M818 Turbo Addition

[Lonnie]

I've been doing some mods over the past few months.

It started with a radiator swap, that grew into a new water pump, belts & hoses..... and before long, a turbo, new exhaust & eventually Jakes.

I got a turbo & manifold with the truck, so I thought it would be easy. It turns out the seals between the manifold sections was poor & you can no longer buy them. Upon inspecting the turbo, I found it with more end play than I liked, so I proceeded to get it rebuilt. Unfortunately it was already rebuilt & there was no available parts to go an additional oversize on the bearings.

This resulted in buying a new turbo... didn't want to end up with a runaway engine due to a bad oil seal in a worn out turbo....

Next I went looking for manifold seals & was informed you cannot buy them. This resulted in a discussion with a guy that ended up selling me a NTC-350 for $300. It was mostly complete so I brought it home. The engine is really big when you see it in a pickup truck.



I ended up robbing the exhaust manifold off of it since it was together & tight. I cleaned & painted it before I realized it would not clear the thermostat housing. Not willing to give up, I tried to flip it upside down. It cleared well but the dowel pin locations no longer lined up. After some time with a drill & multiple bits, I had the dowel holes drilled & lined up on the opposite side.

 

[Lonnie]

Essentially I bought a $300 engine instead of a new $600 manifold. Now I have a ton of extra parts.

I switched the location of the manifold, which gave me more clearance & also a better tubing path.

I could now run the air side tubing around the back of the engine, since the Jakes would not allow me enough clearance to go over the engine.
It would also allow more exhaust tube length to run a muffler in close to the stock location.

 

[74M35A2]

Great work Lonnie. That is usually how this stuff goes. Your engine looks beautiful. Keep us posted, impressive your pickup could hold the weight of an 855 motor, and level? Air bags?

 

[Lonnie]

No, its just a 2500HD with a BDS lift kit. It's still legal with 3400lb in the bed. It squatted a few inches, but not too bad.

 

[Lonnie]

Started the 5" exhaust & soon realized there is hardly any straight sections of pipe before the stack.

I put in a small muffler under the hood & also a stack insert for noise control.

Here are a few pictures before everything was painted.

 

[74M35A2]

Funny, I thought the thread title read "Turbo Addiction". I was like sweet, who doesn't have a turbo addiction? I have 3 turbo diesel engines. 6CTA8.3, ISL, and ISX Signature 600. The latter 2 are homeless for now, but run flawless and ready for their next assignment.

Cool build, thanks for sharing pics. The inlet air filter large enough to work OK?

 

[Lonnie]

Still verifying the filter restriction. An 855 at 2200rpm & 15lb boost is around 1100CFM.
I thought the filter was rated for more flow. I still have to get the filter monitor hooked up.

Currently at 14# boost.


I put a filter housing on the right side to duplicate the factory left side. Used the 5" tubing throughout & tried to mirror image the left side.
The routing was not that bad, but would have been easier if I made it straight over to the fender.




Got the filter housing mounted & painted to look factory.

I had 8lb boost with the stock fueling (#27 button) & EGT's were in the 700 range. Obviously not enough fuel.
Had a #25 button on hand & EGT's went up to 800 with 12# boost & a noticeable power increase.

I ordered a #22 & a #17 to try some more fuel.
Went up to the #17 button & have about 14# boost & EGT is just under 900 at max boost.
It is starting to run decent now except for the boost falling off at the 3-4 shift.

Doing the dual fuel mod next with dual 3/8" lines.

My next thing before going any further is to get a fuel pressure gauge mounted before I make any more changes.
I picked up a 5-250lb gauge that matches the the factory gauges... I will put it in place of the cold start pressure gauge since I do not use it.

 

[US6x4]

Wow! Looking good; your plumbing routing looks very clean. This is everything I want to do to mine. Which turbo and which Jakes did you end up using?

 

[Lonnie]

The turbo is a Holset HT3B with an undivided housing.

I have a set of #25 Jakes that I hope to start installing this weekend.

I'll try to get some pictures of the pressure tubing... most is hidden behind the engine.
I used 3.5" from the turbo & a series of silicone 90's & 45's to follow the arc of the belle housing.
At the Drivers side I transition up to a 4" tube, which then transitions to a 5" elbow into the intake manifold.

Also ... Looking for an air inlet "mushroom cap", or whatever the technical name is. I currently have 2 different styles.
One is flatter with a shield around the bottom & the other is more of a rounded dome. I would like to have a matching set. Anyone have a spare?

