366 tall deck on propane in a suburban?

[Vombrown]

Now I know I will catch some flack here but I found a really nice 3/4 ton truck that has a 366/400 turbo combo in it thAT I can get for a song. I'm a diesel guy, Cummins certified to be exact but I am giving this serious consideration. Its a drop in ready to go drivetrain. I know it isn't the coolest hippest on the block but those motors were torque beasts. I have friends in the southern swamps running them in mud buggies turning 50" terra tires that swear by them. Won't run anything else. So lets not start a 366 bashing thread. Lets discuss ways to pep them up a little. This one is a complete system running and driving. I took it fir a spin today and I gotta say it wasn't the fastest truck I have driven but its faster than my cucv with the 6.2 and my bet is it will tow a good deal more. Ill bet it won't bog down in vertical climbs like a carb would either.


Herds my thinking. Drop the combo in the suburban with some ignition upgrades. Ditch the 100 gallon propane tank and convert it to run on easy to get propane cylinders for gas grills. ( yes I know that they aren't DOT approved). It just seems like an easy swap for what will be a tow rig first and foremost. Dedicated hunting rig and general knock around.

 

[ktmoutfront]

At 8mpg and 4.2 gallons per tank. You will need a number of them to go any distance.

As for torque, we used one to run a massive hydro pump. The SBC 350 would not pull it. The 366 ran it, no big deal.

 

[Vombrown]

My thought process was that if the propane got be a hassle i would swap it to gas and be done with it. I still like it on propane.

 

[yellowK20]

Having the propane tanks inside the vehicle does not sound like a good idea to me . I would find some tanks that would fit under the rig in place of the stock tank even

 

[Hogback Fabrication]

Definitely forget the tiny grill propane cylinders, the 100 gallon unit is more like what you want. You'll be getting single digit fuel economy.

Otherwise that's a good, super simple setup.

 

[Vombrown]

Having the propane tanks inside the vehicle does not sound like a good idea to me . I would find some tanks that would fit under the rig in place of the stock tank even

That is an option for sure. However the sealed 100 gallon tank the truck has with it is compliant for internal use inside the cab.

 

[Vombrown]

Definitely forget the tiny grill propane cylinders, the 100 gallon unit is more like what you want. You'll be getting single digit fuel economy.

Otherwise that's a good, super simple setup.

Truck is getting about 16 mpg currently. With propane being less than half the cost of gas or diesel. Those numbers most associate with the 366 are in 2-5 ton trucks or school buses. When you shed a few tons of weight the little big blocks do pretty well...

Its currently in a 5600 pound truck. I don't know what the suburban will weigh finished.

I honestly think with a little more zip from a better ignition system a s a tune up it might see 18mpg. It should tow a freight train down the road.

 

[sweetk30]

did the doner vehicle have air brakes ?

if so I NEED that motor bad ! ! ! ! for my dump truck .

others guys say 366/427 tall decks make great budget N20 or boosted engines . the low comp ratio and forged parts they work great like this.

 

[Vombrown]

For me it will be a toy weekend warrior hunting rig. I live in the lAnd of gravel roads and crawling around in the mountains. I don't see a lot of highway driving in its future.

 

[FOR MUD]

Gas grill type tanks dispense vapors. Forklift type tanks dispense liquid. I think you can run a bbq tank, but it won't put out the same power as a forklift tank.
Unless you run a higher compression, propane will make less power than gas. There's a reason why companies that sell propane don't run it on their trucks.
Finding propane filling places can be problems, tank placement can be a problem, less power than gas.....So all in all.... I think gas would be the way to go.

Now if your your talking a slow moving offroad only type rig.... Propane a poor mans fuel injection.

 

[obijuank5]

Propane is the shit. I got more power out of my BBC with the propane than I did with the carb. It is very well tuned and can light up the 42s. Fuel consumption is the same. Its a lot.

You will need liquid propane like from a forklift tank. Or add a draw straw to your vapor tank somehow.

