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H1 Hummer Cummins Swapped

LowRam

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Michigan
The tappets are they drilled and /or coated?
Neither. We've looked at using coated tappets, and quite possibly will on the Sand Toys next motor.
We are using the coating on Pistons, Turbo housings, manifolds, and recently a radiator to see if there is a difference.
The coating process itself isn't that difficult, just time consuming. If a person had all the equipment and wanted to do it, they could turn out a very serviceable part.
If you buy everything you need to do it, then getting them coated professionally would be a wash or even cheaper.

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LowRam

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So the week that was;
Up to this point we had been using the billet freeze plugs while building our Cummins motors, this build the goal was under 500hp motor, mostly stock, not a lot of frills. Ok, the Nickel plated gear cover was a frill, but it looks good.
Turns out that the gasket set we used came without freeze plugs and the wrong valve stem guides, but the rest of the kit was very complete.
Off to the local auto parts for freeze plugs. The Large plugs were Dorman 555-124 and funny looking.
They don't stay in while running the motor. Turns out the are listed by Dorman as a Cam shaft plug, but both the local stores I called have been selling them as the block expansion plugs because the were 2-9/32".
Snooping around the web, turns up that you need to really use the Cummins plugs because of the odd size.
After having this happen twice. I made up the following plugs that we will be using when not using the billet units that require drilling and tapping the block.

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LowRam

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Are you using the cummins Grid heater? If so - how are you controlling it?
Cheers,
Sandy
Hi Sandy, no, not using the grid heaters. Most of what we do are fair weather drivers and the Cummins fires right up without them. If I had a call for it, I was just going to make up a timing circuit using a 555 and firing the relays. I'd most likely add an IAT sensor as well so as not to cycle it when the engine is warm. Just a little more tinkering.
 

LowRam

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Couple of new things I've been working out.
The TPS from the Dodge is different enough the I wasn't getting a good voltage swing, so I made an adapter to run a GM TPS. This works well but lacks the last 10 degrees of travel as the Dodge linkage is about 75 degrees vs. the GM 85 degrees throttle body.
Second is with this truck running A/C, the charge pressures climb right up until the single fan kicks in around 170 and runs a bit warm going down the road. So I changed to the dual fan setup. Working out the soft start and staggers Circuit based on the Ford Contour controls.
The fans are Dorman 620-105's and the Plugs you need are Duralast #858 (or cross ref). These are the A/C fans for the Taurus. Slightly smaller Dia than the Dorman 620-106 which is the Taurus Radiator fan. Approx 3/4 inch Dia difference but you need the clearance at the bottom of the shroud to clear the cross member.
Note that the draw at 13.34v is almost 15 amps for both fans running. Start-up hits about 18 amps and I add about 20% for what you didn't read. Fudge it to 22 amps. My power supply will trip at 25.

20180824_120828.jpg 20180824_130939.jpg TPS 1.jpg TPS 2.jpg TPS 3.jpg TPS 4.jpg
 

LowRam

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Michigan
Another point of note, we've been running the Cerakoted manifolds and turbo housings now for a couple months and it is holding up extremely well. In the future I plan to do the bolts as well so the heads don't get rusty.
Not seeing much temp difference in the cooling systems using the coating on the Radiators, so I'm kind of skeptical it there is a cost vs. benefit to it.
 

Sand

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Fantastic info. Especially the TPS. Didn't see that as an issue. My standalone controller the megasquirt might be able to calibrate for the dodge output. I'll be honest I've not delved into it far enough yet...
What's a 555?
 

Sand

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Canada
Integrated circuit timer....may be a new learning project for me as winter approaches. My glowplug relay should be up to the task I'm pondering now too. Not sure if it's a isolated system or run by the 6.5 pcm though.
 

Will L.

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Do you have pre and post radiator coating numbers on the temps?

Or how long it took before compared to now from say 220-180 or anything like that?

