Just like the title says. Anyone recommend one over the other? And why?
I realize one is EFI and other has carburetor.
I realize one is EFI and other has carburetor.
Kawaski FX801V vs FT730V
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fourbybud
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Are you talking about the efi FT730 or just the FT730 because there's a noticeable difference? Your title and post doesn't specify which one you are asking about, nor in what machine these will be in.
FX801 is a proven engine of proven power. The new FT series of efi are just that new, and don't have a long track record yet. The FX801 hos noticeably more torque than either version of the FT. Plus, it actually goes up as HP goes down under heavy load whereas the FT efi drops slightly under heavy load as HP is dropping.
I think efi is the future and I'm sure the Ft730 efi is a decent engine, but I know a lot of FX730's were real lemons and hope this doesn't happen to the FT series.
FX801 is a proven engine of proven power. The new FT series of efi are just that new, and don't have a long track record yet. The FX801 hos noticeably more torque than either version of the FT. Plus, it actually goes up as HP goes down under heavy load whereas the FT efi drops slightly under heavy load as HP is dropping.
I think efi is the future and I'm sure the Ft730 efi is a decent engine, but I know a lot of FX730's were real lemons and hope this doesn't happen to the FT series.
The FX801V is carb 25.5hp 852cc
The FT730V is efi 26hp 726cc and has the new air filter set up.
Both are a curr option on a Ferris ISX2200Z I'm looking at
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The "new" air filter system is just a copy of what B&S started using a long time ago. It is nowhere near as good as the Donaldson system on the FX. I know the cc's etc. on both and I am very familiar with the 852cc Kaw as I run an FX850 and have for years.Personally, I would want the FX801, but that's my preference. Others may want the efi system for the fuel savings and instant throttle response, but I have never found my 850 to have a sluggish or slow throttle response under any condition. They are able to get more power from smaller engines with today's tech, but I still believe in larger displacement for longevity when talking about engines of equal power, or very close to it..
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Cubic inches = torque regardless of the fuel metering device. It will also use more fuel doing it. Typically, fuel injection will yield better starting in all conditions, precise fueling and better economy all else being equal. The EFI will also work flawlessly at 10* and no humidity or 100* and sweltering humidity...and restart easily after a break in very hot conditions that can sometimes be troublesome for carbs.
A smaller EFI engine will definitely consume less fuel than a larger engine with a traditional carb. The EFI also maintains that efficiency over time whereas the units with a carb may need to be tinkered with a bit. Very long term, well that's still up in the air...you have carb rebuilds that is usually fairly inexpensive, but the jury is still out on the EFI units on the long term. My local tech reports that he has seen extremely high hours 2500+ on EFI units needing nothing...but these are not "aged" units with say 10 years on them. By way of comparison, he rarely sees carbs go that long without needing some type of service or rebuild needed.
What is the intended application?
A smaller EFI engine will definitely consume less fuel than a larger engine with a traditional carb. The EFI also maintains that efficiency over time whereas the units with a carb may need to be tinkered with a bit. Very long term, well that's still up in the air...you have carb rebuilds that is usually fairly inexpensive, but the jury is still out on the EFI units on the long term. My local tech reports that he has seen extremely high hours 2500+ on EFI units needing nothing...but these are not "aged" units with say 10 years on them. By way of comparison, he rarely sees carbs go that long without needing some type of service or rebuild needed.
What is the intended application?
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Ok, I meant what is the unit going to be used for? Commercial mowing with several hundred hours per year or used in a residential setting with 50 to 100 hours per year?
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Easy....EFI.... one reason, your unit has a lot of sitting idle time. That said, I would always use a tad of Stabil in every fill and the EFI engine should provide you many years of trouble free use.
That said, I would not be afraid of either unit. The benefits of EFI IMHO outweigh the slight gain in torque from the larger cubic inch engine. Further, the EFI will give you much better economy and mean less fills per year. The larger engine is a proven performer though!
One further comment...how many new vehicles has a carb?
That said, I would not be afraid of either unit. The benefits of EFI IMHO outweigh the slight gain in torque from the larger cubic inch engine. Further, the EFI will give you much better economy and mean less fills per year. The larger engine is a proven performer though!
One further comment...how many new vehicles has a carb?
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I have the FT730v on a SCAG tiger Cat II with a 52 inch deck
The EFI a simple and robust system, much simpler than the ones used on Kolher. It has preform flawlessly for me.
