#lildebbie build thread


New member
Jun 11, 2017
Glad to be a part of Competition Diesel. We have been browsing the sight for a little over a year now and finally decided to join. Thought you guys may find our #lildebbie build interesting. Lil Debbie, our 1997 freightliner mt35 box truck, was purchased in August of 2016 and has since been transformed into a “race truck”. Term used very loosely. The original plan was to do some minor upgrades on the 4bt as a running test platform for the future swap into a Ford Excursion with maybe 300 hp. It would have been a nice commuter/daily driver that would seat 7 comfortably and get decent fuel mileage. We have about 6 years of experience running motor oil and vegetable oil in 2 different 12v trucks and thought this would be a great way to have a nicer vehicle with a motor that will still run the oil. With that we decided to install some 4k governing springs, AFC live from Powerdriven Diesel and bump the timing up to around 22* of timing. This was the first time we had real experience with the AFC Live and man what a difference it made. With just these few simple upgrades it felt like an entirely different truck. Probably the most gain with the least amount of money to date and can be attributed mostly to the AFC Live. Shortly after we installed the upgrades we posted a video online, which gained the interest of Will Terry aka bigblue24v part owner of Powerdriven Diesel. Will proceeded to convince us that we needed more upgrades and run it down the dragstrip, now who can argue with that? One thing lead to another and now we are currently attempting to race it and break into the 13 sec ¼ mile range with #lildebbie. Which with a 4bt and an 8000 lbs box truck may be wishful thinking.

And the build begins. First thing we did was contact bigblue24 about what we should get for some power adders. We ended up acquiring some 5x.012 injectors and some 7mm delivery valve from PDD to see how they would do in the little 4bt. Following that we had to get some bigger piping and an intake horn from the local big rig junk yard. That gave us some 3 in intercooler pipes, 4 in exhaust pipes, 6bt intake horn and an assortment of clamps and intercooler boots (nothing better than some junkyard boots). We then fabricated intercooler pipes to mount to a 6.oh intercooler laying around the garage that could finally be used on a real motor. We also installed a pyro and boost gauge to monitor the engine a little bit. And then the most important part was getting rid of the tiny hx25 turbo and replacing it with a “rebuilt” WH1C off of a chicken truck sitting in the woods.

Intake horn.jpg
Intake horn comparison

intercooler comparison.jpg
Intercooler comparison stock vs 6.oh

intercooler pipe comparison.jpg
2.5 in intercooler pipe compared to 3 in junk yard pipe

Turbo Comparison.jpg
Hx25 compared to WH1C

single turbo.jpg
WH1C mounted on stock manifold

We then decided we would see if the intake boot we had would hold up to the amount of boost the hx35 was putting out and that didn’t go so well.

blown boot.jpg

As you can see in the picture it blew apart at the seams, sending a shockwave through the truck, busted the plastic power steering reservoir and scared the crap out of both of us. With that lesson learned, we refabricated the intercooler pipes so that there are only straight boots on the entire system, replaced with a steel reservoir. Then off to the strip we went to see what all of the upgrades actually did. As soon as we got to the dragstrip the crew was definitely skeptical about letting our bread truck taking a pass down the NHRA sponsored strip (no joke it was a wonder bread truck). Reluctantly they passed it through tech. Probably the only bread truck to have gone through tech at the Atlanta Dragway and probably the last time. Not surprisingly it laid down a blazing fast 23 sec ¼ mile. More to come #followthebuild.

#lildebbie - YouTube
First video of #lildebbie untouched

#lildebbie box truck 4bt - YouTube
After the AFC Live, 4k springs and timing

#lildebbie first time at the track - YouTube
#lildebbie first time at track
Any advice as to how to post the youtube videos so you can see them on the thread, let us know.
IDK if anybody here watches Shameless but if you do you know what I am thinking...

Oh an welcome OP! Don't mind all of us while we have a completely off topic conversation pretending as though the name of your truck is up for grabs LOL
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The next phase of the build came after Powerdriven diesel saw our first pass at the drag strip and asked if there was anyway we could fit a dodge 47rh transmission in the box truck. We quickly remembered we had two cores sitting around waiting for rebuilds and with a little trading we managed to get a Powerdriven 650hp Transmission. Part of the deal was also that we had to meet them halfway at the 2016 NHRDA world finals in Ennis Texas to do the trade. Will also convinced us to bring lil Debbie with us and do a novelty pass and the burnout contest so without hesitation we loaded up lil Debbie and hit the road. We had a great time in Texas meeting both Todd and Will for the first time and watching the Junker Drag Truck battle to the finals in the 10.90 class where he very narrowly lost by breaking out something like .03 of a second more than his competitor. Unfortunately because of the televised event and the schedule running behind the novelty pass and the burn out contest were a bust... Maybe next year.

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bigblue24 junker drag truck staging at 2016 NHRDA world finals

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Lil Debbie in tow

Once back home in GA we began figuring out how we were going to make this tranny work in lil Debbie. Luckily Powerdriven was also able to hook us up with DPC (Diesel Performance Converters) which is not to far from us here in GA. Phil Taylor hooked us up with a triple disc torque converter that has worked flawlessly for us. To make the 47rh work we used a Dodge 12v adapter plate and starter. Unfortunately the adapter plate we pulled off our parts truck (chicken truck) was cracked and worn down pretty good. After some (6hrs) of attempting to tig weld the cast aluminum adapter plate we finally had something that was fused together enough to be acceptable. We then bolted everything up and used the dodge transmission rear mount and fabricated a small bracket to work with the existing cross member. With the trans all mounted the only thing left to do was shorten the drive shaft a little and get a shifter. With a little help from a B&M pro ratchet shifter kit and a local drive line shop we were up and running with our new #lildebbie racing transmission. We also went ahead and put some cheap 60lb valve springs in it.

