L2501 Turbo: A Journey Defined - The tractor, The comparison, The modification, The results...

[Rdrcr]

Hey Mike, quick question:

Did you say you machined custom fittings for the engine block oil drain or are they off the shelf?

Solo

The fitting we’re using for the engine block is an off-the-shelf nylon fitting that we custom machine to press-fit into the block.

I had developed a quick-release AN oil drain fitting setup for the engine block that was amazing but, I couldn’t get it to stop leaking oil. So, I had to go back to the simple press fit setup.

Mike

 

[Hahnsolo]

Yeah, I've been looking through all kinds of sites trying to find nylon or Teflon fittings for this purpose but haven't been too successful. Can you reveal the part number and where you found it?

Solo

 

[Rdrcr]

Yeah, I've been looking through all kinds of sites trying to find nylon or Teflon fittings for this purpose but haven't been too successful. Can you reveal the part number and where you found it?

Solo

I don’t know the size you’ll need and what style fitting will work for your application, however, here is where you’ll find what you’re looking for;

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Mike

 

[Hahnsolo]

Cool. Thanks Mike.

Solo

 

[Hahnsolo]

Hey Mike:

Any idea what the torque specs are for snugging down the turbo to the flange?

Solo

 

[Rdrcr]

Hey Mike:

Any idea what the torque specs are for snugging down the turbo to the flange?

Solo

Not off the top of my head. I’ll have to search my notes….

Mike

 

[Hahnsolo]

Thanks Mike.

Solo

 

[Rdrcr]

^^^^
Sorry for the delay, I've been super busy this week...

Okay. I checked my notes and they state 12-14 ft-lbs for the Turbocharger assembly (exhaust flangle, oil inlet/outlet) and 23-31 ft-lbs for the Turbocharger to manifold. Unfortunately, I was unable to pull up the service manual pdf to confirm.

Mike

 

[Hahnsolo]

Cool, thanks Mike, it's a great place to start. As always, appreciate your help.

Solo

 

[Rdrcr]

Here are a few unposted pictures of the L2501 Turbo assembly;

Mike

 

[Hahnsolo]

Wow! That is amazing Mike! I am currently tearing my hair out trying to come up with an exhaust routing scheme functional and doesn't look horrible. It won't look like that though!

Solo

 

[Rdrcr]

Wow! That is amazing Mike! I am currently tearing my hair out trying to come up with an exhaust routing scheme functional and doesn't look horrible. It won't look like that though!

Solo

Hopefully these pictures can provide some inspiration for you and your Turbo project.

Full disclosure; we will be changing the Turbo Downpipe section slightly by using a smaller diameter pipe exiting the Turbo outlet to allow for improved clearance for the heatshield and better access for mounting hardware. Turbo spool and overall performance will remain unchanged. This modification will also save 3 hours of build time.

Mike

 

[Hahnsolo]

Wow, there’s some irony. I have exactly 4” from the back face of the turbo exhaust to the firewall. I tried in vane to use 2” pipe, but just couldn’t make it happen. I dropped down to 1-1/2” and was able route it out comfortably.

This requires offsetting the exit pipe so the turbo blades shoot straight into the center of the pipe. I also had to make a small plate to cover the other half of the exhaust flange. In the future, it would be easier to mill a single hole in the exhaust flange.

The other trick I found was to weld a short piece of pipe to the exhaust flange from the inside to provide a little extra room for the screw heads. By using 8mm socket head screws with a split washer, there is just enough room for a perfect fit.

Pictures tell the story:

Flange with 1-1/2" pipe welded from the inside provides room for screw heads.

A small cover plate was cut and welded in place to close off exhaust flange.

Pipe was cut down to 1/2" to allow screws to be inserted on tight corners.

Top half of exhaust system from turbo to 2" pipe transition bell.

Because I don't have access to a welding machine, I used water hose clamps to hold things together until I can take it to my welder.

Routing is critical and takes a lot of time tweaking and adjusting angles.

When it's all said and done I think it's going to work pretty well. The rest of the exhaust system will be 2" pipe from the bell to the downpipe and out the bottom.

Solo

 

[X-Pup]

Beautiful artwork!

Love the refinements. It just keeps getting better.

I'm almost ready - Whatever you do, don't stop now.

@Hahnsolo I can't wait to see the rest of your ship.

 

[Hahnsolo]

Hi X-pup:

Making good progress, I’ll keep posting updates on my thread.

Solo

 

[Rdrcr]

^^^^
Looking forward to your progress. I'll continue to monitor your thread!

Mike

 

[Rdrcr]

Hi X-pup:

Making good progress, I’ll keep posting updates on my thread.

Solo

I may have already mentioned it but, we are redesigning the Turbo outlet/down-pipe on my Tractor. We're trying to make the pipe easier to reproduce for Turbo Kits and the current pipe takes a very very long time to fabricate. The new pipe will have additional clearance for the firewall/heatshield and more room for mounting hardware. Similar to your setup, the new pipe will have a smaller diameter outlet and the pipe diameter will increase after it makes the turn near the firewall/heatshield. It should be done by the end of next month. I'll post pictures when it is completed.

Mike

 

[Rdrcr]

I have some exciting news!

We've had our second successful L2501 Turbo HST Dyno! His L2501 was tested with ambient temperatures of 70 degrees and 100% humidity at sea level. It made 34 PTO HP @ 2,105 RPM with fuel set a 2 1/4 turns!!!! His tractor maintained 1,200 degree EGT's, made 9 PSI of sustained boost and coolant temperatures remained a consistent 200 degrees throughout the dyno session.
He's really happy with the performance of the tractor and the Turbo Kit itself.

By comparison, my L2501 was tested at 42 degrees, roughly 90% humidity and just a couple hundred feet above sea level. My L2501 made 35 PTO HP @ 2,105 RPM with fuel set to 2 1/4 turns.

The only difference between our two L2501 tractors is that his tractor does have the injection timing pump modification. Now, I was personally expecting his tractor to produce more power than mine with the advanced injection timing. But, that wasn't the case and I don't have an explanation.
Regardless, both tractors are producing a TON of additional power and our dyno experiences mirrored one another in terms of performance, output and the positive reaction from those present. Admittedly, I'm just as happy as he is!

We have several L2501 S2T Turbo Kits running now in multiple states and Canada. I'm hoping I can persuade a few more of the L2501 Turbo Kit owners to dyno their tractors too, so I can provide additional comparisons. To be clear, however, some guys are running the Turbo Kits as altitude compensation only and their fuel systems are untouched and unmodified. So there is no fuel adjustment (no additional or increase in fuel). These guys are reporting a restoration of lost power (and a moderate increase in power), a reduction of smoke output and a 200-400 degree reduction of EGT temperatures.

Mike

 

[Hahnsolo]

Awesome news Mike! It's so cool to see a new product come to market and be so successful. I can only hope mine performs as well.

Glad to hear you are going to redesign the front end of the exhaust pipe with a smaller diameter. It's so much easier with the 1-1/2" pipe, and the short spacer makes welding easier, with the advantage of making room for the bolts. Looking forward to future updates!

Solo

 

[X-Pup]

It's starting to make the case for keeping the fuel timing retarded (stock) when planning a turbo upgrade.

You would think that the method of removing gasket material to advance the fuel timing would not only advance the timing, but also increase the travel on the cam, which would also increase the potential fuel volume per cycle.

Did this latest dyno result use a turbo kit with the latest changes:
Allowance for hood shock.
Reduced exhaust pipe diameter at the sharp bend coming off the turbo unit?

Just curious at this point.