Snaps Super STOL

[C5Engineer 1170]

You guys have probably seen this a million times but maybe not. This is the vid I show people when they ask why I would want to fly something like an Avid. This is an A model with a highly tuned 670 on it. Very impressive performance!

[Av8r3400 1179]

I don't see or hear much of the 670's.

Are there many installed on Avids, Foxes etc.?

[akflyer 1427]

Brock Sellards does the conversions and is the one that built "snaps" engine.  He has Plane Engine Performance.  He is getting around 90 HP out of a 583 also....  He does it pretty damn cheap too.

[C5Engineer 1170]

I discovered Brock a few months ago. He was my motocross hero when I was a kid. I was giggling like a school girl when I talked to him on the phone. I'm gonna have my 582 "upgraded" a bit next year after I recover from the rest of my rebuild costs. I almost bought an Avid IV brand new for 13K with a 583 on it about 6 months ago. The seller freaked out last minute about liability and yanked the 583 off it and dropped the price a hair. It is pretty sad that people have became that sue happy. Anyways it worked out in the end with mine and someone bought his with no motor for too much money.

As far as 670's go the one Brock built is making over 120hp. Not sure how reliable it is but for showing off what one of these airplanes is capable of on floats it works great. The 583 and 670 have electronically timed ignition. They also have a thing called the RAVE valve that basically is a valve over the exhaust ports. They make their power at a much higher RPM and have a very inconsistent midrange. They were made for snowmobiles where your running wide open much of the time. The 582 is severely detuned for reliability. My motocross bike is only a 250cc single cylinder and it's making over 50hp. 65HP out of a 580cc twin is pretty weak. That would be like getting 150HP out of a big block chevy.  My cousins turboed 1000cc snowmobile is pushing 350HP!! That power to weight ratio is insane! Of course with airplanes reliablity is the name of the game. I won't tell you how many times I've blown up a modded dirt bike or snowmobile. 

[dholly 718]

383 in the vid, that's my story and I'm stickin' to it! Here's a couple 'snaps' [sorry!] I took a year or so ago. Joey, you should put up the pics from backcountypilot here too. cheers

[akflyer 1427]

VERY nice.  I love that cowing! 

I am still thinking VERY hard on the Arcticat 800.  120 HP at 6800.. 100'# tq... fuel injected <insert tim taylor grunt here>  The 800 gets better fuel milage than my 600 and is a VERY smooth running dual plug engine.  It is single ignition, but dual plugs per cylinder... I think it really warrants a conversion.  May have to seel what the local dealer will get me one for.

[dholly 718]

I liked it too but I never did ask him where he found it, too many beers at the SPB that day. 

We need more options @ 100-120 hp, more power to ya if you do it or can get it done. I read the saga of putting a turbo Geo w/SDS ignition in a Rans S-7 floatplane. He's real happy now, but it took -years- of screwing around and I sure don't have that amount of time. I've been watching out for a fresh 912 since I got the floats but no luv yet, so I started on a Jab3300 mount. I dunno, lots of gas but buddy's Legend Cub on Baumann floats was a great performer. (which, btw, is now in Alaska on wheels, pic is from '06 Seaplane Flyin at Speculator, NY). Sure wish I could make up my mind...

[fat finger edit] ^ 532