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HE351CW No Spring Gate

27K views 40 replies 13 participants last post by  towmonster 
#1 ·
I've been planning to do this swap since the beginning of the spring and just managed to get it all wrapped up at the end of this week. The HE351CW is becoming a fairly popular option on these trucks due to the higher flow and boost levels over the hx35. There's tons of threads out there that have bits and pieces of what can be done to successfully run this turbo, and one huge one of 50+ pages in the 24v section, http://www.cumminsforum.com/forum/9...cussion/151365-he351-retrofit-second-gen.html , that started out as a build between another member and JKidd from Diesel Auto Power. Now it’s really more just a compilation of everyone who has done this answering questions and posting pictures to the people who haven't done it. I figured an all-encompassing thread from start to finish of an HE351 swap would be beneficial to everyone who is on the 2nd gen forums 12 and 24.

Now before I got started with this or even bought the turbo I did a fair amount of reading on parts required, bumps in the road involved with doing this, etc. The overwhelming majority of people who do this swap end up ditching the factory diaphragm canister wastegate for a spring gate. Quite frankly, most of the ones I've seen are pretty ghetto aside from ones you can buy (stainless diesel for example, Stainless Diesel Spring Gate - HE351) . People end up running a gazillion hardware store springs trying to control boost and be consistent. This is all assuming the turbo is clocked so the compressor outlet is down towards the bottom of the truck. If it isn't clocked, obviously the stock mounting for the wastegate actuator can be retained, but the intercooler piping becomes more of a hassle, and I wasn't too fond of the "stick up" look anyway. If you don't mind the outlet sticking out up near the hood, then take a look at the thread I posted above as that was not the path I decided to go down.

Next on the reading list was plumbing. There isn't as much discussion on this topic as there was for the spring gates, but still enough to see some options. DAP sells a 4" downpipe for this turbo. You can also buy a weld on flange to adapt from the HE351 to an HX40 style downpipe. The DAP downpipe looked cleaner IMO and that's what I went with: Diesel Auto Power 4.4" HE351 2nd Gen Style Downpipe - 907001 - Diesel Auto Power, LLC . As far as intercooler piping, it’s all over the place. I've seen people fab their own out of 3" mandrel bend 90's and others running one giant section of silicone hose. Nothing out there so far that I've seen really grabbed my attention in terms of simplicity or cost effectiveness, so this area was open for anything I could come up with.

I picked up this turbo out of truck yard in Missouri. Guy was selling all kinds of used parts off anything that came through. 275$ later here it is.
For being used, this turbo was impressively clean. No rust on the turbine housing had even begun to develop. Wheels were spotless. No shaft play. First thing I did was pull all the roll pins in the housings to allow clocking, and set up the turbine in the mill to open up the wastegate passage. A 3/4" drill trued up the existing hole, and then took it out to 1" at the end. I thought about 1 1/8", but it would've been close to making the hole bigger than wastegate puck. Two of the flange holes on the turbine housing are threaded and two are clearance holes. You need to drill out the two threaded holes to use it with the four studs on the factory manifold. Drill them to 13/32". Lastly, I drilled out the rivet in the wastegate actuator arm so that eyelet could be adjusted down the road.

Next I wanted to hang the turbo off my manifold to figure out what was needed for intercooler plumbing. First observation, you can indeed use the factory studs in the manifold with this turbo. HOWEVER, I would not recommend it. They're too short. You can only get about 2 threads of engagement if you do. ACE hardware sells studs. They're M10x1.25 thread, but 3/8-16 is so close that they will work fine if you don't have access to metric. Getting the old studs out is kind of a pain, but soak them in penetrating oil and use a small pipe wrench and take your time and work them out. If you break one, it’s gonna set you back a while. If you're luckier than the other 99% of us and your studs thread in and out easily, you don't need to buy new studs. Just thread them out about 1/4" and you're good. Pipe wrench will destroy the threads, so if you use that method you'll need new studs regardless. Here's mine with new 2" 3/8-16 studs installed:


After the turbo was mounted and clocked in the ballpark of where I wanted it I started on intercooler plumbing. I loosened all the boots on the factory intercooler pipe and after rotating it around and sliding it out about a half inch it looked pretty close to 45 degrees with the compressor outlet. I've used silicone intake parts on a turbo system I did for a 5.3 Chevrolet, so I got dimensions off their 2.75" to 3" reducing 45 degree elbow. Modeled it in cardboard and laid it down in the engine bay. fit looked very close so I went ahead and ordered that.



