6CTA8.3 engine rebuild for Sur Móvil

Hey alright! Glad to hear she's almost ready for the road again! I'm going crazy not having my M928A1 dug into yet, but I'm sure I will in due time. On the bright side, I at least get to see an M923A2 every day, keeps me sane in the meantime!

Wow, holy ****, I can definitely tell that it’s been well over a decade since I’ve done any TIG welding. Didn’t spend much time welding on it because my welder was almost out of fuel, but I did get some done. I really wish I had a foot controller for this welder too, but that will just have to wait for now.

I swear, if it ain’t one flipper thing it’s another!!!!! I drove down to TMG to pick up the last throttle linkage upgrade kit they had, and a couple zipper boots since I needed them too. 10hr round trip, not including the time me and Rob spent just chatting and annoying Samantha lol, not bad for what I’m used to.



Got back home and the next day or so I double checked the bag of parts so I could assemble the last bit of what I needed....only to find out it didn’t have it all. SUMBEACH!!!! In the time the truck has been apart the throttle linkage bracket walked off somewhere, unfortunately it also took with it the throttle linkage ball stud, and the TV stud as well. So now, instead of the brand new one from TMG, I’ll just copy that bracket to a piece of raw steel, drill the necessary holes, find a ball stud and a clevis stud on eBay, and finish up the aftercooler shell build. Hopefully I haven’t forgotten anything else that needs to be done before I can start the engine. I gotta admit, it’s taken a couple hours behind the hood, but I’m finally happy with my TIG welds again. Had to drive to the nearest large city so I could grab a large holesaw for the inlet tube.

I finally got the new intake plenum finished last night and bolted into place today. Got the fuel lines on and started to bleed them and it started. It was running on only one or two cylinders and it was a good thing the neighbor happened to stop by as this was going on, because he noticed a massive oil leak while I was still focused on bleeding the fuel lines. Unfortunately that oil leak happens to be right at the front of the fuel pump, so the **** thing has to come back out again FML!

I just looked at video that I recorded the day I put the pump in place and the o-ring that I thought I may have overlooked in my haste to put the pump on was actually there. So now I am at a loss as to why I have a leak at the front of the pump. I am trying to talk to Will, but he hasn’t replied to my text yet so I’ll be scouring the web to see if this happens to be a common problem or not.

Sorry, I left my phone in the jeep.....Missed my daughter too, she was gonna buy me lunch!

There are 2 o-rings up there. One is the big round o-ring around the main pump body, the other is a square cut one that goes in a machined spot on the gear housing, it is about 1/4 id and 3/8 od, this is the pressured oil supply for the pump. It makes a mess when you leave it out. I don't have access to QSOL any more or I could dig up a picture of it.

Make sure you fill the governor with oil, it takes a long time to fill when using engine oil pressure, long enough that parts can be damaged from lack of lube.

Use grease to hold the seal ring in place

Nice to see her coming together! Also nice work with the welds. I wouldnt try to tig weld without a pedal. Im too used to a pedal to try. Keep up the great work!

Are you planning on an intercooler? Did you cut up an old intake manifold or is that completely new?

Lukes_deuce said:

Nice to see her coming together! Also nice work with the welds. I wouldnt try to tig weld without a pedal. Im too used to a pedal to try. Keep up the great work!

Are you planning on an intercooler? Did you cut up an old intake manifold or is that completely new?

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I waited until I got a pedal lol I could’ve done it without the pedal it it was just easier with it since I had it and I could work on it on the table. Can’t do that with most of the rest of this build but that’s just life.

No intercooler at all, this was a fresh build with brand new material. I’ll be using wet compression for keeping EGTs down. I may add an injector after the turbo but before the intake plenum, but that all depends on how many injectors I’ll need for this size of engine.

Since I forgot to post about it last night, I finally got the engine running last night. Only issue I have now is a massive air leak somewhere under the cab I think and the fuel keeps losing its prime. Not sure what the deal is with the priming, only thing I can think of is that the bleed screw on the pump has a bad gasket/seal so I may try to put a small o-ring in there and see how that does.

Mos68x said:

I waited until I got a pedal lol I could’ve done it without the pedal it it was just easier with it since I had it and I could work on it on the table. Can’t do that with most of the rest of this build but that’s just life.

No intercooler at all, this was a fresh build with brand new material. I’ll be using wet compression for keeping EGTs down. I may add an injector after the turbo but before the intake plenum, but that all depends on how many injectors I’ll need for this size of engine.

Since I forgot to post about it last night, I finally got the engine running last night. Only issue I have now is a massive air leak somewhere under the cab I think and the fuel keeps losing its prime. Not sure what the deal is with the priming, only thing I can think of is that the bleed screw on the pump has a bad gasket/seal so I may try to put a small o-ring in there and see how that does.

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Are you referring to water injection, like water methanol injection used to improve performance?

Lukes_deuce said:

Are you referring to water injection, like water methanol injection used to improve performance?

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Yes, but it’s not always for performance. In this case I’ll be using a nozzle ahead of the turbo for wet compression, sized only for the required air and it’ll be just controlling heat created within the turbo. If I want more after that then I’ll install them post-turbo.

Grabbed a new o-ring from the neighbor yesterday to replace the failed bleed screw seal on the inboard side of the fuel pump. Bled the fuel system once again, also finally wired in the EGT gauge and started the engine. The engine ran for a while, but eventually died and would not start again. It acts like it has a fuel supply issue, so if this new o-ring hasn’t failed, then I have a failed seal somewhere else in the system. I’m honestly really tempted to get an electric fuel pump and install it near the tank.