 

[74M35A2]

The military mushroom caps are easy to find (eBay, etc...), but people say they can be very restrictive due to the amount of actual surface area opening on the underside. If you are going for max performance, it may not be a good option? Possibly true, as the mushroom cap on a conventional over the road truck is much larger, and sometimes double in quantity as well (mostly just for looks, but still).

I wasn't doubting your turbo inlet filter, you're doing great work, and we do what we need to do to get thing done. It could be just fine. Methodical approach. Keep the results posting!

 

[US6x4]

Also ... Looking for an air inlet "mushroom cap", or whatever the technical name is. I currently have 2 different styles.
One is flatter with a shield around the bottom & the other is more of a rounded dome. I would like to have a matching set. Anyone have a spare?

This is the flatter style with the guard on the bottom and is the style I have on my twin cans.
http://armysurpluswarehouse.com/2-1-2-ton-air-inlet-cap/

 

[Lonnie]

Is that link also suitable for the 5 ton? It looks to be the same diameter.
$12 for a new one is hard to pass up.

If you look at my exhaust picture, I shoved a K&N style filter in the turbo for my preliminary start-up tests.
It worked until & got the factory filter housing mounted.

 

[Lonnie]

I spent the evening trying to replace the cold start pressure gauge.... They sure didn't make it easy to get this gauge out.

Pulled the left side dash face loose & it allowed me to barely get a few fingers behind it to loosen up the clamp & fuel lines.
FYI, all the warning placards, serial number plates etc. at the top of dash, also need the top row of bolts removed as they not only thread into the dash face, but also into the dash mounting bracket.

I have a piece of Teflon lined, stainless braided hose rated for 2600 psi working pressure to connect it to the injector pump.

 

[US6x4]

Is that link also suitable for the 5 ton? It looks to be the same diameter.
$12 for a new one is hard to pass up.

If you look at my exhaust picture, I shoved a K&N style filter in the turbo for my preliminary start-up tests.
It worked until & got the factory filter housing mounted.

I believe the item is mislabeled. I purchased this same part for my 5 ton air canister and it fits just like the original. Probably the same NSN.

 

[Lonnie]

Thanks,
For that price I got 2. Shipping was as much as the part. LOL.

I spent 1/2 hr fixing the old one to make it look nice.

 

[Lonnie]

Did the dual fuel mod today.... a 2 hr job that took all day.

Replaced the front line with a new one. Kinked the first line.
Make a trip to the parts store for another line.

Got the front on & went to put in the rear fitting... it hit the head & would not thread in all the way.
2nd trip to the parts store. Got a 1/8NPTM x 1/4NPTF reducer & a 1/4NPTM to 3/8 tube 90.
It cleared the head & I started installing. It broke off in the block 1/8 turn from its final position.
Found the adapter hit the block, twisting it, causing it to break.

Easy out would not grip in the fitting because I could not tap it in being 1/4" from the firewall.
Had to drill a small hole in firewall to tap easy out in the fitting.... came right out then.

3rd trip to parts store to get 1/8NPT close nipple & 1/8NPTF x 1/4NPTF reducer.

5 hrs later I finally got a 2 hr project done.

 

[74M35A2]

That’s exactly how it goes for many that do that mod. A lot fight taking the plug out. No room, breaks, strips, etc...

It is supposed to have a decent effect though. I want to see that truck pull a block wall over soon.

 

[Lonnie]

Funny thing is the plug came out easily.... thought I had it under control. Then everything else went wrong.

Got the fuel pressure gauge in. It shows a max of 210 psi just before it de-fuels at 2200.
Unfortunately I wish it had more at lower rpm, but the 210 seems too high already.
It is just below 200 psi at 2000 rpm.

I have a #17 button in it & the the fuel screw is out 2-1/4 turns. The plug was out when I got it, so I have no idea where it was originally.

Any ideas? EGT is still OK & fuel pressure could be higher down low, I'm just not sure how to get it there.

 

[Lonnie]

Had another learning experience today.

The throttle seemed sluggish & also slow to return to idle.
I could not see how a dual fuel line could cause this.

I had suspected the fuel pressure gauge could have air in the line which allows compression/expansion when the fuel pressure changes.
I noticed it also took longer to stop when you turned the key off... this confirmed my hunch.

I loosened the line at the gauge until fuel squirted out, then tightened it up. Suddenly it was back to normal. The gauge also responded faster.

 

[US6x4]

Lonnie, do you have any pictures of the pressurized piping behind the engine or snaking up to the intake? Of all the turbo threads I've read the past few years you're the first one I've heard of to go this route.