D343TA engine:

[1693TA]

I have one of these in my shop I need a purpose for. I removed if from an OshKosh P4 airfield crash truck that destroyed the transmission behind it. The airfield received a grant to replace the unit, so I inherited the engine. Nothing wrong with it at all except been on my shop floor since 2006. It looks very much like the 1693TA installed in a Mack semi tractor I have and I've used the arrangement number on the truck for gaskets to the D343. I'm told by the guy that built/uprated the engine at the Caterpillar dealer the engine is pushing 600hp. That is what I was told without any proof but this thing would haul the mail for sure.

I know where there is an older Cat tractor in the weeds with the engine blown and cylinder head gone. Don't know the size or condition as have only casually seen it. It's been there a while and the tarpaulin that covered the engine is long rotted away. Bolts on the tracks, cylinder head missing etc. It is every bit the size of a D6 and direct start but no idea to serial or anything like that.

What might be a good sized tractor this engine would fit into without a lot of reconfiguration or major surgery?

 

[Nige]

I may be wrong but I cannot remember off the top of my head any track-type tractor engine installation that used a D343 engine as a power unit. That fact alone is probably your biggest challenge.

D343s were generally used in industrial engine, genset, & marine propulsion applications. Additionally they were installed in early 769 off-highway trucks and 631 motor scrapers if my memory serves me right. EDIT: Add to that list the early 988 wheel loaders, 824B wheel dozers, 983 track loaders, and #16 motor graders. Still no track-type tractor application though.

What is the S/N prefix of the engine you have, 62B.?

 

[1693TA]

I may be wrong but I cannot remember off the top of my head any track-type tractor engine installation that used a D343 engine as a power unit. That fact alone is probably your biggest challenge.

D343s were generally used in industrial engine, genset, & marine propulsion applications. Additionally they were installed in early 769 off-highway trucks and 631 motor scrapers if my memory serves me right.

What is the S/N prefix of the engine you have, 62B.?

I've been looking for photos of the engine and tag I've posted in the past. Not found them yet but will be out to the shop later today and grab fresh if needed.

 

[Nige]

Another option. If it happened to be ex-military it could be a 63M prefix which crosses over to 62B "civilian".

 

[1693TA]

Another option. If it happened to be ex-military it could be a 63M prefix which crosses over to 62B "civilian".

Was an ex USAF unit transferred down to the local airfield. There is an active reserve base there still.

 

[1693TA]

Hope these show up as flash on phone is intermittent:

 

[1693TA]

And just to get TS salivating I'll throw in a photo of my 12V-71T:

 

[Nige]

Interesting……..

The 27U prefix is a military DV036 model listed as a D343 truck engine but derives its parts and service information from a 65B-prefix 1693 engine, specifically S/N 65B2219 which is somewhat curious. Probably because the fire tender application had more in common with a 1693 on-highway engine application than a D343. Make of the info below what you will.



Also somewhat interestingly, it appears as though engine S/N 27U118 was the ONLY engine Cat ever built to that Arrangement & specification. Hence why the military-to-ciivilian chart refers to a specific Serial Number of 1693 engine. I'm wondering if it was originally built as a 1693 but then for some reason Cat stamped the data plate "D343" and put D343 decals on the valve cover. Who knows.?

 

[1693TA]

Thanks Nige. Altorfer, (local Cat dealer) is no good for anything on this engine. However if I use the serial number from my Mack with a 1693TA, they have less problems. This one ran very well really is all I know about it. The engine is are almost identical in appearance to the one in my truck the way they are set up but my truck has a hydraulic "Brake Saver" setup on the back and the larger oil cooler for this retarder.

The shop foreman or manager told me directly the engine was significantly upped in power when the unit was being refurbished with a larger water tank and foam apparatus. The radiator fitted was just over 71" tall and 61" wide being six rows thick. The fire chief said it never ran hot on them.

That is all conversation and may, or not be entirely accurate but that is what I was told. I had seen the truck operated plenty, but didn't see it destroy itself on a response call.

 

[Nige]

Altorfer, (local Cat dealer) is no good for anything on this engine. However if I use the serial number from my Mack with a 1693TA, they have less problems.

I would suggest to use 65B02219 as mentioned above.

If you give Altorfer that S/N they may be able to track some more detailed information down from Cat above & beyond what I can see.

