700R4 transmission in a HMMWV

[MattNC]

Here's the parts ordered/supplied from Bowtie pasted below.

The items needed/adjusted beyond the kit:

TV bracket had to be modified to fit the 6.2 block since the kit was designed for a 350 block.
Needed the dual brake switch to interupt the TCC when braking
Needed to route a 24V to 12V line to power the TCC and the temp gauge
Some misc small parts for bolts etc that needed to be replaced that were in rough shape, i.e. flex plate bolts which the shop bought some from ARP
transmission fluid
4spd shifter from AM general, detents were slightly off for the 700r4 per the shop, but they said they made it work

Transmission: 700R4 Level 3​	​	​
Torque Converter: 1600 700R4 Heavy Duty Diesel (C40HDT)​	​	​
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Dipstick: 700R4 Flip Top Truck​	​	​
TV System: SB [Universal]​	​	​
TCC Wiring: TCC Relay Kit​

Core Charge​	​
***Level 2 Shifts***​	​
NP218 Adapter Kit 32 Spline 50-6901​	​
FM700R4 6.2 Liter Flexplate​	​
Bosch Temp Gauge​	​
Pressure Gauge for Warranty Set Up​	​
***RED SPRING***​	​
Diesel Governor​

 

[Glider]

Odd. They did not mention a temp gauge. Here my list from Bowtie.

 

[MattNC]

Odd. They did not mention a temp gauge. Here my list from Bowtie.View attachment 863272

You can easily get a temp gauge and install it later if desired from any number of sources. Maybe they suggested it since I said I want to tow with it.

 

[Glider]

You can easily get a temp gauge and install it later if desired from any number of sources. Maybe they suggested it since I said I want to tow with it.

I understand now, the gauge is only for monitoring. Not necessary for normal operation.

 

[MattNC]

I'll add my results so far with the 700r4 that I had installed. I now have a few hundred miles on it and I really like it. I had a level 3 build from bowtie overdrives and it was installed locally by a mechanic with lots of military vehicle experience (he has 14 of his own, about half humvees) and 25 years as a GM transmission mechanic.

The install offered a few challenges due to old issues with my humvee, but overall it seems to have been relatively straight forward. I am very thankful for the installers experience as setting up the linkages, the TV cable, looking for wear issues on the humvee, there were a lot of pitfalls where I could have killed that new transmission due to lack of experience. I have the old 2.56 gears in the back and for a few more days my truck is just a 6.2 NA. Next week it will hopefully have completed its lung transplant with a BMI kit in my shop and be a 6.2 Turbo.

On the road it is a completely different truck. The first gear is much lower and it jumps off the line and 2-3 is very good spacing on the gears. It gets up to speed with much less effort. The shift to 4th is a big jump and at 40mph it shifts and then locks the TCC and the rpms are very low. You do need to sometimes downshift to 3rd on the shifter on long gradual hills unless you want to stab the accelerator and force a downshift. If I'm just tooling along and I feel it lugging I just manually downshift. The turbo hopefully will help here, but its not an issue. It downshifts fine on its own on steep hills, its just those long gradual hills that can be a slight issue.

I do have a tach installed, and at 65 mph its 2200 rpm and 2400 at 70 mph. You hear way more the huge amount of air you are pushing at that speed compared to the engine. At 50 mph the rpms are pretty low (maybe 1500 off memory) and you can easily carry on a conversation.

The biggest surprise has been engine temps. Since the low first gear gets it up to speed easier, and then you have overdrive, you just don't rev out the engine like I used to. In 200 miles of driving in 40 up to 72 degree weather the cooling fan has never engaged. On the cool days and highway driving the truck was at 160-180 the entire time. Local driving stop and go it got to the point at 190 where I could see my thermostat was opening and closing with the temp swinging up and down around 190, but it never got over 200. I have a new oem temp sender and speedhut gauge and it always showed the fan kick in around the 215-220 mark.

I'll keep you all posted what it looks like post turbo. I'm trying to get it squared away along with my M1102 trailer so I can take them both out to the show in Denton, NC the end of the month.

 

[Glider]

Great info! Thank you

 

[Glider]

I was inspecting the dual pole switch I ordered. It looks like one side is normally open and another normally closed. I'm assuming normally closed is for brake light. Im hoping normally open is correct for trans lockup. Meaning the presence of 12v causes the tc to lock and the absence of 12v will cause it to unlock.

It was stated earlier the same switch was used with good results. I want to make sure my switch has the same function. Thanks in advance.

