Yet another 6bt swap...

[BA_051]

That last post made no sense at all, sorry about that!

Well a lot has happened since my last posts. I moved back from Seattle to Albuquerque and have started flight school. Working on my private pilot license and will work up to commercial.

During the move the head gasket failed under the thermostat housing... I was about 300 miles outside of Seattle. Even with it 4 inches low in the radiator, engine temps were not an issue. EGT’s would climb to 1200-1300 very quickly in the grades. I had to watch it closely and backed off when it hit 1300... it made the remaining 1100 miles ok...

Long story short, I pulled the head when I got home and took it to a shop to be checked out. They found 4-5 cracks in each exhaust seat and 2 went deep into the head... it was junk... luckily Doug (the machinist) had a 12v head core just laying around. $450 later I had a freshly surfaced and rebuilt head. I also had the injectors tested and they all failed... the spray pattern was horrible and they all popped at 200ish Bar instead of 260 bar (about 800psi low). So instead of paying that shop $90 each to rebuild them, I ordered a set of 5x.012 SAC injectors for $400.

I have most of it back together but haven’t started it yet. Hopefully I will later this week.

[BA_051]

It lives! After bleeding the injectors, it fires up and runs great. Way better than before. The old injectors were low on pop pressure (about 800 psi low) and the spray pattern was erratic and stream like...

New 5x .012 injectors, new head, and I adjusted the wastegate to open at 35 psi. This thing is totally awesome.

An update on the build... I still don’t have heat or AC in the truck or an intercooler.

Eventually I will buy the air/water setup from frozenboost for about $500 for the 1200hp kit.

I will also make my own under dash box so I can have heat and AC through all the vents and have the defrosters remove moisture as well. Unless I can find an underdash combo unit that’s relatively inexpensive (3-400)

I am also in the process of building a 14b front axle. I have the axle, a 25” piece of DOM 3.375x.5 wall pipe for the long side, solid inner kingpin C’s, ford outers and all the kingpin rebuild parts. All I need are brake brackets and brakes. I haven’t decided which style I want to run. But another $500 to finish the axle...

[BA_051]

So I have decided to go with factory Cummins parts to add an air-water aftercooler. To swap it, the aftercooler and all 6 injector lines will need to be swapped. I have most of the parts on order and will be doing the swap next weekend.

And despite what people say about air-water CACs heat soaking, the new Ford 6.7 PSD’s are air-water CACs. If the air-water CAC is designed properly, it will not “heat soak.”

I dont want all the added complexity of a separate cooling loop and 12v electric pump, so I will be plumbing it into engine coolant. I will use the side port behind the alternator to supply cool coolant (it will absorb a little heat from the engine) to the CAC and return it to the upper radiator hose after the thermostat. This will cycle some coolant through the radiator to cool it and provide reduced coolant temps to the CAC.

I also changed the factory 12v manifold to a ported 3rd gen manifold. I used a carbide burr to make the ports rectangular and opened the area internally to allow increased flow to the turbo. I had to buy a cobra head turn down as well to get it to fit between the firewall and the back of the turbo. Unfortunately the Vband on an he351 is 4.4” whereas the cobra head was 4” from an HX40. I cut off the Vband on The cobra head and gas welded a 4.4” Vband to it. I used my OA to weld because the cobra head is cast iron. I used my gr70 rod with a flux designed for cast iron and it welded very nicely.

Part numbers are:
Cummins cobra head: 3927862
Cummins aftercooler: 3919806
Injector lines: 3930739, 3930740, 3930741, 3930742, 3930743, and 3930744

[rang-a-stang]

Sounds great! Lets see it go down!!!

[BA_051]

Well I called Cummins and the warehouse delivery was delayed until Monday so not going to be doing much on it this weekend... I will be replacing the motor mounts and routing some of the exhaust. Oh well, always next weekend.

[Heep-J4000]

Could you post a picture from the engine mounts onto the frame?
I'm organising things to put a 12 valve into my j4000 and like to get some ideas.

Thanks

[BA_051]

So I was able to do a little work this weekend. I didnt get as much done as i wanted but it is some progress.

Here is the cummins cobra head i modified. The factory vband is 4" vs the he351 is a 4.4" vband. I machined off the factory Vband so the 4.4" Vband flange slid over it. I gas welded it and used cast iron flux. It welded up nicely and no cracking. Then i ported it out using my carbide burr so it has good flow.

[BA_051]

And i removed the intake/grid heater and the injector lines and replaced them with the JWAC intake and lines.
I also replaced the factory 1st gen manifold with a 3rd gen manifold that I ported from round to square ports. Everything bolted right up. I still need to plumb the turbo to the intake and run the exhaust.

I built the heater box to clear the first gen style manifold. It works great and even has the blend door in it. I went with a 3rd gen style so I can go back to the factory heater box. It also opens up the option to twin turbo it. I can run my he351 with an ht3b or similar.

There are a few options on the plumbing of the JWAC.
1) I can run a completely separate loop using a 12v pump, radiator, and reservoir. (most complicated)

2) I can plumb it into engine coolant just like the factory marine and industrial apps and dont need anything except hoses. (least complicated)

3) I can run a combo of both. I will plumb it from the outlet behind the alternator into a separate radiator to cool the coolant down to ambient, then into the JWAC. The outlet of the JWAC will feed into the lower radiator inlet. The system is identical to option 2 with the addition of a separate radiator between the engine water pump and the JWAC. It may cause the engine to run on the cool side when boost is not being used, but it will provide a good drop in the charge temp without all the additional hardware to run the system.

injector line part numbers: 3930739 through 3930744
JWAC intake part number 3919806.

[SJTD]

Pichers not working. Buncha minuses.

[BA_051]

hmmm, maybe they are fixed now?

[scout4bta]

No pictures.

[BA_051]

ok pics should be working now. I forgot to add them to my shared album. More work to come this weekend.

[Heep-J4000]

Pictures are working for me!
Like to see more of your build!
Thanks

[BA_051]

I have two different sub projects going on this beast... it is up and running using the JWAC, but it still is not plumbed in. I am looking to find a decent radiator/heat exchanger to use that fits the dimensions I need.

I also just ordered the inner axle shafts ($225 ea) needed to complete my 14b front axle so I can swap that in. I

[BA_051]

Alrighty! So my new 4340 inner shafts came in. They were machined from Yukon 40 spline blanks to the GM 30 spline and are the stock d60 ujoints. Thanks to Branik Motorsports in Illinois for machining them. Fantastic machine work!

I also figured I would upgrade to the 35 spline outers since I was purchasing everything piecemeal... everything went together perfectly, from the Solid inner Cs, the kingpin parts, spindles, you name it, it all went together perfectly... or so I thought...

The 35 spline Ford stubs (11.375in length) I purchased are to long for the Ford outers... the stub would stick past the end of the wheel hub by approximately 1/8in preventing the lockout hub from seating.... The snap ring location was also about 1/4in away from the surface it was supposed to ride against allowing the axle shaft to move in and out 1/4in...

My solution, I used my angle grinder and carefully cut the stub shorter using the old snap ring groove as a guide. I assembled the hub, marked the new snap ring location, and used a metal hose clamp around the splines as a guide to cut the new groove. In the end, it worked great. It all fits together as it should....

Has anyone here experienced a similar issue with the Ford outers and the stub shaft being to long? I made sure I ordered a 35 spline stub for ford axle opposed to the Chevy or dodge axle being it is .600in shorter. I needed the stub to be 11.188in as opposed to 11.375in...