Any Skid steer guys in here? CAT 246.

[036.6turbo]

In typical fashion I bought some broke stuff, and plan to try and fix it.

2000 model CAT 246. It has the CAT 3034 motor, with one extra hole in the block. When I decided to buy it, I knew the 3034 was a rebadged Perkins. What I didn't know was how rare they are. ReMan long blocks run upwards of 12k, rebuildable cores are scarce and pricey as well.

I debated just parting the thing out and cutting losses, but again, in typical fashion, I have devised a repower plan.

See CAT was being tricky back in the day. They were pretty tight lipped about which Perkins was actually in this thing. As it turns out, It's a Perkins 704-30T (UC).

The Perkins 704-30 had (2) "families"
The UA which was a normally aspirated 60hp motor.

The UC which was a Turbocharged motor 80hp. My injured CAT has the UC, which CAT rebadged to a 3034.


So mine spun a main, which apparently starved #2 rod and piston squirter for oil. Cylinder #2 got real unhappy, and well we all know what comes next. So the block windowed out the side and put (3) large cracks in the water jacket. #2 rod journal on the crank took a pretty good amount of abuse and #2 rod ended up in several different places, that it was never supposed to be in. Once the cylinder wall was no longer receiving an oil bath from the squirter, but plenty of coolant, it bored itself out pretty good, right up until the rod signed off.

So there I sat, block is junk, crank could "maybe" be welded and ground back and instead of (4) good connecting rods, I have (3). What to do? Punt, right? Send it down the road. Admit you were a dumbass for taking the gamble.

Nah, I'm not that smart. I called my local engine wrecking yard (RF Engines), told them the casting number on my block (3711H09A/4) and that I was suspicious that it was born in the UK at a Perkins factory. A couple days later they called back and informed me they had not one, but two motors with almost identical casting numbers, with one exception, where mine ended in a "4", both of theirs ended in a "1". Both of theirs came from Daewoo 1760XL skid steers.

I took my block for a nice little road trip and did a visual inspection between mine and the one they had. As one would expect, they are almost identical. The UA blocks do not have the turbo oil drain hole drilled and tapped, but the emboss is there for it. Same type of issue with the dipstick. The UA motor has the dipstick in a different location, but the emboss is there to put it where the UC motor has it.

The motors they had where both long blocks. So I decided to go for it. for $750 they sold me a short block including the rotating assembly. I ended up with both of their crankshafts, because one had significant rust pitting.

My plan is to use he head / cam / injectors / high pressure pump from the UC (CAT 3034) and the block crank and rods from the UA. Turbo oil drain back is a small obstacle to overcome. Obviously new consumables, pistons, rings, wrist pins, bearings etc etc etc. Hard parts will make a trip to the machine shop.

So all that sounds acceptable, save one small thing. The heat treating on the crankshaft. It seems Perkins determined that the UC motor required a bit of additional heat treating. Namely the "fillet radii" got induction hardened along with the journals.


So, again what to do? And this is where I'm hoping for some input. I have a very nice crankshaft from the UA core and I am VERY tempted to use it. But, I also have the injured UC crankshaft that could be welded and ground back. The concern is after welding, what actually happened to all that special heat treating? Maybe it's fine, maybe it's softer than the crank from the UA motor. I'm leaning heavily towards using the UA crank.

This machine will not be a company machine, just one I'm using to build my house and shop on 5 acres of old undeveloped farm land.

Thanks for looking and let me know what your thoughts are.

 

[036.6turbo]

 

[036.6turbo]

 

[gmac32]

I would just use the UA crank. I think you will be just fine

 

[PureHybrid]

I wouldn't worry about the welded crank being soft on the journals, when we HVOF a journal they get pretty hard. But it's going to be $$$ if you find a place to do it

Brother used to have a 236 Cat, I thought it had a mitsubishi

 

[036.6turbo]

I would just use the UA crank. I think you will be just fine

I tend to agree, if I hadn't read the manual, I would never have known there was any difference.

I wouldn't worry about the welded crank being soft on the journals, when we HVOF a journal they get pretty hard. But it's going to be $$$ if you find a place to do it

Brother used to have a 236 Cat, I thought it had a mitsubishi

I have been talking to these guys;
https://crankshaftcraftsmen.com/

Their quote was under $350, I'm just not sure of the durability after the repair. The UA crank may be a better piece, than the repaired UC crank.

Yeah, they've put Mitsubishi motors, Shubara motors, Perkins motors. Motors that were collaborations between the companies, but CAT brands all of them as CAT.

