Hello, and welcome to the forum though I'm a quite new myself. I checked out your youtube on this machine. Will be watching here for updates especially when you get to installing your 4BT. I will be interested in where you source it. The mechanical engines seem to be getting harder to find or perhaps I don't know where to look.

 

My little salesman has plenty of them. The shipping is what kills the deal on most of them though.

 

Welcome to the forum. You are seeking reliability and the 4bt can fit that ticket. Main thing is to make sure the engine is in good shape. The term "Good Used Engine" can often come back and bite you. Have seen minor rebuilds end up costing many thousands of dollars. Where you live snow appears to be readily available. LOL. You mention the Allison AT545. It is probably an OK transmission so long as you don't plan on high speed highway driving. It has no lockup torque converter and no OD gear. Typically found in vehicles that didn't go over 50-55 MPH. In the used Cummins world they are hard to even give away. You mentioned a source that had plenty of them. Haven't seen many such sources lately. Those engines haven't been built in the USA for about 15 years and most companies have scrapped the vans they were in. A lot of what we are seeing these days are the ISBe engines which are electronic, not the standard mechanical 4bt.

 

I see lots of them for sale, rebuilt mostly. Time is on my side. My snowcat might go 12mph tops when it is complete (which is normal in the snowcat world).

I am not after speed. I am after reliability and this fits the ticket. Should be fun even if I have to build one myself LOL.

 

What kind of final drive would you be replacing? What engine would you be replacing? Would your final drive hold up to diesel torque? What are the ratios for 12 mph?

Ed

 

What kind of final drive would you be replacing? What engine would you be replacing? Would your final drive hold up to diesel torque? What are the ratios for 12 mph?

Ed

These normally have a ford 300 industrial inline six and a 3 speed c6 behind them.

I will be using a 4bt allison at545 combo. The OC12 rear diff is more than capable of handling that type of torque since some of them are connected to 6bt engines.

Speed is not important to me. Others with this same combo run about 12 mph top speed. If I eliminate the drop boxes on the rear diff I might get 18 mph top speed. These machines were built for torque obviously.

 

I've always been curious about those snow-cats. There's someone running winter tours on them about 20 miles from me. I think some of his have Isuzu 2.8 diesels (4JB1). They were used to rescue a whole convoy of 4wd enthusiasts who thought they could beat the incoming snow a few years back:https://whatsoninvers.nz/stranded-4.../stranded-4wd-group-on-near-piano-flatwaikaia-bush-road-update-includes-photos/

Will the drivetrain stand up to the extra torque of the 4BT?

 

Just remember the Cummins likes to operate in the 1600-2000 RPM range. Peak torque is in the 1700-1800 RPM area.The old 300 I6 was a great engine but it turns much higher RPM. Might need an OD transmission just to get to 12 MPH.

 

The 4bt and allison at545 is a proven combo with this differential for 12mph. 18mph if you eliminate the rear differential drop boxes. I will be happy with 10mph crawling through snow though...

 

I love Snocats !!!!!!!!!!!!!!!! I know where there is a Thiokol named "Eddie" which has been sitting in a Lemon Grove for about 10 years now after it came back from Antartica. I live near Port Hueneme Naval Base where everything that comes back from Antarctica comes thru. Alas it is in Socal so there isn't alot of snow available , so I have just left Eddie sit. I could probably get it for <$500, and it has a Ford Industrial 4 cyl Pinto motor in it.

I really Like Tucker Sno Cats and the old restored Bombardier Snowmobiles and this time of year when it is raining like it is today, I usually sit in front of the computer looking at pics of them. These are really cool machines and I wish you good luck on your builds. I like your Toyota ??? with the Mattracks !!!

The closest I will ever get is a set of Mattracks on the DeScrambler,,, maybe someday.

Randy

.

 

Hi. I have never owned a toyota. I did however grow weary of the high priced 4bt motors I kept looking at. I came across an NPR frame cut for 300 bucks so I am going to be using that to repower this cat. Thanks for reminding me I have this thread up as I am terrible at updating them.

 

I was just going by the pictures you posted as far as what looked like a Toyota with Mattracks.

In 2003 I was in Moab and a Ford Pickup with Tracks drove by me, so I hunted them down, and it was the Mattracks guys. My Jeep had 3/4 ton axles so they were a direct bolt up to the ones on the Ford so we were good to go. Next day I ran the jeep into a wall and broke the engine mounts loose so I didn't get to mount the tracks on the Jeep.
I have been dreaming of doing it ever since.The pics you put up reminded me of that.

