818 now with turbo and pics.

[Bjmca]

Great work to you all and tons of great info.
But my question is has anyone done a M923?

Thanks

Jeff
Fort Wayne IN
1986 M923A1

Just finished mine over the weekend the pics and writeup are in the 5 ton mods section. Sorry I don't know how to link.

 

[buzzinhalfdozzen]

Bjmca and sbkarmen,

Did you guys remove the valve covers and plug the holes in the heads? Just wondering what size tap to and plugs to use. From my understanding, if you don't plug them the boost pressurizes the rocker boxes and turns into blow-by. Some one please correct me if I'm wrong.

 

[buzzinhalfdozzen]

Answered my own question, see post #72, last pic.

 

[Bjmca]

Bjmca and sbkarmen,

Did you guys remove the valve covers and plug the holes in the heads? Just wondering what size tap to and plugs to use. From my understanding, if you don't plug them the boost pressurizes the rocker boxes and turns into blow-by. Some one please correct me if I'm wrong.

I pulled the covers and plugged mine with the 5/16 Allen set screws available at my local hardware store, but I must say prior to tapping them I attempted to poke a wire down the hole and it felt like it bottomed out. The holes had oil in them so I could not see down it anyway. I am not so sure those holes actually go through the rocker boxes.

Anyone have one off to confirm?

 

[Warthog]

Just finished mine over the weekend the pics and writeup are in the 5 ton mods section. Sorry I don't know how to link.

http://www.steelsoldiers.com/5-ton-mods-hot-rodding/90372-nhc-250-turbo-conversion-m923.html

 

[sbkarmen]

The fuel button is located inside the governor spring cover directly at the rear of the injection pump. There is a square cover on the back, it should still have safety wire on the bolts, and you will see a pipe plug on the hump of the cover. You need to remove the 4 bolts and carefully remove the cover, be cautious not to ruin the gasket, there will be fuel that runs out when you do this.

You will see a plunger under this cover, this is the high speed governor and idle speed control. Carefully remove the snap ring directly at the rear of the governor, Keep one finger on the spring pack so you do not drop any of the parts!!!! There will be a stack of shims that controls spring pressure for the rpm governor, remove them and set aside along with the snap ring and heavy washer and then main spring.

You will have a clear sight of a set screw in the back of the plunger, do not turn it just pull it strait out the rear. You will now have the plunger assembly in your hand which houses the fuel button right in the front, switch it with the new on and reinstall in reverse order.

The most important part is to not drop shims. I would have liked to have some photos of doing mine but I had fuel on my hands and was not about to dirty the camera!

About a 10 minute project as long as you don't drop parts, or drop the snap ring and have to spend another 10 to find it

Good luck, project is looking nice.

thanks BJMCA, that is exactly the kind of help I could use, considering I've never worked on a deisel. So a huge thanks for your time!

 

[sbkarmen]

Well I finally got it done just about, just need to fab an exhaust mount, going to my fab guy to do it should be fine driving there. I also want to get the boost guage on there with a pyrometer, it seems way cooler than before no black smoke under load acceleration. I put a 17 fuel button on there, she has good power now except on the bottom of 4th gear kind of lags, I think I'm just spoiled with the power everywhere else. Anybody have a suggestion on making more grunt on the bottom of 4th? Oh also have to install the air filter assembly on the right fender and support for that as well. I also went with a 45 coming out of the turbo for more clearance, I'm not gonna lie, I got that from one of the guys on this thread, so thanks!!!! Kinda spooked me running the engine with the impeller pretty much exposed like that. I'm glad I got it done the whole project so far set me back $750 for the 4LHR Turbo, bout $490 for all the 5" exhuast stuff (which I have some extra crap left over), bout $425 for the intake tubing, bout $550 on the pressure hoses, silicone hoses, pipes and fitting with silicone clamps. and $225 for the exhaust manifold. So far I have put $2440 into it, but its all new except the manifold, I just didn't want to mess with it later on (don't have time) **** look how long it took since I started asking questions! I figure the fab guy will charge me anywhere from $100-$200... I hope! lol he does really awesome work though, I could do it, but I want it to look nice! Let me know what you guys think!

http://i34.photobucket.com/albums/d109/superbikearmen/20120718_173649.jpg

http://i34.photobucket.com/albums/d109/superbikearmen/20120718_173042.jpg

http://i34.photobucket.com/albums/d109/superbikearmen/20120718_173114.jpg

http://i34.photobucket.com/albums/d109/superbikearmen/20120718_173209.jpg

http://i34.photobucket.com/albums/d109/superbikearmen/20120718_173628.jpg

http://i34.photobucket.com/albums/d109/superbikearmen/20120718_173114.jpg



Here's a youtube vid, and before you guys go crazy on me because of the revs the motor had been running for about 20 min, but my dumb ass friend really shouldn't of been revving that high. but I got some video for you guys to see.

