Cummins HX35 on a LD-465

[Jakob]

I couldn't find any thread that had talked about this, except for the turbo kit threads. I didn't find any real answers there or I read over the information and missed it.

My buddy has a good HX35 he's giving me for free. I can make the turbo physically fit the truck no problem. Is it going to be worth the work though? I know the stock turbo only runs anywhere from about 4psi to 10psi tops. A wastegate and boost controller will be a must. A pyro and boost gauge will also be going on if I do this.
I'm not sure where to get the oil supply from for the bearings on the turbo. As far as intake piping and exhaust, that all is going to be custom work. I guess the biggest question is will the turbo be too much for the engine? With gauges and a boost controller, will the HX35 be too much turbo for the LD-465?

 

[patracy]

The HX35 already has a wastegate built internally. You'll have to modify the oil feed and drain lines due to their designs, but it shouldn't be that hard. The HX35 flows about 570 to 600cfm of air. The early 12V HX35's had 56mm ind. wheels. The later 24V's have 54mm wheels. Both have 60mm turbine wheels. The exhaust housings are 12cm's. The trick will be the turbo design. If the wastegate is mounted directly to the exhaust housing, you're set. You can clock the outlet where you need it. But if the wastegate is mounted on a pedestal of the compressor housing, you'll have to build a mount for it to allow the compressor outlet to be clocked.

I don't have the specs on the various turbos used on the multifuels, but they weren't geared for performance. It was for cleaning up the smoke from the NA engines. My main concern on swapping an HX35 would be peak boost. By design these engines run an extremely high compression ratio. Anything over about 12psi is asking for trouble. As you've got a base CR of about 21:1.

IMHO, I'd leave it alone. Just turn up the pump (slightly!) and enjoy what you have. Getting blood from a turnip is difficult.

 

[Jakob]

I'm only considering it because I need a new exhaust, the turbo is free and the fabrication will only cost parts. I won't have much in the setup as far as cash is concerned. I already have a boost gauge from a past project and want to get a pyrometer anyway.
My only concern, that you talked about a little, was that the turbo might be too much. I assumed, on no kind of factual basis, that the smaller 5.9 turbo would be close to the right size on a LD-465. I was planning on setting the boost at 10psi, that's what I've read here to be the top boost for a stock turbo.
I believe the turbo is off of an older 12v engine and the wastegate is in the exhaust housing. If it would help any, I can get most of the numbers off of the compressor and turbine housings.

 

[patracy]

If you're needing a new exhaust (J pipe), why replace the turbo?

IMHO, take the free turbo, sell it. Spend the funds on parts designed for the deuce. I've got an HX35 sitting in my shop and two deuces. I have zero desire to try to retrofit it in. Running major boost on a super high compression engine will blow head gaskets and cause other internal issues.

 

[Jones]

Figuring out the HX35's characteristics is pretty much a done deal. If you can find the A/R ratio and other specs on the multifuel rurbos you might be able to get some comparison numbers. A diesel shop that does turbo work should be able to help; some even have turbo flow benchs.

Failing that, I'd consider too that the engine it's coming off of is around 360 c.i. while the multifuels are 465 c.i. just to make sure you're not putting a choke in the system.
A smaller turbo will give you quicker spool-up and more bottom end but may not be able to flow enough to feed the engine towards it's top end.
Very wise to go with pyro and boost gauges. They're a good idea even on stock set-ups.

 

[tm america]

It's real easy to get decieved by the boost figures on a stock multi turbo.. For one thing they make alot more boost than most think is possible .. the issue is getting air cooled down before the turbo.The 6bt was an inner cooled motor ..If you inner cool a multi you can safely run much higher boost levels..There are some turbos that came on the multi that can run 20 psi without a inner cooler and still be less than 1200 on the egt.i Have a lds427 turbo that i had on my truck i ran it at around 27psi for about 10000 miles-7 yrs.. No issues.The biggest thing you are gonna run into is setting the fuel curve to fit the way that turbo works..
THe stock whistler turbo i have on there now .. made enough boost top spin the boost gauge past 40psi and break the gauge when the needle hit the stop pin .. i wouldn;t even want to think about what my egt was but they can and will do it if you put enough fuel to them. If i were you i would be looking into how you could install the cummins inner cooler on the deuce not the turbo swap. But whatever you decide to do install a pyro and boost gauge and let us know how it it works out .. Good luck i hope it works out ..

 

[patracy]

27psi on a 21:1 CR diesel? Eeek....

