1951 Cockshutt 30–1.9L TDI Swap

[CTD2500]

Not much has happened with the 30 lately, but I’ll try to keep things up to date here.

I have disassembled the pedal assembly, which includes both brake pedals as well as the clutch. Not much is needed on them besides cleaning, with the exception of the clutch pedal having some wear at the base where it rides on the shaft. I dropped it off with my brother a couple weeks ago to have it bored out so a bushing could be added so the pedal doesn’t flop side-to-side. While I wait for that, I can strip the other pedals, brackets, etc.

It’s getting too cold to paint these days, so I’ll probably be spending the winter stripping more parts, like the floor panels, the seat, the drawbar, etc. Hopefully after the holidays we can scrape up some time to finish the engine adapter so the TDI can finally be installed.

Here is the pedal assembly as is.

These are where the brake pedals mount onto the shaft—which simply bolts to the tractor frame and is able to rotate in the brackets. The right brake pedal rotates free on the shaft, and you can see the link that attaches to the brake shoe lever. The left brake pedal is pinned to the shaft.

On the other end, there is a link that attaches to the left brake shoe lever. Since that pedal is pinned to the shaft, the whole thing rotates to actuate the left brake. Beside the left brake link is the clutch pedal, which rotates free on the shaft and pushes the release bearing using a pushrod.

This is the bore at the clutch pedal pivot. I don’t know if you can see it, but’s worn egg-shaped by about .040” which doesn’t sound like much, but it causes the pedal at the top to wobble sideways almost and inch. The bushing should fix that; the shaft itself looks like it was replaced since it’s not worn and clearly doesn’t have 70+ years of rust on it. The previous owner must have done that.

This is the high/low range shifter that I mentioned in an earlier post. Not much to it. Not sure why I took that picture so off-centre, but you get the idea. On the detent plate, it says “C” and “D” for “crawl” and “direct” speeds.

And yes, I see the runs in my paint. Don’t think for a second that things like that don’t keep me up at night!

***

As for an update on the truck, I ended up swapping the turbine housings on the primary turbos, which has dropped drive pressure a good bit—especially on the lower end—but boost remains the same.

Actually, primary boost isn’t quite the same. It comes in a bit later; I guess the way to explain it is that with the smaller housings, the needle for the primary boost would start to move when the secondary was at 8-9 psi. Now, it moves at 10-11 psi. Not a huge difference, but it’s there.

After that it’s hard to tell any difference in boost, except that drive pressure is only about 1-2 psi higher in those first few pounds. Before, it was at almost 10psi drive before you saw any boost.
Still, above 10 psi, drive pressure pulls away to the max of 34, with boost at 18. (I never got a chance to see max drive pressure between stages with the smaller housings, but I know it hit 30psi long before full throttle.)

I also spot-fixed the bigger leaks on that intake pipe with my crappy flux core, and as you guys predicted it made no noticeable difference. I’m going to completely redo that pipe section this winter anyway, so I’m just gonna leave it at that.

The housings I got came from AGP Turbo. They are .82 T3 single scroll, which doesn’t seem much bigger than the .78 that came off, but with twin primaries the size increase is actually doubled so I didn’t want to go too big. Those .78 housings I think were also smaller than I thought; I think they are meant for a smaller family of turbos, like a GT30 or something, just by the way they were machined out.

I’ve personally never seen a housing bored out like this, where it’s smoothed out all the way to the nozzle. They even cut away the tongue and the tip of the divider. I noticed this before I installed them, and I wasn’t a fan of it, but I decided to try them anyway—partly because I couldn’t spend any more money at the time. If my suspicion is right and these are modded housings from a smaller frame turbo, they might have been smaller than I thought. Like less than 10cm2.

Here are the new .82 housings compared to the .78.

Seems like a big difference in volute size for only going from .78 to .82.

Luckily, they were almost a straight swap, and I thought I could do it in one weekend. As it turned out, the .82 had about a 1/2” shorter inlet, so I had to order a pair of T3 spacers to keep everything aligned. They came in a week though, so it went back together the following weekend.