If you look at my build you will see a Built from Scratch Jeep Scrambler with a 4BT in it. It has the same axles that were in my earlier Jeep so they should just bolt right up to the Mattracks..

Nothing but the $15+K for the tracks and no snow standing in my way !

 

I was just going by the pictures you posted as far as what looked like a Toyota with Mattracks.

In 2003 I was in Moab and a Ford Pickup with Tracks drove by me, so I hunted them down, and it was the Mattracks guys. My Jeep had 3/4 ton axles so they were a direct bolt up to the ones on the Ford so we were good to go. Next day I ran the jeep into a wall and broke the engine mounts loose so I didn't get to mount the tracks on the Jeep.
I have been dreaming of doing it ever since.The pics you put up reminded me of that.

If you look at my build you will see a Built from Scratch Jeep Scrambler with a 4BT in it. It has the same axles that were in my earlier Jeep so they should just bolt right up to the Mattracks..

Nothing but the $15+K for the tracks and no snow standing in my way ! View attachment 126756

Look again, not a Toyota.

 

Really nice progress.. I admire your drive, organization and follow-through. Great team work too! I think I have too many projects or take on too many things but after seeing what you have going on I think I am just lazy- and you video a lot of these projects!!!
I think the Isuzu will be a good fit. The IDI (if I'm not mistaken) should make for a bit quieter ride.

 

Is anyone still here? Well I had enough time off during the pandemic to work on and finish this project. I even had time to build a trailer for this 7500 pound tank.... Now I am at the point where I have some questions for those of you familiar with the isuzu 4bd2t engines.

So for the motor rebuild I tore it down and found a cracked piston ring which was the reason for the blowby on the motor. The liner had minor scratches in it and the liners were all glazed so I decided to ball hone the liners, rering the pistons, and rebuild the motor with all new gaskets. I also replaced the worn main bearings and inspected the rod bearings which appeared to be in great condition and fell within the specs of the tech manual so I opted to reuse them in the build.

The head and valvetrain were also in great shape with no cracks. I replaced the valve seals and decked the head using a hand lapping technique I have had great success with on over 7 Subaru motors (no more blown head gaskets).

This motor has a tremendous amount of power and torque. I am getting fantastic oil pressure. The rings seated nicely after a 3-4 hour motor break in driving around in a field. I have no oil burning or blow by and the break in oil dump had the normal amount of fuzz/shimmer in it that I can tell (no big metal chunks).So now I am at the point of tweaking and tuning. I have been watching videos on YouTube of 4bd motors and noticed they all have a similar noise on camera but in person they sound different (less dramatic and clackity). Take this video for example

and compare the motor sounds to mine

Now on camera for some reason they sound so loud and ticky and in person they sound normal to me with a slight ticking.

This lead me to read this thread Ticking Noise source and makes me think I should tinker a bit more with valve adjustment. I will be tackling that today. Maybe I am just being paranoid but I do not want a catastrophic failure in the middle of nowhere.

I am also curious about what appears to be a giant heater threaded into the intake?? What are those used for?? I left mine disconnected. I am going to be making a cold air intake today and I am wondering if I should skip that because of this intake heater I am seeing??

Any thoughts, elbow jabs, patronizing, or other comments are gladly welcome. This platform is new to me and I had to learn about it fast through self education, this forum, and advice from others so forgive me if I do not understand all aspects of this motor yet...

Pics for attention of course....

 

Nice job.

 

Thank you!

I made a video comparing various 4bd sounds from videos I found on the internet. This may interest some of you.

 

Your 'heater' in the intake might be a heater for starting in cold weather, injects raw fuel in intake manifold and ignites it with spark plug.

Ed in CO.

 

I applied 12v to it and it gets hot like a burner on a stove so I am not sure what it is supposed to do. I have glow plugs and a hydronic diesel heater plumbed into the engine block and heaters in the cab so I have cold weather starting covered. Run the hydronic heater for 15 minutes and I don't even need to use the glow plugs...

 

I think what you're calling a 'heater' in the intake is a voltage dropping resistor-to reduce the voltage to the glow plugs to keep them on during engine warm up. It was powered by a relay that was commanded on by the ecm in the Isuzu trucks. A side effect of that resistor is a lot of heat-so they put it in the intake to further help with warmup. I use mine; I have a toggle switch to control the relay. It does help the engine run smoother when cold. I usually only keep it on for a minute or so. Hope that helps. Joe.

