818 now with turbo and pics.

[Sevin7]

Did anyone block off the hole where it shows vaccum to tell if the air filter was stopped up or block off the cold start pump? I did not and was wondring if this would matter. Was also thinking about useing the line that was to show vaccum for a boost gauge.

I disconnected and plugged the air cleaner tester connection on the manifold. I also disconnected the cold start system and replaced it with a either injection. I am pretty sure it is necessary to disconnect and plug the air cleaner tester but I am not sure if it is necessary for the cold start stuff (mine leaked anyway so the choice was obvious). My plan is like you said, to use the extra connection to obtain boost reading from. I would like to reconnect my air cleaner tester gizmo somewhere between the filter and turbo but it is low on my priority list.

 

[spicergear]

looks good. keep it up. a 939 conversion should be way easier and you could use all the std cummins parts bc hood clearance is not an issue. you could even use the intercooler on the drivers side to help and run a lot of boost.

From the 6CTA to the big 855? Aren't the 900 series trucks factory turbo trucks? I think I'm missing something...

 

[Hooty481]

the M915, M916, M920 have the 400 big cam engine and have turbo. But i think i am correct in saying that the rest still have the NHC250 wich are none turbo

 

[spicergear]

Ahhhhh...I wasn't thinking about those first 3 you mentioned. Right. My M931A2 does have the 250hp turbo 6CTA. Apparently they're pretty easy to turn up too. Lots of marine application with a lotta horsepower in the 6CTA's.

 

[Sevin7]

I think what they are getting at is that a M939A0 or M939A1 (not M915/M916/M920/etc), which are still NHC250's (non turbo), would be easier to add turbo, crossover pipe, and a water to air intercooler because of the increased engine-hood clearance. The M939A2 has the newer, turbo charged 6CTA.

My thoughts that if there is all that extra hood clearance on a A0/A1, why not go with one of the Big Cam engines with a jake and everything already on it? There are take-out NTC400's frequently on GL. Seems like that would be a pretty simple swap as long as the Allison can handle the torque.

Admittedly I don't know that much about 939's or heavy duty diesels so someone please correct me if I am wrong.

 

[jwaller]

I think what they are getting at is that a M939A0 or M939A1 (not M915/M916/M920/etc), which are still NHC250's (non turbo), would be easier to add turbo, crossover pipe, and a water to air intercooler because of the increased engine-hood clearance. The M939A2 has the newer, turbo charged 6CTA.

My thoughts that if there is all that extra hood clearance on a A0/A1, why not go with one of the Big Cam engines with a jake and everything already on it? There are take-out NTC400's frequently on GL. Seems like that would be a pretty simple swap as long as the Allison can handle the torque.

Admittedly I don't know that much about 939's or heavy duty diesels so someone please correct me if I am wrong.

This is exactly what I meant. the 939 and 939A1 has the 250. the A2's have the baby cummins which is already turbo'd. You should even have enough room for the jakes without any issues.

 

[jwaller]

Ahhhhh...I wasn't thinking about those first 3 you mentioned. Right. My M931A2 does have the 250hp turbo 6CTA. Apparently they're pretty easy to turn up too. Lots of marine application with a lotta horsepower in the 6CTA's.

Your A2 correct, the A2's do have turbo's. The original 939's do not. those are what I was referring to.

 

[sbkarmen]

Man I so want a turbo, I go up and down the cajon pass once a week with my m818 converted to m813, man with the 53 Michelins it barely gets up the hill in forth gear @ 37mph according to my gps. I wonder if you could do a complete engine swap with the M931A2 250hp motor? I'm tempted to try jwallers set up, but I'm new to diesels but own an automotive shop, so its doable just don't have the energy any more to be creative or whatever... lol Nice job though!

 

[jwaller]

it's not hard at all. if you can change spark plugs you can do this swap. it really is that easy.

 

[Hooty481]

It was a very simple upgrade. I believe I would install the turbo before i would go to all the trouble of doing an engine swap.

But if I was going to swap engines I would swap with something a little bigger than whats in a m939 series truck.

 

[sbkarmen]

I wonder what the reliability would be with a turbo on a cummings 250? I'm gonna go through the thread again to understand the set up more. Basically its mounting the new exhaust manifold and turbo, getting oil to the turbo unit, plumbing the exhaust and the intake right? sounds easy but I'm sure its a bitch, but I think if its slightly reliable it will be well worth it with the 53" tires. My first MV and boy was I naive thinking it would be no prob going up a steep incline. Live and learn!

 

[Hooty481]

they have been doing it for years. cummins made a kit to do it. it says it in the thread not sure what post it is but you can get all the literature from cummins.