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47rh mounted

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filling up with Powerdriven ATF

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Welded adapter plate

Of course at this point the only thing left to was to take her to the drag strip and see what she would do. once again amused but reluctantly the let us on the track. This time we were able to improve to a 17.07 ET at which would be almost 5 seconds faster just from the auto swap. At this point we were pretty pleased with how the 8000lb bread truck was doing so we decided to take it to the local truck pull and see what kind of numbers we could get out of it. With the crowd gathered round we laid down a whopping 235hp and 553lb which was actually more than we expected. The crowd loved the show and we were very pleased with our set up. At this point some "difficult" decisions needed to be made. Do we take it out and do our conversion as planned or build it more and see just how fast we can make the newly popular #lildebbie.

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Dyno sheet

#lildebbie Dyno Run - YouTube
#lildebbie on the dyno

#lildebbie 17sec drag run - YouTube
#lildebbie running 17.07
Once the racing bug got us, we couldn’t help but find out just how fast we could make this box truck run. It was obvious and easily agreed upon that a compound turbo setup had to be fabricated and tested over the winter of 2016 to be ready for summer of 2017. Rather than buying a newer, better turbo we decided an older Volvo semi-truck turbo, a rotomaster tv7701 turbo would have to do. It is a 65x94 compressor wheel and should easily flow enough air for the little 4bt. It has a t6 exhaust flange with a non wastegated housing. After another trip to the local junk yard we acquired all of the intercooler pipes, boots and exhaust pipe we were going to need.
We grabbed the exhaust manifold off of our chicken truck parts tuck in woods, cut the 2 exhaust ports of each end and welded the ends shut to make a makeshift exhaust manifold for the 4bt.

cut exhaust manifold.jpg

We then began to fabricate the down pipe from the high pressure turbo to the atmospheric turbo. We used some scrap ¼ steel we had laying around and a 3in 90 to route the exhaust into the rotomaster. With our limited tooling we had to drill a 3in hole in the plate steel and weld the downpipe into it in order to make a t6 flange that would bolt to the rotomaster. This is of course not ideal for good exhaust flow but would have to do for the time being.

drilling hole for down pipe.jpg

down pipe.jpg

After that we fabricated a bracket to hold the rotomaster in place.

bottom turbo mount.jpg

With the turbos finally mounted we began to fabricate all of the intercooler piping that would be needed.

small turbo mounted on cut 6bt manifold.jpg

turbos mounted on motor.jpg

piped fitted up on motor.jpg

piped fitted up on motor 3.jpg

turbos mounted on motor 2.jpg

front of engine.jpg

We also had to redo the exhaust. We were wanting to run it up through the hood but weren’t able to due to the way the hood comes up. Following that we decided to run it out the side of the truck with some 4in exhaust.

exhaust 2.jpg

For the oiling we picked up a supply hose from pioneer rubber and gasket down in Atlanta and decided to run the turbo drains together and back into the stock turbo drain return. This is of course frowned upon as it is possible for the drains to backup and push back up into the bottom turbo but we went ahead and figured we try it and see what happens. At this point we wired the waste gate on the WH1C shut due to the limited amount of space we had between the 2 turbos. We then got a PDD performer air filter and threw a 6bt harmonic balancer on the motor since we had one laying around.
Once it was all together and running we took it for a quick test drive. Surprisingly it easily boosted over 80 psi and not surprisingly blew the stock head gasket even with the bolts re-torqued to 145 ft/lbs.


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Thanks for the support guys we have been having a lot of fun with this build! Much more to come.
With a blown head gasket and the first local test and tune of the year coming up we began searching high and low for someone in north ga that had a 4bt head gasket in stock. As you can imagine absolutely no one had one in stock or could get one within a day or two. As a last resort, we tried craigslist and to our surprise we found someone local who had a bunch of old stock 4bt parts. We quickly purchased a few head gaskets considering our chances of blowing one again in the near future. Once we were home the race was on to get the truck back together well enough to at least see what it could do at the track. An added benefit of blowing the head gasket was it gave us the excuse to do a port and polish. Because of the rush we only had time to do a quick port and polish. After getting the new head gasket Sunday evening and spending some late nights after work we were able to get the truck back together and running and re-torqued by wed night. Thursday, we tested lil Debbie out around the house and adjusted the AFC live so that we could keep the boost below 60. At the same time, we also got a “little” carried away and brought the timing up to 29 degrees. Friday night we ran the first pass pretty easy limiting boost to 50 psi which resulted in a low 17 sec pass. We then started to dial up the AFC live until on the 5th pass it was about 80 percent of full fuel. On this pass, we happened to be racing an Acura Integra and gapped him off the line but as fate or more accurately physics would have it, the Integra began to catch up mid track and instead of keeping the boost under 60 psi the competitive side took over and well the pedal stayed to the floor. Lil Debbie still had plenty left in her and ended up running right with the integra and doing a personal best with a 15.76 @86mph. After getting the truck back to the staging lanes it became apparent that once again the combination of high timing, high boost and stock head bolts and head gasket just wasn’t up to the task. Even with the blown head gasket we were still impressed with how much we could throw at the motor. Now after “playing” around as we had been and paying the piper we had two choices; take it back closer to stock or tear it down and build it from the bottom up.

Thanks for posting. We are in the process of assembling a 4bt for the wife.
Just saw the other vid with the Miata; this thing is awesome! LOL

Just saw the other vid with the Miata; this thing is awesome! LOL


I know, time for an update if you're running a second quicker! The 60ft actually looked pretty dang good for a 8000lb 4 banger too :Cheer: