More than thinking-about Cat-swapping the Disco

I have used a 7 inch tablet running Torque with a wireless OBD2 with great success. It's cheap and it works well.

I suppose it could be made permanent with a fixed display and a small Android box. That's all the expensive displays are, anyway...

What's the update rate on that? I have a couple of Bluetooth OBD2/J1708 readers. I'm not running Torque, but the ones I have have a relatively slow update rate. It's fine for what I'm doing with it currently, but I'd want something quicker to update on a vehicle while I'm driving it.
 
It shows RPM in real time, so the refresh must be be pretty fast.

I think the ScanGague/UltraGague runs on the same chips, but they have a cable. Both work well...
 
It shows RPM in real time, so the refresh must be be pretty fast.

I think the ScanGague/UltraGague runs on the same chips, but they have a cable. Both work well...

Good to know. I have an OBDLink MX+ (OBD2, Bluetooth) and that seems to be fairly slow, and then BlueFire (J1708, also Bluetooth). I don't know how much of that is intentional lag on their part vs. inherent lag of Bluetooth/the protocol.

The idea of having an Android or other doesn't bother me at all, and I think would be pretty reasonable really. Would make it easier (I'd think anyway) to incorporate things like a GPS speedo, etc.
 
Good to know. I have an OBDLink MX+ (OBD2, Bluetooth) and that seems to be fairly slow, and then BlueFire (J1708, also Bluetooth). I don't know how much of that is intentional lag on their part vs. inherent lag of Bluetooth/the protocol.

The idea of having an Android or other doesn't bother me at all, and I think would be pretty reasonable really. Would make it easier (I'd think anyway) to incorporate things like a GPS speedo, etc.
Android Torque app is very popular in the diesel world with an ELM327 Bluetooth module in the OBD2 port. Can monitor all sorts of PIDs with real time data.

Sent from my SM-N976U using Tapatalk
 
  • Like
Reactions: Ted
Ted, I found a better option for you to tow behind the RV. You could probably even put the CAT into it, lol. For a measly 75 AMU's, it's yours.

184139193_10225819447499657_8226068304689891835_n.jpg


186461908_10225819446819640_1067434474587946653_n.jpg
 
Today I applied power to the ECU for the first time since I got the thing, and I also confirmed the starter works. Just enough to make sure it cranked, which I expected it did, but good to see that it worked and turned over.

I had soldered up an OBD2 port and hooked up my OBDLinkMX+ (which supposedly supports J1939) to attempt to connect my phone to confirm the ECU looks like it's working. An oversight I had was that the OBDLink software that came with that doesn't support J1939, so I need to find a different program that will, ideally through my existing OBDLinkMX+ or buy another adapter/program.
 
I went by the Cat dealer and got a bunch of Cat parts:

2021-06-30.jpg


Although the C4.4 is still blue, it will soon have yellow filters. I got genuine Cat filters and Cat oil to put in it, to get it running. Although I couldn't get the OBD connector through J1939 working, I decided to go ahead and order a low pressure fuel/lift pump and I think I will try to get it running. If that works and I can get the PTO (i.e. cruise control) functions to work for up/down, I'll order some parts to try to get a throttle working. Those are the things I really need to work out before I work on trying to get a transmission attached, and an appropriate flywheel.
 
Yesterday I got the oil filled up on the C4.4 and also changed the oil filter and the main fuel filter. Now, it actually has yellow parts on it like it's supposed to:

2021-07-01.jpg


The fuel/water separator at the bottom I bought a Cat filter for, but unlike the Donaldson filters which are one-piece, the Cats are 2-piece with a bowl separate from the filter itself. Pros and cons to that design, but the biggest con at the moment is the Cat dealer didn't mention that to sell me the bowl. So, I didn't put that one on yet.

I got a small low-pressure fuel pump from Amazon to use as a primer/boost pump with it on the stand. I'll need to get some fuel hoses, but once that's done, I should be able to prime the system and attempt a start.
 