 

[Chevy1925]

Welding will make the actual weld harder than the material around it unless you then put the whole crank in a hot box to normalize the steel, then do induction heat treating back on the journals. im sure it can be done but id rather take my chances with the UA crank over the welded crank. im guessing perkins upped the hardness on the fillets for the thrust bearing side due to the added torque the turbo gave. in an everyday use application where its will see a shit ton of hours, i get the reason. in your case, i dont see you putting enough hours on it.

 

[036.6turbo]

Welding will make the actual weld harder than the material around it unless you then put the whole crank in a hot box to normalize the steel, then do induction heat treating back on the journals. im sure it can be done but id rather take my chances with the UA crank over the welded crank. im guessing perkins upped the hardness on the fillets for the thrust bearing side due to the added torque the turbo gave. in an everyday use application where its will see a shit ton of hours, i get the reason. in your case, i dont see you putting enough hours on it.

I agree. I also believe that when the journal was heated for the induction hardening, the heat didn't magically stop at the tangent of the radius, some portion of those radii came along for the ride.

UA crank it is.

Thanks.

 

[WolfLMM]

You’ll have to grind the nitriding off. If you don’t it will lead to high porosity. I would go with the other crank over weld repairing.

welding hardened steel is very tricky, I wouldn’t do it.

 

[036.6turbo]

Well, the plot thickens on this deal. One more difference had emerged between the N/A block and the turbo block.

"Piston cooling jets"

I saw that the turbo motor had them, when I disassembled it. The rod that broke, destroyed the jet for that cylinder. When I disassembled the N/A motor, I honestly didn't look.

I dropped off my parts at the machine shop, while I was waiting to get those back, I was rereading the service manual and found where there were used on the turbo motor only. The first machine shop wasn't tooled up to add those features. When they completed their work, I dropped off both blocks at a different shop, that could map the locations from the old block, then add those features in the new block.

Initial inspection of the two blocks made it look like there was a single main oil galley down the length of the block and all we needed to do was drill and tap 3/8-24 holes in (4) spots (one for each jet), spot face those spots, then install and "aim" the jets. As we would learn, there was a second oil gallery just for the jets. It was never drilled, when the N/A block was produced.

The second shop wasn't tooled up to drill that length of hole, it would require a "gun" or "rifling" drill bit. This issue much like the crankshaft issue, had me kind of debating to use them at all, or just run it without them. No real good options exists to install them so it will be run without them.

The owner of the second shop said its done all the time, he's a big cummins guy, swaps 12v's into all kinds of stuff, I'll post a picture of one of his builds. But I digress, plan now is to install an EGT gauge, and run it like I do my LML, if it gets close to 1300 deg, back out of it.

Live and learn I guess.

 

[036.6turbo]

Second shop owner work, pretty cool stuff.

 

[Chevy1925]

thats a hard one to say. you cant really equal a 12v to that engine, much like you cant say a duramax is the same as a 12v cummins.

your application is much like a marine application but not the same load. the engine will see governed decent rpm's for extended time and then loaded up as hydraulics are worked. thats what going to work the pistons and heat them up. if they are strong pistons like the 12v cummins stockers, run with it. if they are known to crack or have issue, thats concerning.

can you just run her N/A? or lower boost levels? is the engine mechanically controlled or electronically controlled fueling?

 

[036.6turbo]

thats a hard one to say. you cant really equal a 12v to that engine, much like you cant say a duramax is the same as a 12v cummins.

your application is much like a marine application but not the same load. the engine will see governed decent rpm's for extended time and then loaded up as hydraulics are worked. thats what going to work the pistons and heat them up. if they are strong pistons like the 12v cummins stockers, run with it. if they are known to crack or have issue, thats concerning.

can you just run her N/A? or lower boost levels? is the engine mechanically controlled or electronically controlled fueling?

Mechanically controlled.

I could possibly run it N/A, but I'd have to try and find an intake and exhaust manifold. Parts for this thing have proven to be difficult to find.

The connecting rods appear to be the weak link on this motor, all of the failures I have been able to research, are a "windowed block" from a broken rod. I haven't seen any cracked pistons or pistons with holes in them. But, let's be honest, I'm just going by reading threads in equipment forums on the internet. Nothing very scientific.

I'm using a MAXIFORCE BBK3036 rebuild kit, kit includes new pistons, but thats all I know about them. Cast, forged etc etc the kit description really doesn't specify.

Caterpillar 3034C/T Turbocharged | Maxiforce

Maxiforce sells diesel engine parts and replacement parts for John Deere, Cummins, Perkins, Caterpillar, Yanmar and International Harvester/Navistar.

maxiforce.com

 

[Chevy1925]

Mechanically controlled.

