NHC 250 Turbo Conversion in M923

[ODdave]

I think it looks great. One of the best 900's I have seen. The stack looks like its ment to be there imo.

 

[monkster]

Do mine.

 

[Bolkbich]

Hey Brad, did you ever get the boost gauge installed ?

 

[Bjmca]

Hey Brad, did you ever get the boost gauge installed ?

I got the gauge mounted in the new pod on the column with the pyro, it's hooked up but the light is not wired in yet. I will shoot a pic tomorrow and post it. They both look good mounted there, are easy to see, and I did not have to cut any holes to mount them.

I just got my hands on a cummins pt pump rebuilding and calibration instruction book from a truck shop so I'm doing some reading on pump setup before I get into it any more.

I just ordered a number 12 and number 10 button.

For anyone that's interested the cummins part numbers for the fuel buttons (Idle spring plunger) are as follows:

#5 cummins 141623
#7 cummins 141624
#10 cummins 141625
#12 cummins 141626
#15 cummins 139894
#17 cummins 140417

 

[Bjmca]

Also for anyone who cares to know about the governor spring and shims: "each .001 inch shim thickness will change the speed approximately 2 rpm. Shims are available in .005, .010, .020 thickness. If over .150 shims are required, replace the spring."

From talking to some of my truck guys they tell me it's not so much about the max rpm being able to rev higher, it's about the point at which the governor starts de-fueling as it nears it's max rpm. Obviously it's the drivers responsibility to not over rev the engine, so this may not be for everyone.

 

[Bolkbich]

How much boost is it making?

 

[Bjmca]

How much boost is it making?

I seeing a max of 14 psi. Truck is running pretty clean with really no smoke, but it pulls better. Can't wait to get my other buttons to add some fuel

Here's the new autometer guages mounted on the column with autometer mounting pods. They use a standard hose clamp to mount to the shaft.

Pretty easy to see while driving without cutting holes to mount.

 

[Brian46]

Hi again guys, after many other projects around the place I finally got to work on my M923. I rounded up the parts to fit the turbo on the NHC-250 to get a little more from it. Before anyone starts screaming about blowing it up, have no worries, I have a big cam on standby . I will start with some pics and work from there. Here goes...........

what turbo did you end up using?

 

[Jayco36REQS]

It would great to see a parts list it took to do your Turbo conversion..... I am wanting to do this on my 923A1 as well.

Awesome truck you have!!

 

[foxtrot1551]

It would great to see a parts list it took to do your Turbo conversion..... I am wanting to do this on my 923A1 as well.

Awesome truck you have!!

x2 on that parts list! Great looking rig you got there. Did I miss the video or are we still waiting to hear it?

 

[350TacoZilla]

Your MONEY, your TRUCK, do what ever you want to do, as long as YOUR happy, that is what counts, no matter you do, it could be worst, it could be a bobber

it actually looks like the perfect redneck pickup as a bobber, which is the plan for mine. Bjmca I would love to see your truck sometime, I had hopes of finding a A2 8.3 turbo truck but they all went out of my budget pretty quick so I got a nhc250 standard 923 and your turbo setup looks like it could be put together for decent cost to pacify my need for the turbo whine lol .

what are the junkyard intake pipes off of dodge rams?

also did you do the dual fuel line mod the 800 series guys swear by?

 

[jrod66]

dual fuel line mod? I have not heard of this yet, could you elaborate? thanks.

 

[Mike Barns]

hi bjmca,

to pull my "Jaguar" hunting tank, I use a M931 tractor with the same engine. With 35 to in your neck pulling get really hard smile. I guess you are specialist in NHC 250, what do you think - makes it sense to do the same for a better, reliable puller?

Mike

 

[350TacoZilla]

sorry I should have put that the tractor guys swear by. I think all 855's have this capability though, not sure till my truck gets here for me to look directly at it. basically you put a T on the fuel line at pump and feed both ends of the head not just the one, supposedly nets you 10-20 hp, motor runs smoother and better mpgs. from what I gather most (if not all) 855's have two ports on back of rear head where fuel supply and return come out, the front head has same ports on the front so you just tap into fuel line and run into the front head so the front 3 injectors get same amount of fuel as the rear 3 do regularly. i have also seen it mentioned that the N14 cummins came with the fuel lines this way from factory after a certain year so there may be merit to the claims.

 

[jdknech]

so where did you plum the oil feed from? thats the only part that has me scratching my head at this point.. i am planing on starting my turbo install this coming weekend..

 

[crewcab454]

I removed the petcock fitting from here and attached my oil feed line.

 

[Jakelc15]

Very nice. I'm also wondering which model turbo you used.
Btw 1300° exhaust = engine damage. Aluminum melts at about 1220°. The pistons are made of some kind of aluminum alloy and probably won't take that kind of temp for long. The piston will start sticking to the liner and then it's all over.
Also the injectors will take all the pressure you can give them but at a certain point the pressure is making the injector spray onto the liner instead of the piston. Washing the oil off the liner which makes the piston start sticking.

But I will be adding a turbo to mine soon too!

 

[jdknech]

I removed the petcock fitting from here and attached my oil feed line.

Thank you Sir! that is what i needed...

 

[Vintage iron]

I just finished the dual fuel line mod on my M923 with a Cummins 250. Yes the trucks runs noticeably smoother and stronger. The negative side is that I lost 100 RPM on the governor.

 

[jdknech]

I just finished the dual fuel line mod on my M923 with a Cummins 250. Yes the trucks runs noticeably smoother and stronger. The negative side is that I lost 100 RPM on the governor.

easy to get back with shims... but i don't understand how the duel feed would make you lose 100rpm?