Propane likes compression and timing. You got timing and that's about it lol. If there is any way to bump compression on it it would be a very strong setup.

 

[diesel4me]

I had a 235 straight six that had a dual fuel conversion kit when I got it--it could run on propane or gas...

I did not keep the setup on it and ran it on gasoline only (sold the kit for almost what the '56 Chevy pickup cost me!)...

The engine in that truck ran sweet,and on propane it felt it had more power--after several years I had an oil filter hose fail on it (it had an external canister add on oil filter,bolted to the intake)--that made the #1 rod bearing start knocking--when I pulled the oil pan off it,the engine inside was clean as brand new--no "black" anywhere..found the engine had been rebuilt,it had .030 under rod bearings...only that bearing was down to copper,the rest of them and the crank had no damage at all..

I bet engines run on propane will outlast gasoline ones 3 to 1 just due to the oil staying clean,no carbon or soot..the spark plugs in that engine looked new when I removed them too,like "out of the box"--no deposits at all--that was not the case once I started using gasoline only in it..

 

[Vombrown]

Propane is the shit. I got more power out of my BBC with the propane than I did with the carb. It is very well tuned and can light up the 42s. Fuel consumption is the same. Its a lot.

You will need liquid propane like from a forklift tank. Or add a draw straw to your vapor tank somehow.

Propane likes compression and timing. You got timing and that's about it lol. If there is any way to bump compression on it it would be a very strong setup.

The more i read I find out that some of these motors were factory built to run on propane. They have a higher compression ratio. If I decide to pull the trigger on this and buy the rig for the drivetrain I will be able to check all of that. Chevy headgaskets go on very easily. Shaving the head isn't a big deal either. We can push compression up if we need to.

 

[big dan]

I built an adapter to run mine off BBQ tanks in case of an emergency but I wouldn't try running it on them all the time. You'd have to carry too many.

As far as power goes I didn't notice a difference when I swapped my stock 350 from gas to propane. I have a brother in law that I convinced to swap his Toyota and he gained power.

I did bump my timing way up and would like to increase my compression mainly for the efficiency but it runs good right now.

 

[Vombrown]

This setup was installed in a grain truck. Turbo 400 was rebuilt. 366 freshened up and installed. It is currently residing in a 3/4 ton ford truck ( barf). I have searched and searched online. I could only find a couple of builds with this engine. None on propane. All report it is a towing rig with excellent low rpm torque.

 

[paratrooper307]

This setup was installed in a grain truck. Turbo 400 was rebuilt. 366 freshened up and installed. It is currently residing in a 3/4 ton ford truck ( barf). I have searched and searched online. I could only find a couple of builds with this engine. None on propane. All report it is a towing rig with excellent low rpm torque.

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Not too many people build them because as has been discussed it's not a performance engine and it's mostly limited to industrial/heavy duty applications. It's got good guts, it's just not a particularly exciting engine from a performance standpoint and there aren't a lot of parts for them. Good luck with the build, it's always fun to do something different, even if it's not the easiest or most sensible route.

 

[Vombrown]

Not too many people buildwouldneed because as has been discutoei's not a performance engine and it's mostly limited to industrial/heavy duty applications. It's got good guts, it's just not a particularly exciting engine from a performance standpoint and there aren't a lot of parts for them. Good luck with the build, it's always fun to do something different, even if it's not the easiest or most sensible route.

I haven't committed to it as of yet but it is looking good. On my end all I would need would be a short 205 to have a complete drivetrsin.

 

[FOR MUD]

Not too many people build them because as has been discussed it's not a performance engine and it's mostly limited to industrial/heavy duty applications. It's got good guts, it's just not a particularly exciting engine from a performance standpoint and there aren't a lot of parts for them. Good luck with the build, it's always fun to do something different, even if it's not the easiest or most sensible route.

From the sounds of it he's not looking for a hot motor, just something slightly warmed over....But dependable, good low end toque....Which I think this motor has the potential to be.