Identify this Cat! Please!

[TheBuggyman]

With the vast knowledge and resources on this board I'm hoping that someone can identify this Caterpillar engine a fella is offering me for my M813 repower.

Here goes:
Model# 3406DI
Serial# 70v29102
Arrangement# 5R6706

Thanks in advance for any help you can give,

Eddie

 

[DaveP]

looks like a 4 & a quarter?

 

[poppop]

I don't have much to offer but I think the 3406 was the inline 6 used in a lot of medium duty trucks. I have a friend with a GMC Topkick with the 3406 in it.

 

[DaveP]

I don't have much to offer but I think the 3406 was the inline 6 used in a lot of medium duty trucks. I have a friend with a GMC Topkick with the 3406 in it.

wow! 3406 in a top kick!
talk about a kick with some kick!

 

[dlawbrey]

A call to your local Cat dealer should be able to answer all your questions.

 

[tennmogger]

The 34 part is the cubic inches per cylinder, 6 cylinder, DI probably direct injection. I could be wrong so still better to call CAT. That would make it a little over 200 ci, not a very big engine displacement.

 

[LAH]

A 3406, if memory serves, is an inline 6 of 893 cubic inches. Horsepower ratings ranged from about 280 to 425 depending on set up. These are fine engines with a mechanical pump, tubro & aftercooler. Hope this helps.........Creeker

 

[garp]

ok, I have limited info tonight. But here is what I do have. This is a 3406B, Direct injected, Jacket water aftercooled. 350 hp gross. advertised is 330 hp @1900 rpm. Hi idle limit @ 2300. I beleive this to be the front engine fora 621e/623e or 627e scraper. So i am going to assume it will need the flywheel housing changed to a truck style. Also i think this will have a cooler for powertrain oil that would have to be removed,at this time the rear seal would have to changed out to a dry flywheel type. As for the meaning of 3406, 3400 is the family type. 6 is the obviously the number of cylinders. displacement is 14.6 liter or 893 cubic inch. other engines in this family are the 3408 and 3412, a V8 and V12. I will take the numbers to work tomorrow and see what else i can find out.

 

[Capt.Marion]

A Direct Injection (DI) Cat 3406 is generally listed as a plain 3406 or a 3406A. It is an inline 6, turbocharged, and aftercooled, too, I reckon.

 

[garp]

95% of 3406A models are not DI, but rather are PC. Precombustion chamber with glow plugs. A few late A's were DI or it was converted at overhaul. An easy way to tell between an A or a B is the fuel injection pump. An A has a rounded body pump mounted away from the front cover via a housing about 3 in in dia. and a foot long. Bs and Cs have a flat topped pump, a plate on the side of the body with about 15 or so 1/4 bolts holding it on and is right up against the front cover with the front 2 fuel lines actually under the air compressor if so equipped.

 

[TheBuggyman]

Garp,
You hit the nail on the head and described the engine right down to that funky powertrain cooler line! You now your stuff, that's for sure! A call to Cat did not give me these kind of results. They did tell me that there is advance timing in the pump (did I say that correctly?) so it will act like a OTR engine and not be lazy between low and high idle. Do you have info on pistons as far as HP limits? How easy is it to turn this motor to 400-424 HP? Torque? It appears to have a truck style bellhousing (I guess) but it is set up with an automatic style "flexplate".
I can get a brand new surplus one of these complete with turbo, air compressor and pump. Missing the pulleys and some brackets, build date of OCT 17th, 1988. What would be a good price for one? I think this will work well in my M813 with the JWAC so no intercooler will be needed. Do I need a lift pump this engine or can I use the Cummins set-up?

Thanks for everyone's input!
Eddie

 

[TheBuggyman]

Here are some pics of the engine if it helps and yes, there are two brand new engines, PM if interested.

 

[TheBuggyman]

So, the numbers show it to be a "B" engine but the location of the pump makes it an "A" engine? Or is it a "B" engine with the pump set back to clear the compressor?

 

[Jakelc15]

I work on cat engines and equipment pretty much all day. The 3406 is not a bad engine. Most have a precup type injection and is costly to reman. I think it is underpowered for your truck and would not be cost efficient to "build up" such an old model. Expect to drill out exhaust studs allot because they seem to break off every couple of years. A 31 series engine would be a better alternative. A 3126 would be best, an inline 6 with much more power and torque. Most new cat acert engines and other truck engines are electronicly controlled. The 3126 can be either. A 3116 is the 3126's little brother and more comparable to your 3406. There's also a 3046, jap built 6 cylinder, also under powered for a large truck. Ok, starting to rant! Let me know if you need anything in particular.