It's been a while since I've gotten to touch the C4.4 between the latest long RV trip, getting the RV ready for said trip, and the standard day job/etc. bits. But yesterday I got to actually plumb up the small low pressure fuel pump for it, put on the Cat fuel/water separator, and give it a look-over. I think I need to make some proper battery cables to connect the starter to the battery in hopes of it actually turning over. But otherwise, it looks ready to go. I should also throw some coolant in so I can run it for longer than a minute or two without concerns of it overheating and blowing a head gasket (which... hopefully it wasn't sold because it had a blown head gasket).

The next steps after first start are buying the transmission and then trying to find the box and specs for the throttle position sensor. It seems like a lot of the electronic Cat engines use a PWM signal for throttle position, which is provided by a separate box which outputs the PWM based on the input of a rheostat. So I need to look into that some more and figure out what box I need to buy.

I also am hoping I may be able to reuse the flywheel that this thing has on it already. It looks as though the flywheel has an adapter bolted to it for the splined drive that the hydraulic pump it came with used. I need to unbolt that adapter and see what it looks like underneath, but hopefully I can attach a clutch pressure plate to it. We'll see. That will take a lot of measuring and research to find something appropriate I imagine.

Vehicle wise, I am thinking about whether I want to do some of the other vehicle-side items ahead of the engine being ready, but my thought is probably not. I'm going to get the drivetrain operating correctly on the stand before I bother trying to put it in the car, and I have enough other things to do relating to the RV that are higher priority that I think I'll just keep focusing on the drivetrain. There will be plenty of wait/downtime in there I'm sure, but hopefully the swap can happen this winter.
 
Today I managed to fire up the engine for the first time. I'd hoped to at some point this week, as I had all of the equipment I needed. I had the required boost/lift pump for the fuel system and hose for the fuel tank, even had 5 gallons of diesel fuel to use. I had the wiring traced out, I knew which wires were which and had (at least I thought) an idea of how they all worked.

The first step was putting power to the fuel pump to prime the system. It did that within a couple minutes (just like the manual says). A neat part of the Cat fuel/water separator is that, having a clear bowl at the bottom, you can immediately see 1) if you have fuel and 2) if there's water in it. So I could see quickly once fuel was going through, and then the little fuel bubbles from the return line eventually turned into a slow stream.

I then crimped together some battery cables to go to the starter. Interestingly, the engine power and ground setup on this are both at the starter. I suppose that's a good idea, at the very least it's convenient wiring wise. So I made short cables for that with some 4 gauge wire I had around, and then I jumped the starter with a wire to make sure that it would crank well. Sure enough, cranked well and sounded like it had good compression on all cylinders, no smoke while cranking.

So then it was time to apply power. There are a number of discrete inputs going to the harness along with a "SWITCH RETURN" wire, which they all seemed like they were supposed to go back to. So I put the "IGNITION SW INPUT" to the "SWITCH RETURN" wire and cranked. Nothing. Tried again, nothing. Sprayed a little ether in and it fired on that, then immediately died. Ok, something's not right.

While I don't do Facebook anymore, there are a couple of really good groups on there that I log on to from time to time for, and one of them is a Caterpillar engine technical help group. I posted my question there and quickly got a response that the Ignition SW Input needs +12V. Did that and then sure enough, fired right up! It runs well and strongly from what I can tell with no smoke observed. I then tested the PTO functions (which will be used for cruise control) and those work as expected, too.

Now that I've confirmed that I can make it start, it's time to start working on sourcing a transmission and also the appropriate components for a throttle. From the manual I was able to get, it looks like the throttle needs to be configured. It also is going to require a PWM input. The ECU provides an 8V power output and ground (plus of course a signal wire), and something needs to produce the 500 Hz PWM signal to go back. Really, this should be something that can produce that PWM output based off of an analog input. In an ideal world, I'd be able to simply use the TPS and throttle body from the Land Rover's existing engine as the analog input, just obviously tucked off to the side out of the way where it's not serving a true function. That would be convenient, and it seems like that shouldn't be too difficult of a setup to come by. But I'm a mechanical engineer and electrical stuff like that I don't know as much about.

