I bought a 2000 CAT 246 that needed to be repaired. Broken rod, hole in the block, basically total failure. It has the CAT (Perkins) 3034 4 cylinder turbocharged diesel engine. It requires a block, at least one rod and a crank or crank repair that involves welding and regrinding. Sourcing parts has proved to be a major problem. CAT wants 12k for a long block. There are several on eBay at that same price, Drews salvage has a rebuildable core for $6,500. All off those are out of the question, I'll cut my losses and part the machine out before spending that much. One option I am trying to explore is, using a naturally aspirated Perkins 704.30 from a Daewoo 1760XL skid steer. Perkins number for the CAT engine is 704.26 family is "UB" Perkins number for the Daewoo is 704.30 family is "UA" CAT block casting number is 3711H09A/4 HP rating is 74? I believe? Daewoo block casting number is 3711H09A/1 HP rating is 63? I believe? As you can see the only difference in the casting numbers is the last digit. Both motors are 2.9l, visually from an external comparison, the blocks seem to be identical with two exceptions.; 1. The CAT 3034 has a threaded hole for the engine oil dipstick. the Daewoo has a pressed in dipstick tube, located a bit higher on the block. The emboss is still there on the Daewoo block, just not drilled and tapped. 2. The oil drain from the turbo back to the block is the same situation. The CAT 3034 has a drilled and tapped hole for the turbo oil drain. The Daewoo only has the emboss. I can purchase the Daewoo short block including rotating assembly for under 1k. My thinking is to recondition the Daewoo short block, then use the cam, injection pump, cylinder head and turbo from the CAT. I have no way of knowing if the turbocharged engine used more robust pistons, rods and crank, but hopefully the rebuild parts from the CAT kit (including pistons) would work in the Daewoo. Am I crazy for considering this as an option for a personal use machine? Looking for some constructive feedback, thank you. https://es.ruttsmachine.com/assets/pdf/literature/es/Perkins-Engine-Number-Guide.pdf
There ARE a lot of if’s.. but 1k vs 6500... you’d almost b crazy not to try.. Just make sure to lock the timing on your old injection pump if it has a locking bolt..
Thanks , I was thinking the same thing.
My CAT has the 704-30T UC motor, the Daewoo is a 704-30 UA motor. The specs are identical. I think the donor from the Daewoo can be made to work.
It would be good to document for progress as there are a lot of those out there with rods hanging out
The “T” stands for TURBOCHARGED..
There are a lot of those with that issue. I would be curious what the machine is worth as a parts machine. If you could get 10K out of it as it sits, I would take your 10K and use it (with some additional money) to get some thing else. It certainly isnt worth an OEM replacement engine, but putting a non oem engine into can suck as well. Those Frankenstein machines can be a PINTA.
Somewhere here on the forums someone swapped in a different engine and wrote about the whole procedure. Without looking I don't remember what engine he used. I had the same thing happen with my 248, I was able to convince Caterpillar to give me a long block and I paid a local heavy equipment mechanic to swap it for me.
I'd say you don't have much to lose. Maybe back the screw off a little if anything, no idea what that would involve on that fuel system, maybe just back off the RPM a couple hundred?
Find a Perkins dealer Recently installed one direct from Perkins off boat with slightly newer emissions as a running complete with fuel system for $6800
Was really affordable
The last pictures show a 404 series but the OP has a 704 series which is a totally different engine. My question is what is the history on the Daewoo setup? At first I was thinking it was a running take-out but then you said short block so that makes me wonder. What I was thinking originally was a running take-out that was non-turbo and save all the time and aggravation of swapping parts, just put it in and have less power. Who cares, a skid steer seldom runs at full power anyway in my world, mostly used for maneuvering things slowly. If it has to be a short block, then beware that the pistons can be different, or they might be the same. I would just compare the volume of the piston top combustion chamber between the toasted engine and the good short block and if the same, go ahead with your plan with the head, camshaft, etc. If it looks like the piston tops are lower compression on the turbo motor, then I guess you have more work to do and decisions to make.