Regarding the fuel setting information it would need someone with access to one of the old fuel setting microfiches (@OzDozer perhaps) to suck out all the relevant numbers. However that would only give you 425BHP as per the data plate - probably more than enough for an engine from that era.

 

[1693TA]

I'd be interested in knowing what to look for as far as original, and anything modified as I've never been around these at all.

 

[kshansen]

Not that I can be of any help but did have a bit of experience over the years on the versions used in the 988 87A loaders and a few of the ones used in the 769 Cat Haul Trucks.

Just curious, is this a spacer plate engine? Many of the earlier 988 engine I worked on were before the spacer plate design.

One more side note. One of the first Cat engines I worked on was actually a four cylinder version of this D343 or 1693, it was in a scraper might have been a 619 but memory could be off. From what I have heard the four cylinder version was some what rare

 

[1693TA]

I have heard that term but really don't know. My truck is a 1978 and the engine is original to it and I've been told it is a spacer plate engine. This red engine from the OshKosh P4 chassis was built in 1973 and looks virtually identical.

I've had neither engine apart with exception of the cam box and cover on the red one to extract a broken bolt holding the cam box down. I had to remove the camshafts for that but the broken fastener extracted easily and it went right back together. Attempting to get a gasket set was difficult at the Cat dealer, (Altorfer) as nobody there had heard of the engine series. Once I provided the serial and arrangement number for the truck engine, they were able to find the parts on their computer.

 

[1693TA]

Don't know if these decals make any difference or not pertaining to anything:


This is a 78 RL-755LST and has the 1693TA that runs like a top:



And just because we like them so much:

 

[Nige]

Don't know if these decals make any difference or not pertaining to anything:

The first one looks interesting, as though it could contain details related to the DV036 military designation, but unfortunately it's impossible to decipher from the photos. Do you have any better shots of it.?

 

[1693TA]

The first one looks interesting, as though it could contain details related to the DV036 military designation, but unfortunately it's impossible to decipher from the photos. Do you have any better shots of it.?

I will be back out there tomorrow morning. I have several photos but that is the best and not very good.

 

[OzDozer]

You won't find much information readily available on Cat military equipment, as it's all built to military specs, and the military division of Caterpillar is the only place you would be able to acquire the info.

The only other alternative is to go looking for the military TM- manuals applicable to the engine or the fire truck model it was fitted into.
I'm guessing it was originally a USAF-spec Oshkosh fire truck? All the military manuals are publically obtainable.

I've just gone through my microfiche drawer and a 27U D343TA doesn't rate a mention. There's plenty on the 65B 1693TA engine, though.
I also have a book of rack setting charts and once again, nothing on any 27U engine - but the rack settings for all the 65B varieties are listed there.

Nowhere does the rack settings provide for more than 425 continuous HP from any version of the D343TA or the 1693TA.
I'd have to guess that this engine has been specced as a "one-off" application, for "maximum intermittent HP" of 600HP, to ensure the fully loaded firetruck has adequate performance to reach the crash site within a set level of time, with that time frame set by the USAAF senior officers.

I'll wager somewhere in the specifications for this engine, there's a time limit set on the 600HP power output, the same as all "intermittent" power specs.
It's interesting that there's a "7" before the D343 model number, I'll wager that means something to some old Cat engineer.

This is where you find your manual for your fire truck/crash truck - but you'll need the model number of the truck.

Army Publishing Directorate

armypubs.army.mil

 

[Nige]

I've just gone through my microfiche drawer and a 27U D343TA doesn't rate a mention. There's plenty on the 65B 1693TA engine, though.
I also have a book of rack setting charts and once again, nothing on any 27U engine - but the rack settings for all the 65B varieties are listed there.

The FIP & Gov Gp for the 5R-2236 engine arrangement is listed as a 9L-4616, the torque control 9N-1072, and there is also a 9L-4878 "Fuel Inj Misc Gp". I will see if I can find either a Test Spec or a Performance Spec for the engine.

EDIT: The 9L-4878 turns out to be the fuel injection valve & lines Gp

EDIT #2: It might be a stupid question but does the Oshkosh Corporation potentially have any information on the engine as part of their fire truck manuals.?

 

[OzDozer]

Here's what my rack setting books say for the 65B prefix 1693TA.

 

[Nige]

I still can’t get past the fact that the 5R-2236 military engine Arrangement specifically crosses over to a single commercial engine S/N for parts & service information - 65B2219……
That is unusual to say the least. I wonder what’s so special about that particular Serial Number.?