During the downtime of waiting for the booth, I spent a day or two working on making a custom mount for using the factory wastegate actuator. All this was mocked up purely from scratch with scrap pieces we had laying around at work. I ended up building two different systems. The first was unsuccessful due to clearance issues with the drain tube. The new one I built was much cleaner in the end anyway. When doing this kind of stuff it's easier to work backwards. I just eyeballed about where I wanted the actuator to sit and worked from there. The first piece I built was to bridge the roughly 1" space between the lever on the turbine housing and where the actuator arm sat (you'll see what I mean in the pictures). I found a little piece of 300 stainless in the scrap bin to use. Tapped one end 5/16-24 NF to thread onto the actuator arm and then drilled the other end to 11/32" which is standard clearance for a 5/16 screw.

Being machined.

Finished piece.
Threaded that on and moved on to the piece that attaches to the lever on the turbine housing (replaces the factory eyelet). We didn't have any 300 round stock, but did have a small section of 5/8" 440C so I used that. I tapped the bottom 5/16-24 NF and milled the sides down to the same thickness as the factory piece it was replacing ( .200" IIRC). The hole that attached it to the lever on the turbine housing is somewhat of a close tolerance fit so that the movement isn't sloppy when opening and closing the puck. It could be drilled 19/64 if that's all you have access to, but I opted to bore it .293" to give it a nicer fit without much wiggle. The diameter of the lever on the housing is .290".

Being machined.
I bolted this to the last piece I made and stuck it on the turbo to see where about my mounting brackets would be needed. It was clear at this point the drain flange was going to be what I fixed all this to, so found a piece of 2" angle iron and sawed it 3" long. I slot all holes from this point on to allow for adjustment later on. The two outer holes mount with the factory drain bolts and the middle is 1" to clear the drain tube.

You can use the stock drain bolts if you want, but I'd recommend longer ones. Again, ACE will have them: M8 coarse thread.

The last piece needed was just a flat plate to tie the wastegate canister to the angle iron piece I just put on. A 5" long piece of 1/4" plate did the job. The one end was drilled for the two m10 studs in the canister along with a 1/2" slot to clear the actuator arm. Then I bolted that onto the canister, adjusted everything around to get the arm running as straight up and down as I could with the lever on the turbine. Marked where the plate ended up laying on the angle iron. Took them both off and machined 2 matching 11/32" slots about 1" long in both of them.


Assembled it all and here's the finished product


Clearance with the downpipe


Everything fit up nicely on the truck, so next I needed to plug the solenoid that is used with the common rail trucks. There are 3 holes if you look inside the boss on the compressor housing. One that connects to the scroll that allows pressure to enter the boss, one that connects to the barbed outlet that originally was used to control the wastegate, and one small hole in a fillet near the top that leads back into the shroud. This shroud hole needs to be plugged to allow the 40+ psi this turbo is capable of supporting. Originally I just planned on making a cheapo out of a M22x1.5 drain plug. Many others have done this. But a much simpler solution for me was to take the small upper o-ring off the solenoid and stack two 3/32" o-rings underneath the threaded portion of the solenoid.

This sealed off the shroud hole very effectively, past the burst pressure of the original wastegate hose that's used actually :doh:. It still allows flow through the barbed outlet, however, encase you wanted to use that as your boost reference to control the wastegate. You can get near 30psi this way, but the majority choose to run a boost elbow/controller. I took the one off my hx35 and the plug out of the manifold and used that instead. There is some pressure drop through the charge air piping and intercooler, not enough to make a huge impact, but the manifold is the best place to have accurate boost control. I used some 1/4" fuel line hose and some leftover wire loom protector and routed it along the front of the engine bay and down to the wastegate canister. 4' is all you need. Less than 20$ for that, two clamps from NAPA, and a vacuum cap assortment.

Boost elbow location

Connection to the canister

Small vacuum cap I used to plug the barb


My silicone elbow for the intercooler piping showed up by this point. First test it was just a little too long to fit right, so I cut off 1/4" from the small end and that was all it needed. For 20$ it beats the heck out of a hacked up piece of mandrel bent.



