kurtty
ArboristSite Operative
how come there isnt any rotary engines in chainsaws. they are high RPM and have very good power to weight ratios. i bet one in a chainsaw would be a pretty ideal combination.
your thoughts?
Why no Rotary engines in chainsaws?
- Thread starter kurtty
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how come there isnt any rotary engines in chainsaws. they are high RPM and have very good power to weight ratios. i bet one in a chainsaw would be a pretty ideal combination.
your thoughts?
J.Walker
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Rotary Engines in chain saws
Kurtty
Domar saws gave it a try.
Maybe CuttingScott can tell us what year they offered that model. I just know he's got one!
Kurtty
Domar saws gave it a try.
Maybe CuttingScott can tell us what year they offered that model. I just know he's got one!
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16:1mix
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Neat animation, thanks for posting!
klickitatsacket
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the dolmars had the same problem that all rotary engines had; durability. With new composit materials though, I think the rotary is on a come back with a vengance. I seen some new airplane rotarys last week that are about the right size for an ultra lightweight and powerful saw. I can not remember the company but they are out of Great Britain. The rotary engine is one of my very favorite engines out there.
Lakeside53
Stihl Wrenching
Horrible fuel consumption and emissions... The epa will no-doubt kill off any attempts to make a saw from them.
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I have an '84 RX7 project car. I rebuilt the 2 rotor motor in it, lots of little seals and things to get right for the rotors. Trouble with this engine is it has poor fuel economy, very hot exhaust, and high emissions, which is why Mazda gave it up in '97. They have since come back with more computer and engine management stuff, but the fuel economy is still poor compared to a piston engine. The real thing about the Wankel is torque. Lots of it straight up to the redline. Artic Cat had a Wankel sled that was hard to beat in hill climbs.
This is the RX7 motor:
Here is a Wankel Hercules bike in Germany:
Suzuki sold a wankel bike in the US in the '80s, I think.
Here is the Sachs Dolmar Wankel saw:
I sure would like one of these for my collection.
And here is my Sachs 6 hp single rotor air cooled Wankel, just hunting a MiniBike frame for it. I saw 11k RPM on the tach holding it against the governor!!!
I am fascinated by the Wankel, have books on it and 2 examples to actually play with, but I doubt it will ever replace any other motor. Two-strokes have ports, and are less efficient that four-strokes, and I guess the same is true for the rotary design, since it has ports as well. The Sachs engine uses a 50:1 prelube, and the RX7 has a small oil pump that feeds crankcase oil into the carb for apex seal lubrication, so I guess it is just a version of a two-stroke after all.
It still is a cool motor, though!
This is the RX7 motor:
Here is a Wankel Hercules bike in Germany:
Suzuki sold a wankel bike in the US in the '80s, I think.
Here is the Sachs Dolmar Wankel saw:
I sure would like one of these for my collection.
And here is my Sachs 6 hp single rotor air cooled Wankel, just hunting a MiniBike frame for it. I saw 11k RPM on the tach holding it against the governor!!!
I am fascinated by the Wankel, have books on it and 2 examples to actually play with, but I doubt it will ever replace any other motor. Two-strokes have ports, and are less efficient that four-strokes, and I guess the same is true for the rotary design, since it has ports as well. The Sachs engine uses a 50:1 prelube, and the RX7 has a small oil pump that feeds crankcase oil into the carb for apex seal lubrication, so I guess it is just a version of a two-stroke after all.
It still is a cool motor, though!
how come there isnt any rotary engines in chainsaws. they are high RPM and have very good power to weight ratios. i bet one in a chainsaw would be a pretty ideal combination.
your thoughts?
Sachs Dolmar tried this with the KMS-4 AROUND 1975, never became popular. Heard they were hard on fuel and ran hot,maybe some other problems other members can enlighten us . Pioneerguy600
HolmenTree
ArboristSite Guru
There was a saw dealer here in Northern Manitoba who had a KMS-4 Dolmar with only a few hours on it . I could have had it for $500 20 years ago.,but he passed away a few years back and the business has since closed. His family may know where the saw is.
I heard almost all these saws were sold in Britain. And yes they were very hard on fuel.
Willard.:greenchainsaw:
I heard almost all these saws were sold in Britain. And yes they were very hard on fuel.
Willard.:greenchainsaw:
Kansasplains
New Member
Here is the Sachs Dolmar Wankel saw:
I sure would like one of these for my collection.
