818 now with turbo and pics.

[Vintage iron]

Nice score! but were is the intake manifold? The turbo intake is different. Air enters from the top on the turbo manifold and air enters from the side on none turbo intake manifolds. Post up pictures of your install and I will be interested to see how your M818 preforms with 16.00R20 tires and pulling that Half-track on a low boy.

 

[jwaller]

Nice score! but were is the intake manifold? The turbo intake is different. Air enters from the top on the turbo manifold and air enters from the side on none turbo intake manifolds. Post up pictures of your install and I will be interested to see how your M818 preforms with 16.00R20 tires and pulling that Half-track on a low boy.

there isn't room under our hoods for the std turbo intake to fit, so I and most everyone uses the stock milspec intake.

 

[Vintage iron]

There are two different crossover pipes that Cummins makes for turbos. One is raised to make room for a Intercooler the other is tight to the head. I am sure the NONE INTERCOOLER type will fit no problem! Jwaller you did a great job, by the way.

 

[jimk]

Below is something I found online (I can't remember where). May be of interest here.


-----Original Message-----
From: Powermaster@cummins.com [mailtoowermaster@cummins.com]
Sent: Tuesday, August 19, 2003 2:03 PM
To: xxxxxxxxxxxxx.com
Subject: Re: RQST00000169662 - NHC 250 engine manual
Summary: NHC 250 engine manual

Solution:
Thanks for your Email message.
The Cummins NH250 engine is 855 c.i.d. small (2 in.) camshaft engine rated
250 hp @ 2100 rpm with 654 lb-ft torque @ 1500 rpm and clutch engagement
torque at 600 lb-ft @ 800 rpm. The engine weighs 2500 lbs. and is naturally
aspirated with a 6 gal lube system. The engine is still in production
mostly for military applications and there should be no problems finding
replacement parts for this engine model.
In the NHC250 era, some applications needed a way to supply more air to the
engine to help eliminate black smoke problems, especially in higher
altitudes and Cummins developed a turbocharger 'smoke kit'. The kit included
all the components required to install the turbocharger on the engine, as
well as information about required changes to the fuel pump and injector
settings that increased engine horsepower from 250 to 270 hp. Some Cummins
distributors may still have the Service/Parts Topic that provides the
details of the 'smoke kit'.
According to Cummins Service/Parts Topic 73T10-1 dated January 1973, Cummins
Service/Parts Topic 72T18-1 dated June 1972 contains comprehensive details
of ratings, fuel pump codes and specifications/part number of the
significant components of all recent NH and NT models. These topics indicate
that naturally aspirated engines should be derated 3 % for each 1000 feet in
altitude.
We also have a more current bulletin no. 3379020-00 dated April 1975 titled:
NH220/230 and NHC250 Turbocharger Conversion Kits. This bulletin has
comprehensive part numbers, instructions and information about components
and changes required to install the turbocharger smoke kits on these engine
models. Your local Cummins distributor should have this bulletin in their
files and can determine if the parts are available or if current parts can
be used.
If the above topics are not available, then the Cummins distributor may want
to refer to Cummins parts catalog 3379590-00 dated March 1979. This parts
book covers the Cummins Small Cam NT-855 model engines for automotive
applications which includes NTC-250 and NHCT-270 engines.
Gannett Direct Marketing in Louisville, KY, handles all Cummins literature.
If a payment arrangement is worked out, by credit card, they can arrange
shipment of Cummins literature.
However, they deal in bulletin numbers, so before you call you need to have
all the bulletin numbers ready for the literature you need. You can reach
Gannett by calling 1-800-646-5609 or call 1-800-DIESELS and select the
literature option or email to inquiry@gdms.com .

 

[1943ht]

VINTAGE IRON .. I'll grab that intake manifold off that 400 just to see if it will fit on the 250 engine .. it would be nice it was a direct swap with the low profile intake ..

This might be a duhhhh question .. but it looks like the air-cleaner must have to be switched from driver side fender to passenger side to accomidate the turbo air intake .. is that what folks have done? I of course have a heater, and living up north its something I'm interested in keeping functional ..can someone please post some pics of their install with the air intake plumbing for the turbo?

 

[Sevin7]

I can post a pic of my air cleaner and associated ducting when I get home tonight, although I ran my turbo with the air suction to the rear, so yours will probably end up differently.

To add to the previous post, is any extra support needed to be added when moving the air cleaner to the passenger side? The driver's side fender has some extra support to accommodate the constant increased weight. I thought the passenger was pretty sturdy as it will support two adults but I am suprised how much my now relocated air cleaner bounces and vibrates over there just going down the road. When it was in the stock M809 location, it didn't do that. I have heard the stories of Vietnam trucks' fenders breaking off and strapping over the hood to prevent that. My truck mostly sees only paved road travel other that the occasional trip to Haspin. Have any of you other folks who have added the turbo beefed up the passenger side fender?

