Hi Gordon,
Welcome to the Fly Rotary list. I am probably one of the few (I am only aware of two now flying) Plugs Up installations currently flying - there may be more, but unknown to me. I have flown my installation for close to 12 years with
around 600 hours on the installation in my RV-6a (Tractor installation).
There are no technical reasons that I have found precluding safely flying Plugs Up. In fact, there are some advantages. The biggest disadvantage is that almost all vendor products (such as motor mounts, gear boxes, etc) are designed
for the automobile orientation - so some one-off parts and modifications may be necessary.
Also, You will almost certainly have to cobber up your own oil sump - you can see my (red/blue) oil sump in the one photo which has a plate covering the engine "bottom" and a sump(red box) below the engine line. The curved blue tube
(from top of sump into plate is aluminum tubing. Do NOT use anything other than metal tubing - hose, even stainless steel braided hose, can possible collapse under the suction when hot. Also any air leaks in that particular tube - will mean the ability of
the oil pump to suck oil will be compromised. I know of one instance where a hose (instead of metal tube) was used and eventually collapse - starving engine bearings and causing engine to seize.
Two advantages are 1: You can just about forget worrying about flooding the Plugs Up engine. The plugs are on top and exhaust ports on the bottom - so excess fuel quickly drains out and does not flood the sparkplug holes. 2: The fuel
injectors in the block are not directly over the exhaust ports as they are in the auto installation. Gravity will cause any fuel leaks at the injectors to drop straight down missing the hot metal of the exhaust header (unless of course, you route your exhaust
header under the injector area). I think the spark plugs are also easier to access - a minor point.
My engine uses the engine bolt holes in the front iron housing (next to the front aluminum housing) intended for mounting air conditioning components to support the "rear" of the engine. Then I pick up the bolt holes in the rear iron
housing (one next to flywheel) on each side to support the front. These pickups use a triangular plate of metal with the small end attached to the motor mount with one bolt and the base of it attached to the engine through two bolts which also hold the gearbox
to the rear housing. Photo attached which may help explain it better. There are certainly other (and perhaps better ways), but this has worked for me.
But, lots of information on this list will be applicable regardless of engine orientation.
Best Regards
Ed
Sent: Sunday, January 15, 2012 8:29 AM
Subject: [FlyRotary] Newbie to list
Hi all,
I’m new to the flyrotary (FR) list and am building a Defiant with two turbo 13Bs. I am looking at mounting the engines “plugs up” as described by Neil Kruiswyk and tried to contact him at the home.com address listed on the FR website.
My e-mail keeps bouncing back. Does anyone have a current address for Neil?
Beyond that, I would like to identify others that have mounted these engines sideways (plugs-up). How many hours do your projects have on these installations? What issues have you uncovered that may be related to the plugs-up orientation?
Has anyone found (more than expected) difficulty cooling that may be related to air pockets in the cooling jacket?
What about engine mounting? How do you grab the engine block? Have you looked at the stresses at the attach points?
I’m also considering a constant speed prop. Tracy Crook advises me that his PSRU will accept only electrically adjustable props and I have identified IVO and MT as possible suppliers. Are there other electrically adjustable props in this
power category? Are there other PSRUs that accept a hydraulically actuated prop adjustment?
Thanks in advance for any advice you all can offer.
Gordon C. Alling, Jr., PE
President
acumen
Engineering/Analysis, Inc.
540-786-2200
www.acumen-ea.com