I can do that, if the group thinks it would be beneficial. Yep. If I could get 10k for it, I would definitely part it out. The machine has a few things going for it; 1. It has the Loegering track system installed on it with fairly new tracks. 2. It spent it's life with one concrete company (not a rental machine). 3. That company used Michigan Cat for all of it's service. 4. Most of the major hydraulic components have been replaced by CAT within the past (4) years. Don't get me wrong, it still has a few warts, but to put back into service for personal use, I think it's a good candidate. The bore, stroke and compression from both engines is listed as identical, I think it would be fine "as is". Perkins wants 12k, mines a different series of engine. CAT was a bit confusing in the way they applied their own identifications, to third party supplied motors, but yeah, yours and mine are very different. I should know more as to the condition of the Daewoo motor today. The yard I'm dealing with actually has two of them. Both were being offered as cores, no claim that either one would run. The day I was there, the cylinder heads were still in place. One of them, the valve cover was loose, and it was apparent water had gotten inside of it, it was froze up. The other one was sealed up tight, red plastic plugs in any opening that would let water in. Valve cover was still bolted down. It was free and would bar over. That is the one I told them to pull the head off of, so I could get a closer look. I can absolutely do some volume comparisons on the pistons, as well as pin to deck height, pin to pin on the connecting rods, etc etc
That brings me back to my question. If the one that is all sealed up runs good, why take it apart at all? Put it in and run it as non-turbo. I doubt you will notice a difference for a home use machine. Unless you are running high power attachments or moving large piles of heavy, loose material long distances.
The first things that come to mind, would dealing with fabricating a different intake and exhaust system for the normally aspirated Daewoo motor. The turbocharger is integral to both of those on the CAT turbo application. The Daewoo had neither an intake manifold or exhaust manifold on it. But it would definitely be a possibility. I should know more later today.
That is a bummer then. I would rather scare up the manifolds if they can be found than to open up a good running engine. But I could go either way on this one since the fab work to make it fit will be significant and keeping it original is always a good plan.
Well, I finally heard back from the yard that has the two "core" motors. Apparently the one that was sealed up well, had a cracked block. So that leaves me with the one that had the loose valve cover, the only good news there is the rocker arm shaft was missing so all the valves were closed. At this point, beggars can't be choosers. All they will state as to the condition is they guarantee the block, crank and rods to be machinable. I'll pick it up this afternoon, get it home and map out a plan. I other news, I found the service manual from Perkins for the 704-__ engine family. There are some differences noted between to UA and UC motors, but one of those will be addressed with the new pistons, the other most notable one has to do with the heat treating of the crankshaft. But again, it's a compromise I'll have to live with. I'll attach snips of the manual. Remember, "UC" is the CAT 3034 (turbocharged). "UA" is it's normally aspirated brother. "UB" is a smaller displacement variation.
just a question- why do these engines fail or did i miss something? another note- turbo engines usually have a steel insert for the top ring lands and use a keystone top ring to aid in longevity but i'm not sure about these newer small engines
I'm not sure, to be honest. In reality mine's a high hour machine, the oil pressure sending unit was broken (picture above shows the spade connector, missing from the sending unit) . I believe the idiot light in the cab was probably on all the time and the previous owners were ignoring it. When that main bearing spun, it lost oil pressure, if the warning lights were in proper working order the machine should have been taken out of service. At that point it would have needed a rebuild, but the block, crank and rod would have been serviceable. I will be using pistons for the turbo application for the rebuild.
It was my impression that the smaller 404 series, which is a Perkins Shibaura based unit, is the one that has more failures in Cat skid loaders. Model 3024 I believe. This is a 704 which has no relation. The 404 is an engine design that Perkins just borrowed from IHI Shibaura, that Cat uses because they own Perkins. The 704 may be an original Perkins design or come from somewhere else, but it has nothing in common with the 404 that I can tell.
I am absolutely no expert, but I tend to agree and hope you are right!
I was working for a Cat dealer at the tale end of those engine problems. It was mostly in the small engines used in the 216 skid steers and that size of MTL. Cat warranted any that failed in the warranty period and did policy adjustments on those that failed after the warranty periods. Usually they supplied a new engine and you had to pay the labor to swap. I heard a couple of stories about what was happening in the failures. One was that there was a problem in the turbo which would cause oil burning and low oil levels. The other had something to do a a cylinder getting scored and also start blowing oil out the exhaust till then ran out of oil. The last and most probable story to me was that the crankcase pressure was vented to the inlet of the turbo and the fumes would take out the turbo and one or more of the cylinders and run the engine out of oil. In any case I was told the way to check the engine on the quick was to have the engine running at low idle and then remove the oil fill cap. If there were a problem you would see the blue smoke coming out. It worked that way a couple of times for me.
