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WAM 120 Flyers Question

D

dlomheim

Well Known Member
For your guys flying behind the WAM120 in RV's it would be fun to see some information of your real world performanc, total costs to install, and any pictures (web sites to go to, etc.). I am finalizing my RV-9A installation with a Mazda 13B rotary and am always anxious to see how others are doing it as far as hanging radiators and fabricating exhaust systems, etc.

Thanks for any info...

Doug Lomheim
RV-9A; 13B FWF
OK City, OK
 
WAM 120 Flier answer

You've probably heard enough from me already, but in case you haven't, here's some "real world" information about mine: 985 lb weight with basic interior. 160 mph TAS at 8,500', about 4.8 gph at 65% power. Starts right up in cold weather (so far I've started at 27F, so not THAT cold, but I live in NV). No mixture, carb heat to deal with, just get in, wait for glow plugs, and start. I like the safety of JetA or diesel in case of fire. I'm using about 1 qt of oil every 12-14 hours. I've got 110 hours on it so far and no hiccups.

The Wilkcsh factory has been super supportive and helpful, and very professional. I like the CI-Log instrumentation with data logger. after every 5-6 flights, I send the data to the factory, which they convert and send back to me as Excel sheet with all engine parameters for every second of the run - very cool.

Another good thing about the engine is that it is all mechanical, requires no electrical power to run.

Downsides: I had to have my exhaust protrude about 8" below the belly of the plane to keep the soot from getting all over the belly. once I extended it, I've had no soot. It smokes a little on take-off and initial climb, until I back off the power, then it cleans right up. I have had several radio calls about the smoke, to which I respond "It's a diesel, it's supposed to smoke!". The factory is working on a different head with a new combustion design to take care of the smoke. Its not a big deal as far as I'm concerned.

Installation was fairly straightforward. WAM provided the engine/gear mount, made by the same guy who makes them for Van's and it fit perfectly. I used a Rotary Cowl from James Aircraft, which I modified somewhat to work with the WAM. There are some pictures of my installation on other threads, but if you would like, I could try to post more.

Engine cooling was not a problem from the beginning. I mounted my radiator just behind the engine, down low, with a plenum carrying air from the front scoop, around the head/oil sump. I did have to tinker with the intercooler in order to get the air chest temps right, since they were a bit high at first. But once I got the right size intercooler for my installation, and got enough air to it, I've had no problems, even taking off at 110F ambient.

I'm real happy with my WAM 120 so far. If there are any other questions, just let me know.
Kurt
 
WAM install cost

I forgot to include my costs. With the engine, mount, MT CS prop (like $9K!), cowling, radiators (the engine came with them, but I had new ones made to fit my cooling system), I figure I've got $33-36K invested. Plus my time, of course, which isn't worth much, according to my wife!
Kurt
 
There are 2 or 3 flying in the UK on -9s. If you can lay your hands on them, there are a couple of good articles in the LAA magazine. The latest from a couple of months ago entailed a re-design of the cowl and coolers which netted a really worthwhile drag reduction and fuel flow improvement - not to mention a seriously cool looking cowl.
 
WAM RV9's in UK

Paul, there are actually 5 WAM 9A's flying in the UK, with a 6th one almost ready. Could you let me know which month LAA magazine to find the article you mention? Or the name of the owner / builder? I can't seem to find it. If someone's found a way to reduce cooling drag, I'd really like to see it.
Kurt
 
G-CETP RV-9A

I'd pretty much like to echo Kurt's comments with our RV-9A / WAM-120 installation. We cruise at 120kts / 138 mph IAS and that IAS is pretty constant with altitude. We use 16 lts / hour (4.23 gal/hr), that's total fuel consumption divided by total airborne hours. We have a little smoke on take-off and one of the jobs on our "to do" list is extending the exhaust pipe to get the black stripe off the belly.

It's hard doing an "apples for apples" comparison of FWF prices because you end up taking a load of stuff out of the finish kit etc etc, but the engine is a similar price to a lyc or equivalent, and there's not a lot of hidden extras. The only big extra cost is that the engine drives you to an MT VP prop. What we do know know is that our finished 'plane weighs a little less than similar 9A's and cost us about the same to build as other 9's with a new engine and VP prop.

Installing the engine would have been a dream if only we'd been able to buy a cowl. We made our own plug, mould and cowl & we're pretty happy with it, but it took a lot of time & effort. We used the Wilksch "chin mounted" radiator so we bought the engine with the cooling system ready plumbed. It's a bit more draggy than Kurt's installation, but offers a simpler installation.

What really makes the WAM engine great in UK is the fuel cost. We burn 16 lts/hr of Jet A1 at ?0.67/lt or say ?11 / hr for fuel cost. If we had a Lyc we'd probably be doing say 25 lts/hr at ?1.47/lt or ?36.75 / hr. Although fuel cost isn't the only cost in owning an aeroplane it's the only one you have much control over and at ?11 an hour we just go out & fly!

Dave

 
Fabbing a cowling

Doug

We never considered it - Mostly because we weren't aware of it. A second issue would be that there are none in the UK we could take a look at so at the time we made our cowl (2006/7) we'd have had no way of knowing whether the engine fitted in a James cowl. In fact at that time nobody was flying a 9 with a Wilksch engine so there was no established cowl design to follow. We felt it would be prudent & simpler to use the Wilksch cooling pack & take an aerodynamic hit rather than pioneer a whole new cooling layout.

Dave
 
dlomheim said:
Dave:

Did you ever consider going with a Sam James "alternative" cowling vs. fabbing your own? I am using that on my RV-9A (w/Mazda 13B) and am slinging my radiators under the engine...

http://www.jamesaircraft.com/Alternate_Use_Cowl.html

Doug
Click to expand...

That's exactly the cowling I used on my WAM 120. I had to modify it a little, but I'm sure that was a whole lot easier than starting from scratch. Because the engine sump hangs pretty low, it takes up much of the lower "scoop" area. I mounted my radiator behind the sump and made a split duct to carry cooling air from the inlet, around both sides of the head/sump, then through the radiator. I believe that with additional modifications, the same cowling could be used with the stock WAM chin mounted coolers.

If anyone else chooses to use the James cowling with a WAM installation, I would be happy to send a few sketches and photos showing how I modified mine. Or I could share my ideas on how to modify the James cowling for use with the stock WAM cooler arrangement.

I now have 125 hours on my plane, with excellent service so far.
Kurt
 
James Alternative Cowling

Kurt:

Do have any pictures you can share of you FWF installation and James Cowling duct work?

Thanks.

dl
 
Real World Numbers

Sam Lucas followed our intercooler/radiators set up, in fact I got them frabricated for him. Sam and I spent a couple of days taking a mould off our cowl, which complely messed up ours, but no problem as I regarded it as bing experimental anyway.

In the Uk we tend to fly lower than you guys in the US, generally below 3k.... hey its a small country!!

We cruise at 140mph at 2100 rpm, about 4.5 uk gallons an hour. WOT gives 160mph plus.

I am working on a new cowl which I hope will reduce drag a bit more, I would like to get 150 at 2100.

Kurt has done a great job on his aeroplane but has the advantage of extra space taken up by our nose gear in which he was able to relocate his coolant rad. WE should have built a taildragger!!!

Here is my blogspot which has some detail of the RV9 cowl, I will try to post FWF shots tomorrow. http://aerobuilder.blogspot.com/
 
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