The air filter works. I too would prefer the Donaldson type, but this a good filter system and will kick out the heavier dirt, and keep the filter cleaner. There is a problem with the rubber duck bill falling off, but I put a clamp on mine. This system is less restrictive and one reason the smaller motor makes more power.
People talk about torque and torque mows grass...NO. they are mistaken. On a car or truck torque matters. Not an engine that runs at it's HP peak, HP matters. The engines makes 26 hp at 3600 rpm. You are going to run it at 3600rpm . why does it matter how much torque it makes at 2500 rpm? Peak hp is what matters.
The EFI a simple and robust system, much simpler than the ones used on Kolher. It has preform flawlessly for me.
The air filter works. I too would prefer the Donaldson type, but this a good filter system and will kick out the heavier dirt, and keep the filter cleaner. There is a problem with the rubber duck bill falling off, but I put a clamp on mine. This system is less restrictive and one reason the smaller motor makes more power.
People talk about torque and torque mows grass...NO. they are mistaken. On a car or truck torque matters. Not an engine that runs at it's HP peak, HP matters. The engines makes 26 hp at 3600 rpm. You are going to run it at 3600rpm . why does it matter how much torque it makes at 2500 rpm? Peak hp is what matters.
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Not exactly. Lets take a 28hp 725cc engine. Then we take a 28hp 850cc engine. Both engines have the same hp, however, the bigger engine has more torque at virtually any engine RPM and is capable of more work due to higher torque.
ie; You're mowing along at say 8mph cutting say 1.5" of good dry grass, but you have a small valley or dip in the yard where water sticks around a bit...it's extremely lush grass, much thicker than the rest and maybe still wet. When you hit it at speed the mower drops rpm on the smaller engine, you reduce speed to compensate, to maintain blade tip speed and quality of cut. The larger engine barely drops at all and you maintain your speeds...this is torque at work.
So even though both engines make the same horsepower, one makes more torque and is capable of maintaining rpm (and hp) to maintain blade tip speed as well as ground speed to provide a better quality of cut throughout tougher conditions. So yes, torque does matter quite a bit when mowing grass commercially, especially for those that starts early in heavy dew conditions or when it rains.
I hope this clears up any confusion in the matter.
Edited to add:
I can build a 565cid tall deck Chevy engine for a boat that makes 625hp and 700lb ft of torque that runs on pump gas.
I can also build a 468cid big block Chevy (454 bored .060) that makes 625hp and 550lb ft of torque that runs on pump gas. (premium in both cases of course)
We can then install these engines into a 24' HTM cat....and while they both top out at about 100mph, the larger engine gets to that speed FAR quicker as it accelerates much quicker than the smaller engine. Doesn't matter if it's from a dead stop, a 30mph roll on or a 70mph roll on. Lets say you hit rough water and have to back out of it for a couple of passing yachts going up river and throwing off some 4' rollers...both boats have been running side by side, as soon as you get through the rough stuff guess which one is right back up to top speed and which one is a quarter mile behind? This is torque at work again...same hp, same top speed, but clearly we see which engine is capable of more work.
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HP power is a funtion of torque and RPM.
for it produce more HP at a given RPM, it has to produce more torque.
An engine that makes more hp at 3600 rpm, also makes more torque at 3600 RPM.
Like I said, low end torque matters on an engine that varies RPM, but on an engine that runs at it's peak HP, peak HP is the ONLY factor when determining how much work it can do.
for it produce more HP at a given RPM, it has to produce more torque.
An engine that makes more hp at 3600 rpm, also makes more torque at 3600 RPM.
Like I said, low end torque matters on an engine that varies RPM, but on an engine that runs at it's peak HP, peak HP is the ONLY factor when determining how much work it can do.
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Ok...simply untrue...torque is producing the work...but a larger displacement engine simply MAKES MORE TORQUE at a given rpm. Since you agree that hp is a by product of torque, then you must also logically agree that torque is what performs the work under load.
Now this will likely blow your mind...but when you're spinning along at 3600 with a low load, you aren't making rated horsepower or torque...nowhere near it....SHOCK! DISMAY!! SAY IT AIN'T TRUE!! Yup, very true. When an engine is dyno tested to measure horsepower and torque, is it simply set at the governed rpm and freewheels basically? Nope...it's measured UNDER LOAD. So you see, when you're loafing along mowing sure the engine is at rated rpm of 3600, but it's not making anywhere near 28hp...as load increases rpms ideally stays at 3600 while both torque and horsepower increase. The engine making less torque will start to drop rpm before the engine making more torque...that will almost always be the larger displacement engine.
