Dodge 440-3 Motorhome Engine Mod's Share Your Experience

[squidphil]

Hi Everyone, Phil here = total newjack here

Just want to say that I’ve ended up on this forum a few times in the last few years and have
always found the shared info so useful in what I’ve got accomplished so far = Thanks for sharing,
it has helped me!

I’m restoring a 1973 Grumman 28’, Yes this RV was made by the company that later became
Northrop Grumman. The chassis is a Dodge RM400, 440-3 engine and the 727 Torque Flight
Transmission. It has so much thick aluminum on the body that it’s more like a tank and that’s
the main reason I got it…Close 2nd is that only has about 21K on it and has spent more time
sittin’ than it has on the road. I will never be a full-timer but if once a year it could make a haul
and a weekend per month it could get me to a different state park = that would be what they
call Livin’ the Dream Hahahahaha!

I have:
1. Ripped the roof off (Koolest engineered Fiberglass roof EVER! Hated to ditch it but it
was 40+ years old and cracked in several places with very long term water damage)
Replaced with temp tin roof, eventually would like to weld up shaped aluminum hat
channel, similar to a School and Commercial Bus design covered with tread plate welded
at the seams and coated with truck bed liner, sounds like a lot of work but when I think
about it I think I would never have to worry about the roof again, even when I crawl up
there with a lawn chair and cooler to escape
2. Gutted the interior, Very Sad to remove the best puke orange shag carpet and absolutely
awesome engineered interior but it was all water damaged and covered in rat turds
Hated to throw out all those 8-track tapes!!!
3. Re-cored the radiator and flushed engine with several cycles of rust remover
4. Changed the water pump
5. Changed to SKIRTED thermostat (Milodan) None on it when I got it.
6. Changed to proper Brake Master Cylinder Chevy version on it when I got it.
7. Replaced Front Brake Booster
8. Changed Tires from Bias to 225/70R19.5’s (Single Piece Stud Pilot (Budd) Rims)
9. Changed Belts to new V-Belts

Here’s where I need some group help:

440-3 engine is notorious for running hot and problems that result, especially manifold prob’s are commonly solved or at least greatly reduced through Headers & Dual Pipes = If you switched to headers and/ OR Dual Pipes and this solved or greatly reduced your issues Please share : Make and Model, Long or Short, and ANY special mod’s / also for Dual Pipes. Any Starter issues? Spark Plug Wire issues? Heat Soak elsewhere issues?

In reference to the NOTORIOUS Carter ThermoQuad Carb…I already know that even saying the name of
this carb usually inspires a Republican/Democrat type fiery debate and it’s pretty much love ‘em or hate
‘em type thing = I’m way past that and really would just want to replace it with the MOST easily adjusted, best performing alternative = If you switched from the ThermoQuad to anything else and
solved or greatly reduced your issues Please share: Make and Model and any pertinent info, especially
add-ons or mod’s necessary for the swap. Want to make sure you drove at least 500 miles at one time with
this carb = didn’t experience any vapor lock or hard start issues due to heat.

Any other mods to your 440-3 (Motorhome) engine that you’d like to share.

Thanks for takin’ the time = If you know somebody who might share who doesn’t hang on the forum anymore please
pass on my digits eight 3 oh 68eight-two48five, text or call anytime that’s close to Texas time <grin>

[Mizen]

Originally Posted by squidphil

Hi Everyone, Phil here = total newjack here

Just want to say that I’ve ended up on this forum a few times in the last few years and have
always found the shared info so useful in what I’ve got accomplished so far = Thanks for sharing,
it has helped me!

I’m restoring a 1973 Grumman 28’, Yes this RV was made by the company that later became
Northrop Grumman. The chassis is a Dodge RM400, 440-3 engine and the 727 Torque Flight
Transmission. It has so much thick aluminum on the body that it’s more like a tank and that’s
the main reason I got it…Close 2nd is that only has about 21K on it and has spent more time
sittin’ than it has on the road. I will never be a full-timer but if once a year it could make a haul
and a weekend per month it could get me to a different state park = that would be what they
call Livin’ the Dream Hahahahaha!