Here is the hotpipe with one primary installed.

And here’s both.

Back in the truck.

Here are the 3.5” downpipes with everything else out. That was easily the hardest part of the build, and I never saw them from this angle before (had to build them with the turbos installed) and I thought they looked cool so I took a picture of them.

Just for fun, this is the .82 compared to the 9cm HE351 gated housing.

So yeah, I dropped some drive pressure in the atmosphere stage, but boost there is still a bit lower than expected. It’s weird; it will start to make pressure when the manifold turbo is at 10psi, but it stays at 1-2psi while total boost continues to climb. I kind of think it has to do with the VGT on the 62 driving the compressor harder at all boost, RPMS, throttle position, and so it is flowing enough to make it hard for the primaries to keep up. Even though two 57 SX-E’s can vastly outflow a single 62, I think them being driven by fixed-vane housings make it so they can’t keep up until things really get going. If I had a simple wastegated manifold turbo it might be a different story.

Maybe the answer is bigger compressor wheels on the primaries? Lol $$$

Actually, it seemed like primary boost climbed a bit better with these .82 housings, so maybe they drive the chargers more efficiently in the mid/upper range. I feel like those .78 housings were just restrictive. Maybe that’s why they’ve disappeared from the market since I bought them.
It’s also noteworthy that my max fuel isn’t the same as the last time I drove with the .78’s installed because I reinstalled a fuel plate with a DIY grind profile in my pump to try to limit low end smoke and I haven’t gotten it set to the same max fuel as before. Total boost was down from 70 to 60, so I’ll have to see what happens when that is brought back up.

Messing with turbos is a never-ending journey. But that’s why we love them.

 

[Powerstroke Cowboy]

Thanks for the update. Things like this just take time. Hence the reason I am avoiding a project that I have.
I am looking forward to seeing the engine mounted up. Do you know the weight of the engine? I've been tossing the idea around mounting one inplace of an old v8 gas moter on a boat. I could run red fuel, plus should be better on fuel.

That's a very neat looking turbo setup, again, you've obviously put time into it. If I knew that your 62 was a vgt, I've forgotten it. Must be a terminator. I wonder if the atmosphere turbos would produce more boost up top if the vgt was opened more so they could be driven harder? Just thinking out loud.

 

[bateman]

I’d be interested in how you cut the fuel plate when you get your hands on one.

 

[CTD2500]

Thanks for the update. Things like this just take time. Hence the reason I am avoiding a project that I have.
I am looking forward to seeing the engine mounted up. Do you know the weight of the engine? I've been tossing the idea around mounting one inplace of an old v8 gas moter on a boat. I could run red fuel, plus should be better on fuel.

That's a very neat looking turbo setup, again, you've obviously put time into it. If I knew that your 62 was a vgt, I've forgotten it. Must be a terminator. I wonder if the atmosphere turbos would produce more boost up top if the vgt was opened more so they could be driven harder? Just thinking out loud.

I’m not sure what a TDI weighs, but I’m sure it’s lighter than the original engine. That one has much thicker castings than the TDI, plus the TDI has an aluminum head, so it’s likely a fair bit lighter.

I just did a search, someone on TDI Club shipped one and said it weighed 256 lbs with the turbo, manifolds, but without the injection pump. They didn’t say if the flywheel was part of it, but probably not.

As for the Turbonator VGT, the only adjustment is the starting point of the vanes, which makes it not spool up if I open them more. The actuator is mechanically operated by drive pressure so I don’t think there’s much I can do with it besides artificially adding pressure on the top end to open the vanes more, which I’m not sure how to do. I’ve given some thought to an external wastegate, but using that to drop drive pressure might cause the vanes to close and end up self-cancelling or some other wonkiness, so I wasn’t gonna mess with it.

I mean, if primary pressure is low because the manifold turbo is driving harder, that shouldn’t effect how many lbs/min are coming into the engine. I’m just not used to seeing primary boost that low. I think I might try more fuel to see what happens. If drive pressure in the hotpipe gets high enough, that might slow the manifold turbo down a bit and let the atmos catch up.