I'm glad to hear some more specifics on the problem even if you are not completely sure. We have quite a number of these engines out there with the Perkins badge on them and they are not troublesome in genset service. But most too new to know for sure. But most of them are NA as well.
I have a (4) cylinder Perkins in my old Massey Backhoe. I did an inframe on that this spring. That engine purrs like a kitten now. To be honest, the Perkins was one of the reasons I decided to try and resurrect this CAT. But there are quite a few differences between the Perkins AD 203.4 in my Massey and this 704-30 motor.
For those still following along, here of some pictures of the things I will need to overcome, using the UA block, for the UC application. (fun fact, both blocks have UA 3.0 cast into the side of them.) Most all of the issues revolve around the turbo charger; 1. Draining the oil from the turbo. 2. The differences in crankcase ventilation, from a NA application and a turbo application. One exception is the oil cooler on the UC. These pictures show the water return (or feed, not exactly sure) from the oil filter head.
Turbo oil drain.
Crankcase vent. It's a bit tough to explain in these pictures, but if you look at the wiring butt connectors, coming out of the fuel solenoid cut off, the black plastic hat looking thing right behind them is the crankcase vent cap. I guess I didn't get a picture of the UA block vent drain location, but just like the other holes, the emboss is there, just no tapped hole.
This picture shows the UC hardware not used on the UA. The fitting assembly on the left is the turbo drain. In the middle is the crankcase vent intake. On the right is the crankcase vent drain. Visiting machine shops today, wish me luck, LOL. More to come.
Ask them if they can JB weld that hole in the block.
Can’t you just drill and tap out the turbo drain. The raised boss is there. It just drains into the block and pan. Crankcase vent should be easy to just vent externally from the valve cover.
Actually that hole is the least of the problems with that block. I absoulely would reair that hole and use that block IF; 1. It hadn't spun a man bearing. Gear driven cams have very little tolerance for line boring. 2. It didn't have (3) large cracks in the water jacket. 3. It didn't wear cylinder #2 beyond repair from continued operation between the time the oil galley was blocked (by the spun main bearing) and the time the rod broke and the piston stopped going up and down, LOL Yes, I very confident all of the issues I show here are easily overcome.
On my 248 with the same engine the oil pump cover plate broke internally so the oil pressure dropped to zero in a flash. Number 4 rod cracked the block. You can see the whole explanation and pictures here: HeavyEquipmentForums
I had saw your thread prior to starting mine. Needless to say, your experience doesn't give me warm fuzzies about mine, but I'm in so deep now, I plan to see it through. Do you still own that machine? If so, how has it performed since the repower? I do believe the 404 had more failures than the 704, but either way its a bad deal. For what it's worth my machine had over 9000 hours on the original 704 Perkins.
I still have it although I'm not wracking up the hours like I did when my business was running. I haven't had any further problems but I've always wondered whether they made any improvement to the oil pump. It's always in the back of my mind.
Well for the money CAT charged me for the new one, I hope it's the latest and greatest. Pump alone was $340.00, IIRC. Block I acquired turned out to be standard bore with just a honing required to clean it up. Same story with the crank, just a polish. It's std / std. The basic overhaul kit came from Highway and Heavy Parts, it came out to just over 1k with shipping. I had to get the cam bushing and oil pump from CAT, those two items totalled $400. Everything is at the machine shop now. Just in a waiting pattern now.
I discovered another difference between the UA and UC engine families. The UC has piston cooling jets the UA does not. So the total count of features that need to be added to make the UA block suitable for the UC application jet climbed to (7).
can a GOOD machine shop add the old nozzles if the block is otherwise the same?
After calling dozens of them, this shop says they can add the cooling jets; https://mountainmachine.net/
How did your project turn out? I'm wanting to do the exact opposite of what you were doing,I have a good turbo engine and I want to put my NA parts on it and install it in my 226.
Mine has been running great. I am very pleased with the outcome.