Out of around 50 people to have done testing on radiators, your the first to not have instant response of praise.

I’ve only seen 2 hummers- yours being the 3rd I have heard of but not seen obviously, that have had radiator coated. The other two it made a huge difference. One is a hot rodded p400 and the other a hot rodded dmax. Both fought heat issues that were ended by coatings. That’s what convinced me to do my hummer radiator no matter what.

The difference it made on the p400 was amazing. He couldn’t keep his temps under 205 on the freeway regardless of t stat. Going up to Mt. Charleston here he could only do 40 mph at 215f. After coating his cooling stack and no other changes he can do the speed 55/65 in parts and it never hits 200. I was with him for that part. He said he came up Bakers grade and never went below 80 mph. I wasn’t there for that part.
Those are the two worst roads near Vegas. Baker has signs along side it telling people turn off their A/C or the car will overheat- and our favorite road game is count the burn marks on the asphalt where over a dozen cars literally overheat to the point of catching fire every year there.

I would love to see any recordings or notes you have on it pre and post treatment. Also which brand and type you used. I know cummins makes the fan and btu load different, but the radiator being coated should kill it.

The fact if adding fans on a hummer is concerning. Hummers never overheat at slow speeds where electric fans help. Usually only high speed where aerodynamics steals air from top grille intake, and the electric fans block the really high cfm of the manual 20” fan by thier limited small cfm capacity.

Overheating is primary faulty on any hummer, regardless of engine, so any info is appreciated.
 

LowRam

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Location
Michigan
Integrated circuit timer....may be a new learning project for me as winter approaches. My glowplug relay should be up to the task I'm pondering now too. Not sure if it's a isolated system or run by the 6.5 pcm though.
The glowplug circuit could be modified to do the same thing I think.
 

LowRam

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Location
Michigan
Fantastic info. Especially the TPS. Didn't see that as an issue. My standalone controller the megasquirt might be able to calibrate for the dodge output. I'll be honest I've not delved into it far enough yet...
What's a 555?
Let me know what you find on the Megasquirt, haven't played with one yet but I'm sure someone will show up with one before long.
 

LowRam

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Location
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Will, I don't have before and after numbers, we coated it as part of the build. I'd be interested to see some real testing numbers too from one that was taken out, coated, and replaced with no other changes.
A lot of things play into the setup. The first truck on here was .020 over, Hamilton cam 188/220, stock valves, 13mm P-Pump, 5x22 injectors, 66 over 88 compounds and the piping was done by us. The intercooler is a Vibrant, no condenser in the stack, separate plate type Oil cooler, Plate type Hyd cooler, and two separate Derail dual fan Trans coolers mounted in the tunnel.
He drives it hard playing on the dunes running as high as 1300 egts and 85/35 psi on the boost gages (wastegated) and the only change we made after finishing was to delete the temp switch and run the dual fans full time. No coating on the stock radiator. We also never re-installed the baffles since it was working so well.
This latest we utilized the stock trans cooler separated from the oil cooler section mounted on radiator just below the intercooler with the Condenser sandwiched between them and the Radiator. The single 60 Turbo, Marine cam, 12mm P-pump tuned by Farrell Diesel services, 5x14 injectors, Piping we built, full baffles that seal to the hood. Currently single 16" fan with a temp switch. This setup runs to the high side and doesn't cool the condenser well enough to keep the charge pressures down and at one point while we were watching during the charging the highside pushed past 350 before the fan kicked in. Not so good. The temps that day were in the 90's and so was the humidity.
My call on the coating is a seat of the pants based on 40 some odd years playing with hot rods and modifying vehicles. I have a truck I'm putting together for me (Shh, don't tell anyone) and I think I will probe it out with sensors pre charge cooler and at the intake. Placing pad sensors on the radiator near the inlet and outlet. Having a mini weather station at home I can get Baro and temps to take into consideration and set up a test grid to take notes. All luxuries that take time and additional money over what a customer is willing to pay. Then I will be able to run it coated and non-coated and get real numbers. My testing will not take into consideration the money I spent to find out it didn't work, and believe me, some people will defend wasted money/Zero results to their grave.
 