[media]http://www.youtube.com/watch?v=LN9U1teI-F0[/media]

 

[jwaller]

Well I finally got it done just about, just need to fab an exhaust mount, going to my fab guy to do it should be fine driving there. I also want to get the boost guage on there with a pyrometer, it seems way cooler than before no black smoke under load acceleration. I put a 17 fuel button on there, she has good power now except on the bottom of 4th gear kind of lags, I think I'm just spoiled with the power everywhere else. Anybody have a suggestion on making more grunt on the bottom of 4th? Oh also have to install the air filter assembly on the right fender and support for that as well. I also went with a 45 coming out of the turbo for more clearance, I'm not gonna lie, I got that from one of the guys on this thread, so thanks!!!! Kinda spooked me running the engine with the impeller pretty much exposed like that. I'm glad I got it done the whole project so far set me back $750 for the 4LHR Turbo, bout $490 for all the 5" exhuast stuff (which I have some extra crap left over), bout $425 for the intake tubing, bout $550 on the pressure hoses, silicone hoses, pipes and fitting with silicone clamps. and $225 for the exhaust manifold. So far I have put $2440 into it, but its all new except the manifold, I just didn't want to mess with it later on (don't have time) **** look how long it took since I started asking questions! I figure the fab guy will charge me anywhere from $100-$200... I hope! lol he does really awesome work though, I could do it, but I want it to look nice! Let me know what you guys think!
]

I would say that oil return line on the turbo is too small. in the pic it looks like about 1/2". needs to be 1" or bigger. if its too small you will see blue smoke from the exhaust as the oil begins to push past the oil rings in the turbo and come out the back side. it can also push out the front and start to oil down the intake pipe.

 

[sbkarmen]

yeah its half inch, I talked to a cummins mechanic and he said it would be fine? I see your point though, I didn't see any smoke what so ever. I'll probably end up making another line then, great!

 

[sbkarmen]

I still have to plug the oil ports in the rocker assembly. maybe that extra pound of boost will help the bogging in the lower RPMs in 4th gear

 

[martinsaunders06]

I still have to plug the oil ports in the rocker assembly. maybe that extra pound of boost will help the bogging in the lower RPMs in 4th gear

I put a turbo on my 816 3 year ago and all still ok but I would say don't worry about those holes as they are NOT drilled right through so will not affect any boost , certainly that's the case on my cummins. Martin

 

[sbkarmen]

Here are some pics after I picked up my truck from the fab guy I used. He did a mirror image of the fender support for the right side. He also made the exhaust mount that welded up to the support pipe right on the bottom. The airfilter and tubing he ended up putting a bend in it to make it get to the correct height to mate with the filter housing and cut a nice round whole on the cowl. just have to do some touch up paint. One of the local steel soldier guys desertrat came by and got to see it first hand himself. kinda cool don't know to many military truck guys other than myself.

I ran the truck up the cajon pass to compare to before and noticed where I used to only 32mph I now was going 48mph!! In the same gear 4th with my 53" michelins. At another point at the top of the hill I used to go 34mph, I now go 52mph which is the top of 4th gear, I just about could pop it into 5th... As far as engine temp goes it was @ 400-500 running around the town, but up the hill it was dong 700-800 with it flogged up the hill... up until the intake boot popped off cuz the thing was clamped down on the lip and not properly installed it did get up to 1100 and I quickly pulled over to the next exit and fixed the problem, I knew what was going on cuz my boost guage went to zero. No smoke absolutly zero and it was verified by desertrat! lol took him for a cruise today! lol

Now I was thinking since I only have 12 lbs boost max should I go with more fueling and put a 10 button in instead of the 17 I had already? It seems like it needs more and I still haven't blocked the oil port in the rocker covers, do these actually improve boost? If anyone can answered these I would sure as **** appreciate it, this forum thread has been a blessing already, I'm so stoked about the truck and am glad I did it.

 

[Dieselking22]

I want to see a video of these with a turbo

 

[sbkarmen]

I want to see a video of these with a turbo

go back a page I posted a youtube video of it running.

