Cat D336

[Truck Shop]

Anyone on here familiar with that engine?

 

[Bluox]

4.5"x5.5" V-8 double over head cam front and rear timing gears, pre cup injectors called a 1676 in a truck 54B.
A 42H in a 980 wheel loader.
Never seen one.
Bob

 

[Truck Shop]

I know where one is, just setting in a set of KW frame rails. Only one I've seen.

Thanks Bob.

 

[Bluox]

That is a good place for it.
Bob

 

[Truck Shop]

From what I have been told through the years it was a turd.

 

[kshansen]

Well I have to admit I did rebuild a couple of those 42H engines. Lots of timing gears up both ends and the balancer weights down near the bottom.

One thing that I thought was neat or strange is you did not use a feeler gauge to set the valves by the service manual. The adjusters had swivel feet on them that pushed down on the valve stem and the screw to adjust them had notches around them with a spring finger that held them from turning!

Procedure was to use bolt in flywheel housing to lock in position to set valves, if I recall you did half them then rotated crank 180º and did the others. The actual settings were done by turning adjuster down till there was slight drag on the swivel feet then back off a specified number of "clicks".

One thing that no one ever explained to me is why the rods had a very thin edge on the big end that ran against the crankshaft. At least one of the ones I worked on had groves worn in the crank from this thin edge. Crank was sent out to a shop that rebuilt it not sure if it was welded or chromed but brought back to standard. That must have been 30+ years ago so memory is a bit rusty!

Also seem to recall that there was a larger version of that engine, something on the 5.4 bore size that was made in 8 and 12 cylinder versions. Seem to recall one of those was used in a 773 haul truck.

 

[Tyler d4c]

Was it moreless the 3408 predecessor?

 

[Bluox]

Was it moreless the 3408 predecessor?

It's a 4.5" bore so more like a 3308 that wasn't.
Bob

 

[Bluox]

Was it moreless the 3408 predecessor?

The D346 is a 5.4" bore V-8 overhead cam.
Bob

 

[petepilot]

and was rated at 340 hp in highway truck app.

 

[Truck Shop]

Very few were sold for on highway, had to be a fuel guzzling engine. Too many moving parts.

 

[kshansen]

Very few were sold for on highway, had to be a fuel guzzling engine. Too many moving parts.

And with all those gears and cams I imagine it was not cheep to build. Also as I recall at idle it made all kinds of rattling noises. Separate intake and exhaust cams so every time the lobes for one cylinder went past full open the cam followers would snap the cam it the direction to take up the back lash in the straight cut gear train.

There was also a 5.4 bore 4 cylinder inline "D340?" engine that was the same with the snappy clattering noise at idle. I believe the six cylinder truck engine version was a 1693 if memory is working the version used in off highway equipment was call the D343.

 

[Vetech63]

Too many moving parts

More than a 2 stroke Detroit?

 

[Truck Shop]

More than a 2 stroke Detroit?

twin gear trains.

 

[1693TA]

That

And with all those gears and cams I imagine it was not cheep to build. Also as I recall at idle it made all kinds of rattling noises. Separate intake and exhaust cams so every time the lobes for one cylinder went past full open the cam followers would snap the cam it the direction to take up the back lash in the straight cut gear train.

There was also a 5.4 bore 4 cylinder inline "D340?" engine that was the same with the snappy clattering noise at idle. I believe the six cylinder truck engine version was a 1693 if memory is working the version used in off highway equipment was call the D343.

That is correct and I have two 1693TA/D343 engines. They have a sound of their own at idle.

 

[firedozer]

The D343 was a 6 cylinder double over head cam.

 

[kshansen]

The D343 was a 6 cylinder double over head cam.

Yep! Worked on many for those in the 988 Front end loaders before they came out with the 988B which had the 3408 V8

The 769 and 769B Haul trucks used the D343 as well as well as other machines.

 

[Bluox]

That

That is correct and I have two 1693TA/D343 engines. They have a sound of their own at idle.

The 5.4" x 6.5" engines.
The D343 I-6 has one timing gear train on the back of the motor and uses a cam follower that sits on the valves under the cam.
These are the ones that the valve lash is adjusted with a philips screwdriver.
The D346 v-8 D348 v-12 and D349 v-16 have rocker arms under the cams and a gear train on both ends of the motor and that makes a lot of noise.
All are spacer plate motors and overhead cams.
The I-4 was used in a 619 scraper wheel tractor and used that serial number, and was not a spacer plate motor.
Bob

 

[1693TA]

1693TA in my 1978 Mack RL755LST:







Factory set at 425hp and runs very well.

 

[1693TA]

D343 Originally from a Oshkosh P-40 airfield crash truck. I'm told this one is set at 550hp and it runs very well/strong, but I have no proof of anything but the size of the radiator in the truck would surely support the rating:



I found two snapped studs for the cam boxes when I went adjust the valves so removed the camshafts to extract the broken studs:



Valves with adjuster caps you adjust with a #3 Phillips screwdriver for clearance to the base circle of the camshafts:



Here is an adjuster: