flyrotary@lancaironline.net Mailing List Archive

Robert;

I adapted the Velocity factory mount for the Franklin 220 hp for my NA 20B. It uses 5/8” dia. 4130 tube for the mount, and it has proven to be fine. The additional hp adds a bit of stress, but is small compared to the jolts of hard landings, and I had a few of those in the early going. The thrust loads from the prop are likely not going to be more than about 800 lbs.

Of course it is all dependant on good mount design, but with that anything over ¾” would be overkill. The mount I have is a ‘bed’ type, which supports the engine off the front cover and rear housing (see at my web site http://members.cox.net/alg3/airplane.htm; and take the link to the ‘Rotary Engine’ at the left).

Al G

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Robert Bollinger
Sent: Thursday, August 20, 2009 5:36 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Diff Betw Late Model 13B & Renesis

Does anyone have any suggestions about tubing size for my 300hp 20B? I have made several mounts for my Ford V6 in my BD4. That has given me lots of experience making mounts for up to 200hp. But what about 300hp? Any thoughts would be appreciated.

On Tue, Aug 18, 2009 at 10:44 AM, Rob <rob@mum.edu> wrote:

I'm about to begin building my engine mount for my 20B on my BD4. I'm using a bed mounting plate like Tracys mount. What size 4130 tubing does everyone recoment that I use? I have a lot of 3/4x.049 tubing in stock. Would that be ok or should I use something larger diameter? Any suggestions?

Robert

Robert Bollinger
MR722 MUM
Fairfield IA 52557
(641)472-7000 ex2068
(641)919-3213 cell
rob@mum.edu

----- Original Message -----

From: George Lendich

To: Rotary motors in aircraft

Sent: Sunday, August 16, 2009 10:38 PM

Subject: [FlyRotary] Re: Diff Betw Late Model 13B & Renesis

Bryan,

Yep! that's what I've heard as well.

George (down under)

George,

The side seal tolerances are many times greater than the traditional seals. Plus they have a “keystone” shape to them. I have heard that many racers use the longer seals in an attempt to close that gap.

Bryan

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich
Sent: Sunday, August 16, 2009 5:35 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Diff Betw Late Model 13B & Renesis

Bryan and Jeff,

I have spoken to a number of people about the Renensis and they all tell me that none of the compression seal sizes( lengths) completely seal against blow-by, hence the need for the extra O-ring type seal in the rotor sides.

There are a number of lengths available and it has been suggest to me to use the longest, as at our usage, as compared to racing, their never going to reach their maximum length. Their length is governed by the fact that their being more exposed the exhaust heat, because of the side exhausts. It's my feeling that that little cut away in the exhaust side ( of the rotor) makes them even more exposed.

I hope that makes sense.

George (down under)

Jeff,

The grooves for the outer water jackets are in the rotor housings vice the side housings.

The rotors have an additional outer ring. Some of the tolerances are not in the DVD due to the fact that these components are unique to the Renesis.

I can get those to you if you decide on the Renesis. Otherwise, pretty much the same.

Bryan

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Jeff Luckey
Sent: Sunday, August 16, 2009 12:56 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Diff Betw Late Model 13B & Renesis

I just watched Bruce Turrentine’s video on how to rebuild a gen 2 13B. (Pretty good video considering it was done by one guy and a tripod – and the price was sure right, $30 delivered.)

I’m considering using a Renesis and was wondering if there are any significant differences or gotchas between the 2 engines that I need to know about.

Also, I’ve been looking for the Shop Manual for a 2004 Renesis/RX-8 and found a couple on EBay. The actual printed manuals cost anywhere from $100-200, but there seem to be electronic versions of these manuals available for <$20. Has anyone used the electronic versions – likes or dislikes?

Given the choice among publishers like Haynes, Chilton, or Mazda, which is best? I would tend to go w/ Mazda but sometimes Japanese manuals can loose something in translation.

Thanks,

Jeff Luckey