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Thread: Forklift ?? Flathead engines
01-11-2009, 03:08 PM #1
Forklift ?? Flathead engines
I have been poking around for a bigger lift. (8Klb+) and I keep running into gas and propane models with flathead engines. What is the story? Why are they so common? Where they cheap to build or just run forever? Some of the ones I looked at are still good runners with plenty of pneumatic tires so can drive out into the lot to load at really low prices. Should I hold out for a modern powerplant?
Also found a diesel or two. Is it worth it in a forklift? This machine will only be accasionally used.
01-11-2009, 03:28 PM #2
Propane better than either if used some inside but used propane lifts tend to be more expensive plus so is the fuel in terms of "hours per bottle" I never ceased to be amazed how quickly my CAT 15,500 lb propane goes thru a bottle of propane, whereas my previous CAT 12,500 lb diesel lift seem to never run low on fuel.
01-11-2009, 03:34 PM #3
aside from the very good points about shelf life of diesel, if you want to have a gas forklift the flatheads are damn near indestructable
the venerable continental flat head 6, f224 iirc would be the ultimate survival engine of choice in my opinion.
they seem to run forever, with or without water, little or no maintenance, and when taken apart for a head gskt one would swear that there is no way this engine should ever restart let alone run.
but run and run they do, much like the energizer bunny.
if you find a lift that suits your needs and has a decent running continental 6 cylinder, you could do much worse in my opinion.
01-11-2009, 03:49 PM #4
What year did they stop building flatheads?
01-11-2009, 03:55 PM #5
I think they must just last.Your not really looking at a high prefomance application anyway but seeing some people run them you would think they were race cars.I have a mid 60s 10k Clark on propane still runs great also have a 130 Hyster with a deisel mid 70s both are good I only use them ocasionally They should out last me.
01-11-2009, 04:32 PM #6
The Continental Gas/Propane engines are bulletproof and dead-nuts reliable if you keep them maintained. Keep the valves adjusted, change the oil every now and then, watch for worn parts, etc. Properly adjusted they'll start in any weather and purr like a warm kitten.
When you look at a lift truck, listen for rod knocks, funny squeaks, etc. I bought mine for half of scrap with a brand new Continental overhaul in it because it "was down on power". Turns out the valves were never adjusted! Half an hour with a set of valve wrenches and she was pulling stumps.
I'd NEVER own a Diesel or gas forklift. Too much stink, too much crap to fix, fuel has a limited shelf life, etc. Propane engines also have fewer maintenance issues, as the gas burns clean. You'll change the oil after 300 hours and it will be almost as clean as when you put it in.
Swapping bottles is a small price to pay. They'll usually drop a rack of bottles for a minimal charge, sometimes free. If you already have a Propane tank, get a liquid tap set up to fill your bottles.
Wisconsin Motors has all the Continental L-Head manuals available online here:
01-11-2009, 04:56 PM #7
I'm not sure when or if they stopped making the "L" Head engines for industrial use. I too have had several that would run regardless of condition. I sold my last forklift with a Continental Engine and now only own a Hyster with a Hercules "L" Head. I see more of the Continentals (industrial). Not to be confused with the Aircraft Engines.
Here's a link to the engine information and rebuild.
Anyway to your original question. If I had to buy another forklift and it would be stored indoors I would opt for an Electric. They are great to use when the doors are closed and come in Pneumatic tire models. Get a company to come in monthly to check and clean the battery and you are good to go. I get about 6-7 years on a battery and used ones are easy to find.
My first electric was a surplus Pettybone-Mercury that lasted almost forever. It was just hard tires so it wasn't good outdoors. I have a Yale Electric also with hard tires we use in the shop all the time. It will lift about 6k. I would like to get a 3k when the cash is right.
In addition to the electric we use one diesel Komatsu 5.5K that is excellent. One old gasoline Datsun 7k that is ok and one big Gas Hyster 15k that has the Hercules "L" Head. It sits outside and starts right up with a splash of gas.
Last edited by Walter A; 01-11-2009 at 04:57 PM. Reason: sp
01-11-2009, 07:32 PM #8
Continentals were good sound engines that were used thru most of the 70's and were being replaced by the riceburners, Perkins OHVs and GM'4s, V6 .Continental parts are getting harder to find and more expensive but not near as bad as Hercules Stuff. You should be able to move up to the later OHV stuff if you shop around for a deal.If you don't mind the hassle of LP Tank filling or having extra bottles around it still sounds like your best game if you are using it as little as you say. I failed to check your location before I posted this, but if it is a cold climate, a block heater would help?
