cummins 250 with turbo

[eddiec]

Well, as most of you know, I am currently without a MV. But with the upcoming arrival of my (new) 1963 m543, I have been doing a lot of searching, and studying, both on the sight, internet, as well as at all of the truck shops around this area.
My soon to be, "thanks Hot Rod" is at present time a gasser, but will be converted, either a mack or the cummins. in my resent questioning, i have learned that a jacobs exhaust brake does not hurt the engine at all, for either engine. I had been leaning toward the mack because of the turbo, but recently been told, and shown civy examples of, the cummins with a turbo installed. I have also been told that other than the changes in adjustment on the IP, there is nothing to do but bolt it on.
I know, the srossover tube will not fit between the hood and the valve cover, but you do NOT use one.
What is used is an intercooler. The air will go fron the turbo, through the intercooler, to the intake. I didn't think it would work either, but the ones that i was shown will fit between the brush guard and the radiator, just have to make the connecting brackets. (or pull a favor at your local cummins shop, and international dealership, very easy to do if you tow for them.) and i do believe that we will all agree that the cooler the air is coming into the engine, the better.
nope, no pics. delivery will not be till march, but then the fun begins.

 

[WillWagner]

"intercoolers" aka, charge air coolers were only recently introduced on the Cummins iron...1991. Prior to that, they were aftercooled, but only 350 HP and above for pre 1984 and from 300 HP up starting in 1985. If you get a 290 to 300 HP engine, they won't be aftercooled and you can still find jakes for them. There is also a low profile turbo x-over that might fit under the hood of an 800 series truck, they were used on Ford L series trucks. You will need a different fuel pump if you turbo a non turboed engine...unless you like lots of black smoke! You'll need another exhaust maniflod too. I think the cooling package stack would be too deep to fit an 855 and a charge air cooler/radiator package too, but people do make units that are of the side by side type.

 

[bigelk50]

Just wondering if you have an update for us?

 

[73m819]

if you put the cummins in, you will need 809 sheet metal, as the cummins is longer then the mack or the multi

 

[papabear]

That's what I thought to Ron

 

[Alredneck]

 

[Coldfusion21]

2+ years for an update? Seems like this one might have gotten lost.

 

[bigelk50]

Thought it was a long shot, but perhaps still a shot.

 

[martinsaunders06]

i turboed my 250 back in march using parts from a 290 and have using it since with no probs. originally i used a temporary cross over and ovalled the tube so the bonnet would fit just to see how things went but since then i have fitted a larger cross over along towards the rear rocker cover and over as there is more than enough room there.. I kept my original fuel pump albeit it has been tweaked as i wasnt looking to get gready for power and my engine does not produce any black smoke and it still runs very clean which is contrary to what will wagner said could happen ,spose im just real lucky with that then.Martin

 

[bigelk50]

Thanks for sharing! Sounds like it works great. You must not be getting too much fuel if it is not pouring out black smoke. Do you happen to have any pics?

 

[martinsaunders06]

yeah will have truck out this weekend at a steam rally so will take some up too date pics and post. martin

 

[bigelk50]

Thanks I am looking forward to it, as I am starting to collect parts to do the same to my truck.

 

[jimk]

I am working on a similar project. Like Martin, I don't plan to get greedy using the NHC250. Target is 12psi +/-2psi. That may be as high as you want to go with no intercooling. 15.8:1 pistons should be ok here but more boost might require a piston change (cumming did this with each HP increase). Timing may need to be retarded a tad. I haven't got to my road test yet but makes 5.5psi at 2100(no load) 6psi at 2200(no load). No smoke to speak of during that, but no load isn't going to say much. I have my gauges installed, just l lazy I guess. Seems some here may have missed JWaller's fine thread ( below, more pics here). There is a link somewhere in it for Pittsburgh Diesel's web site w/ tech article on Cummings hop up. Folks here may enjoy that.


http://www.steelsoldiers.com/5-ton-up/28133-818-now-turbo-pics.html

p.s. Road test shows 16psi at 2100, more detail in link above, page 8, post 72

 

[bigelk50]

I read that thread. It is very helpful. I like your cross over! where did you get your parts from?

 

[jimk]

Thanks Reub, I posted my source/cost for the tight turn section in other thread. Chassis Shop? The straight bit was NAPA exhaust stock, maybe 48" long. Used most of it. The 90* was left over from the donut. There is a little bend near turbo that was salvaged from the big rig hardware, just a few degrees there(not shown in this pic). Silicone was Innes(?) or what came with the used parts. Press tested my pipe at 20psi. Bumped it to 30 and blew an improvised PVC cap across yard. Substituted a paint cup and it too blasted into low earth orbit(clamps need to be real tight). Amazing what 30 psi can do.

 

[bigelk50]

Thanks! Looks like it should not be too hard to build one. Yeah even 30 psi can be dangerous!

 

[decodeme2]

Let us know about the extra power, and if it was worth it..?...
Kevin..

 

[treysoucie]

bumpski, any more info on these turbo swaps into the nhc250?

 

[Stalwart]

I kept my original fuel pump albeit it has been tweaked as i wasnt looking to get gready for power and my engine does not produce any black smoke and it still runs very clean which is contrary to what will wagner said could happen ,spose im just real lucky with that then.Martin

You weren't lucky, he was incorrect that a turbo install will add smoke. Additional air in a Diesel will make LESS smoke, not more. More fuel = more smoke.

 

[jwaller]

bumpski, any more info on these turbo swaps into the nhc250?

sure thing, search for my name and you should find my turbo conversion. lots of pics and such. I do have kits available for the swap.