The official 6bt conversion thread

[j41385]

Instead of glow plugs the B series uses a heated intake grid, Like a toaster. Less junk to burn out, and one unit that serves all 6 cyls. (or 4)

The one wire that goes to the injector pump powers the fuel shutoff solenoid, so when you turn the key off the engine stops. This could be eliminated by fabing up a rod that goes into the cab. Push the rod in to turn fuel on, start the engine, take the key out and put it in your pocket, and drive. When you get to your destination, pull the rod out to stop the engine, and its that simple. Out of simplicity, I would use the electric solenoid though, it's more like a modern truck.

[xxxtina63]

The reason I ask about differences is that I've found several available and the non turbo engines are usually less expensive. What they come out of, I have no idea. I guess they are actually 4B3.9's, according to this thread http://www.4btswaps.com/forum/showthread.php?t=917. Most that I've found are rated at around 105 hp, while the turbo ones start at around 120-130 hp. My guess is, if the guy knows his stuff, they are the older style engines, probably with a ton of miles on them regardless of what's claimed.

AverageF250, how does the M5HR2/BW1356 compare in length to a NP435/NP205 regarding crossmembers and driveshafts? Yes, I know that your F250 came divorced, but thought I would ask in case you knew. Also, you must be running the M5R2 hydraulic clutch? How hard is it to adapt it to a bump pedal assembly?

Also, if you're running 35's and 4.10's and it puts the 4BT in the sweet spot, then, if I did my math correctly, 3.23's would require a 27.5 inch tall tire, about a 235/75/15 right?

One more thing. Using a manual trans is one thing, but what about autos? Can you use say a gas AD, because I always thought the diesel transmissions had lower shift points? Would it require a different governor/valve body to get along nice with the 4BT?

[averagef250]

The 105 horse 4BT is turbocharged. There's no way it could make that power without a turbo. The aftercooled 4BT's, The 4BTA is the 120 horse version. The 4BT's I've seen do not use the heated intake grid. They have an electric injection pump timing advance setup that works like a choke while the engine warms up, it's still just one wire though.

The M5R2 and 1356 is atleast 6 inches longer than a 435/205. It's also wider and the frame must be notched a small bit for clearance. You can also bolt a 205 to '92 and up M5R2's, they are 32 spline.

Yes, gas autos have much higher shift points. You must not only run a diesel governor, but tweak the governor for the very low cummins shift points. I'd say only go auto if you drive feather footed and have lots of money to spend rebuilding them. Everyone I know that started thier cummins swap with an auto has gone manual after a couple autos bit the dust. We're not just talking a little slipping either. A friend just had a $1200 custom low stall billet 4L80E converter shred behind his 300 horse 4BT. He gave up on autos and I built him an NV4500.

The hydraulic clutch is real simple. You pull the lever off the clutch pedal pivot, cut it off, bend a piece of 3/8X1 flatbar to offset the lever a couple inches (this gets the master away from the firewall reinforcement ribs), weld it back on 90 degrees from where it was, holesaw a hole through the firewall and drill two holes. The 87-97 master rod is the right length and everything. It's way easier than I ever though it would be and works perfect.

[xxxtina63]

Man you're good!!!

[Jake11]

After you lay out 5000$ to 10000$ on saving 50cents a gallon.
Just how is this gonna break down? Are you all outta your minds?
It's fun to play "diesel truck" and such. If it's a daily "wannabe"
then have at it. In 10, maybee 20 years you can break even.
What a bunch of BS

[willowbilly3]

After you lay out 5000$ to 10000$ on saving 50cents a gallon.
Just how is this gonna break down? Are you all outta your minds?
It's fun to play "diesel truck" and such. If it's a daily "wannabe"
then have at it. In 10, maybee 20 years you can break even.
What a bunch of BS

Jake, you're a little touchy at 1:38 in the morning. Can't sleep??

[averagef250]

Come on Keith you big grump, I put the whole mess of 4BT and 5 speed in my '71 for $3000. I've spent a lot more than that on past big blocks.

It's not for everyone I spose. I'm not holding a gun to your head and making you go diesel.

This threads been going for what? Two weeks and there's already been atleast one good deal on a 4BT found. If you can't scrounge for parts and find good deals on stuff it's not for you. Retail on a diesel and 5 speed would break the bank. You have to find deals on the stuff to make it a viable option for most of us average income Joes, but they are definitely out there.