How badly do you want it? My Dolmar dealer had one that he sold to somebody for their collection. It was only $1500.
volks-man
Arboristsite.com Spooner
watch a wankel powered dolmar in action:
http://www.youtube.com/watch?v=teEREL4BMGo
http://www.youtube.com/watch?v=teEREL4BMGo
husq2100
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i believe they are running wankel engines in go karts in the USA, i have heard power to be 30hp.....
cheers, Serg
cheers, Serg
Erick
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It's 50hp
I'm a big fan of the Wankel/Rotary engine as well
Here's the kart engine in action
Looks about the perfect size for a saw........ Dean you paying attention??
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Erick
Addicted to ArboristSite
I had a '84 was a fun little car to drive, I could probably get that car back cheap right now.
I've got a '91 convertible project waiting on me to come get it. How much did you wind up investing in the rebuild.... if you don't mind me asking.
I don't know that they would get such bad fuel mileage if people could learn to keep their foot out of it......... ahhh who am I kidding that car just begs to be rode hard, that's what makes it so much fun to drive. It just screams all the way to the red line, and begs for more.
By far not the fastest car I've ever owned, or the best handling, or the nicest......... but it's right at the top of the list for fun factor.
My brother and I have a lotus 7 rep with a 13 twin turbo rotary in it, Im not a huge wankel fan but they are a light high performing engine. Alot of companies have tried them, Audi, mercedes, Citroen,NSU, Suzuki and norton made motorcycles with them. The AMC pacer was designed around the idea it would be rotary powered. The KGB had russian made rotary that was fast but didnt see more than 10.000 miles before they went bang. My FIL has a firefighting pump which is rotary.
Capable of putting out huge HP but require huge amounts of fuel to do it. We have alot of them in NZ. A mate made a 4 rotor by welding up the cranks of two 13b's. VERY high powered until the welds gave way.
Capable of putting out huge HP but require huge amounts of fuel to do it. We have alot of them in NZ. A mate made a 4 rotor by welding up the cranks of two 13b's. VERY high powered until the welds gave way.
Erick
Addicted to ArboristSite
Mazda makes a factory three rotor engine that was put in a station wagon if I remember correctly but it was never available in the states, a 20b I think it was/is.
Seems like it was out your way Timber???
Seems like it was out your way Timber???
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husq2100
Addicted to ArboristSite
yes there are some guys in oz that build very serious rotary engines for cars and boats...... big power!
i believe that mercedes were they first to develop it in the c111, this car ended up doing over 400km/h.... but they felt they couldn't get the reliability out of the motors for production cars
serg
i believe that mercedes were they first to develop it in the c111, this car ended up doing over 400km/h.... but they felt they couldn't get the reliability out of the motors for production cars
serg
bullseye13
ArboristSite Guru
I have to agree with a lot of you here. My favorite engine is a wankel engine. I actually have a 1971 Arctic Cat Lynx, with a sachs 303 in it.
Coolest_Sled_Ever haha
But since it dosent snow anymore in pa---Ive been thinkin......:greenchainsaw:
Coolest_Sled_Ever haha
But since it dosent snow anymore in pa---Ive been thinkin......:greenchainsaw:
Freedom motors
Freedom motors has been claiming to be coming out with rotary power tools for a few years. They just need your money to make it happen.
http://www.freedom-motors.com/
Freedom motors has been claiming to be coming out with rotary power tools for a few years. They just need your money to make it happen.
http://www.freedom-motors.com/
Kansasplains, I want one but not $1500 worth!
Erick, I got a racers price, from Mazda motorsports, which was supposed to be a deal, and gaskets, apex seals, sides seals, rotor and housing bearings, gaskets, etc. ran about 1500 donuts if I recall right. And you are right, it is a hoot to drive, shifting at about 8500 in each gear, G force pushing your face back, blue lights in the mirror, argghhhggh.
Maybe this summer I can get it back on the road.
Erick, I got a racers price, from Mazda motorsports, which was supposed to be a deal, and gaskets, apex seals, sides seals, rotor and housing bearings, gaskets, etc. ran about 1500 donuts if I recall right. And you are right, it is a hoot to drive, shifting at about 8500 in each gear, G force pushing your face back, blue lights in the mirror, argghhhggh.
Maybe this summer I can get it back on the road.
