Hi. I recently purchased a late 90's D5C dozer with a blown motor ( appears to have thrown a rod). It is equipped with a 3046 turbo diesel which is rated at 95 fwhp. A little hunting around on the net leads me to believe the engine is made by mitsubishi and is the same as the mitsubishi S6S. In fact the cat motor has S6S-D cast into the head. I have access to a running S6S from a cat forklift. The lift motor is a naturally aspirated version rated at 120hp. Seems strange to me that the NA version would make more power than the turbo, but this is all new to me. My question has several parts. Firstly is the 3046 cat a re-branded S6S. Second are the long blocks the same, and can I just bolt the cat turbo, manifold, pump etc to the NA S6S forklift motor? My other option is a used cat 3046 turbo from a smaller machine rated at 85hp. It needs a turbo, but runs well apart from that. I know for a fact the bore and stroke is the same on all 3 engines. if I use this long block with my pump and turbo etc. , will the engine's power be sufficient. Which of the two options would you recommend? I thought about a fresh rebuild, but due to the window in the block, I dont have a decent core. Any suggestions would be appreciated. P.s. I know its poor etiquette to have your first post be a question. ... but hey... i need help. So sorry in advance.
No need to apologize. I'm no expert but the NA engine probably has different pistons and possibly other internals different from the turbo engine. If it were me, I would go with the used 85hp engine and swap your injectors, injection pump, and turbo onto it. Just my 2 cents.
Agree with 02Dmax
One possible idea. Can you post the s/n's off all three engines? Might be able to check major parts using SIS to see if they are the same part numbers, like pistons, head, rods, crank and cam.
The problem is that the s6s is a 6 cylinder and the 3046 is only a 4 cylinder.
Are you a betting man?
Ok after looking it up I see the 3046 is 6 cyl too. I was thinking it was only 4. When I think of a d5 I think of the 3304 and 3204 they used to run.
Thank you everyone for the response. I will try my best to dig up any numbers from these three. The replacement Cat motor is 1000's of miles away and will require a call to the seller, but I have some photo's of the other two The machine's current engine serial number is: 5XK14612 with the arrangement number: 6I-3537 it also has 71001 cast into the side of the block. The Mitsubishi S6S from the Cat forklift has this serial number: S6S-009477 and 71127 cast into the side of the block I hope this is of some use. Dave
do these numbers work for anyone? I got a reluctant cat tech to agree that the engine family is the same, but he didn't give me a conclusive answer as to parts interchangeability. Assuming that this is correct, would rebuilding the cat motor using, the block, crank and rods from the S6S with the head, pump, cam, turbo and everything else from the existing 3046T cat motor be a reasonable thing to do?
I'm sure you're not alone. The 3044 is the 4-cylinder version............... Anyhow, to the OP. FWIW I think you may be batting a loser because if one block has 71001 cast into it and the other 71127 that ought to be the first clue that there are some differences between the two blocks. How big those differences are - who knows..? The Cat 30xx-model engines are/were all made by Mitsubishi so at least that part of the story is true. I would imagine there will be some similarities between the two engines but I'd also imagine that things like the front and rear gear trains, oil cooler(s) water lines, etc, could well be a PITA. Maybe it might be possible to use the long block from the forklift engine and hang all the other bits on it from the original D5 engine to make a "hybrid" of sorts. The one thing that would worry me (if true) is the difference between 95BHP turbocharged and 120BHP non-turbocharged within the same engine model. Like you commented, it's not logical on the face of it. If true that would lead me to believe that the 120BHP motor would most likely have a higher compression ratio plus different fuel pump settings and injectors. Why not post some photos..? Also why not try to get some photos of the 3rd engine from the seller and post them as well.
Too bad nobody can tell you if the pistons in the forklift engine are the same as the pistons in the dozer engine. If they are, you'd be able to just bolt your manifold, turbo, piping, fuel pump, and whatever else onto it and hammer down. I would be fairly certain the pistons would be the only things different internal iron-wise.
If the 95 vs 120BHP story is correct I would also suspect that the injectors and at a minimum the injector pump internals (maybe the whole pump) would also be different.
I'd be on the lookout for piston oil cooling nozzles on the turbo'd engine versus plugs in the passage for non-turbo.
I will try
cat pics
try more than one
What are the numbers on the Cat PIN plate in your first photo and is that plate on the D5C..? Also what is the number hand-stamped under the PIN plate..?
*9DL00998* same number I will work on the other pics and info tomorrow. Thank you everyone for your interest and help.
So, here's another scenario. As long as you watched the torque/trans temps, why couldn't that engine just be bolted in? Probably be a pretty fancy little D5 with an extra 25hp?
I agree , put a pyrometer on it and a boost gauge and let it rip. On the flip side , hp and torque are different animals , I wonder what the torque rise difference is? I would think it would be close. The fuel pump could also be derated somewhat. Also wonder if you could pull the pan and head off and remove a piston and rod to see if they are spray oil cooled. I wouldn't write it off yet.
