• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

H1 Hummer Cummins Swapped

Will L.

Well-Known Member
Messages
8,672
Likes
8,472
Location
Boulder City Nv
Used to be some good hotrod shops near you. Maybe check with them about custom options if you cant buy components and tig up yourself. Custom radiators and cooler systems are not crazy expensive. Often guys find it’s better priced, especially when it fits nicer and lasts longer than mass production.
 
Messages
45
Likes
33
Location
Orange, California 92867
Used to be some good hotrod shops near you.
Yeah . . . lots of them closing doors - or have guys not as smart as you would think. They are hurting so bad any custom anything walks in the door means $$$ signs hit their eyes. I have a TIG setup and can weld up my own custom stuff. Even the local Stanadyne Authorized rebuilder and as the 6.5 specialist shop I did work for closed up in late 2017.

I toyed with the idea of using a Duramax Intercooler and cutting off the perpendicular outlets and tig re- welding them to be then side outlets - but then I just have a hard time wanting to put anything in front of the radiator at all to dump any heat at it first.

The intercooler mounted down just above the road and on a hot day picks up road heat / asphalt heat - but it does the job still - just not so well in slow moving or stop and go freeway traffic. I have an intercooler spray system for water - but it can only get maybe 10 degrees cooler over nothing.

I think I will start with increasing by about 60 percent the size of the intercooler at the present location and see what happens. it is the cheapest easy R and R swap in to do.
 

Sand

Well-Known Member
Messages
244
Likes
302
Location
Canada
20181219_144229.jpg Final belt routing and layout. Might be good for Chevy-cummins swaps as well. The shop I'm at is looking at possibly templating the tensioner and alt/ac brackets for production. They do lots of Cummins-Ford swaps.
 
Messages
55
Likes
33
Location
Ca
Sand,

What do you do as for alternator wiring? Not sure how different the Humvees are from the pickups, but I'm gonna ask anyways & maybe someone will know. I have a 96 K3500 & I'm doing a 12 valve swap. I've been back & forth on if I should run a dodge alternator or not. I ordered a transgo internal regulator so that it can run without a computer, but I still need help figuring out how to hook up the voltmeter & tachometer. The pickup uses the alternator for those, but the dodge alternator does not output those. You can use a dakota digital unit, but that's just more computer's & wiring & such.

How do you usually hook up these alts?
 

Will L.

Well-Known Member
Messages
8,672
Likes
8,472
Location
Boulder City Nv
@Sand that fits nicely in there. Like thethe calipers too, Keep it up.

On both Hummer and the K3500: I would adapt Gm alternator to the engine. They are good units that have descent lifespan and already you can keep the wiring intact. Just need to check the rpm is correct and adjust pulley size if not.
 
Messages
55
Likes
33
Location
Ca
@Sand that fits nicely in there. Like thethe calipers too, Keep it up.

On both Hummer and the K3500: I would adapt Gm alternator to the engine. They are good units that have descent lifespan and already you can keep the wiring intact. Just need to check the rpm is correct and adjust pulley size if not.
Ok awesome. How do you determine the correct size pulley you need? I'm guessing I wouldn't be able to just bolt the cummins 8 rib pulley onto the 6.5 alternator?

I was running a cs144 on my 6.5. Should I stick with that or change to something else?
 

Sand

Well-Known Member
Messages
244
Likes
302
Location
Canada
No plan yet. See how hot it gets....
I'm open to thoughts. The donor dodge had no shielding. Hummer has aluminized fiberglass sheild all over the cab portions that share the engine bay.
20181228_183610.jpg
Alternators- find a shop that rebuilds. They can swap pulleys, add tach outputs, whatever you need. Online pulley calculators are good. Find your stock sizes and speed and input your desired speed. It will give you the pulley size you want. Rockauto had pulley diameters listed with most pulleys. Browse till you find your match.
 

Will L.

Well-Known Member
Messages
8,672
Likes
8,472
Location
Boulder City Nv
Yeah, like Sand said- you could determine and order. The balancer pulley to alternator pulley is a ratio. If the cummins balncer pulley is identical to gm diameter, then you need same size 8 rib pulley as current. If not, you’re going to have to do some pain staking math.
Might be easier and faster to have the dodge alternator add the tach?

Your other thread mentioned time constraints and $ constraints. Bad combo. Trucks fall under the 2/3 rule of life and especially when doing anything custom.
1. Get the job done right
2. Get the job done affordably
3. Get the job done quickly
Pick any 2 of the above 3 is the 2/3 rule- so it’s up to you how to go from there.

If I were in a bind, I would leave the dodge alternator in place. Get the entire rest of the truck done, Then fix this detail last. Because if you HAVE to drive it you could. You just need to put a good battery charger on it daily because you won’t actually have a working tachometer and slightly lessen battery life but so what if emergency to move or use truck a week or two until you get the new dodge alternator or gm pulley found/ made.
 

FellowTraveler

Well-Known Member
Messages
2,592
Likes
1,869
Location
Nature Coast
8 rib pulley needs to be matched to the GM alt shaft "diameter and taper" the overall diameter as measured on the ribs is where you measure not on the lips of the pulley.

You can also get the 4/6BT mechanical tach drive that mounts into the opening of the timing cover oil fill and use mechanical tach....but costly.
No plan yet. See how hot it gets....
I'm open to thoughts. The donor dodge had no shielding. Hummer has aluminized fiberglass sheild all over the cab portions that share the engine bay.
View attachment 55183
Alternators- find a shop that rebuilds. They can swap pulleys, add tach outputs, whatever you need. Online pulley calculators are good. Find your stock sizes and speed and input your desired speed. It will give you the pulley size you want. Rockauto had pulley diameters listed with most pulleys. Browse till you find your match.
Yep, no shielding on the Dodge Cummins because the IC piping routing however since you have brought the compressor outlet up next to the exhaust manifold radiant heat more likely than not could cause heat soak of the IC piping adding to the already hot discharge air that the water/air ex-changer has to cool down "the smaller the Cm2 of the turbine the more heat will be generated." You want a shield that can stand up to say 1.8k f @ the minimum IMO DEI makes a good product that is alloy & glass mat backing w/adhesive comes in different sized sheets and is easy to shape around whatever needs to be protected.

That silicone coupler needs to be moved to back of your Cummins better yet removed and a metal clam-shell connector used instead between the compressor outlet and the IC pipe.
 
Last edited:
Top