[xxxtina63]

I guess the reason I find it interesting is that 10 yrs ago when I rebuilt my 390, I didn't have access to Fordification or a lot of good used parts . I tried to buy the best parts I could afford and the only machine shop within about 45 miles is the local NAPA. At the time, I didn't realize they had the market in their pocket, charging a ton for machine work . My ignorance. While they did a very good job, the "new", unassembled long block came home at about $875. Add in the parts I needed to put it together, non NAPA, like carb, intake, distributor, etc, and I ended up close to the $2000 mark. The result was tons of power at 10-12 mpg, which was fine when gas was $1.27. Now it would cost about $10 per day just to drive to work and back.

I don't regret the 390, and I would do it again, but had I known then what I know now, the 4BT swap wouldn't be too much further away and get 25-30 mpg. You can't find good bumps around here and most parts are long gone . A rusted out diesel with a zillion miles will fetch around $5000. To find a gas truck with descent miles (little over 125k) also start around 5k, and most only get 14-18 mpg on a good day. Not much of an improvement over the 390, especially considering initial purchase price. I guess I could sell out and join the hybrid/electric crowd , but I kind of like my 67. While the truck is no longer a daily driver, I would like to make it one once again, at least in the summer. I don't want a newer truck, I want my bump back. When you go from 10 mpg to 30 mpg with gas at $3.00+, it doesn't take a great long time to get your money back, especially since they last to around 350k. That equals what, like two new 390's in life with triple the mileage?

[wt4speed#2]

Now are we talking .50 cents per gallon total figure or .50 cents per gallon initial fill-up then factor 8-12 miles per gallon better mileage than a gas motor. cause I'm thinking in some place the gas is lower per gallon , but the increase in miles per gallon make it mighty attractive.

[averagef250]

Don't forget if you're in a position to get thinner oily anything for free you may not even have to buy fuel!

[xxxtina63]

THANK YOU!!!! At least someone can see my vision. As a restaurant manager, I have an unlimited supply of fuel. Here's some links to veggie fuel:
http://greasecar.com/
http://www.plantdrive.com/
http://www.deepfriedrides.com/

[mljjones67]

That is exactly how I want my truck. Nice 4bt (aftercooled bigger cam, maybe a bigger turbo) Nice greaser kit to run the vegie oil. I can wait to smell like frys going down the road. Its gonna make people hungry where ever I go!!!

[mljjones67]

You still have to start and stop on diesel. I think????? Pretty sure you do????

[averagef250]

If you cut the grease with diesel you can usually get it started on grease if it's warm out. Also seen those kits for putting heated wires around the injector lines to start and run on grease, Can't say whether they work or not.

I figure I'll put a 20 gallon or so tank in my toolbox in the bed that's heated by the engine coolant. On trips long enough to heat the tank, I'll burn the mix of ATF, motor oil and 80/90 my shop generates. I'm working on a filtering setup to clean the oil right now before it goes in the tank. I've got a crapload of "franz" toilet paper filters including some large industrial ones that stack 5 rolls. I figure I'll use a power steering pump driven by an electric motor to push the oil first through a coil of tubing above my shop stove to heat it then force it through the TP filters. Whatever comes out should be pretty clean.

I'll have some 4BT install pics tomorrow. Yanked the 4.9 from a '94 F-250 4x4 and getting ready to lower in it's new diesel heart.

[xxxtina63]

As far as cleaning veggie oil, we use Magnesol. It's a powder that will bond to contaminants, making them bigger so they can be more easily filtered out. As a business, we pay around $55 for 50 lbs. It's worth every penny. I've seen the stuff on E-bay advertised as a veggie fuel cleaner, but only if you want to pay $19.95 for 4 lbs.!!! While I can't get it for personal use through the company, if you have a business, you may be able to get it for a wholesale price as we do.

Temperature is key to WVO/SVO. To the best of my understanding, the greasecar kits use an electric heating element inside an aluminum tank. And yes, If you want to use straight veggie, you do have to start and end with diesel. Otherwise, stuff will get plugged up. Not sure how hot the oil has to be ideally. I do know that it's pretty thick still at 150*. At around 225*-250* it really thins out. At 300*+, it's almost like water. I too have been considering the heater hose route to heat oil, but I'm not quite sure how many miles it would take to heat it. Personally, I don't want to burn anymore diesel than I have to because I would have to buy it.

BTW, looking forward to the '94 pics!