 

[springer1981]

I was inspecting the dual pole switch I ordered. It looks like one side is normally open and another normally closed. I'm assuming normally closed is for brake light. Im hoping normally open is correct for trans lockup. Meaning the presence of 12v causes the tc to lock and the absence of 12v will cause it to unlock.

It was stated earlier the same switch was used with good results. I want to make sure my switch has the same function. Thanks in advance.

Not 100% sure but it seem to me the NO would be the brake lights ... then when you stepped on the brakes the lights would come on.

 

[Glider]

Not 100% sure but it seem to me the NO would be the brake lights ... then when you stepped on the brakes the lights would come on.

I always get that backwards. I think you are right

 

[springer1981]

I always get that backwards. I think you are right

I'll also add they have different connectors for the different systems so the current brake light switch wires will only fit the correct connectors on the new brake switch.

 

[MattNC]

I'll also add they have different connectors for the different systems so the current brake light switch wires will only fit the correct connectors on the new brake switch.

Glider. I forgot to mention in my update we debated back and forth on using the dual brake switch or not. We decided for now to just use the Bosch relay setup bowtie ships the transmission with that taps off the brake light signal to trigger a relay to open the TCC circuit. Bowtie provides the wiring diagram too, and it’s easy to install. The only potential issue is the relay temporarily see a 24v signal from the brakes instead of 12v. So far in a few hundred miles it’s been no issues, but longer term I may look to getting a relay rated for the voltage. It’s mounted next to the windshield washer for easy access or replacement and that’s where I mounted a waterproof 24 to 12v converter to power the TCC and the temp gauge for the transmission.

 

[Sharecropper]

Update on 700R4 in my M1028 -

When I began assembling my new P400 6.5 drivetrain in 2018, I reached out to Chris Gardner at Bowtie Overdrives in Hesperia, California for his recommendation for a rebuilt 700R4. At the time, I had planned to keep the engine naturally aspirated, as the P400 is rated at 225 HP and 375 FPT NA, and this should be plenty for an old guy like me to cruise around in . Chris is owner of Bowtie and drives an M1008 as his daily driver, so I trusted his recommendation to install Bowtie's Level 2 700R4 behind the P400. The Level 2 is rated for 450 HP and 450 FPT, so heck this would be plenty strong enough, I thought. But then in 2020 a strange thing happened. For some unknown reason, at 69 years old I suffered my first mid-life crisis . Suddenly, 225 HP just wasn't enough! I had to have more! But because I had already invested substantial cash into a custom set of Stan's ceramic headers for the P400, and in order to turbo the P400 I would have to discard the headers, I began to look for other ways to "wake up the beast" and satisfy my newfound craving for power. My research led me to Tom Rabold at Bullet 4WD in Australia. To my surprise, Bullet had developed an aluminum intake for a 6.5 diesel which accommodates an Eaton Harrop HTV2300 Supercharger! In addition, Bullet had also engineered a thin intercooler which fits between the intake and blower, and is coupled with a closed-coolant system including a grille-mounted radiator, 24v circulating pump and coolant reservoir. In several discussions with Tom at Bullet, he indicated that their 6.5 diesel racing trucks with this system were producing upwards of 300 HP and 550 FPT. I promptly wire-transferred the purchase price to Australia for the complete kit (if you have to ask how much, you probably couldn't afford one).

What all this leads me to is this - I am preparing to purchase a new 765R4 transmission form Chris at Bowtie in order to handle the additional torque of the supercharged P400. Their 765R4 is the strongest 700R4 you can get on steroids Bowtie Overdrives - View Item . Subsequently, I will be placing my Level 2 700R4 in the classifieds for sale. It already has the Advance Adapters 32-spline output shaft to mate to a NP208, so it is a true bolt-in replacement for the OEM TH400. It is currently bolted to my P400 on my engine stand and has not been turned over.

Just wanted to keep you guys informed of those dreaded mid-life crisis and what they do to you.

 

[TOBASH]

I have a Whipple supercharger on my civilian H1 one and I enjoy it however turbocharging a P 400 is probably the best way to go. You need to buy the turbo charger type heads and then get a turbo charge intake and exhaust manifold and the turbo charger itself. If you have a true P 400 block it will be pre-tapped for oil flow.

If I were you I would contact Travis at rubber duck 4 x 4 and he has all the parts and he is a damn nice guy and he understands P 400s. P 400 heads are not hard to get and neither is the P 400 turbo manifold and exhaust.

I understand that you like your exhaust headers however if you really want that motor to move, get rid of the idea of supercharger and throw in a turbo charger. It will be half the price.