So really, now it's time to edit the video to post, and do some more research into the next aspects of what I need to do. I think the transmission and throttle are the next big ones, and then the flywheel, clutch, and throwout bearing will follow.
 
With the C4.4 now running, I felt comfortable going ahead and buying a transmission. So, I found a T56 from a C5 Corvette locally for a good price from a wrecking yard and picked it up.

I had targeted the Corvette T56 specifically for a few reasons. With the low redline of the diesel (2200 RPM) I wanted to have a more significant overdrive to have reasonable RPM on the highway as it's not easy to change the ratios in the axles on the Rover, at least to something taller to give me more highway speed. Right now with the stock transmission, overdrive is 0.73 (or 0.72, I forget) and 2200 RPM equates to something around or under 70 MPH. While this isn't a car you drive fast, I do want to be able to go highway speeds with it. This T56 has an overdrive somewhere in the 0.5 range (0.50 to 0.56, depending on model - I believe this one is 0.50) and that will give me a nice overdrive that will still give me good highway performance.

The T56 is also stout - perhaps not bulletproof, but I think it should hold up to the torque of this engine. While the stock C5 Corvettes made less torque, they also made much more horsepower, and the lower torque wasn't by an enormous margin. I do plan on using thicker fluid than the stock ATF recommended, which should help the transmission hold up to the torque.

So, why a Corvette T56? They tend to be cheaper than the Camaro/Firebird equivalents as they don't simply bolt in to a lot of other cars. Plus, since they're designed to work with a transaxle, the back of them has a nice machined round centered surface that works well for centering up with the stock transfer case (which I intend on using). I will have to convert the transmission to a mid-shift setup instead of the forward shift, but I was going to need to do that anyway since F-bodies have the shifter in the tailhousing.

Additionally, I was going to need to do something with the front plate, as I have to figure out how I want to adapt it to the engine. Some measurements will need to occur to figure out where the input shaft will need to line up, and then I will have to have some work done with the flywheel - either remachining this one, getting a different one, or having something machined to attach to this one. I'm leaning towards option 2 if there is a different flywheel available that will bolt up and accept a clutch, which I think there is. Really all I need to figure out is a flywheel and matching pressure plate, as the friction disk should be straightforward. And then figure out a throwout bearing to release the clutch as well. I am thinking depending on dimensions I'll either have to do something with the front plate to adapt to the SAE bellhousing I have, or else have/make a separate bellhousing that replaces the front plate altogether. Which makes more sense will become apparent once I do some more measurements.
 
With the C4.4 now running, I felt comfortable going ahead and buying a transmission. So, I found a T56 from a C5 Corvette locally for a good price from a wrecking yard and picked it up.

I had targeted the Corvette T56 specifically for a few reasons. With the low redline of the diesel (2200 RPM) I wanted to have a more significant overdrive to have reasonable RPM on the highway as it's not easy to change the ratios in the axles on the Rover, at least to something taller to give me more highway speed. Right now with the stock transmission, overdrive is 0.73 (or 0.72, I forget) and 2200 RPM equates to something around or under 70 MPH. While this isn't a car you drive fast, I do want to be able to go highway speeds with it. This T56 has an overdrive somewhere in the 0.5 range (0.50 to 0.56, depending on model - I believe this one is 0.50) and that will give me a nice overdrive that will still give me good highway performance.

The T56 is also stout - perhaps not bulletproof, but I think it should hold up to the torque of this engine. While the stock C5 Corvettes made less torque, they also made much more horsepower, and the lower torque wasn't by an enormous margin. I do plan on using thicker fluid than the stock ATF recommended, which should help the transmission hold up to the torque.

So, why a Corvette T56? They tend to be cheaper than the Camaro/Firebird equivalents as they don't simply bolt in to a lot of other cars. Plus, since they're designed to work with a transaxle, the back of them has a nice machined round centered surface that works well for centering up with the stock transfer case (which I intend on using). I will have to convert the transmission to a mid-shift setup instead of the forward shift, but I was going to need to do that anyway since F-bodies have the shifter in the tailhousing.

