group 31 batteries. Group 31 = BIG!

 

[astr]

I've been putting 300-500 amps through my starter for a long time now. They seem to handle it okay.
500 amps is when it needed cleaned out, just over 300 amps normally.

Sounds like you are running a 12 volt starter on 24 volts! And no smoke yet?

 

[Dougal]

Sounds like you are running a 12 volt starter on 24 volts! And no smoke yet?

It's been in about 18 years now.

 

[astr]

It's been in about 18 years now.

If I tried that, with my luck I'd be at the intersection of Nothing and Nowhere when the starter would seize

 

[Dougal]

If I tried that, with my luck I'd be at the intersection of Nothing and Nowhere when the starter would seize

It's certainly one of those "out of the comfort zone" mods. It was only about 7 years ago I bought a clamp meter and actually worked out what was going on.
Prior to that was all blissful ignorance.

 

[Nexxussian]

If it makes you feel any better, using a 6 Volt starter on a 12 Volt vehicle is fairly standard in vehicles old enough to have 6 Volt systems, when they are converted to 12.

I would avoid extended cranking though.

I know you are specifically discussing 12/24, but it's the same increase (100%).

VW, on the air cooled engines, actually used to sell a starter that was a 6 Volt motor with a 12 Volt solenoid.

I forget what model it was original equipment for, but racers used to buy it as a "high torque" starter.

Not that I'm recommending a parallel switch, Pops had one in his Class 8 Kenworth, it was reliable enough that it got removed and a 12 volt starter installed.

Of course that could have alot to do with trying to crank a tired 855 CID Cummins.

It's the only experience I have with those switches though, so I can't reccomend them.

 

[Granite Grinder]

JDM 80 series use 24V start, 12V run

 

[Dougal]

JDM 80 series use 24V start, 12V run

I'm also using 24v start and 12v run. But I suspect it's a quite different system.
Mine uses a series/parallel switch like Nexussian said above. I've found mine quite reliable, except for the previous owner replacing a fuse with a piece of wire heavier than anything else in the car. Used the fire extinguisher that day.:whoops:

Don't think I can blame the switch for that though and it survived fine. It was a buildup of crap in the starter solenoid that somehow provided a dead short.
First time I reinstated everything including the fuse and had to wait until it happened again to see what the real problem was. I hate intermittent faults.

 

[astr]

If it makes you feel any better, using a 6 Volt starter on a 12 Volt vehicle is fairly standard in vehicles old enough to have 6 Volt systems, when they are converted to 12...

Here we are talking about a 24 volt starter on a 12 volt system. As Dougal has demonstrated, a 12 volt starter will run on 24 volts but I doubt if you could get enough "crank" out of a 24 volt starter on 12 volts, thence the parallel/series switch.

As vsa911 suggested, a 24 volt starter without the gearing offset would bring the starter closer to the tranmission, possibly within acceptable limits.

 

[astr]

Starter problem resolved!

Now that the patent applications have been filed, I can disclose my revolutionary idea! A simple, elegant, all-mechanical solution to the starter problem that should appeal to all “manual” folks here on MUD.

What do you think?

 

[Nexxussian]

Remind me never to arm wrestle you.

 

[Nexxussian]

Here we are talking about a 24 volt starter on a 12 volt system. As Dougal has demonstrated, a 12 volt starter will run on 24 volts but I doubt if you could get enough "crank" out of a 24 volt starter on 12 volts, thence the parallel/series switch.

As vsa911 suggested, a 24 volt starter without the gearing offset would bring the starter closer to the tranmission, possibly within acceptable limits.

I was replying in regards to posts 445 & 446.

It sounded (there and some places previous) like people were suggesting to build it 24 Volt and run a non gear reduced 12 Volt starter.

My appologies if you didn't appreciate the post.

 

[Dougal]

Awesome idea.

 

[astr]

Remind me never to arm wrestle you.

Arm wrestle me - you'll have to arm wrestle my wife. After all, this whole automatic transmission thing is all at her insistence so she's the one that will have to pull the handle!

 

[astr]

I was replying in regards to posts 445 & 446.

It sounded (there and some places previous) like people were suggesting to build it 24 Volt and run a non gear reduced 12 Volt starter.

My appologies if you didn't appreciate the post.

Absolutely no offense taken! We can blame all the confusion on Dougal because he insists on running his 12 volt starter on 24 volts.

 

[vsa911]

It's impressive that there have been so many posts about the 12v/24v starter option. While it's possible in many different variations I'm personally leaning toward modifying the current 12v starter at the housing to mount close to 90 degrees ccw (viewed from the rear) along the side of the transmission. Doing two housings identical with one for a backup (and the ability to swap the modified housing onto a new starter if there was ever a failure) would probably be prudent. This would allow for the rest of the components to be completely stock, and make a starter swap "in the field" a little easier.

Are most people on here of the idea that this attempt would be more difficult? Personally, I couldn't weld bubble gum to the bottom of a desk and expect it to hold. I've gotten some very capable welders to help me do some pretty nutty things over the years, and this is along the lines of some of the things we've had to contrive to get past some obstacles.

I don't mean to concentrate so many posts to this topic, but I'm at roughly the same point astr is trying to stuff this contraption into an unwilling chassis. I took a huge shortcut with the A442, but it didn't make the starter any smaller or more convenient.

 

[astr]

The approach that I'm taking is to mock up the front-mounted starter just because it's easy to do on the junk engine that I have. This will assure me of a having a workable solution (not elegant but workable) in hand before I pull the 3FE. I'll pull just the engine, leaving the A440 in the truck. I can then swap the AW450 bellhousing onto the A440F and see exactly where and how great the interference is going to be.

I'd still like to take the hybrid tranny for a test drive in the NPR. I should have done it earlier this weekend as almost all of the snow was gone but I had other commitments. Now, we just got another 8" of snow!