In my humble opinion as someone who will be throwing a turbo charged P 400 into his civilian hummer.

IMHO

 

[Mogman]

I think he has already sunk his fangs into the dash on the supercharger deal.

 

[Sharecropper]

I have a Whipple supercharger on my civilian H1 one and I enjoy it however turbocharging a P 400 is probably the best way to go. You need to buy the turbo charger type heads and then get a turbo charge intake and exhaust manifold and the turbo charger itself. If you have a true P 400 block it will be pre-tapped for oil flow.

If I were you I would contact Travis at rubber duck 4 x 4 and he has all the parts and he is a damn nice guy and he understands P 400s. P 400 heads are not hard to get and neither is the P 400 turbo manifold and exhaust.

I understand that you like your exhaust headers however if you really want that motor to move, get rid of the idea of supercharger and throw in a turbo charger. It will be half the price.

In my humble opinion as someone who will be throwing a turbo charged P 400 into his civilian hummer.

IMHO

Mr. TOBASH;

Respectfully, I must ask - are you an experienced diesel mechanic? I've been fooling with these things since 1969 and installing turbochargers on diesels since 1985. While I do not claim to be an expert, I have learned a great deal from my experiences over the years. I have owned more turbocharged GM diesel trucks than I can remember. And I have learned to trust experienced engineers more than salesmen from companies named after carnival game toys.

I can assure you that I have a true P400. It has never been cranked, turned over, or installed in a truck. And I can also assure you that there are very few new P400's long blocks available anywhere on the planet. An acquaintance in Germany thought he had located one in Holland for $17,250 US, however upon review of the photos, the engine was simply a cleaned-up and painted used 6.5. New P400's arrive from GEP with no paint except inspection dots on each nut and bolt. There are no new P400 heads available, only an occasionally pair from a worn-out P400 or reconditioned 6.5 heads with the additional drilling to be passed off as genuine P400 heads. If you are not sure which you are looking at, I suggest you request a certified chain-of-custody statement.

From my experience, the 6.2/6.5 platform's design lacked sufficient cooling capacity to produce abundant power. A basic law of nature is - the only way to produce power is to burn fuel. Burning fuel produces heat. When air is compressed, the heat within it is also compressed resulting in the release of heat. The inherent design problem with a turbo is it uses hot exhaust gas to compress (and therefore heat) the intake air. It becomes a visous cycle - to produce power, fuel must be burned. That combustion then produces more heat, which then powers the turbo which then produces more heat. The cooling system of a vehicle can only remove so much heat, and that determines how much fuel can be burned and how much power can be safely produced. That is why a marine diesel can produce so much more power than a road vehicle - it uses cold lake water to continuously cool the engine, thereby allowing more fuel to be burned and more power to be produced. Heat destroys engines. I have fought heat in my diesel engines for 37 years. That is why for my P400 build, I chose to pressurize the intake air via a supercharger, and remove the hot exhaust gas as fast and as efficiently as possible.

The Bullet Supercharger was developed by engineers in Australia who also happen to race their diesel trucks from one coast to the other in 110-degree heat. They developed a special cast-aluminum intake for the 6.5 to accommodate the Eaton blower, and also developed an intercooler which fits between the intake and blower. The intercooler is a closed coolant system with a 24v pump to circulate coolant between the intercooler and grille-mounted radiator. They also engineered the intake with 1/4" phenolic spacers between the intake and heads to slow the transfer of heat as much as possible. With a DB2-5437 marine pump with .330 rotor and marine injectors, proper engine timing and pump flow setting, their 6.5's can produce 300 HP and 550 FPT on their dyno. I will trust these results from engineers any day over a 4x4 salesman who needs sales to feed his family.

To further reduce heat in my P400, I am also drilling and tapping my intake to facilitate the addition of a Snow Performance Water/Methanol Injection system Boost Cooler Water Injection Kit for Turbodiesel - Water Injection - (snowperformance.eu) . I will be adding posts and photos to my rebuild thread, if you are so inclined to follow.

This will be my last post in this forum. I had hesitancy to make this post, but felt compelled to set the issue straight. I have no desire to engage with you in a debate about what you believe versus what I know. Think what you may, and post what you like; I will not reply.

Good luck to you in your endeavors.

 

[Mogman]

The P400 is easily and instantly identifiable, no question, all P400 engines have (according to GEP) a girdle between the block and oil pan, and they do come painted, at least the block is.

I understand that supercharging will result in lower EGTs compared to a turbocharged engine because you are not packing up all that heat against the exhaust ports.