 

That makes total sense. I have it disconnected right now because the motor has bare bone for electronics. I do have the glow plugs connected to a timer though so I guess that helps. This motor fires up really nicely with the new piston rings and the liners deglazed...

 

Pretty cool piece of machinery. I have always been curious, how fast will it go?

Randy

 

Hi Randy. Thank you! Building him was a tremendous amount of work solo. I am not quite sure. We have only had 1 driving session in an open muddy field. We did get up to 20 mph about halfway through 3rd gear with the transmission in NORMAL mode. Someone in the snowcat forums did some calculations and they think I will hit 40 on packed snow flat out with no incline/decline in 4th gear with OVERDRIVE mode on. I have my doubts. I am thinking it will be a really harsh scary ride at that speed. I am not sure rock quarry belts were designed for those speeds either.

Once we get a bit of snow, even if it is a few inches to places we normally frequent I can get back to this post with some actual data. The driving we did do was just to get the feel, make some adjustments, and break in the motor/seat the piston rings. I do know the acceleration is pretty dramatic surprisingly.

Here is the link to the first episode of the new series we have started for the entire winter setup.

 

Nice progress. Let it snow! Rain or something!

 

Thank you!! I am keeping my fingers crossed for early snow....

 

I forgot I made this thread but wanted to update it with this years snowcat trip that turned out really well.

4bd2t just ticking along and having some fun.... I did install a transgo shift kit at the end of last season and rebuilt the 250k mile jatco jr403e transmission since it blew the planetaries at the alpine snowcat jamboree last winter....

I have a few things I want to fix like a pesky pinion seal leak that will require a speedi seal since the surface of the pinion is pitted...

A constant amount of upkeep but really really fun to drive as you can see from my latest vlog....

 

Are there different gears for the drop boxes?
Ed in CO

 

Are there different gears for the drop boxes?
Ed in CO

Drop boxes? Not that I know of. They did make a drop boxless oc12 on the super imp.

 

That's really cool and looks to be running great. Great to see it out and about. Are those skidoo trails you're buzzing around on?

 

It's an entrance to a main forest service road but yes, snowmobiles and snow cats and skiers all share the same entrance...

On a sidenote I purchased some brand new zexel injectors to replace the existing ones with 250k miles on them. It may quiet the motor down a bit, it may not. I thought I would give it a try....

 

Pretty cool piece of machinery you've got there. There was one for sale outside of Fillmore CA a few years ago that I looked at. It had came back the Antarctica and would have needed a lot of work to even get running. It's name was "Eddie." I think it had a Industrial Ford 4 cyl engine . Not a Pinto Motor.

Randy

 

There were three of those near me with an old guy who used to run snow tours with them up a mountain. They're pretty much dormant now and last used on a rescue mission when a 4wd group (38 people including kids) got stuck in a snow storm. The poilce and air-force were screwing around with bringing in helicopters (weather was no good) and snow-groomers (were taking days to transport them there). In the mean time the old guy was up all night checking the machines over, had a minor heart attack and drove in and got them:

Police handling of 4WD snow operation "hopeless", rescuer says

Man who helped rescue stranded 4WD enthusiasts trapped Central Otago back country has blasted the police's effort to help.

www.stuff.co.nz

Here's a video of them being rescued by a D8 dozer that went in a month or so later, chained all the broken vehicles together and dragged them out.

Teamwork retrieved snowbound 4WDs

Fresh footage shows how 13 stranded four-wheel-drives were retrieved from deep snow.

www.stuff.co.nz

 

There were three of those near me with an old guy who used to run snow tours with them up a mountain. They're pretty much dormant now and last used on a rescue mission when a 4wd group (38 people including kids) got stuck in a snow storm. The poilce and air-force were screwing around with bringing in helicopters (weather was no good) and snow-groomers (were taking days to transport them there). In the mean time the old guy was up all night checking the machines over, had a minor heart attack and drove in and got them:

Police handling of 4WD snow operation "hopeless", rescuer says

Man who helped rescue stranded 4WD enthusiasts trapped Central Otago back country has blasted the police's effort to help.

www.stuff.co.nz

Here's a video of them being rescued by a D8 dozer that went in a month or so later, chained all the broken vehicles together and dragged them out.

Teamwork retrieved snowbound 4WDs

Fresh footage shows how 13 stranded four-wheel-drives were retrieved from deep snow.

www.stuff.co.nz

It never ceases to amaze me how dumb people can be at times. Even we know not to go out further than 5 miles if we are alone with no other catters with us...

