3 cylinder anyone?

[Bob S.]

Another view.....

[leshoman]

Frank. This is looking impressive. Looking forward to flight photos and video

[PropMan]

Yes. I just wish it was mine. Bob has a front row seat at the LE S3VW skunk works.
I have a few months before that stage. But there will be 2 XLs flying in Texas with the S3VW this summer!

[sciguy]

Another view.....

Bob,

Thanks for the picture. That little Scarlet looks great. I'm wondering it the top cylinder obstructs the view enough to be a pain in the butt. That said, I spent a good number of years flying behind a rather large P&W 1340 that made taxiing a bit interesting but became no problem once at a normal flight attitude. Can the engine be mounted with one cylinder straight down?

Thanks for playing,

Hugh

[Bob S.]

I personnally don't think that one cylinder will be that much a distraction...

Canting the engine off to one side or the other only puts that one cylinder closer to the ground... I don't think that would be good should you go over center.....


Here's a view of the oil tank being designed and installed under the rudder pedal area....

[Tom XL-7]

Bob, Frank;
How does the firewall forward compare to the 1/2 vw?
Tom XL-7

[Bob S.]

If you will look at the first picture below, you will see the (lower two) holes for the motor mount are in the very corners of the 'firewall'. much further out than what you need for the better half VW (full case). Corner mounts would probably be OK for a cut-case engine too as you will have to make a similar mount for it.

In process of designing a mount that will accept the odd engine pulses so they don't vibrate the engine/ engine mount off the fuselage frame..... 

Motor for motor the weight is in favor of the S-3 Radial but weight for the oil/oil tank is the ONLY add I can see EXCEPT if you use the electric start then you will add #'s for the starter....  Will get a total weight when the mount is built....

[Bob S.]

OK, Found other pictures:  The current engine mount is 6" long from firewall face to mounting lugs on the engine.
  Because the mass and it's distribution is a bit different between engines, The flight mount will move forward to 7 inches. This solves several problems. At this point I roughly calculate no CG changes from a 1/2 vw installation.
 On the Scarlett, the Walbro carb sticks up on a approx  70 degree angle centered laterally. Because of the triangulation requirements for a radial installation,clearances for the carb from the triangulate is an issue....but at the seven inch location not worrisome at all. There is even clearance to reach in and tune the carb....

[PropMan]

Great explanation Bob.

 I'd like to add the 3VW weighs in at 72 lbs with OUT the starter, and just at 80 lbs WITH the starter, Not sure what the oil tank will weigh, probably a couple pounds. 
The prop IS heaver by 3 lbs, almost double a 1/2 VW prop. It has a larger diameter and more chord due to power made at low rpm, this equates to MORE thrust= better climb performance. Hopefully in a short time we will have performance data for everyone.

[Dan_]

If I am not mistaken, Walbro carbuetors do not use a float bowl, so should be able to be oriented in any direction.  

You could ask Verner if it can be rotated to clear the tubing...

[scottiniowa]

Really been enjoying the progress on the motor Frank

Does that starter really weigh 8#'s   as a B & C starter for 180 hp weighs in at 7.7 or 7.4#  Just wondering out loud.

[PropMan]

Scott, It's actually a starter assembly for the 3VW. the 8 lbs includes: starter, starter ring, a mounting bracket, larger(not much) alternator, probably a few other small parts I'm not thinking of. Not sure what the individual parts weigh, hope not to remove them for a while.

[Dave Stroud]

It seems about a year has passed since no comment on this topic. Any updates or did it go to another
thread elsewhere ? Thanks...