 

[Sevin7]

Here is the pics I promised a couple weeks ago, I forgot. Notice mine is installed backwards (intake side to the rear) of the way they normally are, it was the only way I could get it to fit. So your results may vary but I hope the pics help.

 

[jimk]

Fuel pump stuff.
http://www.steelsoldiers.com/5-ton-up/73444-nhc250-cummins-fuel-rail-pressure.html

 

[jwaller]

Here is the pics I promised a couple weeks ago, I forgot. Notice mine is installed backwards (intake side to the rear) of the way they normally are, it was the only way I could get it to fit. So your results may vary but I hope the pics help.

looks good, that is different and I never thought about running it that way. can you show some of your exhaust?

 

[Hooty481]

hey do you all care to show a picture of where you hooked your oil lines into the engine...

 

[Sevin7]

The turbo/exhaust manifold combo that I bought wasn't going to fit any other way otherwise I would have gone with normal configuration. My way seems less desirable since the exhaust is routed in a complex manner and that the air flow at speed blows the heat from the turbine side to the compressor side. I'm just lucky that I was able to get it to work at all. Every other way I tried the oil cooler, thermostat housing, or hood got in the way.

Hope the pics are what you were looking for. If not let me know and I can take some specifically for you, I already had these on the computer. (In the first one disregard the twine and zip tie and ignore the duct tape in the others.)

I appreaciate you paving the way for the rest of us by starting this thead. Thanks.

 

[Sevin7]

Turbo Drain Connection

Let me know if you can't figure everything out from this picture, I can take others. Mine had a 3/4" NPT (I think, but maybe 1") plug in that hole . I removed it and installed a hose barb for 1" hose. The hose is a 7/8" wire reinforced hydraulic hose. My turbo had a ~7/8" OD copper line for a drain line. The fitting on the bottom of the turbo was a weird one so I slid the hose on the copper line and used two clamps to attach it since the reinforced hose isn't meant to be clamped. On the other end I since I couldn't get a barb for a 7/8" hose, I used a knife to remove some the ID so it fit and clamped it. It is a little rigged but it doesn't leak, I'm not so sure that it would hold any pressure though.

P.S. I have some left over 3.5" aluminum tubing and silicone connectors that I used for my cross over pipe if anybody is interested.

 

[big block 88]

I think it will be just fine and the performance gains should be noticable.

That being said you really don't have to mount the turbo driectly to the exhaust manifold you could do a remote mount system and have much more room and your down pipe could be a straight shot. Also intercooling it would be a huge improvement also and would clean up under the hood a bit by eliminating the boost tube from runnig over the engine.

 

[Sevin7]

I think it will be just fine and the performance gains should be noticable.

That being said you really don't have to mount the turbo driectly to the exhaust manifold you could do a remote mount system and have much more room and your down pipe could be a straight shot. Also intercooling it would be a huge improvement also and would clean up under the hood a bit by eliminating the boost tube from runnig over the engine.

I hadn't thought about going remote. I like your ideas but they do sound like a bit more money than I was wanting to spend. In fact I couldn't believe how much adding the turbo as it is now cost me. I thought that since I got the turbo and exhaust manifold for only $200 that I wouldn't be in for too much $$. The cross over pipe and the exhaust tubing ended up being probably double the cost of the turbo/manifold. For those looking at undertaking this modification, beware of how much money it is going to cost.

 

[Hooty481]

was the drain plug that you removed did it have a 1/2' square hole to remove it. i think thats the one that i have seen.

 

[Hooty481]

Ive got my turbo mounted and oil lines run. The Over flow tank is mounted on the fire wall and the 2 5/16 lines and the big line has been extended as well.

The exhaust is going to be really easy to hook up. I have a 90degree elbow coming off the turbo going straight down and then I am going to be takeing part of the existing muffler where it hooked onto the original J-pipe and cutting it off so i can hook flex pipe onto it to run from the new 90 to the factory smoke stack.

The problem... yea theres a problem. I only have 2 inches from the top of my turbo to the cross member on the hood. I can have almost 3 inches if ia notch or cut out part of the cross member. I am open to any and all ideas on what i can use start coming off the turbo. If i can get something to clear the hood then i can hook what ever else i want on to it. one guy suggested a pre-formed rubber elbow. I am entertaining the idea. He didn't have one but told me where i could get them.

Let me know what your think!

 

[Vintage iron]

I am working on putting a intercooler on mine. I have decided on air/air or water/air. Water to air is more flexable. But I this a R model Mack intercooler will work in front of my M813 radiator. I will just need to push the grill guard out a bit.

 

[Hooty481]

here are a couple pictures... one is of my 90degree elbow coming off the exhaust side of the turbo and the other is of how close the top of the turbo is to the hood...

 

[R Racing]

Why dont you do a 45 degree or greater to move you back to clear the rib ?

 

[Hooty481]

there is only 2 inches from the top of the turbo to the rib i dont know of one that will clear