 

[martinsaunders06]

Here are some pics after I picked up my truck from the fab guy I used. He did a mirror image of the fender support for the right side. He also made the exhaust mount that welded up to the support pipe right on the bottom. The airfilter and tubing he ended up putting a bend in it to make it get to the correct height to mate with the filter housing and cut a nice round whole on the cowl. just have to do some touch up paint. One of the local steel soldier guys desertrat came by and got to see it first hand himself. kinda cool don't know to many military truck guys other than myself.

I ran the truck up the cajon pass to compare to before and noticed where I used to only 32mph I now was going 48mph!! In the same gear 4th with my 53" michelins. At another point at the top of the hill I used to go 34mph, I now go 52mph which is the top of 4th gear, I just about could pop it into 5th... As far as engine temp goes it was @ 400-500 running around the town, but up the hill it was dong 700-800 with it flogged up the hill... up until the intake boot popped off cuz the thing was clamped down on the lip and not properly installed it did get up to 1100 and I quickly pulled over to the next exit and fixed the problem, I knew what was going on cuz my boost guage went to zero. No smoke absolutly zero and it was verified by desertrat! lol took him for a cruise today! lol

Now I was thinking since I only have 12 lbs boost max should I go with more fueling and put a 10 button in instead of the 17 I had already? It seems like it needs more and I still haven't blocked the oil port in the rocker covers, do these actually improve boost? If anyone can answered these I would sure as **** appreciate it, this forum thread has been a blessing already, I'm so stoked about the truck and am glad I did it.

?are you blind? If you read the previous post it tells you those holes are not drilled right through so they will not give you any more boost

 

[sbkarmen]

?are you blind? If you read the previous post it tells you those holes are not drilled right through so they will not give you any more boost

No I'm not blind, I kinda wish I was now because I would take offence to what you said, out of respect for everyone who gave their opinion, I didn't want to contradict anyone? Some people said you have too, and some like yourself said its irrelevant. I checked the rocker covers on mine and don't see it doing anything... I'm just going to up the fuel and call it a day, its got enough juuice going up the hill.

 

[martinsaunders06]

No I'm not blind, I kinda wish I was now because I would take offence to what you said, out of respect for everyone who gave their opinion, I didn't want to contradict anyone? Some people said you have too, and some like yourself said its irrelevant. I checked the rocker covers on mine and don't see it doing anything... I'm just going to up the fuel and call it a day, its got enough juuice going up the hill.

You asked the question and you got the answer from someone who did this and has run it for 3 + years and yet it's as if you totally ignored it- perhaps you could of said thanks very much for your reply and help , but instead it comes over as you obviously don't believe me and my reply didn't exist . Tap the holes and blank them then you will know and I won't take offence either. Martin

 

[sbkarmen]

Really? whatever dude.

 

[jimk]

I agree with Jwaller. The small oil line is a concern. Discharge oil tends to be whipped full of air, like top of a black cappuccino. The nat aspirated heads are the ones with the open ports though I'm not sure if that means all of them. They do get swapped sometimes. Pretty easy to tell if you have them. Plugging them adds 1 psi at WOT redline. Power increase from the change will be insignificant if you are under fueled because all you'll get is an added push on the piston during the intake stroke. Same can be said for adding a turbo. Adding fuel raises boost. Pretty quickly too.

I tried to update post #72 a while back but could not due to some new policy. Basically, another year w/no problems of any kind, always cool egts, ~700-750*F, 800*F max (post-t probe), enjoy the whistle off idle and being quiet at speed, maybe 280-290hp the way it is currently fueled, more than made up for what going to super singles lost.... Still a dog by big rig standards (about as kindly as can be said with the current SS rules of conduct policy). Compared to a my ex wheezing de-rated old EM7-315 Mack- the NHC-T uses twice the fuel and makes half the power. To be fair gearing is also a factor in that comparison.

 

[bubba_got_you]

You asked the question and you got the answer from someone who did this and has run it for 3 + years and yet it's as if you totally ignored it- perhaps you could of said thanks very much for your reply and help , but instead it comes over as you obviously don't believe me and my reply didn't exist . Tap the holes and blank them then you will know and I won't take offence either. Martin

PMS? i think it might be a good time to get used to people wanting a 2nd opinion. i work on trucks everyday and still have people want an other opinion. if we all just went off of what one person said we would still be using steam to get around because the scientific minds thought there was nothing more to invent.
OR maby he just didn't see it and when you replied like a jerk he didn't like it.
you may begin to see the snowball effect now.