I might do that later today; I was gonna remove the fuel plate since I took too much material off the bottom so it does nothing to cut low end smoke. That was partly not my fault though—I think—because after I ground the plate and mocked it up in the housing next to the AFC foot, I realized it hung more than 1/8” below the AFC foot, which nullified the foot I left on the bottom because it was below the range of play. That was a cheap Ebay plate, so maybe it was made incorrectly? I thought both the AFC foot and fuel plate should be even at the bottom.

@Bateman, I can take a picture of that plate when I get it out, for what it’s worth. It’ll show what I’m going for, at least.

By the way, if anyone has any stock fuel plates they’d like to part with, let me know.

 

[CTD2500]

Here is the fuel plate I ground.

The issue I mentioned is that when it’s placed next to the AFC foot like it would be when installed, it hangs below the foot. Seems like it should be level, in fact I just saw a video on YouTube where the guy’s stock plate appeared to be even with the foot.
This makes it so my grind misses the mark; the next one I do I will have to mock it up like this first to make sure the curve is in a better spot.

The reason I cut the midrange so far back is because I use a stop screw that I added to limit the AFC foot, and I can adjust it quickly from the outside of the pump.
That little bolt that holds the slotted adjuster on the front of the housing. I drilled that through and tapped it so a longer bolt could be threaded through to stop the AFC foot where I want. A jam nut holds it on the outside.

I got this idea from someone else, so I can’t take credit for it. But it’s useful for quick, easy full fuel tuning. In this picture, it’s backed out enough to not limit at all; the foot itself is the limit (with full travel mods) because I want to see what the turbos will do with full fuel.
My pump is a 160 maxed at 430cc and my injectors are from Dynomite, and are similar to a 5x.018” in power, but less smoky.

Using the screw without a fuel plate cannot limit low end fuel/smoke though, which is why I put a plate back in. But I only need it to limit at the bottom, while the screw can still be used for the top end—hence the aggressive cutback higher up. I don’t know how that tuning method will work out, but I guess I’ll find out.

First, I need a cut that actually lines up with the AFC foot!

 

[Powerstroke Cowboy]

Wow, that's lighter than I thought it would be. That makes me think it would be a good canadit for the swap I would like to do. Thanks for the Information, I never thought to google it.. :doh:

If your is run of drive pressure then I agree there not much you can do. I also agree a gate would just cause the vains to close down more a negate the desired results.

Your primary flows a max of 78lb/min and together the atmosphere turbos flow a max of 128 lb/min. That more air than a s476sxe flows.

So drive pressure for the atmosphere turbos is higher than the boost they are producing? If that's the case, I would think the exhaust side is to tight.

 

[CTD2500]

The S200 turbine wheels are 61.5mm, and two of them equal a single 87mm turbine (area wise). The .82 housings combined would be roughly 22-24cm2, which is an estimate, but I can’t see it being overly restrictive. It could be better, sure, with bigger hotsides. But also more lag.
What I found in my research is that these 57 SX-E turbos with a .82 housing seem to run with 1.2-1.5 times exhaust pressure over boost. This is as a single on small high RPM import gas engines, though, which is tough to compare. That said, I am at about 1.9 times drive over boost.

I could be wrong, but these are my thoughts.

After this turbine upsize I did, and seeing drive pressure drop mostly on the low end, as well as boost coming in a bit later but ultimately being roughly the same as before, I feel like the exhaust flow and pressures are about where they should be; I think it’s the VGT driving the manifold compressor harder using the same exhaust energy, and that is dropping primary boost.

With the primaries pushing generally constant, driving the secondary compressor harder—in my experience—drops primary pressure, but raises total pressure. Driving the secondary compressor slower does the opposite. It’s the same amount of air coming in; the secondary is just taking more of it stuffing it into the final stage which manipulates primary vs total boost pressure. Of course, exhaust wastegating around the secondary plays a role too, but that is not valid here.