That pretty much wrapped it up. Last thing to do was pull the oil inlet fitting out of the hx35 and thread it into the HE351. Attached the oil feed hose, tightened everything up, and fired it up. Some AFC tuning and it spooled to 40 like a champ. Cleans up instantly after 10psi. I'll get on some rollers after I finish a dual feed setup I'm assembling. I hope this helps anyone else out there thinking about doing this swap and fills in any gaps in information about the process start to finish. I'll post a parts list with costs, and if I can find the scratch paper I drew all my dimensions on for the wastegate mounting I'll post that too.

Thanks to JKidd and DAP for the injectors and downpipe. I'm helping a friend of mine build an HT60 compound setup for his 24v and JKidd's been a great guy to deal with on that project too. The 5x12s I’m using to fuel this setup ran smooth from the startup all the way up to 2800 and totally cleared the idle haze I had with stock injectors. They also have probably the best customer service of any company I've dealt with yet. Certainly have my vote in the future and I'd recommend them to anyone else.
 
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#3 ·
I've never been a fan of the spring gates and I like clean systems. It was a good weekend project. Very happy with the results. And that's ok.... I referenced yours and Cowboy's fuel system builds several times in the dual feed setup I'm assembling :thumbsup:
 
#4 ·
Nice job.

Good idea to make a "How To - HE351" thread and it should be made a sticky since this topic comes up fairly often...it would help cut down on HE351 questions if the info is right there at the top.
 
#5 ·
There are almost a zillion ways to go about doing this, my main goal was to make it simplistic and informative. Fabrication makes anything possible, but not everyone who gets on here has that ability. And since most run this as a single hopefully what's here will cover all those bases.
 
#7 ·
This is fantastic. I wish it would have been around when I put mine together a couple of months ago. The precise measurements would have been fantastic to have!
Also, your comment about one of the holes leading to the shroud and keeping the turbo from spooling past 40; I used a simple plug for my design and had issues reaching above 40 psi with mine. I'm not 100% sure that the shroud hole is sealed, so I will most likely attempt to plug it your way and see if that helps.
Again, thanks, and great write up! :thumbsup:
 
#10 ·
if i recall and i could be wrong but cant you run this turbo as a exhaust brake and if so with your set up which is awesome and super clean can you use that feature? im thinking this might be my next project now really like how it turned out
 
#14 ·
Well some bad luck has put me down. To make a long story short about two days ago I noticed a pinging noise coming from my front end that sounded like exhaust vibration. In my search I took the downpipe off and also the intake tube. The shaft play was scary. After pulling the whole thing apart I could see the wheels had started rubbing the housings. Not enough that the housings were beyond polishing out, but the center section is beyond repair. The sealing ring on the turbine shaft stuck and tore away the bore inside the cartridge. Shaft play was well within Holset spec when I bought it. 2 weeks worth of running and failure beyond repair. Just goes to show everyone that even if you think it's good...better safe than sorry. Now I'll be buying another turbo, and rebuilding and balancing like I should've done the first time.
 
#16 ·
I still retained the stock rod and actuator as well...anyway
Two reasons:
The first being that when I mocked up that setup, as it was my original plan, there were clearance issues with the drain tube.
The second being that over that roughy 7" vertical distance of the bracket to bolt the actuator to, it undergoes a fairly serious amount of bending when the actuator starts extending; much more than you would think. It is actually more of a headache than the route I ended up going, and much less rigid. That flexing will impact the wastegate operation. Hope that makes sense.
 
#19 ·
Nice work on the set up.

Sorry to hear your turbo quit on you.
 
#20 ·
Random, I finally got the hole plugged using the two o-rings on the solenoid, but I wanted to know, would it be a bad idea to use JB-weld to plug up all of the holes in the solenoid?
 
#22 ·
I figured I would run a line from the manifold as you did if I run the original WG.

I currently have a spring gate setup and am not seeing the performance of my compound setup that I believe I should be getting. I am trying to diagnose the issue and wonder if maybe there is a leak coming from the shroud. Might take off that solenoid and plug it tonight.

Thanks!
 