Will L.

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Yeah, everytime I see this person now that owns the 2 hummers, instead of saying “hi” to each other it starts with them saying “No!” Then I say “Ok, maybe next time.” Reference of me asking him to share details on the builds - especially the p400 is what I want to share on here. But that person is in the public eye and it will look bad so it stays buried for now.

So I want to do mine and release all the info for hummer specific. Most the coating world won’t bother with any more testing to prove, because everyone in racing world proved it long ago, Nascar outlawed it, etc. Balancing my recored radiator vs brand new wih coating - and since Chris already ordered a brand new unit to have coated and ready to go for Hummer customers, leaning that way.

If I go that way- will do bench testing of two side by side if time permits.

That cummins puts out quite a bit more umf than mine ever will. Haha
 

LowRam

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Here is some temp numbers I did take while looking running the truck after a road test.
The first pic is Temp on the Turbo compressor outlet
The Second pic is of the temp on the Intake plenum
The Third Pic is the Condenser
The fourth pic is temp at the Charge Cooler


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LowRam

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You are right, there has been a lot of testing done, and in the racing world air dams and baffles are key components that with any additional help can be an advantage.
For the hummers with the canted radiator setups, a compromise was made to get the most area into a small space and as the military added armor and additional weight the cooling fans changed to compensate. Look at that hyd fan drive sometime, yikes!
Sometimes my hands are tied when it comes to cost/customer requirements/time on project so I have to make compromises too. Always makes me cringe, and I end up working free after hours trying to come up with solutions. Not good for me either.
 

Sand

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I was looking over my truck tonight and changed the fuel filter. Thought I'd check the fluids while I was at it. Opened the coolant cap and about 4 liters of coolant overflowed out....lol. when I crack the bleed screw on the coolant crossover when running it just bubbles steady.

Couldn't be better timing! I just picked up a 89 gmc 2500 with a 5 speed and small block in it for $150 this week as my run around while do I my cummins swap.

I'm stripping off most of the Cummins except the head and doing fresh gaskets and a paint job on it. Any gaskets I should chuck and just use the Right Stuff?
The Hummer will make it for a few drives yet. It needs to go across town to my buddy's hoist.
If you don't mind I'd love to post some progress pics and notes - and a bunch of questions here on this thread. It might be great to keep it all in one place. 20180823_140252.jpg
 

Sand

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My go at cooling upgrades is a full Hydraulic driven fan. I spent some time last week machining the back off of a Cummins vacume pump to build an adapter for a tandem hydralic pump. The front half of the pump runs the fan motor and the back half power steering. In its original life it ran off the back of a big air compressor in a Cummins powered bus. I'm finding the whole assembly too long and may forget the vac pump and mount it right in the timing cover directly. It will need some "special" machining make it work. 20180819_221220.jpg
 

LowRam

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Location
Michigan
No, I don't mind and long as the moderators don't. I like the "Keeping it in one place" concept. It allows people a chance to compare ideas a little more easily I think.
The hyd pump looks good, if you need vacuum there are electric pumps available.
As far as Cummins gaskets, most of which are O-rings, everything else, use what you get. the only really important one is the Head Gasket. Bite the bullet and get a Cummins one. If it's that far torn down I'd replace it for peace of mind. Make sure you check bolt stretch and replace if you need to. I've taken quite a few apart doing rebuilds and haven't seen one that I'd have felt good leaving in yet.
As far as torque, the bolt are a "Toque to Stretch" type and they are called out as an angle on the last step. Follow the sequence to the letter but take them to 140. Some rebuilders do 150, but that's pushing the limits of the 12mm threads when you start adding boost pressures.
 
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