420 industrial with turbo added

[VTPSD]

I posted this over in the main customization forum, but thought it might be appropriate to post over here too.

I bought this tractor a few weeks ago. Posted on here trying to figure out what model it is. Thanks to some knowledgable people on here i think it is a 1975 420. I have been sorting out all of its issues, and now that I got it working well and not leaking much of anything anymore I decided to add a turbocharger (mostly for fun).

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The charger is from a saab turbo car. The compressor map looked about right for this engine, and i calculated it would make about 5 psi of boost at 2000 rpm. Which is exactly what it does. I just finished it up this morning and drove it 12 miles to a friends house and ran it on the harley rake all day long and then drove home. A good trial run for sure. It actually gets down the road better now, its very hilly around here and it will pull hills in 8th that it would not before. It also makes it just work a bit better in general. I am very pleased with it. It comes out of a lug much easier now where it would bog before, it spools up and pulls. Not dramatic, but noticeable. Fun weekend project and it makes all the right sounds now.

here are some pictures of the process from yesterday and today


all the parts to make the swap happen

ready for surgery

the space i have to work with

harvesting the flange

cleaned up

turbo adapter

test mount

timing cover with oil drain added

drain installed

i broke a fitting for the oil feed so i couldnt run it the way i wanted. Had to make do this straight fitting work, dont love how the line is routed, will redo later.

not loving this, have to re-order new hose ends.

cutting the stock opening bigger

fitting stack

and done, doesnt look half bad, actually.

the only issue i had all day was it got a bit hot and spit out a small amount of coolant after climbing the mountain all the way home. it is about a 2000 foot elevation climb so it works HARD to get back up home. It did this last time i had it on the road too. Just barley boils a bit, i throttled her down and get home and it wasnt really hot anymore. Im sure the turbo doenst help this, but it was doing it before as well. Coolant does appear to flow, but it is pretty brown and old looking. Might be time to have the radiator cleaned and change the thermostat. It did run all day long and didnt get hot, which was nice.

short clip of the sound, i think it sounds nice

 

[barryb77]

That is just awesome, in my opinion diesels need a turbo whine.. Did you have to do anything to the fuel, turn up the fuel to equal out the air fuel mixture??

 

[Bladehauler]

Sounds GREAT ! and looks factory ! might want to flush the fins on that radiator too !!

 

[pedalstomper78]

I love to see projects like this. Gives me hope for society knowing that there are still "can do" people out there. Kudos!

 

[RickB]

Neat installation! Might consider replacing the radiator, Those cores get pretty well plugged inside & out.

 

[farmall 55a case]

Awesome!

 

[VTPSD]

That is just awesome, in my opinion diesels need a turbo whine.. Did you have to do anything to the fuel, turn up the fuel to equal out the air fuel mixture??

Have not touched the fuel yet. Honestly, I am not sure how to do it on the CAV pump. I have a parts pump from a 4610, so I will see how it works on that one first before I mess with it. I also ordered and EGT gauge that I want to install before I mess with it.

 

[VTPSD]

thanks for the kind remarks everyone! Hopefully I can get the cooling issue sorted and some new tires on this thing and it will serve me well for many years. It has already been worth its weight in gold. The turbo makes it a lot more fun to operate too. Had a blast running it all day moving dirt and getting lawns ready for seed.

 

[barryb77]

This has me wanting to put a turbo on my lil ford 1520. I know of a couple older Chrysler Lebarons with turbos, I can get for cheap. So how do you figure if a turbo is the right size or not. You mentioned you compressor map? I am just know getting to understand turbos.

 

[VTPSD]

This has me wanting to put a turbo on my lil ford 1520. I know of a couple older Chrysler Lebarons with turbos, I can get for cheap. So how do you figure if a turbo is the right size or not. You mentioned you compressor map? I am just know getting to understand turbos.

im certainly no expert, but i have put all kinds of turbos on things that were not supposed to have one, so i have some experience. Basically I sort of know just by looking at it that the saab turbo is close to the right size based on what other smaller diesel engines use. Also I chose this turbo because it is oil only (no water cooling) and it was compact with an internal wastegate. I did find a compressor map to see if i was even in the ball park for size.
Here is the map.

I calculated about how much air (lbs/min) this engine flows using an online calculator. Basically its just how much air an engine with a known displacement can move at a given rpm. Basic volume math. Then check that against the map. To calculate pressure ratio you just use this formula (14.7+desired psi)/14.7. My ratio at 5 psi is then 1.34. Running 5 psi at full bore should flow about 10.3 lb/min. So this turbo is actually on the big side for this tractor, but keeping the boost low, i think that is just fine. Better than too small. You want to turbo small enough that it will give some boost in your usable powerband but not so small that it surges and restricts flow at full bore.