At 1500ft above sea level you're at [SIZE=-1]59.27 :1 CR.
[/SIZE]

 

[Jakob]

I had thought about just selling the turbo, but it only goes for about $250 or so. The Deuce turbo costs about $300-$400. Right off the bat, I'm behind at least $50. The truck is a non-turbo right now (hence the LD-465) so I don't have any of the parts to start with.
I hadn't thought about an intercooler, but that wouldn't be a bad idea. Even if nothing else changed, it would cool the intake charge to some degree. Finding a place to put it might be a little more difficult however.

 

[tm america]

Yep 27 psi..on a 22 to 1 diesel....They hold together pretty good..I ended up changing the motor because it had alot of blow by but it was like that before i turned the fuel up.I really didn't expect it to hold up to the abuse i put it through.. ..With how it is set right now i can run through first second and third as fast as it goes through first when stock..I would imagine when it hit over 40 psi i was around 35-40 hp.. i was in fifth goin up a hill and it took off like i was in first.. i thought i got rear ended by a semi .. scared the poopies out of me

 

[patracy]

Ooops! Totally spaced out on the LD-465 not being an LDT-465. If it's free, then go for it. FWIW, the intake manifold is also "cooled" by the engine coolant. It's a crude aftercooler setup on our trucks. The HX35's map is good up to 35psi and overspins at about 37psi. Far more than you'd want to run on these trucks. The charged air output only starts warming up over 28psi.

 

[mudguppy]

... inner cooler ...

Intercooler or Aftercooler.

... the intake manifold is also "cooled" by the engine coolant. It's a crude aftercooler setup on our trucks. ...

no, it isn't.

A. the same manifold is used on the non-turbo'd motors; meaning that the intake was never designed to 'cool' a compressed IAC.
B. even if it was, the results documented on this site by a member's testing yielded an 11°F drop in IAC temp at 12 psi boost. this is essentially worthless as far as charge air cooling is concerned.

... The HX35's ... overspins at about 37psi. ...

while this is very general guidance, i think it's misleading; boost does not directly correlate to shaft speed. the turbo shaft speed for 37 psi at 1600 engine rpms is very different than 37 psi at 3000 rpm.

the only way to accurately discern appropriate IAC boost limits per rpm is via flow rates compared to the HX35 map.



to the OP - you'd be better off bolting on a C or D turbo. the HX will work, but you'll be working it harder than designed at mild HP levels. drive pressure will also likely suffer which could lead to HG problems.

 

[tm america]

A. the same manifold is used on the non-turbo'd motors; meaning that the intake was never designed to 'cool' a compressed IAC.
B. even if it was, the results documented on this site by a member's testing yielded an 11°F drop in IAC temp at 12 psi boost. this is essentially worthless as far as charge air cooling is concerened..
i agree the intake manifold was designed to warm the intake air .not so much to cool it....I think the general design of a multifuel engine makes for higher egt than most diesels have.... Combating that should be one of the first concerns ..Or adding a turbo will be of little use when it comes to increasing hp..I am gonna make up the exhuast and intake tubes to run twin turbos on my truck as soon as i get use to using my plasma table ..I have to do alot more research .. i wonder if it would be much help to run say two c turbos...One to drive the other .. I think it would yield a huge drop in air intake temp..Not sure how much loose in boost you would get doing this.. But i have extra turbos layin around and some spare time.. so why not..If anyone has any experience with dual turbos I have a bunch of questions i could use help with?

 

[patracy]

Not the best pic in the world, but here's a pic of the HX35 map (baby blue)

 

[Jakob]

to the OP - you'd be better off bolting on a C or D turbo. the HX will work, but you'll be working it harder than designed at mild HP levels. drive pressure will also likely suffer which could lead to HG problems.

Not what I was expecting to hear, but this is the kind of information that I wanted. I thought the turbo would be too much, not that it would be too small.

 

[Jones]

I've got a charge air cooler (intercooler) ahead of a stock deuce radiator on the baby HEMTT. You can see from the first two pictures that it isn't much wider than the radiator.
My set-up is for the 6BT Cummins but one for a multifuel would just have different plumbing.


Can take some more detailed pictures tomorrow and post them if it'll help.

 

[Jakob]

Just knowing it will fit is fine for me, thanks.

 

[Jones]

Jakob,
I'd almost have to look through the pile again to be sure but I think it was off of a GMC or maybe Isuzu box truck (like a FedEx or UPS delivery truck) if that helps.
I think there were also some that would fit but were only 12" or so, top to bottom. I went with full height figuring the cooler the inlet air, the better.

Here's what the bottom mounts look like. Mine are just a couple of pieces of "hat channel" with a plate welded across one end.

 

[Jakob]

It looks to be an Isuzu NPR intercooler?