Why no Rotary engines in chainsaws?

[Kupreanof]

Hate to resurrect this thread, but I'd hate to start a new one on this even more and I wanted to add this to it:

How about an air powered rotary saw?
http://www.engineair.com.au/
http://www.engineair.com.au/airmotor.htm

 

[sawbones]

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???

I had a buddy that worked on a few rx7's for me that was factory trained by mazda. He did a lot of hipo work on the 13's.

He told me about the 4 rotor (mated 13's) , that produced 600hp :jawdrop:




here's the sachs saw.

 

[056kid]

a performer..

http://www.youtube.com/watch?v=7L3DhuxJees

 

[scotclayshooter]

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Mazda still make a rotary the RX8

 

[MO-Iron]

Rode a RE-5 Suzuki motorcycle when going to college. Bike was an unbelievably fast powerhouse, but used a gallon of gas ever 32 miles to do it.

MO-Iron

 

[Erick]

This ones kinda quick...... love to see it make a full run.

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[SawTroll]

Just what we didn't need - GRRRRRRRR :chainsawguy:

 

[ironman_gq]

I heard about a quad rotary that made closer to 900hp it was custom built not just two 13b's welded together.
Mazda recently went back to the rotary in the RX8 3 rotor motor I guess it was redlined at something around 9500rpm's and had no vibrations. I remember seeing it on Top Gear with the British guy driving it

 

[Maldeney]

Rode a RE-5 Suzuki motorcycle when going to college. Bike was an unbelievably fast powerhouse, but used a gallon of gas ever 32 miles to do it.

MO-Iron

Hell that ain't bad! My 600RR honda sucked up a gallon every 28.....

Um I guess that was due to being at 15K RPM the majority of the time!!:jawdrop:

 

[Maldeney]

This ones kinda quick...... love to see it make a full run.

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WOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!I MEAN WOW!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Kinda give me a chill

 

[Brmorgan]

How 'bout this rotary chainsaw?:

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Here's a four-rotor Mazda:
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One of the fastest off-the-line starts I've seen. The previously posted vids were really impressive too, especially the older model. I'd love to pull up next to someone with that and just let loose. Talk about a sleeper!

I like this rotary on a dyno:
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Especially when they really wind it out and get the whole exhaust and side of the block red-hot. It blows my mind that we can make engines that will continue to operate like that.

 

[Maldeney]

That is freaking Insane.




opcorn:

 

[sawbones]

How 'bout this rotary chainsaw?:

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The guy that built this 13B hotsaw many years ago had passed away and the saw sat in a garage for years.

The guys running it are Darrel and Rodney from around the port angeles area here in washington.

They tracked down the builders daughter and she lets them take it to shows now.

Not much longer after the day they made this run they found the throttle was only opening about 3/4. It runs much faster now.

You might see they have wheels under the motor . That cause their really old
and need a little help

this can saw be picked up by 2 men and run in competition without the wheels though.

This saw is started with a honda 5hp.

 

[oldsaw]

Rode a RE-5 Suzuki motorcycle when going to college. Bike was an unbelievably fast powerhouse, but used a gallon of gas ever 32 miles to do it.

MO-Iron

I had a '76 Honda 550 that didn't do any better than that, but had less power. Funny since my '78 750 often got well into the 60s and 70s if I was nice to it. Only dropped below 40mpg once, bucking a horrible wind going to Minot, ND. Couldn't get it out of third gear with the Windjammer fairing/sail. But would typically get in the mid 40s to 50. Waaay more power than the 550 too.

 

[bigjake]

AS a poor bast#rd that had to work on the older mazdas

flood flood flood needs apec seal YOU CAN HAVE THEM

 

[Hddnis]

...

Especially when they really wind it out and get the whole exhaust and side of the block red-hot. It blows my mind that we can make engines that will continue to operate like that.

Some of the things we are doing now with metallurgy are indeed amazing. The guys that work with this stuff are nothing short of genius.




Mr. HE

 

[oldsaw]

The real answer to the original post is complexity and cost. Hard to beat the simplicity of a single cylinder 2 stroke. We can talk fuel consumption later.

 

[166]

Here are 3 short video's of KMS-4 #1 of 4 I took a couple years ago.

Notice how much that saw is vibrating sitting there idling in the first few seconds.

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[Hddnis]

Thanks for that vid, 166, that saw sounds awesome.



Mr. HE

 

[Erick]

It's pretty impressive for that thing to just sit there purring like a kitten..... but it's REALLY impressive when you consider it's sitting on a hard steel plate.