Additionally, I was going to need to do something with the front plate, as I have to figure out how I want to adapt it to the engine. Some measurements will need to occur to figure out where the input shaft will need to line up, and then I will have to have some work done with the flywheel - either remachining this one, getting a different one, or having something machined to attach to this one. I'm leaning towards option 2 if there is a different flywheel available that will bolt up and accept a clutch, which I think there is. Really all I need to figure out is a flywheel and matching pressure plate, as the friction disk should be straightforward. And then figure out a throwout bearing to release the clutch as well. I am thinking depending on dimensions I'll either have to do something with the front plate to adapt to the SAE bellhousing I have, or else have/make a separate bellhousing that replaces the front plate altogether. Which makes more sense will become apparent once I do some more measurements.
You had me at Corvette.
 
  • Like
Reactions: Ted
C5 Corvette transmission next to C4.4 Caterpillar. If I leave the two together will they mate naturally like cats do when left alone?
 

Attachments

  • 69381D08-7D46-4823-B97F-E5F30E707644.jpeg
    69381D08-7D46-4823-B97F-E5F30E707644.jpeg
    138 KB · Views: 32
I'm a bit late with this, but first start of the C4.4 video:

 
Today I had the pleasure of hosting @NealRomeoGolf to show him the shop and the project. Hopefully I demonstrated my loyalty to Caterpillar, even if I picked him up at the airport in my Cummins-powered truck (which has the best air conditioning of the fleet currently). :D

We talked about some of the future aspects of the project. I'm getting some ideas on the flywheel (both with some input from a Cat group I'm on and also thinking about sources to call). The other aspect I need is a throttle input to the ECU.

The ECU on this thing looks for a PWM input from a sinking output driver (PWM that goes to ground if I understand the terminology correctly) at 500 Hz (+/- 50 Hz). The ECU provides an 8V, 100 mA power supply to go to this PWM sensor/converter, although it seems that the 8V power supply is there for convenience rather than the ECU needing the PWM sensor/box to utilize that power source. The documentation does say that the PWM source should produce an output within 150 ms of being powered on, which I suppose is the time before the ECU considers the input to be invalid. Valid ranges are 10-22% PWM for idle and 75-90% at full throttle.

While getting a device that could produce this PWM is simple enough, the catch is tying it to the throttle position, which is the real key. What I would really like to do for this would be to get some kind of device that would use the throttle position sensor that is on the current engine/throttle body as an input, and then use that to produce a PWM output. I'm not sure what would be a good device for something like this.

On my bus thread, I'd asked about devices that would be good to use/program for controlling an array of cooling fans for the engine. @masloki and @ElPaso Pilot had suggested NodeMCU as a stone simple option. No idea whether it could do this kind of analog input to digital output, or maybe this gets into a Raspberry Pi, or something more complicated? It seems like it requires very little in the way of computing power to do something like this. Looking at the description for the Arduino Uno Rev 3 (https://store-usa.arduino.cc/products/arduino-uno-rev3/?selectedStore=us) it lists it has PWM outputs. And now searching, it looks like based on this:

https://www.electronicwings.com/nod...ased ESP8266 has the,is adjustable up to 1KHz.

It can do 500 Hz (max of 1 KHz). And about halfway down that page, they seem to have an example of exactly what I'm trying to do. The difference being they're using the PWM output as power to power an LED, whereas as I understand it, the output driver should be sinking (going to ground) not providing voltage.

It would be kinda nice if I can end up finding a board that can provide solutions for both this on the Cat, and then also the electronic fan control on the bus, more than anything since that way I can try to learn one sort of programming for both.
 