Chevy LT1 350cid 370hp, 380lb ft. small block.
Chevy L78 396cid 375hp, 415lb ft. big block.
Basically the same hp, larger displacement higher torque...guess which one could do more work??
Ever seen any engines used in mills?? Cutting wood? Constant rpm, but varying loads. How about irrigation?? Constant rpm, high load. Gen sets...I can go on...but none of these applications cares about horsepower...they care about torque.
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That is not what Kaw's own chart shows brother. It shows torque rises as the HP drops. I have said on here many times that HP is what HP is what mainly matters in the mowing game as the blades, pulleys, etc all are designed to work at their intended speeds with the engine at 3600 +/-, but that isn't exactly the entire story. The torque curve is what matters and the flatter the curve, the more usable it is for our mowers. Torque is what gets weight/mass moving and HP is what takes over at higher rpms and keeps it moving, so a flat torque curve is very useful.
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I would agree with you two, but then we would all be wrong.
Horsepower = Torque x RPM / 5,252.
that is math. to make more HP at 3600 rpm the engine HAS to make more torque at 3600. It is simple math, its the equation above.
The torque under the curve does matter for most engines, it does NOT matter for an engine that runs at a steady RPM, all that matters is the HP/ torque that it makes at that RPM.
I'm 100% sure I'm correct, again, because it is MATH. i'm not sure how you argue with math.
Horsepower = Torque x RPM / 5,252.
that is math. to make more HP at 3600 rpm the engine HAS to make more torque at 3600. It is simple math, its the equation above.
The torque under the curve does matter for most engines, it does NOT matter for an engine that runs at a steady RPM, all that matters is the HP/ torque that it makes at that RPM.
I'm 100% sure I'm correct, again, because it is MATH. i'm not sure how you argue with math.
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Just wondering how many dyno pulls you've run? Chassis dyno and engine dyno? Also, let me know how your engine holds up at 5252rpm....but lets examine math a bit.
Horsepower and torque is always equal at 5252rpm...no secret there, most everybody knows that and nobody is arguing that. You simply say it's all about the horsepower and that simply isn't true...most everybody who has ever built engines and ran a dyno knows that as well. It takes both and depending on the application as to what you want to do with the power curves.
I can build you a 468cid Chevy with good oval port heads that has incredible low end grunt and never need to turn over 5000rpm...in fact, if it's a torque monster for say a tow rig...the right cam, intake and carb or EFI can make brutal torque starting well below 2000rpm with a flat torque curve all the way through the rev zone...it's doing a lot of work down low. It might only be a 400hp engine, but produces 550lb ft of torque from 2000 to 4250rpm before starting to roll off to 400lb ft at 5252rpm...where horsepower is where the math says it should be...400!
I can also build the same size engine using good ported rectangular port heads, a big roller cam with a correspondingly port matched intake and multiple carb/EFI induction. This engine is gutless and worthless in the same tow rig application and worthless in any boat unless it's a jet boat. It has no useable torque below 4000rpm but then comes on strong. At 5252rpms the torque and horsepower is at 450, not much more than the above example...but care to guess what it's making at 7800rpm?? Work that with your calculator...problem is without knowing all the variables, it's a guess even with your calculator, but it could well be almost 700hp! That's why we have engine dyno's and chassis dyno's.
Which engine does more work?? Oh wait, at what rpm? The big horse engine capable of much more work at higher rpms is useless in a tow rig...and equally useless in a prop driven boat, you won't even get the boat on plane while a kid in an old 4cylinder 90hp Bayliner zips by your mega motor boat. The engine is not capable of providing enough torque at the low rpm to get the boat on plane...remember, a boat is a single gear affair. Put a small enough gear (prop) on it and it will finally get on plane and top out at 50mph....your calculator doing "the math" will show that boat capable of running 90 mph! Yet if it doesn't have the torque to get on plane it tops out at 25mph or so. (a jet boat would love this engine as when punched it immediately goes to very high rpm negating the need for low end torque)
As the above shows, there's far more to it then simple math...there's far more variables at work here. If you know all the numbers, you can use math to determine how an engine will perform in the intended application/s to a point to be sure...if you know how to crunch all the numbers...only the dyno can truly show the numbers. And the dyno app shown earlier in the thread is off considerably as well. It's extremely vague and shows no graphs...it can't. That's what the dyno is for.
Bottom line, engine manufacturers design and build engines designed for the application, or an engine that will perform well in many applications. If the engine is for a mower, manufacturers of the mower must gear their accessories to operate in the sweet spot of the engine.