 

I am looking for an SAE 3 bell housing from a 6bd motor (on the left) as I want to mount an allison behind the 4bd2t. If you know anyone that has one I would like to buy it... I blew my second jatco jr403e that I "bulletproofed". I am going to tear it down to see where it failed.

 

Aww man, these videos keep getting more entertaining. Kids love them too. I never thought I'd see an old Tucker Sno-Cat in action! I've only seen one in a museum: Tucker Sno-cat
You'll probably get a kick out of the modified tractors a Kiwi took to the south pole too. Ed HIllary was supposed to be doing supply drops for the Tucker Snow Cats and figured he had enough fuel to get there first: Tractor: Massey Ferguson

The Isuzu bellhousing is close to SAE 3 but not quite. Depending on whether the flywheel/torque converter attachment works for depth you may be able to either redrill another trans case to fit the Isuzu or machine up an adapter ring and copy the bolt holes through.
@char1355 put up SAE measurements here: Flywheel Identification

 

Aww man, these videos keep getting more entertaining. Kids love them too. I never thought I'd see an old Tucker Sno-Cat in action! I've only seen one in a museum: Tucker Sno-cat
You'll probably get a kick out of the modified tractors a Kiwi took to the south pole too. Ed HIllary was supposed to be doing supply drops for the Tucker Snow Cats and figured he had enough fuel to get there first: Tractor: Massey Ferguson

The Isuzu bellhousing is close to SAE 3 but not quite. Depending on whether the flywheel/torque converter attachment works for depth you may be able to either redrill another trans case to fit the Isuzu or machine up an adapter ring and copy the bolt holes through.
@char1355 put up SAE measurements here: Flywheel Identification

Well, I have 3 trans cases to mess with now since I scored another jatco jr403e for 250 bucks with 90k miles on it. Ones of these things has to hold up at some point right?? I am going to tear apart the one I just destroyed and see what happened. My guess is the planetaries burnt up again. Seems they are super fragile in these things.

Well at least he keeps me busy. Found a flat tire today too so the remaining 6 tires that are not foam filled will be getting foam filled now. Oh the fun I am having

 

Good morning,

I am familiar with the Derale coolers. I run a larger 2 electric fan Derale cooler in one of my vehicles (auxiliary radiator on a 1962 Volvo to handle the thermal overload of air conditioning)

I have a question on using a "snap switch" with an "ON" of 165 and an "OFF" of 180.

It appears (if I understood the video correctly...) that you are powering down the Derale cooler just when it is needed the most.

Russ

 

One of the "problems" I am currently trying to figure out is why that fan never turns on or why the temp sensor I have installed on that line never registers above 140 degrees (where the gauge starts reading) yet I can touch the transmission pan and tell that it is definitely well above 140 degrees. I am thinking the cooling loop I have created is somehow not flowing correctly/enough/at all which is why I am seeing that. Also if that is true I have found out why both transmissions have now suffered the same fate of blown planetaries (video is uploading as I type this).

I am currently reading through amassive thread since the transmissions we have are similar/identical in design as the early nissan skyline transmissions. It is making sense to me now. I have a game plan setup for the spare transmission I sourced on Monday. Hopefully this will be the last time I blow a transmission for awhile... Check out the massive thread here Jatco RE4R01A 4speed automatic info

You have those two numbers reversed: on at 180 off at 165. I must have misspoke in the video which does not surprise me at all...

 

To me it's a simple as something restricting oil flow and hence pressure. I'm sure you'll find it. The pump making cavitation sounds is a huge clue.

Your usage doesn't seem intense enough to damage a a healthy transmission that goes in trucks grossing about 7 ton.

 

Heres an update. I sourced a 6bd1 sae 3 bell housing off of an excavator powerplant. I can now bolt any sae 3 transmission I want to the isuzu 4bd2t. I have an allison at 545 that I am going to start with. Does anyone know if they make these starters in 12v off of another application rather than the 24 volt original? It would solve a ton of headaches for me. I suppose there is a size cross reference chart somewhere?

I may cut the center section of the bell housing out so I can use the original rear main seal setup that I have on the 4bd2t right now. I will have to check if the flywheel I got will bolt up and allow that to work.

Pics, recovery video, thoughts??

 

Your 4BD2T starter should be 12v and 3 bolt. What's stopping that from fitting?

 

You beat me to it. For some reason I did not think it would fit but it does albeit turned out at more of an angle. Here is where I got with it yesterday.