I managed to find a flywheel that I think will work for using a standard automotive clutch. One of my Cat groups pointed out the old Perkins 1000 series engines were what evolved into the C4.4, and the flywheels are the same/bolt up. So I found a flywheel that had come off of a Perkins 1000 series engine, designed for a clutch (albeit not an automotive clutch in what had come out of it originally). So I've purchased it and it's on the way. Once here, I'll confirm that it seems to fit up, and then I can start looking for a clutch that will work, and then also figuring out if a special pilot bushing/bearing may be required for it to work with the T56 input shaft.

So, that's good progress. Now I should probably also figure out and order the stuff I need for programming a throttle input/output to provide PWM to the ECU for throttle position.
 
I managed to find a flywheel that I think will work for using a standard automotive clutch. One of my Cat groups pointed out the old Perkins 1000 series engines were what evolved into the C4.4, and the flywheels are the same/bolt up. So I found a flywheel that had come off of a Perkins 1000 series engine, designed for a clutch (albeit not an automotive clutch in what had come out of it originally). So I've purchased it and it's on the way. Once here, I'll confirm that it seems to fit up, and then I can start looking for a clutch that will work, and then also figuring out if a special pilot bushing/bearing may be required for it to work with the T56 input shaft.

So, that's good progress. Now I should probably also figure out and order the stuff I need for programming a throttle input/output to provide PWM to the ECU for throttle position.

 
:yeahthat:

There's a lot of bits that need to come together to make it all work...
 
I went ahead and ordered an Arduino Uno, which looks like I can use it to program the PWM output for the throttle position going to the Cat ECU. Now I need to learn how to write software.

I hate software. :)
 
I'm doing some more digging into the T-56. I expected I was going to have to tear into things on it just to change out parts and get the appropriate changes. I'm not going to start ordering anything yet as I need to get more details figured out. This transmission supposedly has 80k miles on it, which isn't a lot, but if I have to tear into it anyway I'll probably replace at least some of the wear parts. The Corvette apparently has aluminum shifter forks and the steel shift forks are preferred, as are bronze shift pads. Given how much I like a direct feel with the transmission, I think that makes sense to go with. I'm hoping that I won't need to replace the input shaft, and I'm thinking I probably won't. However it won't surprise me if I need to replace the main shaft with one of the shorter ones. I'll also likely replace the synchros. We'll see what I find internally. But I am thinking I need to find another transfer case to play around with.

The transmission has some factory features that I don't expect I'll want to use. For one, it has a reverse lock-out solenoid. Good reasons for that, but not something I'm worried about. On the Corvette transmission it's in the position where I'm going to put the shifter anyway. I'm not too worried about adding a vehicle speed sensor with GPS speedos and the like, but I'm not going to worry about that one yet.

If the input shaft can be made to work as-is, then I'll work on trying to find/get an adapter plate machined for it.
 
I'm doing some more digging into the T-56. I expected I was going to have to tear into things on it just to change out parts and get the appropriate changes. I'm not going to start ordering anything yet as I need to get more details figured out. This transmission supposedly has 80k miles on it, which isn't a lot, but if I have to tear into it anyway I'll probably replace at least some of the wear parts. The Corvette apparently has aluminum shifter forks and the steel shift forks are preferred, as are bronze shift pads. Given how much I like a direct feel with the transmission, I think that makes sense to go with. I'm hoping that I won't need to replace the input shaft, and I'm thinking I probably won't. However it won't surprise me if I need to replace the main shaft with one of the shorter ones. I'll also likely replace the synchros. We'll see what I find internally. But I am thinking I need to find another transfer case to play around with.

The transmission has some factory features that I don't expect I'll want to use. For one, it has a reverse lock-out solenoid. Good reasons for that, but not something I'm worried about. On the Corvette transmission it's in the position where I'm going to put the shifter anyway. I'm not too worried about adding a vehicle speed sensor with GPS speedos and the like, but I'm not going to worry about that one yet.

If the input shaft can be made to work as-is, then I'll work on trying to find/get an adapter plate machined for it.

As long as you aren't forced to skip-shift it'll work out well, lol. Worst "feature" on a 'Vette EVER.
 