This really isn't that difficult, but I've been fortunate to grow up around this stuff. My mother and father had matching '40 Ford coupe drag cars they raced together. Since I was born in November, I made a lot of quarter mile passes during the summer racing season while I was in the oven. Subsequently I started working on high performance cars when I was old enough to hold and turn a wrench and had great mentors learning how to build engines, so I have a pretty good insight into this stuff as I've been involved with it my entire life...and a bit beyond!! LOL Luckily, so has the engine & mower manufacturers!!
Horsepower and torque is always equal at 5252rpm...no secret there, most everybody knows that and nobody is arguing that. You simply say it's all about the horsepower and that simply isn't true...most everybody who has ever built engines and ran a dyno knows that as well. It takes both and depending on the application as to what you want to do with the power curves.
I can build you a 468cid Chevy with good oval port heads that has incredible low end grunt and never need to turn over 5000rpm...in fact, if it's a torque monster for say a tow rig...the right cam, intake and carb or EFI can make brutal torque starting well below 2000rpm with a flat torque curve all the way through the rev zone...it's doing a lot of work down low. It might only be a 400hp engine, but produces 550lb ft of torque from 2000 to 4250rpm before starting to roll off to 400lb ft at 5252rpm...where horsepower is where the math says it should be...400!
I can also build the same size engine using good ported rectangular port heads, a big roller cam with a correspondingly port matched intake and multiple carb/EFI induction. This engine is gutless and worthless in the same tow rig application and worthless in any boat unless it's a jet boat. It has no useable torque below 4000rpm but then comes on strong. At 5252rpms the torque and horsepower is at 450, not much more than the above example...but care to guess what it's making at 7800rpm?? Work that with your calculator...problem is without knowing all the variables, it's a guess even with your calculator, but it could well be almost 700hp! That's why we have engine dyno's and chassis dyno's.
Which engine does more work?? Oh wait, at what rpm? The big horse engine capable of much more work at higher rpms is useless in a tow rig...and equally useless in a prop driven boat, you won't even get the boat on plane while a kid in an old 4cylinder 90hp Bayliner zips by your mega motor boat. The engine is not capable of providing enough torque at the low rpm to get the boat on plane...remember, a boat is a single gear affair. Put a small enough gear (prop) on it and it will finally get on plane and top out at 50mph....your calculator doing "the math" will show that boat capable of running 90 mph! Yet if it doesn't have the torque to get on plane it tops out at 25mph or so. (a jet boat would love this engine as when punched it immediately goes to very high rpm negating the need for low end torque)
As the above shows, there's far more to it then simple math...there's far more variables at work here. If you know all the numbers, you can use math to determine how an engine will perform in the intended application/s to a point to be sure...if you know how to crunch all the numbers...only the dyno can truly show the numbers. And the dyno app shown earlier in the thread is off considerably as well. It's extremely vague and shows no graphs...it can't. That's what the dyno is for.
Bottom line, engine manufacturers design and build engines designed for the application, or an engine that will perform well in many applications. If the engine is for a mower, manufacturers of the mower must gear their accessories to operate in the sweet spot of the engine.
This really isn't that difficult, but I've been fortunate to grow up around this stuff. My mother and father had matching '40 Ford coupe drag cars they raced together. Since I was born in November, I made a lot of quarter mile passes during the summer racing season while I was in the oven. Subsequently I started working on high performance cars when I was old enough to hold and turn a wrench and had great mentors learning how to build engines, so I have a pretty good insight into this stuff as I've been involved with it my entire life...and a bit beyond!! LOL Luckily, so has the engine & mower manufacturers!!
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I have a 2016 Ferris is2100z 61" with a 26HP Vanguard and a 2013 JD z930R 60" with a 25.5HP Kawasaki FX801. I love the Ferris but the FX801 is a beast; in fact I had planned to sell the JD and get a isx2200 with a 30+ HP motor but I ended up finding a isx3300 72" with a Kawasaki FX1000-EFI. Still selling the JD.
I understand the above arguments of displacement but my smaller displacement (minor difference) mower is stronger. Could be the mower design (deck, TuffTorq vs ZT4400s, etc) so I can't say. I think you'll likely be happy with either and if they are the same price just pick one. EFI should be better on fuel but will likely cost more if needing repairs. Good luck to you, hope you love the Ferris like I do!
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The 801 (852cc) is a beast compared to the 730 (726cc)...I believe that's exactly what has been said. No replacement for displacement.
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