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tacoma200
06-16-2009, 08:54 AM
I have heard that vertical engine don't last as long because gravity pulling down on the pistons wears the cylinder and piston out faster. No, I'm not sure I believe this. Vertical is the better design for most ZTR's and I see the trend going in that direction. Does any one have hard evidence that one type is better than the other? Or is there no difference at all? Of course with a Horizontal engines you get into all kinds of problems like the mule drive.

kaferhaus
06-16-2009, 09:19 AM
All I know is that after tearing down dozens of single and multi cylinder vertical shaft engines I've never detected any additional wear on the "down side" of the cylinder walls or pistons.

That being said, the cyl and pistions will always wear more nearer the exhaust valve side of the cyl. However even that you don't see much if you're anal about changing the oil regularly.

Our engines last a long time.... but we're anal about maintenance. I used to "re-build" them but the parts have gotten so expensive that it's actually cheaper to just buy a new one and strip the old of of good parts.

Most of these engines do not have cam bearings (some automotive engines don't either any more... ) and that seems to be what finally "toasts" them.

And while many guys do change their oil frequently they do not keep the valves adjusted... either out of ignorance or laziness... my dealer says most engines that he sees destroyed are from burnt/dropped valves and oil starvation (oil pump failures)

In the "old days" LOL, when I was poor, I bought many a used clapped out mower for next to nothing, did a valve job and replaced the rings on it and used it for years afterwards.... but back then parts were comparatively inexpensive and my time was worth nothing.... spent many nights up until midnight or so rebuilding "junk" into something I could make money with. But... back then you could buy a "overhaul" kit for a single cyl Briggs for under $60 including new valves. The old cast iron Kohlers (good engines those were) were only a little more.

lawnspecialties
06-16-2009, 09:34 AM
I've never heard that, either.

Some manuafacturers (Hustler, etc.) only use vertical shaft engines to eliminate the mule drive. I had a 27hp LC Kawasaki SuperZ years ago with the horizontal shaft. That's when they used a gearbox which was pretty much a disaster.

Come to think of it, that's the only ztr I've ever owned with a horizintal shaft engine. I guess I never thought about it until now, but I've never had any major problems with any of my vertical shaft engines.

topsites
06-16-2009, 11:46 AM
Old wive's tale.

LEM
06-16-2009, 12:20 PM
Horizontal shaft engines can be more expensive if they have output shafts front and rear. Some mower designers would run the hydro pumps off one side, and the blades of the other. I believe that Grasshopper, for one, does this.

Some mower designers claim that the horizontal shaft engines have better lube systems. I've never heard a good explanation for why they believe that.


LEM

dakota2112
06-16-2009, 01:50 PM
Theoretically speaking, isn't a vertical shaft engine more prone to leaking? The main crank seal in a horizontal engine only has to work when the engine is running. But in a vertical engine, the main crank seal is fighting an oil leak nonstop for 365 days a year, isn't it?

(I have no real-world evidence to show this being a problem though)

SfTD_service_CENTER
06-16-2009, 01:51 PM
headgaskets are weaker on a vertical shaft engine. i have done tons of headgaskets on opposing car engines and it seems that like the vertical shaft motor on mowers that the heads are what have the issue. those being flipped have alot of movement that i can see would be a issue, that being said subaru is a over head cam engine and the mowers are pushrod so lol. but with heat disapation and the way they sit i can se a horizontal shaft motor running more efficient with heat disapation, because the way it sits the heads are high in the air and seem like than can catch some extra air, but if you carefully examine the specs at kaw power and kohler web sites i think the engine power advatage goes to vertical shaft motors, i havent loked in a while but i suggest anyone who is curious do so. im just saying what the specs say too so i have no brake dyno to test any of this.

a neat engine design for a mower would be a v4! they ran them in hondas vfr 750 and 800 still do i think. and won championships with the rc45 race bike which was that design, maybe a horitantal shaft mower with the v4 would be a great new concept for power on a ztr platform i dont hear of any 4 cylinders other than the badboy.

kaferhaus
06-16-2009, 02:45 PM
I'd like to see one that did nothing but drive hyd pumps for the drives and deck. Hyd spindles would be awesome.

TomberLawn
06-16-2009, 03:33 PM
I'd like to see one that did nothing but drive hyd pumps for the drives and deck. Hyd spindles would be awesome.

Like a WAM. They are all hydraulic.

chesterlawn
06-16-2009, 05:18 PM
Do they make water cooled vertical engines for mowers?

TomberLawn
06-16-2009, 05:56 PM
Do they make water cooled vertical engines for mowers?

Yes, my dad's JD345 has a 20hp liquid cooled Kawi. And I'm pretty sure the 26-27hp Kawi l/c that is common on zero turns is a vertical shaft.

SfTD_service_CENTER
06-16-2009, 07:17 PM
I'd like to see one that did nothing but drive hyd pumps for the drives and deck. Hyd spindles would be awesome.

that would be nice just have a engine that ran a pump.

i just was talking with a guy who bought a new zg327 kubota just for his own lawn he loves it looks like a real machine he said it weighed 1800lbs it was on a trailer at a gas station and i looked at the drive shaft to the deck and from what i saw it looked pretty heavy duty, all cast housing and such just like a tractor would be. anyway i could see it easily being setup to what you said a hydraulic driven deck! never know kubota might come out with somthing like that, the thing had hydraulic lift and it has integrated motors for the wheels i mean they arent to far off from complete hydraulic as it is!

traman
06-16-2009, 07:44 PM
well i guess marine outboard motors got it all wrong for the last 60years

nosparkplugs
06-16-2009, 07:57 PM
Were really getting bored, both are good designs.Each engine manufacture has mounting spec's so long as a engine has a spin on oil filter & full pressure lubrication you could almost mount these engines upside down.