Like how they say boost is a measure of restriction, a turbo has to outflow whatever it’s charging in order to build pressure—and the more it outflows it, the more pressure it makes. In this case, the 62 has the advantage of the VGT essentially “gearing it up” so it drives hard while the fixed vane 57’s are unable to use the exhaust energy in the same way, until the high end. Is that why primary boost builds to 1-2psi early on, but then hangs there until much higher throttle when the 62 finally plateaus (due to the vanes opening wide) and the primaries really come online?
Is primary drive pressure 30+ psi because it’s doing it’s work of driving the compressors the way it should, but the 57mm compressors just can’t overtake the 62 by a large amount because it’s spinning exponentially harder?

Would larger compressors build more primary boost pressure, with the hotpipe drive pressure being the same? I did experience this years ago using a GTA42 primary, one with the 70mm compressor and one with the 75mm; with the same hotside, the 75mm made boost sooner and hit harder (this is with the interstage cooling). I think even if shaft RPM is lower, the larger compressor moves more air per rotation and thus “spools” faster. Would the same thing happen with these primaries if I upsized them to a 60 or 62mm?

Again, this is all speculation and I could talking out of my ass right now. Larger compressors are not really needed, I think, because lb/min flow is ultimately more important than pressure. If they “spooled” faster, that’d be OK, but what do I gain from that? The power curve is pretty seamless right now, plus that would probably be more air than my fuel system would ever be able to use.

Do I make sense or no? I’m gonna give myself E.D. thinking about this stuff too much. I almost wish I didn’t add a port to check hotpipe drive pressure because now I’m hung up on it, although if I had no gauge there and saw primary boost that low, I might have swapped SMALLER turbine housings on to drive the 57’s harder, which would have been very bad. Tuning blind is no good!

I’m gonna try a run with full rack travel next and see what the numbers are.

 

[56cummins]

I get what you are saying. Its still weird to have that high of bp. The primaries should just spin faster with the void created by the 62 putting in all the work. The new turbine housings look like they should have done more than they did. Would be nice to try a different style turbine, like your current ones clipped, or a 9 blade Garret G series.

 

[CTD2500]

That’s an interesting thought, that the primaries would spin easier to fill a low pressure system. I was thinking about it today, what if I temporarily unhook the VGT actuator and tie the lever so the vanes are open and go for a drive? It would be laggy as hell, but if I get those 57’s spooled with the 62 neutered I can see if the drive/boost ratio in the primaries changes. Will the boost be higher?

It would be nice if I could swap a wastegated S300 in place to see the difference, but the VGT has different dimensions so it’s not a straight swap.

I was also thinking of checking boost at the primary compressor outlet to see what it’s at, as opposed to after the interstage cooler.

To be clear, I don’t necessarily think there’s anything wrong with the system. There could be, but I’m trying to figure out if this is how compounds run with a VGT vs a wastegated secondary or if there’s an actual issue.

 

[Powerstroke Cowboy]

For what it's worth, my 6.4 runs high back pressure to boost with the factory turbos. The secondary is a vgt as well.

 

[CTD2500]

Yeah, some of the OEM stuff isn’t great. When I ran the wastegated K03 on my TDI, the drive pressure was something like 35 psi for 19 lbs of boost. I think it hit 9-10 psi of drive before 1 lb of boost even registered.

So I drove the truck with the VGT disconnected and locked wide open today. Pretty miserable to drive like that. All three turbos wake up at pretty much the same time, which is pretty late. Hard not to roll coal like that.
Anyway, primary boost did raise a bit. I saw 20/30 at one point, and a peak of about 25 boost with close to 40 drive. I think it averaged about a 1.5 or 1.6 ratio until the upper end. Not a super big change, but it was repeatable. Total boost still hit 60 even with the VGT wide open, the 62 probably running about a 1.8 PR.