I could possibly run it N/A, but I'd have to try and find an intake and exhaust manifold. Parts for this thing have proven to be difficult to find.

The connecting rods appear to be the weak link on this motor, all of the failures I have been able to research, are a "windowed block" from a broken rod. I haven't seen any cracked pistons or pistons with holes in them. But, let's be honest, I'm just going by reading threads in equipment forums on the internet. Nothing very scientific.

I'm using a MAXIFORCE BBK3036 rebuild kit, kit includes new pistons, but thats all I know about them. Cast, forged etc etc the kit description really doesn't specify.

Caterpillar 3034C/T Turbocharged | Maxiforce

Maxiforce sells diesel engine parts and replacement parts for John Deere, Cummins, Perkins, Caterpillar, Yanmar and International Harvester/Navistar.

maxiforce.com

can you dial back the pump a bit to pull power down? or just say F it and run it to see what happens. its not like you will be abusing it daily

 

[036.6turbo]

can you dial back the pump a bit to pull power down? or just say F it and run it to see what happens. its not like you will be abusing it daily

There are adjustments for "maximum" fuel, so yes, I think I could back that down. Do you not think an EGT gauge would help indicate when the motor is being pushed too hard? Possibly be too late, before it shows on the exhaust temps?

 

[Chevy1925]

not really. the point of the oil jets is to keep the pistons cool constantly due to added fuel and boost. cylinder pressures are higher as well as temps. the other issue is you dont really know what these things run at stock.

if you back fueling down, you take care of the issue. you will constantly thermocycle the pistons and thats what leads to cracking. the oil jets help control that. EGT's are too late imho and without a guideline, its hard to say

 

[2004LB7]

is there any way of making your own squirters or modifying the ones you have to get their oil by a different means other then the stock location? something like in this photo?

or perhaps even modify the rod to provide the oil?

 

[036.6turbo]

not really. the point of the oil jets is to keep the pistons cool constantly due to added fuel and boost. cylinder pressures are higher as well as temps. the other issue is you dont really know what these things run at stock.

if you back fueling down, you take care of the issue. you will constantly thermocycle the pistons and thats what leads to cracking. the oil jets help control that. EGT's are too late imho and without a guideline, its hard to say

Thanks James, I appreciate your input.

is there any way of making your own squirters or modifying the ones you have to get their oil by a different means other then the stock location? something like in this photo?

or perhaps even modify the rod to provide the oil?

Possibly? The odd part with these are, I do not believe that they provide a constant stream of oil.

The Banjo bolt that retains the jet to the block, has a spring and check ball built into it. Almost like a pressure relief valve. Maybe it's an RPM thing? The ball stays seated, until the pressure reaches a certain point, then allows oil in? Or maybe when the crank rotates and blocks the oil passage for that journal, the pressure spikes and the ball unseats? The second one is highly unlikely, but the fact remains, something has to unseat that check ball, for the oil to flow into the jet.

Sooooooo, have said all that, is adding a constant flow of oil somehow detrimental? I mean, if a constant stream is okay, then why did the factory go to all the trouble to install a spring, check ball and retainer clip, to a 3/8"-24 bolt?

I have obviously got in way over my head. This will most likely prove to be a very expensive mistake on my part. But hey, it's a learning curve.

Here's a couple obligatory pictures of a new piston, not that it helps much, LOL. The obviously have the top ring land inserted, and have some sort of coating on the skirt. They are cast, and a bit hefty, heavier that a BB chevy, but lighter than the pistons from the Perkins in my backhoe (those have 5 rings on them, LOL)

 

[TheBac]

Oil jets are probably designed like Dmax ones....they only work above a certain PSI oil pressure.

Earlier you said the boneyard had two engines, both NA longblocks....wouldnt they still have the pieces you need for the shortblock you bought?

 

[036.6turbo]

Oil jets are probably designed like Dmax ones....they only work above a certain PSI oil pressure.

Earlier you said the boneyard had two engines, both NA longblocks....wouldnt they still have the pieces you need for the shortblock you bought?

Most likely.


Possibly? Not sure. RF Engines in Morrice (out your way).

I had asked for the dipstick from one at the time of inspection, to be included with the sale. At the time of pick up, the dipstick wasn't there, I reminded them, they finally found it, but the young man who brought it back, said it went dumpster diving for it. LOL. So I guess I don;t know what they scrap vs keep.

If I run it N/A, I'd need those injectors and injector pump as well.

I like James idea of turning the fuel down.

I'll call RF monday, get idea of what they have and how much they want for it.