A little more HP won't hurt the machine. Cat is famous for derating the HP so the machine lasts longer. We have a 623F scraper with a 450 HP truck engine in it and it does just fine.
Does anyone know if these engines 3046/S6S are wet or dry liners? Aparently it makes all the difference($$$$) when rebuilding. Anyone know?
3046 engine S/N 5XK14612 is dry liners, at least I'm assuming so because there is no separate Part Number quoted for a cylinder liner (or liner seals) at either the cylinder block group or cylinder block assembly level. Neither is there a procedure to remove and install cylinder liners, which generally suggests that whatever is in there was installed at the factory and is not intended to be removed. On that basis I would assume that the S6S is also dry liners.
Happy Oi Oi Oi Nige.
Iam pretty sure Nige hails from the ol' country Garrie, and was never a convict ......but I could be wrong. Cheers, Greg PS. Happy A Day to you too.:drinkup
Hi all. I received an email from a member regarding the status of this project, so I figured a little update wouldn't hurt. Keep in mind, as well as being the world's worst procrastinator, I am also a paraplegic, so I need physical assistance with almost all of this job. This may go a ways to explain the lack of progress. Anyways, shortly after posting the thread I bought the running S6S engine from the forklift. Stole it for 1000$ Things paused for a while but in the summer of 2015 my father and one of my old employees pulled the old cat motor out. Anyway. After that...here's what I know. In spite of the fact I could never get anyone at CAT, CAT lift trucks or Mitsubishi to confirm it..... the engines are the same. The block and crank are the same and the cat flywheel bolted right up. So after much consideration and advice from others in the know. I decided that the best move was to run the N/A S6S in its entirety. It was suggested to me that I have the pump calibrated to produce a similar amount of power as the cat motor. So I took the pump to Sharma Diesel Injection Service in Mississauga, ON for calibration. They disassebled, inspected and resealed the pump, then calibrated it to make approximately 100hp. They also replaced the lift pump and nozzles on the injectors. So that stuff sat in a tote bin until early this fall when a bit of ambition struck me. I had a ship mechanic working on it, but he can't complete the project with me. Somewhere along the line I have acquired a d5c service manual, parts manual as well as a downloaded copy of a Mitsubishi S6S service manual. This has helped immensely. So I am in the midst now of changing the gear train, front cover and rear plate. This must all be done to accommodate the hydraulic pump from the dozer motor. The difference is the the 3046t has straight cut gears and the s6s are helical. So heres the question? The gears are the same diameter and the markings are oriented the same, but all the helical gears have a different number of teeth than their matching straight cut gear. I intend to verify the timing mechanically before starting. but does anyone know if the number of teeth matters if pull your diameters are identical ? My goal is to have the motor running on the floor by spring, so the ReRe can begin first thing when the nice weather arrives. Any thoughts or words of caution would be appreciated.
With gear trains the number of teeth on the gears to a large extent don't matter. what matters is the ratio between the crankshaft and various other moving parts that the gear train drives, such as the camshaft. The ratio between camshaft and crankshaft has to be 2:1 or the engine won't run. You can easily figure out what gear ratios you have by calculating as you go through the gear train by starting from the crankshaft gear. I would have guessed the gears would have been the same but from your post it's obvious that they are not. Straight cut vs helical is often for reduction of noise. The only thing that would concern me is the overall ratio between the crankshaft and the gear that will drive the hydraulic pump on the dozer. In the donor engine that gear is simply an idler gear, in the dozer it serves a function therefore the speed that gear rotates compared to crankshaft speed ought to be approximately the same. If it is not you run the risk of overspeeding the hydraulic pump if it spins too fast or suffering low flow if it spins too slow.
Any chance of a picture or two of the two gear trains? But as Nige says number of teeth are not important in among themselves it is the ratio of one to another. Think of it this way, if one pair of gears has 20 teeth on the driving gear and 40 teeth on the driven gear for every two turns of the driving gear the driven gear turns one revolution. Now if the driving gear has 25 teeth and the driven gear has 50 the result would be the same 2:1 ratio. It can get a bit confusing if you are dealing with a set of three gears. If the middle gear is just an "idler gear" in other words the only thing it does is transfer the power from the driving gear to the final driven gear the number of teeth on it does not have any real effect on the speed of the driven gear. However if as it sounds in this appication there is a pump coupled to the "idler gear" and difference in the tooth count will effect the speed of the pump, either running faster or slower. Like I started out asking about a picture it would help if you could also give us a count of the teeth on each gear for both gear trains. It might be that they just changed the pitch of the gears when they went from straight to helical but did not actually change the resulting ratios. Hope this does not muddy the waters too much.