01-11-2009, 10:37 PM #9
MY little orange Clark is a 1985 build and has a Y112 x 4 cylinder Continental...so presumably they were still available new then, just as a data point. I would not think many more years after that, though...
Hyster seemed to switch over to GM engines (at least for LPG and gasoline) around the same time...my 7k Hyster has a GM 250-6 engine in it which I think is a 1982 build IIRC.
I also would not ever buy a forklift for my uses in anything but LPG. Can't run the others inside the building.
I was amazed the first time I changed my engine oil just like A_P posted and it was still golden-clear....just like someone poured it out of the bottle.
Depending on your skill and interest in such things, forklifts can sometimes be had very cheap if you're willing to put in the time to do the repairs. Oftentimes there's a relatively inexpensive part (say $50-$100 for discussion purposes) which would take $1500 of "pro" labor to change. A good parts and shop manual are a must though.
01-12-2009, 12:06 AM #10
Found one really cheap and big but has "occassional locked up brakes" whatever that means.
I cant run it inside. Cant fit it through the door.
01-12-2009, 12:06 AM #11
flathead engine mfd.years
I was very involved with forklifts and industrial powered mobile equipment from 1963-2001 and saw a lot of machines come and go.The Continental F series flatheads were still showing up in new Cat lifts and Miller and Lincoln welders in the mid-late 80's.The 1985 Diesel and Gas Turbine Catalog of 1985 listed the Continental 4 and 6 cyl F series and the Y 112 flathead engines as available while also showing their new line of OHV small gas and diesel engines.The 1994 catalog did not list the flatheads.Some things the flathead had going for the equipment designer were; lower profile than OHV for smaller engine compartment and less parts for lower cost and simplicity.Yale in late 50's thru mid 60's used a Chrysler flathead 6(Plymouth) but the Continental in a Clark or Towmotor would outlast it in the same service.I think the Continentals must have been the last of the commonly used flathead industrial engines.
01-12-2009, 12:59 AM #12
Those little 4 cylinder Clarks like you have from the mid 80s are great forklifts. They run well and are easy to operate.
01-12-2009, 01:41 AM #13
probably the most unique thing about the Continental engine was that
Its crankshaft was not on the centerline of the cylinders.
It was offset slightly so the power stroke (down) was a straighter shot, to lessen piston wear. This meant that the up stroke took more degrees of rotation, but that was at less piston skirt pressure
01-12-2009, 02:37 AM #14It was offset slightly so the power stroke (down) was a straighter shot, to lessen piston wear.
01-12-2009, 09:16 AM #15
Rich, This offset crank centerline was another trick engine designers learned early on could be used to customize power output range and other things they wanted to control or influence.Much like modern "hot rodders" are playing with connecting rod lengths to influence piston/crank pin angularity at points of maximum pressure.It seemed to be employed a lot by designers in the 20's-40's. The early Motor's manuals had some good cross sections of current(at the time) engines that showed the use of this arrangement.Another was the inclining of valves (related to cylinder bore) in an engine to aid the flow of fuel and combustion gases.
01-12-2009, 02:11 PM #16
Keep in mind for forklift service you want a torquey little tractor motor.
The flow-related inefficiencies of flatheads and side valves don't amount to much.
Strangely enough the GM 262 cid 4.3L V6 seems to be a common choice for larger lifts, usually in anything Hyster 8k and up even Toyota buys it and puts it into a certain number of their lifts.
If I won the Lotto I'd be after a Hyster S150A amongst a few other things...that has a 6 cyl continental in it
01-12-2009, 02:30 PM #17
On typical LP forklift, if one drive wheel slips you aren't going anywhere.
01-12-2009, 02:36 PM #18
I had a Yale (6000#?) with a Chrysler flathead. The thing to beware of with them is that Chrysler's industrial flathead had very little interchangeability with other Chrysler engines. I was told that the water passages were larger and that if you replaced them with a standard Chrysler flathead you would have big time overheating problems. It was also very brutal- no power steering. Doing it again I would have opted to spend money for something better
01-14-2009, 10:44 AM #19
Have to look at one with a chrysler slant 6? Not flathead. Is it possible to convert to propane?
01-14-2009, 11:21 AM #20