I comes down to cost look most higher Hp air cooled V-twins are vertical mounted. Vs lower hp engines horizontal.

The in-line engine will have a heavier duty Iron block, and a real cam shaft with bearings. This will add to the weight of these engines.

All these modern air cooled V-Twins are throw away engines.no rebuilding its cheaper to just buy a whole new air cooled engine, for this reason I am done with air cooled.

Not to mention the big block Kohlers are bored out, and have teflon coated pistons their is very little room for error or metal in these engines now
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tacoma200
06-16-2009, 08:49 PM
Traman, most outboards see very few hours use. I'm not saying a vertical engine is better or worse (just asking for opinions). I don't think an outboard is a very good example of engine longevity though. They have high rates of failure if you figure it by working hours. Mostly they suffer from not being used enough I doubt many outboards see 1'000 hrs but I could be wrong?
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nosparkplugs
06-16-2009, 09:22 PM
Tacoma200, I was just about rasied on the Water, been boating for years! the last thing you want is your marine engine to fail, you life can/does depend on a marine engine:nono:. I would say that Outboard engines are great examples of well built engines at least the top shelf models:)

We used the crap out of our boats, waterskiing, going wide open four hours. A marine engine requires a good winterizing buy a qualified owner or tech to get the longevity.

Marine engines gas or diesel are the gold standard for durability & performance. Water is very dense, and it takes lots of torque to break the co-friction of a boat hull/water, and lots of torque to spin a propeller under load:waving:


Traman, most outboards see very few hours use. I'm not saying a vertical engine is better or worse (just asking for opinions). I don't think an outboard is a very good example of engine longevity though. They have high rates of failure if you figure it by working hours. Mostly they suffer from not being used enough I doubt many outboards see 1'000 hrs but I could be wrong?
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tacoma200
06-16-2009, 09:48 PM
I wasn't really speakimng quality but longevity in hours.the fact that you used yours a lot means you probably means you didn't experience the problems most boater have from lack of use or long storage periods. I don't think a two stoke non.pressurized out board will run as many hours as a 4 stroke conventional engine with a pressurised lubrication system. I think outboards have a high failure rate per hour on average compared to say a four stroke lawnmower engine. How many people get as many hour out of an out board. I too am an out board fan but I know they face many challenges due to the elements and two stroke design(yes 4 strokes are taking over). Most people take a boat out less than a dozen times a year. I was just saying it wasn't the "best" example of longevity in an engine. I think a lc diesel would be the best example as you have pointed out in the past. Cheers!
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SfTD_service_CENTER
06-16-2009, 09:48 PM
a true markor of a engine that is good is when you can leave it alone for ever and it runs and runs, not a motor that needs to be looked after like a baby!


from what i have seen honda three wheelers had aircooled motors that have the piss run out of them and they still are arround till this day 22 years after they were stoped being made i say that horizontal shaft engines overhead cam or not have a better way to keep cool and just hold together longer from better lubricity.


wankle thats a good motor for a lawnmower! lol

nosparkplugs
06-16-2009, 10:11 PM
The WANKLE engine:laugh: You know those things burn oil right out of the box, and do their entire life. Oh!! their is nothing like a beer keg running your car





a true markor of a engine that is good is when you can leave it alone for ever and it runs and runs, not a motor that needs to be looked after like a baby!


from what i have seen honda three wheelers had aircooled motors that have the piss run out of them and they still are arround till this day 22 years after they were stoped being made i say that horizontal shaft engines overhead cam or not have a better way to keep cool and just hold together longer from better lubricity.


wankle thats a good motor for a lawnmower! lol

SfTD_service_CENTER
06-16-2009, 10:21 PM
great photo! yeah mazda twin rotor motors have a little spayer that shoots it right into the motor to make sure it gets some oil lube! i love ktm! they have them same thing on their fourstrok bike engines the 250 and 450 race bikes, they had a huge oil glass window and if it had oil in the window while the bike was sitting straight up it was good ther was no oil level height just a maximum amount before you blew the seals.

nosparkplugs you ever hear about that motor that looks like a cam shaft in a tube and compresses the fuel as it spins sort of like a wankle but a diferent shape it is suposed to be revolutionary but i think it never worked i wish i could remeber the name you might have like it! it was in pop sci magazine or pop mech, anyway try to look for it you might think it is cool!

marcuslawnguy
06-16-2009, 11:00 PM
I wonder how much a zeroturn would cost that had a hydro drive and blade system. I would think maybe 2000 more on what they want for them now.

ancjr
06-16-2009, 11:19 PM
I had a 1985 Rx-7 back in the day, which I loved. But I admit that the Wankel has a large surface area combustion chamber which makes them thermally inefficient and are comparatively low on torque to gasoline, and certainly diesel. That being said, physical size and weight for a given HP is about unbeatable with Wankel. They'd make great line trimmers IMHO.

4.3mudder
06-16-2009, 11:53 PM
I think that that vertical would last longer. Saying that, I have noticed horizontal engines cannot articlute well in hilly conditions. Oil sloshes everywhere, and ends up in the muffler thus creating a choo choo mower until the oil burns off. I can get on many different inclines and slopes with my z, but that dam troy bilt, you get on one well here comes the train... I think that it is somewhat of a poor design. But, since Kohler makes them I guess that are OK. But, I still go for a vertical over a horizontal any day.