As long as you aren't forced to skip-shift it'll work out well, lol. Worst "feature" on a 'Vette EVER.

Yeah, that is absolutely not going in.
 
The next major step in the C4.4 conversion arrived today, the flywheel:

AMSf6AFNf_H0ux6tyZ_XnvcVf35WoaPMHcDpCGjca5lXYWHAa06zHlK0kN7bgoKbkBjODP-Th-04Q2B7jO88sypgFGHzbsJZ1q961xwhfcV-6uTyJCICXNLX1RfWNzPyKUzCcrsBezziEJ_HYOagQM1hEr-JFFvizuKm8fCjpGJtTZu8gc714Acdwd7Zp_zLVVwYw9vsHEdDu-94M9sv-5gR8db7Niu5UpCgHPEjpOHEFTvI16p546uT0se1LB3Jb6gm40CYoKAwpb_1r_wHveHjLNM_JUkwDplQUdsFlrAdDo5KJSDKMdelwxi-yTH9b-GDq54mMb6btOpVlxb2Jd4eVWYNNjCMc3vm_HrS91b2bphgJINwh7zb64zZEf4YAxG0jCLAGDz_BjAhCHOK2JTprc6TujudmaZXYtqHPKJPlPVQy6ZRCF4-g-J9t90HWz9ppsjUmKj6Verte4QjdvD36yuUQ0woNc6Atj7eABVvzBL3BxLqa-B1iIE6TMrjzzJcvOF9KxBiK87dT3Ycni5OpFeh_xctkkt_TQgJumclBCVa-cPwkF1p_y17OGOAgJQlDW_wV2vat-DcWVGUZcSBFRCDRAPjp1WOc6wLGFW3aFnKi1pI4Vu49jcfUaSI8og0kY5fM_BgNGiToG5FXN7f9Vc-n_wagjgcW0R1OIhZCdIG0IZGCnW3ay1vOsn7xkAVVRSC9pQz45SjdXoLVZFLy7nnbXusPb3BaWh7zeTEcYT0J3UirjFhQ8Y8W__Hu_-uK68-ES9VTfDbuTzMGV-0jxPXs4SqjsyBltvL6InOIfAdfGXOk8pUX1Ayi6VluQhhHQhR6m2UM7p9hLTmSS4u-lXo6wxmZvIWKh4uMwrcrd-mJkR9puw4zXg6cnPDJJoR6rljfyqrlTo0Zo9kOwkpfMPuUTF4HZlZxTDpEdOIwlgcO3EswRdGmxNU3tncvQKShmi_=w1008-h756


This flywheel came off of a Perkins 1000 engine that was attached to a wood chipper, oddly enough, but it did have a clutch. The flywheel seems to be drilled for two different clutch bolt patterns, so I'll need to take some measurements and talk to some clutch manufacturers to see what I can find that will work.

The flywheel itself will need resurfacing, simple enough to be done at any machine shop. And I will also need to buy some new shorter bolts to attach the flywheel to the crankshaft, as the ones that came off are too long. Interestingly, the flywheel is drilled with 12 bolt holes (as is the crankshaft), but only 10 are tapped. I was told that this is normal and expected, just something that Perkins did and carried over to the Caterpillar variant.

After I get the shorter bolts, I'll confirm that the starter meshes properly and then make sure the engine runs without any abnormal vibrations. Once that's confirmed, I'll feel comfortable ordering a clutch and having the flywheel resurfaced, and also working on getting a pilot bushing sorted out. The flywheel had a pilot bearing in it which, aside from being in bad shape, is the wrong size for the transmission. A pilot bushing would do just fine, and so I'll likely just find or have one of those made up. Ideally, I can find one off the shelf.
 
For reference, this guy was selling the pressure plate that the wood chipper used as well. It looks to be a 6-bolt pattern:

s-l1600.jpg


s-l1600.jpg


s-l1600.jpg


Which, now looking at it, I'm realizing corresponds withe the more inner diameter holes that are centered at more or less 12, 4, and 8 o'clock on my photo above. So it seems I need to measure those and find something that fits.
 