 

[jwaller]

They are more reliable with the turbo IMO. the EGT's are lower and the engine is less prone to low RPM lugging. All the parts needed can be found in a class 8 junk yard and done in an afternoon. the only fabbing that needs to be done is the exhaust pipe and air intake tube from the turbo to the intake. easy stuff.

 

[sbkarmen]

cool I'm going to be on a look out for a turbo set up in my area, I'm in Fontana CA, it supposed to be the trucking capital of the world (whatever...). The question I had was on the #10 or #20 button?? What is that for fuel trim or something? Fill me in guys I'm so lost when it comes to deisel, I'm mean I understand the function and am really familiar with gasoline engines but deisel stumps me! lol

 

[sbkarmen]

anybody know of anyone who has a turbo manifold set up @ a salvage yard? I tried in my area got a couple of numbers with no luck here in So Cal. If you guys see something let me know! Man this thread is so pivotal on my needs its not even funny!

 

[sbkarmen]

Ok guys just found a turbo unit for a NTC 290, I want to purchase a new turbo unit will a HX50 work? there are N14 and a whole mess of others. do you guys no which one is best bang for the buck or just overall the best one? I'm also about to tackle this job just like some of you, got some great ideas too. The one thing that's holding me back is the oil pressure line and return line, don't know where the heck they are, I just got the hood up and couldn't find anything. after that I think it should be good as far as physically mounting it. Then I've got to worry about the button for the fuel mixture control?? and the blow by thing I have to plug in the rocker cover assembly. Any help will be appreciated, the more pics the better! lol thanks so much so glad I joined this forum!

 

[Hooty481]

The oil pressurenline will come out of the top of the oil cooler. There should be an oil analsis port there that you tap into. It's where we have all tapped into. There is pictures of in this thread.

The return line is a big hole in the side of the engine under the exhaust manifold. You will just get a fitting and switch it out with the plug.

I am running the #10 button in my pump. I have the pump from a 290 cummins on mine as well. You can adjust your pump to run as good as my pump.

The holes under the valve cover are super easy to plug. I can't remember the size of the plugs I used I am thinking they were 5/16 or 3/8. You will be able to tell when you get the cover off. Just get a die and Thread the holes. Be sure to put grease on you die to catch the shavings.

One thing that you will want to do is to plug the line on the intake that show the vacuum that tells wether your air filter is stopped up. You can plug it or use it for a boost gauge.

 

[1943ht]

Welcome to the "Disease" Did a turbo on my M818 last fall using this thread and a little "Just Take The Plunge Attitude"

It really helped having a major truck grave-yard right down the road

As stated by others .. the modification is not to difficult .. In my modification I built braces and supports for my passenger fender when I relocated my air-cleaner from the drivers side .. you can make it as involved as you want

Just ask questions and answers will be provided .. SS is a wealth of info

 

[sbkarmen]

Well I found the plug for the return line for the turbo, I just need a good photo if possible of the oil fitting for the pressure line, and there was something somewhere that I read where you have to plug something in the rocker covers or something like that. The other and final thing is the buttons for the fueling?? I should get her done no problem but just need a little more detail. I can't find any bone yards for semi's out here online anyway. I bought a turbo exhaust manifold off a 290, I want to buy a new or refurbished turbo unit instead of a used one, just don't want to putz with it for a long time after I get it done. So I'm having trouble understanding which turbo unit I should use like HX50, HX60, N14 yada yada yada...

 

[sbkarmen]

The oil pressurenline will come out of the top of the oil cooler. There should be an oil analsis port there that you tap into. It's where we have all tapped into. There is pictures of in this thread.

The return line is a big hole in the side of the engine under the exhaust manifold. You will just get a fitting and switch it out with the plug.

I am running the #10 button in my pump. I have the pump from a 290 cummins on mine as well. You can adjust your pump to run as good as my pump.

The holes under the valve cover are super easy to plug. I can't remember the size of the plugs I used I am thinking they were 5/16 or 3/8. You will be able to tell when you get the cover off. Just get a die and Thread the holes. Be sure to put grease on you die to catch the shavings.

One thing that you will want to do is to plug the line on the intake that show the vacuum that tells wether your air filter is stopped up. You can plug it or use it for a boost gauge.

Thanks Hooty, yeah I'll use that intake line for the boost, gotta figure out the button thing and where to buy it, I saw the forum on pump.

I couldn't find the thread where it shows the oil cooler, I guess I'll check the truck out in the morning and go from there.

I'm going to use oval tubing for the cross tube and then with 90 degree silicone hose return in back to round tubing so its more flat over the rocker covers.

thanks for your input gonna see if I can find the thread for the pressure line now.