 

[garp]

Ok, First off. This i an A model, check the serial number tag above the governor housing. Should have either a DI or PC on here. with a build date of 1988, I would say DI. With out breaking down the arrangement I dont know for sure what pistons are in there. Most off highway engines are set up for torque, not so much horsepower so hard to say right off. And yes this engine does have a timing advance, works centrifigally, similar to a gov flyweight set.

The flywheel housing would have to measured to determine its SAE size. The flywheel should have an internal gear that drives the retarder drive. It will not accept a truck style clutch.

Exhaust studs do break, but if someone puts the manifold back on with out makin sure its flat and the slip joints seized up. and uses a 1/2 in air gun instead of a troque wrench. They will definitly not last for crap.

A 3100 series engine is not bigger nor does it have more power. A 3116 is a 6.6 ltr, a 3126 is a 7.2 ltr. A 3406 is 14.6, do the math. These engines were built up to 425 on highway and 450 off highway.

As far as a transer pump, it should have a gear pump mounted on the drive for the injection pump. This will draw fuel fine. A B model has a different front cover that mounts the air comp higher so the injection pump can be mounted directly to the front cover.

As far a 3046, they are used in larger skid steers and small excavators, under 100hp, not usre why that one was even brought up.

 

[TheBuggyman]

Garp,
Thanks for the info. The NHC-250 in the truck is 240HP and around 650ft lbs of torque, the 3406 is 350HP and probably over 1,000 ft lbs and I want it turned up to 400HP which will probably give at least 1200 ft lbs of torque. Do you concur? Is 400HP easily attained in an "A" engine w/o fear of meltdown? Even in stock form the 3406A will be a huge difference from the NHC-250.

Overall, what are your feelings on a swap such as this? Is it worth the time and money to do it? What is a new 3406A worth such as the one I have? Don't be afraid to hurt my feelings, my pregnant wife says I don't have feelings anyway! I want honest opinions here and constructive help/criticism.

 

[No.2Diesel]

I am excited to about your search for a new drivetrain. Good luck. Are you intending this to be for the M813w/dumpconversion?

 

[TheBuggyman]

I work on cat engines and equipment pretty much all day. The 3406 is not a bad engine. Most have a precup type injection and is costly to reman. I think it is underpowered for your truck and would not be cost efficient to "build up" such an old model. Expect to drill out exhaust studs allot because they seem to break off every couple of years. A 31 series engine would be a better alternative. A 3126 would be best, an inline 6 with much more power and torque. Most new cat acert engines and other truck engines are electronicly controlled. The 3126 can be either. A 3116 is the 3126's little brother and more comparable to your 3406. There's also a 3046, jap built 6 cylinder, also under powered for a large truck. Ok, starting to rant! Let me know if you need anything in particular.

Jake,
This motor is a DI for sure. My old 955H had a precup 3304 (or D330, I can't remember). My truck currently has the NHC-250 that is truly underpowered at 240 HP, this motor is 330-350 HP out the box and 30-40% more torque so I don't feel that the new engine is underpowered even before I turn it up. I'm thinking 400 HP to be safe as a new power level, I've heard 425 is ok w/aluminum pistons.......

Thanks for your help!

 

[TheBuggyman]

I am excited to about your search for a new drivetrain. Good luck. Are you intending this to be for the M813w/dumpconversion?

No.2,
Yep, it is for that one. I've decided to do the repower and a quick restoration on the truck. With the kid on the way I probably won't make Aberdeen this year but I'm hoping to do some other events. Looks like I'm sticking with the factory 5-speed for now, do you know anyone who can go through mine while it is out of the truck?

 

[No.2Diesel]

Well despite everything I hope you make Aberdeen 09' as we intend to bring the finished product there.

We were going to stick with the 5spd but we figured sometime in the future we'd have to pull the whole f'ng thing apart to "do it right." We also took into consideration that 1,450lb.ft. of torque would be going through a single 15" clutch and stock pressure plate. I'd have to say that big time slippage would occur.

Nominal torgue rating for the 5spd. is only 650lb.ft. With the added weight of the wrecker and doubling the engine torque it would certainly be putting a constant overload on the teeth, case, and clutch etc. Its probably only a matter of time before the 5spd. would explode with all of that torque available just off idle Let me see if I can dig up a torque/hp curve table.

But who's to say that the transfer case and axles are going to hold up in the long run with a modified drivetrain. I guess we'll just have to put an Oshkosh HEMTT transfer and axles in there!!

The other issue would be brakes....