I have:
1. Ripped the roof off (Koolest engineered Fiberglass roof EVER! Hated to ditch it but it
was 40+ years old and cracked in several places with very long term water damage)
Replaced with temp tin roof, eventually would like to weld up shaped aluminum hat
channel, similar to a School and Commercial Bus design covered with tread plate welded
at the seams and coated with truck bed liner, sounds like a lot of work but when I think
about it I think I would never have to worry about the roof again, even when I crawl up
there with a lawn chair and cooler to escape
2. Gutted the interior, Very Sad to remove the best puke orange shag carpet and absolutely
awesome engineered interior but it was all water damaged and covered in rat turds
Hated to throw out all those 8-track tapes!!!
3. Re-cored the radiator and flushed engine with several cycles of rust remover
4. Changed the water pump
5. Changed to SKIRTED thermostat (Milodan) None on it when I got it.
6. Changed to proper Brake Master Cylinder Chevy version on it when I got it.
7. Replaced Front Brake Booster
8. Changed Tires from Bias to 225/70R19.5’s (Single Piece Stud Pilot (Budd) Rims)
9. Changed Belts to new V-Belts

Here’s where I need some group help:

440-3 engine is notorious for running hot and problems that result, especially manifold prob’s are commonly solved or at least greatly reduced through Headers & Dual Pipes = If you switched to headers and/ OR Dual Pipes and this solved or greatly reduced your issues Please share : Make and Model, Long or Short, and ANY special mod’s / also for Dual Pipes. Any Starter issues? Spark Plug Wire issues? Heat Soak elsewhere issues?

In reference to the NOTORIOUS Carter ThermoQuad Carb…I already know that even saying the name of
this carb usually inspires a Republican/Democrat type fiery debate and it’s pretty much love ‘em or hate
‘em type thing = I’m way past that and really would just want to replace it with the MOST easily adjusted, best performing alternative = If you switched from the ThermoQuad to anything else and
solved or greatly reduced your issues Please share: Make and Model and any pertinent info, especially
add-ons or mod’s necessary for the swap. Want to make sure you drove at least 500 miles at one time with
this carb = didn’t experience any vapor lock or hard start issues due to heat.

Any other mods to your 440-3 (Motorhome) engine that you’d like to share.

Thanks for takin’ the time = If you know somebody who might share who doesn’t hang on the forum anymore please
pass on my digits eight 3 oh 68eight-two48five, text or call anytime that’s close to Texas time <grin>

Hi Phil,
Looks like you have lots of work ahead. I ran a 440 with the thermoquad carb in 3 differently vehicles for 30 years with endless carb issues. Questioned a mechanic near end of last vehicle and he solved my problems with this solution. On a cold morning block wheels or get some one to hold brakes on. Start vehicle and put it in gear, adjust choke until it idols smooth and enjoy. It stayed running smoothly summer and winter until I sent it to the wreckers.
Hopefully this will help with your engine.

[Chargerman]

I have had many 440’s but never in a motorhome. That ThermoQuad would already be in the scrap pile if it was my choice. I always run Holly carbs, usually 750CFM but more than you will need. I would go 650. Then I would swap out the radiator for a larger capacity aluminum one. Then I would add a coolant heat transfer to the coolant. This really helps reduce heat and improve cooling properties. I would also add full length headers and heat protecting boots onto the spark plug boots to protect the wires. Low restriction mufflers will also be a good idea. Once I had this done I would find a real good Holley “tuner” guy in your area to jet the carb for you properly. Be sure he has the equipment to properly measure the exhaust gasses. I would also be sure to dump the tranny fluid and filter and replace with a high quality fluid. Ideally replace the transmission pan with a deep one and install a separate trans cooler if it doesn’t have one.

I realize I’m talking some bucks with this but it will help assure good performance and reliability in the future

Good luck with your project.