 

[TOBASH]

Mr. TOBASH;

Respectfully, I must ask - are you an experienced diesel mechanic? I've been fooling with these things since 1969 and installing turbochargers on diesels since 1985. While I do not claim to be an expert, I have learned a great deal from my experiences over the years. I have owned more turbocharged GM diesel trucks than I can remember. And I have learned to trust experienced engineers more than salesmen from companies named after carnival game toys.

I can assure you that I have a true P400. It has never been cranked, turned over, or installed in a truck. And I can also assure you that there are very few new P400's long blocks available anywhere on the planet. An acquaintance in Germany thought he had located one in Holland for $17,250 US, however upon review of the photos, the engine was simply a cleaned-up and painted used 6.5. New P400's arrive from GEP with no paint except inspection dots on each nut and bolt. There are no new P400 heads available, only an occasionally pair from a worn-out P400 or reconditioned 6.5 heads with the additional drilling to be passed off as genuine P400 heads. If you are not sure which you are looking at, I suggest you request a certified chain-of-custody statement.

From my experience, the 6.2/6.5 platform's design lacked sufficient cooling capacity to produce abundant power. A basic law of nature is - the only way to produce power is to burn fuel. Burning fuel produces heat. When air is compressed, the heat within it is also compressed resulting in the release of heat. The inherent design problem with a turbo is it uses hot exhaust gas to compress (and therefore heat) the intake air. It becomes a visous cycle - to produce power, fuel must be burned. That combustion then produces more heat, which then powers the turbo which then produces more heat. The cooling system of a vehicle can only remove so much heat, and that determines how much fuel can be burned and how much power can be safely produced. That is why a marine diesel can produce so much more power than a road vehicle - it uses cold lake water to continuously cool the engine, thereby allowing more fuel to be burned and more power to be produced. Heat destroys engines. I have fought heat in my diesel engines for 37 years. That is why for my P400 build, I chose to pressurize the intake air via a supercharger, and remove the hot exhaust gas as fast and as efficiently as possible.

The Bullet Supercharger was developed by engineers in Australia who also happen to race their diesel trucks from one coast to the other in 110-degree heat. They developed a special cast-aluminum intake for the 6.5 to accommodate the Eaton blower, and also developed an intercooler which fits between the intake and blower. The intercooler is a closed coolant system with a 24v pump to circulate coolant between the intercooler and grille-mounted radiator. They also engineered the intake with 1/4" phenolic spacers between the intake and heads to slow the transfer of heat as much as possible. With a DB2-5437 marine pump with .330 rotor and marine injectors, proper engine timing and pump flow setting, their 6.5's can produce 300 HP and 550 FPT on their dyno. I will trust these results from engineers any day over a 4x4 salesman who needs sales to feed his family.

To further reduce heat in my P400, I am also drilling and tapping my intake to facilitate the addition of a Snow Performance Water/Methanol Injection system Boost Cooler Water Injection Kit for Turbodiesel - Water Injection - (snowperformance.eu) . I will be adding posts and photos to my rebuild thread, if you are so inclined to follow.

This will be my last post in this forum. I had hesitancy to make this post, but felt compelled to set the issue straight. I have no desire to engage with you in a debate about what you believe versus what I know. Think what you may, and post what you like; I will not reply.

Good luck to you in your endeavors.

“Respectfully”, given that I have both supercharged and turbo units as well as n/a units, AND I have a P400, and my Military unit also runs a Bow tie Overdrive heavily modified transmission 765R4, and I’m also running methanol water injection, and I have EGT sensors to monitor it all, I figured I would discuss and share this with you. Now, not so much.

My response to your initial post was well intentioned and polite. Future responses would be less so, if you were not now on my ignore list.

 

[Glider]

Update: the 700R4 is installed but not yet complete. The shop I used did most of the work. I need to finish shifter linkage, and run 12v signal to trans for brake switch. I did drive it about 50 miles on the interstate manually shifting. My recorded top speed was 75mph. It will run 70mph but struggles on inclines. I'll have more info when the small bits sorted. I do not have a tachometer.

 

[Mogman]

Was the 700R4 built with a pressure switch to automatically lock the converter in 4th? If so you would usually have leads that would go to a lockup disable switch.

 

[USCDOC]

It has been an amazing upgrade for me. I did however do the turbo upgrade offered by B&S. Adds another 100hp ish. I still have trouble on hills on the freeway with passengers, but it’s way better. I also have 40” tires. If I went down to smaller tire, I’m sure it would help