Maybe these primaries would have been better suited with a third 57 on the manifold, although I’m sure overall drive pressure would be much worse like that. The smallest turbine wheel the Turbonator fits is the 68, so I would have been stuck with a small gated housing if I ran an S200 on the manifold. I also like how the 62 VGT cleans low end smoke, so there’s that.

It’d be interesting to see how the 57’s run with the 65/74mm turbines; at that point I’d basically be running Aurora 3000’s as primaries, minus the purple.
I think I’ll leave it for now and play around with max fuel settings before dropping any more money on it.

 

[Powerstroke Cowboy]

Hmm, it would be interesting to see how it would respond to bigger atmosphere turbos.

You can rule out the vgt holding them back.

 

[CTD2500]

I did eventually get around to finding a quiet road out of town to try a full throttle run with full rack travel allowed. Top boost was 75 psi, with 20 from the primaries. The drive pressure gauge had been removed by then so I don’t know how high that was, but I generally know what it would have been. I was getting tired of driving around with the gauge on my wiper arm.

So boost pressure ratios were 2.36 (20psi) on the primaries, and 2.58 (23psi) on the manifold. Both running in a decent spot.

I would note that primary boost with the VGT was locked open was 25 psi—up from 20 with the VGT in play—which is likely because the manifold turbo was slowed down.

The interesting thing was that exhaust smoke output was 99.9% clean. That has never happened with any turbo setup I’ve ran, so these obviously flow a good amount, even though the boost pressures are a little wonky compared to past setups. This also means I’m capped for power, so as much as I’d like to experiment with larger primaries, there’s not much point. I will have to look into increasing fuel if I want to do that.

Anyway, in the near future I intend to rework some of the pipes, partly to fix the leaky welds, but also to hopefully help with air flow. There was a bit of chip damage on the 62 compressor wheel, I think maybe from a bit of welding slag trapped in that skinny Y-pipe section—which is impossible to check or clean out properly. So I ordered a new wheel from AGP Turbo, who had new takeoffs in stock, and while I was there I noticed they have a 3rd gen style housing for the S300 SX-E, so I got that too.

Here’s why.
Firstly, my housing had some cratering from whatever went through the compressor wheel, but also because the 90 degree outlet has a much tighter bend than what I have now.

This is the current clamp-on setup. Notice there is about 4” between the inlet and outlet.

This is the new housing from AGP. The bend is much tighter, and I think matches the dimensions of an HE351.

When you look at this picture of the clamp-on elbow in the truck, you can see why I’m going this route.

Because the elbow is so long, it puts that charge pipe out over the intake pipes, and it has to have a that bend toward the alternator to miss the air filter box. Those welds in that bend are leaking anyway, and with the AGP housing I can tuck that pipe in and have it do a simple 90 down. I can also clock that compressor outlet down, then I can redo the primary Y-pipe.

I’m not a fan of those skinny, bendy pipes that go overtop of the manifold turbo. I think if I had the Y connection as close to the primary outlets as possible so it becomes a 3” right away, it would probably flow better. But I couldn’t fit a 3” pipe over the secondary turbo without hitting the hood because the VGT is so big.
With the secondary compressor outlet tucked down, I think there’s room to route the 3” pipe in front of the secondary turbo and have it swoop back over the valve covers and connect like it did before, by the master cylinder.

It takes a lot to explain, but it’s pretty simple. Fewer bends, bigger pipe, fewer welds.

As far as the tractor goes, I’ve got the chassis covered in plastic sheets to keep the dust off, and I’ve rearranged the garage so everything is out of the curtained-off area. Over the winter I’ll be stripping parts in there while I wait for machining the adapter for the engine. (This is part of why I’ve busied myself with the truck: too much waiting!)

 

[CTD2500]

Some progress quicker than expected. I removed the 62 compressor housing tonight and swapped the AGP housing on. I still have the boot and elbow from the old setup so I’ll probably just weld that back onto the charge pipe after cutting off the upper section with the leaky welds.

Here are the two housings compared.

And here his the AGP housing on the truck. See where the outlet lands compared to the old one; the charge pipe is way out of line.

