Have a 980 B with the 336 V8 overhead cam engine. Looking for heads or an engine upgrade that would replace this engine without a ton of custom work. I've heard that this motor was experimental and they stopped making them.
They had hell with this engine in the 621 scraper for the same reason and put out a kit so that you could fit a 3306 in it. It wasn't experimental, it was just a piece of crap. I'll see if I can find the part number of the kit.
Hold on a minute, if you put in a 3306 be sure you get the correct fuel setting and reset the pump to it. If you don't you will be breaking the trans input gear case and every one you replace it with. I may be wrong but I think you have a 980A. Later Bob
This is a little off topic but it does apply. My local service manager was a great guy and very help full. He's now retired. None of the new guys have enough gray hair to answer my questions on the old 980B's and 988A's . Tctractors helped with my last problem and Bob/Ont is helping me now. He also bled Caterpillar yellow. So one day I asked him what did Cat make that was no trouble. The answer was the V-8 336. He said never buy a 980A.
I couldn't find the kit in my sources. You can get with your local dealer and the parts guys can find it. I have also heard of 3406's being used in the scrapers.
Don, the 621B's came out with the 3406 engine. As I cautiond earlier. I saw one 980 with a V8 Detroit in it that ripped two trans cases apart and then we repowered it with a 3306 truck engine and it ripped out another case. That was many years ago(1977) and knowing what I have learned since then, the 3306 should have went onto the dyno and had the fuel system set to what the 336 was. That would get involved. My advise is repair the 336 or part out the machine. Later Bob
Bob I don't disagree with the HP and even torque matching on the two engines, but the 3306 will stay together and the D336 won't. If Cat made a kit to replace that engine, that is a pretty strong statement from them that the D336 was faulty from the get go and not worthy of updates to get it up to par. I had a 621 (23H) with the D336 down in the pasture until 2 years ago, minus the heads of course, that I gladly sent to China as scrap when it got so high. Does anyone have a technical or service bulletin for the 3306 kit? I would like a little more history on it.
You are 100% right about the 3306 Don. Later Bob
I was just going with what i was told about the 336 that they tried it in trucks but the truckers didn't like it. The heads cracked from overheating the engine because it lost it's coolant. My boss isn't much on watching gauges or noticing green fluids on the ground. Found a O-ring let go on a oil cooler. Have a guy that says he can weld the heads so we might give it a try. The cracks are around the threaded holes that the pre-combustion chambers screw in.
Good luck with that one ........... he won't be the first guy who says he can do that and I'm sure he won't be the last. I haven't seen one of them succeed yet. You do however have nothing to lose .........
Ok first i should correct myself... We have a 980 not a 980B and it is a D336 V8 with twin overhead cams. The D336 was used in Heavy construction equipment,Trucks (was numbered the 1676),and boats. I agree with not trusting the heads being welded and i got the boss onboard with that. We are thinking about swapping it out for the 3306 that was used by Cat to replace the D336. I am waiting for a guy from Cat to let me know about the power matching and the possiblity of a kit. Will let you know if i find out anything from them. Thanks for all your help, Ron
Ron, I realize this is a very old thread but were you able to find information on replacing the D336 engine in a Cat 980A with a 3306? Thanks, Tom
Read the above replies from Bob/ont. The transmission case is to weak for the 3306. Maybe if you lower the horsepower it would last.
Oarwhat, I was referring to Caterpillar releasing a kit (parts list and instructions) for replacing the engine. I know they did this for replacing the D336 in a 621A with a 3306. Caterpillar acknowledged that the D336 turned out to be an undependable engine and offered a solution for its customers of the 621A. I want to know what they offered to their 980A customers. The D336 installed in the 621A was rated at 300hp and the version of the 3306 that they offered as a replacement had a 270hp rating I believe. As far as the replacement engine having too much power for the transmission case, the pump can be turned down where it is matched with the engine it is replacing. Thanks, Tom
I think if it was me I would be comparing a 980a and a 980 b for differances. by the way we used to call the 336 shake and bake
I had a bad transmission in a 980B. I found a cat rebuilt for a 980A at a very reasonable price. I looked through all of the parts and only the case and a couple parts were different. That's when Bob/Ont told me the 3306 would break the case.