Looks like the pressure plate has a number on it - Maybe 3401?

upload_2021-9-29_17-2-14.png
 
I don't want to order that same style clutch. I think I've found some other options. I'll keep working on.
 
I finally got the new flywheel tightened down with the new (shorter) bolts fully, and ran the engine briefly. The starter engages no problem (I made sure to crank it over several revolutions to confirm that was repeatable) and there are no vibrations. So, seems like a good flywheel.

Next step is to get a clutch figured out and on the way.
 
Oh, short video :)

 
There haven't been many updates lately on the Disco, and I haven't had much bandwidth to work on it with trying to work on my other Caterpillar powered vehicle (the RV) and getting ready for our upcoming trip.

However, last night I finally got started on the Arduino program to convert a signal from a throttle position sensor to a PWM output. I started off with the same program I used/copied for the fan controller for the RV and started modifying it to take a resistance (voltage) from a TPS sensor. The documentation I found shows that the C4.4's ECU wants a signal of 10-90% PWM (but may be set to as tight as 22-75%). Outside of the set max/min parameters, the ECU will throw an error. So, I've got a few ways I can test this to see if it works, the first one being with some kind of simple program to just manually have the computer provide PWM outputs increasing and decreasing based on time to see if the principle works.

One thing is that the ECU wants the TPS signal to be 500 Hz +/- 50 Hz. I looked into the Arduino's PWM outputs and they have different frequencies depending on the pin, but most of the pins will default to within that range. So, that makes things simple as far as the program goes.

Once we get into the new year I hope to get a clutch figured out and ordered, while also working on the TPS signal output to see what I can deduce there.
 
I literally just heard the teacher from Charlie Brown while reading that. Good luck with all that. :)

Just know that them fancy jets you fly sometimes have similar kind of stuff going on in the background, hopefully designed by someone smarter than me. :)
 
Although there hasn't been a ton of progress on this project as far as work goes, I've been doing a lot of thinking and researching on it when I have some time to look around the internet.

Like I said last month, I started work on the program that will allow me to do a PWM output to have a throttle pedal. I haven't tested this yet, but that seems like that's more or less figured out, and I have backup plans in place if that has issues. So, I'll get to it.

The clutch pressure plate pattern on the flywheel looks like it matches a stock Cummins 5.9 bolt pattern. Since the flywheel has multiple bolt patterns, I need to call and see if there's another (6-bolt) pattern that will work, but this one seems pretty straightforward. The friction disk will then, of course, need to match the transmission input shaft. The input shafts are a known weak point on the T56, and so I think I'm likely going to upgrade to a "Viper" spec input shaft, which doesn't taper down like the stock shaft does, and is stronger. I figure with the stronger torque pulses of the diesel 4-cylinder, that'll be a good thing.

Another thing I'm going to look into doing to help with the 4-cylinder torque pulses is see if a Fluidampr is available (or could be made to work) with the engine. Really the torsional vibrations that come with a diesel, and especially a 4-cylinder diesel, are the biggest concerns with gearboxes, so anything you can do to help minimize that helps. I think that could be a good direction to go to help with that.

On the output shaft side, this one gets a bit more questionable. The Corvette output shaft (which is really just part of the transmission main shaft) is very long. I may be able to cut it and then machine it down to correct spline count and allow for a more compact adapter between the two, but I need to do some more measurements and see what's feasible. The real goal is to keep everything as close to the stock locations as possible since that will make linkages and driveshafts easier, but we'll have to see how that all works out. The body on frame setup makes this much simpler.

Originally, my hope had been to do the engine swap over this winter, but that will get pushed out - especially with waiting on Laurie's new car to come. But if I can get around to calling a clutch manufacturer and figuring out what I need there, then I'll be heading in the right direction.
 
Oh, shift forks. The shift forks are aluminum and steel are an upgrade, especially steel with brass pads. That's what I'm going to go for while I have it all apart.
 
Back
Top