#23 ·
A quick way to check for shroud leaks is to screw the solenoid in and then using a compressed air source, put air through the barb. If you take the intake tube off the turbo you can easily feel whether or not the shroud hole is leaking. Just put your finger up where the hole is and check. It tends to make a funny sound coming through the shroud hole vs just coming back through the compressor. There will be air coming through no matter what because of the feed hole in the bottom of the solenoid boss, you just need to feel for it in the vicinity of the shroud hole. Then you'll know if it's bleeding boost through there.
 
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#24 ·
UPDATE:

I sourced a wheel and shaft from a VGT turbo off a 6.7 truck. Now, its been stated all over this forum that the HE351CW has a 60mm turbine wheel. However, a few people who have actually measured (myself included) discover that its a 58mm wheel. So although the compressor is the same on the VGT turbos, the turbine shaft is bigger by 2mm. While waiting on a rebuild kit, I decided to bore my exhaust housing for the VGT turbine. Final bore dimension was 61.5mm. Picked up my rebuild kit and newly balanced wheels and put it together last night, but didn't do any testing. This morning I warmed it up for about 5 miles and did a few 40 psi pulls. Max EGT I saw was just a hair over 1200*, which is 150* less than with the stock turbine wheel. 65mph cruising EGTs are down 100* from the stock wheel. No noticeable difference in spool time. IMO, a worthwhile upgrade for anyone who can get a VGT turbine on the cheap. I'll monitor my shaft play for the next week to be sure that, if there is something else that caused my last failure, I catch it before it happens.
 
#25 ·
Interesting. I have a 351VE turbine wheel sitting here. I've wondered a couple times how it would work in a CW, but haven't tried it for fear of losing performance.
Good info.
 
#29 ·
IIRC, the VE wheel is 60mm instead of the 58 in the cw. Would be a decent upgrade if you had it laying around and could do the machining on the housing. But to go through all that work you may as well get something larger

Im in the process of refurbing a 351he with a super hx40 turbine wheel that is 64mm. Things got a little more complicated than i bargained for when i found out i had to radius the opening after boring it out. It looks like one of my carbide router bits will be close enough to the blade profile though.
 
#26 ·
Took the truck down to Cincinnati today, so I had a chance to do some highway testing. Doing 65mph with cruise control I never rose above 650* egts going uphill. A few instances in the straights I dipped under 500*, average was around 600*. Crushing boost was always under 5psi. 80 degree ambient temperatures outside. Definitely an improvement over the smaller turbine wheel.
 
#27 ·
Now that you've had more time behind the wheel, have you noticed any difference in spool up at all?
 
#31 ·
The internal gate is pretty ***ty IMO.. especially in a twin setup with that small of a housing. A big (50mm or better) external is the way to go. Obviously alot more fab work but if your starting from scratch like myself, def the way to go. Im planning on plugging the internal gate hole and possibly welding on a new vband outlet centered over the wheel.

People have sucessfully fit that wheel in and kept the internal gate for what its worth.
 
#32 ·
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not my welding btw, this is just the idea ill probably replicate.

I missed your post at the bottom of page 2 about you putting the vgt turbine wheel in.. how did you do the radius for the blade? Rotary table and a router bit? And was a straight radius bit close enough to the profile? PICS?
 
#33 ·
The VGT wheel did not require radiusing. The profile in the housing matched it already. If you wanted to radius it for the super hx40, more than likely I'd just grind the form onto a high speed insert, put in in the boring head on the Bridgeport, indicate the bore of the housing and manually bring the quill down until it cleared for the wheel. If your mill has cnc controls just use a form cutter and circle mill it.
 
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#34 ·
How is your silicone hose to the intercooler/boost tube holding up? (Concern about the heat.)
Also where did you source it from if you are still using it.
Thanks
 
#35 ·
Still holding up good now. I haven't checked for physical splitting, but it still holds 40psi. I got them from frozen boost. I don't know if their quality is the greatest, but they have good pricing on a lot of turbo related parts.
 
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#36 ·
Frozen Boost recently started sourcing at least some of there boots from a cheaper source. You can tell the difference in the bag they come in, the cheap ones have a very crankily bag, where the better ones have a more rubbery bag.

The better ones didn't like over 45 psi. Both uppers and lowers started blowing.

Honestly, I'd be tempted to use the cheap ebay one, they arn't as rubbery, so you can't get them on the intercooler, but you can get it on the other piping. But they are thicker and don't stretch as much. However, I have not tried using them before, so this is only what I've seen and my speculation.
 
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