GDR i have the same problem my 3046 spun a main bearing and the cap broke i would really love to buy the main caps off your blown engine please contact me at [email protected]
Hello all. I am new to this forum. I have a quite similar problem to GDR, in that we have a Cat D4C that poked a rod out the side of the engine. There seems to be an immense difference in cost for rebuild parts for a Cat 3046 versus an S6S. I was planning to repair the block and purchase an S6S rebuild kit w/ pistons, rods, crank...the whole enchalada, as it were, but want to make sure the pistons and sleeves will fit. Does anyone know the piston diameters of a CAt 3046 motor? Engine serial #5XK07791 if it matters. Also, GDR, were you successful in completing your project? Thank you
To the original poster one thing I did not see mentioned was the most likely difference in oil pumps or at least in the pickup tube between the forklift and the Dozer motor. Hate to see you go thru all that work and crap your new engine when it runs out of oil the first time it works at a reasonable angle. The forklift motor probably has a flat work area style oil pickup. Should be easy to swap before you install the engine.
I've had some serious delays...but here's where I'm at. S6s is the same block and crank. Turbo have a different piston and head. I'm in the midst of bolting the gear train from the cat 3046 to the s6s. It has to be swapped for the hydraulic pump and the s6s gear train is helical as opposed to the 3046 which has straiht cut gears. This is my first diesel apart so I want to get it right. I sent the pump out and had them bench tune it to make approx 100hp. These engines are available in go ratings from 60 to 140hp so...as they say..."its just fuel and air". The dozer pan and pickup are going on the s6s....as I've already made that mistake once in my life (ran a Yamaha R1 out of oil during a 6 mile wheelie!). I have found out that there is little if any cooperation between cat and Mitsubishi. Cat won't even acknowledge the engine family is the same even though it has stamped S6S right into the head. You are going to find that some parts will need to come from Cat, others from Cat lift trucks. You're into some serious $ at the machine shop as these are a dry liner block...so they're not just a simple bolt in. Even with a cheap China rebuild you'll still have 5k wrapped up by the time you are done. You're going to need a serial and build number from an S6S-DT...which is not that easy to find. I even tried callng Mitsubishi direct but they weren't much help, as they look up stuff based on us having the numbers...not the other way around. And wether the cat build is the same specs...is a total crapshoot. I suspect theres plenty of expertise on this forum that can let you in on some of the difficulties youre going to face without these correct numbers. Truth is you'd be better off find a running cat DP 40-dp100 series forklift and steal the mitsu s6s motor out of it. Then if you choose to rebuild it you can buy mitsu s6s parts with confidence because youll have the numbers. Theyre out there fairly cheap. Ive seen 3 or 4 in the last year under 7k cdn... (5500usd). My motor is going in first warm week in April.
First of all, I am so glad to see your response, GDR! It is clear you have a good understanding of the roadblocks. I am concerned that I will make a mistake and it is good to have the guidance of you and others on this forum who are much wiser than me about this project. Please help me to understand your comment about the dry liner expense. Is that because of the cost of pressing out the old liners and pressing in the new? Or? My thought is that having a 0 hour rebuild with new crank, pistons, rods, valves, guides, seats, oil pump, etc will make the dozer worth more than putting a high hour used motor back in it, so I don't mind a little more expense as opposed to the cost of a running take out. Plus I look at this as an opportunity for me to get an education (and my dad always said, "...you can't get an education for free..."). Here is a list of the parts in the kit I am looking to purchase. Total kit cost is about $1500 This kit includes: Full Engine Gasket set 6 Liner cylinder,semi-finished ,without flange 6 pieces Pistons with pins and locks, Bore Size=94mm.PN# 32A17-00100,remark with #770 . oil ring thick 4.5mm Piston Ring for 6 Pistons,STD size oil ring thick 4.5mm 1 set Main bearing STD size. 1 set Rod bearing , STD size. 1 set Thrust Washer, STD size. 1 set Camshaft Bush , STD size. 12 pieces Valves 12 pieces Valve guides 12 pieces Valve seats 1 piece Crankshaft 6 pieces connecting rods 1 piece oil pump I figure I might just as well put in the new crank for the price, as I would bet the rod journal is mucked up on the crank I have after the rod bearing going bad. I figure the block mains should be ok, but I will get it all disassembled and look before I order. I imagine there are things I am not thinking about, so please feel free to point out all of the errors in my thinking. Thank you all in advance for teaching "the new guy"...
It’s 2025 & still no resolution to the CAT3046T? What to do in this situation? There’s a lot of these tractors sitting idle due to engine troubles.
There sure is a solution it cost 15000 or so New block crank rods and a rebuild kit have your head redone and bolt it up. Ive done 2. And loctite the rod nuts the 3 or 4 ive taken apart the nuts where laying in the pan.
You rite, like mines. I think i finally sourced a used block.
When I take my pan off, that's the first thing I'm looking for.