The International Cessna^® 170 Association

doug8082a wrote:Hatz Classic??? It's a 2 place open cockpit biplane. Originally desgined as the Hatz CB-1 and then modified into the Hatz Classic. Looks a lot like a 3/4 scale Waco.

Hatz Ass'n website: http://www.weebeastie.com/hatzcb1/
Hatz Classic: http://www.hatzclassic.com/

I'll be hanging a radial on it.

Doug,

I used to drool over the Hatz CB-1 Biplane in Sport Aviation back in the 80's. From the website, I see the Classic is available in kit form. Cool. Are you planning on one of the new experimental radials?

Miles

Darn tootin'! One Rotec R3600... if you please

The Classic is designed for 150-160hp Lyc O320. The R3600 is 150hp and exactly the same weight as the Lyc. With the 3:2 reduction on the prop they claim it can produce most, if not all, of the 150hp at takeoff.

So Doug,

Does selling your 170 cover the cost of the engine AND materials, or just the engine? My dad has been drooling over that engine for his Hatz, I keep telling him to keep building and when it comes time for an engine, I'll sell my blood to help out...

Doug,

I haven't paid much attention to the Rotec engines, but a few guys in EAA Chapter 1000 who went to Oshkosh brought some pictures for the meeting last night including some of the R-2800 (I think) and R-3600. If they run as good as they look, they're going to have one heck of a market.

Keep us abreast of your progress. Are you thinking of an on-line builder's log by any chance?

Miles

Check 'em out at: http://www.rotecradialengines.com/

Go to the "Customer Projects" section and check it out. The R3600 is a relatively new engine, so there aren't many of them flying at the moment, but several in process. There are plenty of R2800s in the air. Check out the Nieuport 28 with the R3600:
http://www.rotecradialengines.com/custo ... Jarvis.htm

Once I actually get going I'll do an online builder's log.

See and hear an R3600 run:
http://www.rotecradialengines.com/Clips ... stclip.wmv

Looks like it would be a cool engine in a 170. I see they feel it should turn a 76-55 prop. I relize it will nver be certified. Bill K

The 76x55 prop is for the R2800 which is 110hp and wouldn't pull a 170. The R3600 is 150hp and the largest prop currently deployed on that model is a 94x67 on the Nieuport 28.

Prop sizes for both engines and R3600 specs are discussed here:
http://www.rotecradialengines.com/R3600development.htm

Scroll down to the bottom for a shot of the R3600 prop.

Doug

I have been very involved with the Hatz for a number of years, building and flying. It is a really sweet flying biplane, both Classic and CB-1.

My neighbor is putting the Rotac on a Pober Jr Ace. Look carefully at the size of the engine, ie physical diminsions, and the size of the Hatz front end. You may find the engine is rather small and the front end of the airplane will look funny. Just something to look into before you commit to the engine. There was a thread on this on the Hatz forum (which is down now but should be back up in the next few days)

Sincerely

Bill Rusk

It would be interesting to know what the engine to propeller shaft gear ratio is on that engine. For it to swing a 94 by 67 prop it would have to be pretty well geared down.

blueldr wrote:It would be interesting to know what the engine to propeller shaft gear ratio is on that engine. For it to swing a 94 by 67 prop it would have to be pretty well geared down.

The Rotec website says there is a 3:2 propeller speed reduction unit (from the dome on the front it looks like a planetary system similar to the big radials). However, I didn't see anywhere the advertised the RPM at which the engine (or prop) is rated.

Miles

Bill Rusk wrote:Doug

I have been very involved with the Hatz for a number of years, building and flying. It is a really sweet flying biplane, both Classic and CB-1.

My neighbor is putting the Rotac on a Pober Jr Ace. Look carefully at the size of the engine, ie physical diminsions, and the size of the Hatz front end. You may find the engine is rather small and the front end of the airplane will look funny. Just something to look into before you commit to the engine. There was a thread on this on the Hatz forum (which is down now but should be back up in the next few days)

Sincerely

Bill Rusk

Here's a picture of a R3600 hanging on a Hatz Classic fuselage.

http://www.rotecradialengines.com/0Kurt ... gineOn.htm

Looks pretty darn good to me. I wonder if the too-small situation was a R2800 on a CB-1?

Miles

Thanks Bill. You and I spoke once or twice a while back. Someday I hope to fly out to Broadhead.

The diameter of the R3600 is 33.46" (slightly larger than the width of an O320) and the depth is 25.2" (including accessories), so the only thing I'd have to worry about is the fore/aft placement. I don't know the depth of the O320, but from what I've seen of construction photos, the front of mounted Rotec is pretty close in location to where the O320 would be. I'm going to follow up with Jeff Shoemake (Makelan - source of the Classic plans) for recommedations on the engine mount when the time comes.

Hmmmmn. So one of these on a 170 would be like a baby-190?

Now you're talkin'