Here are the pipes temporarily installed. The compressor outlet just has the old setup’s boot and elbow on it. It got dark out so I didn’t have time to cut and weld the whole charge pipe together.

It really makes better use of the space like this. Tomorrow I might mess around with the Y-pipe after getting the high pressure charge pipe tacked together.

 

[Powerstroke Cowboy]

I like that new housing a lot. From the looks of it, it will clean up you piping. Less bends will flow better.

It sounds like your setup is running pretty good.

Did you ever run compounds without both stages being cooled? If so, how big of a difference did you see cooling both stages?

 

[CTD2500]

I ran compounds from 2012 without interstage cooling until about 2015, when I added the second cooler. Since I didn’t move the turbos when I did that, I could still swap to the non-interstage pipe in about ten minutes, so I ran it back-to-back one day. At full throttle/boost it was smokier and down on power a bit without the cooler, but it spooled faster off the line, which is what led to adding the check-valve so the secondary could have its own air supply until primary boost came on.

I’ve never dyno’d it, but the performance differences with and without the second cooler were quite noticeable just by driving.

AGP is one of those vendors that I’m glad I found in recent years. They make nice stuff! Their turbine housings for the different generations of Cummins are nice too.

 

[CTD2500]

A bit more progress this morning, but I had to stop because I ran out of 3” bends. I’ll have to go buy some more before I can continue.

Firstly, I got the high pressure charge pipe tacked together. I had to add a little mitre-cut section to bridge the gap; no big deal.

Then I moved onto the primary Y-pipe.

Here is the old one. I was never a fan, but that was the best I could come up with at the time.

Here is the beginning of the new one. The rest will be single 3” pipe from here out. Several weeks ago, I managed to find a silicone Y-pipe with two 2” inlets and a single 3” outlet, so I ordered it, not sure at the time how I would use it. Much easier than making a metal one.

Here it is in the truck. It was always very close to the manifold turbine on the one closer to the block, which is why that side was always V-banded.

I’m holding the next bend in place here. I didn’t want to weld it yet; I’d rather have all the bends I need to finish it before I commit.

I’ve drawn a blue line on this one to show how I plan to route the rest of it. Hopefully it clears the hood!

 

[CTD2500]

I hope no one minds the lack of tractor content. There’s really not much progress being made with that at the moment, so this is all I have to talk about.

 

[Powerstroke Cowboy]

I am enjoying watching the tractor build and the progression of your pickup! Keep em coming I say! Looks like the piping is coming along nicely. Should be a.cleaner installation.

Sounds good. Thanks for the information. I would like to cool between stages when I do compounds. I'm sure egts would be lower as well.

Yes, AGP has a huge selection of turbos and best of all, a wide selection of exhaust housings for them.

 

[CTD2500]

Update.

I finished rebuilding the crossover pipe for the turbos. The way I wanted to do it as shown in the last post with the blue line did not work, (the 2nd gen hood slopes down as you go forward so space runs out fast) so I managed to squeeze it overtop of the VGT housing without hitting the hood. It’s all welded up (using a TIG this time) and it looks good, and shouldn’t leak like it did before.

These are the updated pipes tacked together. Crossover on top, and the modified high pressure pipe to the intercooler to match the new compressor outlet on the 62.

After TIG welding and paint. It was decently warm that day, plus I brought the space heater in from the house so I could get these done in time.

Here is the crossover installed. I changed the angle a bit where it attaches to the next pipe near the master cylinder because later on I want to build a 3.5” intake horn plus charge pipe and I wanted to leave room for that. Gotta keep myself busy, lol.

Here it is fully assembled.

It has more space between pipes like this so there should be less rubbing (the only close spot is the crossover going over the VGT housing), it’s easier to work on—like being able to reach and adjust the VGT actuator, and I think it’ll flow slightly better than those two skinny pipes with all the bends in them. The metal Y-section on the old one necked down too, which I didn’t like much. The boot I used for the Y is pretty wide open in comparison.