Info needed for Rotec radial install in Model 4

[Lynn Matteson]

I bit the bullet, and am installing an R2800 radial in my Model 4. The Jabiru finally gave it up last Saturday, and I'm going the round motor route this time. I sent out an email to Joe Meyers, just now, and figured I'd mention it here as well.

Lynn Matteson

[avidflyer]

Hi Lynn, can't help on the radial install, but am curious what happened to the Jabiru? Jim Chuk

[Lynn Matteson]

Hi Jim-
I was hoping someone would ask...quite a story.

Myself and a friend (Fred) lifted off at 7:40am and by 7:51am we were stopped in a hay field...all of 11 minutes for the flight. We were headed to Sturgis, Michigan for a fly-in b'fast, and had just started to settle in for the roughly 1-hour flight, when I was setting the red knob for LOP operation, and the engine started to pop and bang. I'd never had this response from the engine in the previous 1100 hours of LOP operation, so this came as a surprise. Before anybody thinks this was a result of LOP, it wasn't...an exhaust valve head had popped off, it turned out, and then the racket started. About 6 seconds after the noise started, it got very quiet...I was busy looking down at my retract pressure gauges, as I had the floats on, and the wheels were up at the time. Fred said "There goes the prop!" I got the wheels down, and started looking for a field to land in...we were in farm country, and there was a slightly undulating field ahead and below, and I slipped it down, avoiding the first dip in the "runway" and greased it in just like I knew what I was doing. :) A close-by neighbor came over and helped us fold the wings back and drain the fuel tanks. During this operation, a Sheriff deputy arrived, and asked if we were ok, and of course we were. He left to follow up on the props' whereabouts, but didn't come up with anything but an address where we later inquired about it. I called my flight instructor, who called in help in the form of two guys and a trailer, and while Fred and I were heading back home to get stuff, they had the plane loaded on the trailer, we secured the wings, and headed for home. All in all, the whole ordeal took just around 5 hours from lift-off to having it back in the hangar.
When the engine finally seized from the piston hammering on the valve head, the prop flange bolts...all six of them...sheared off due to the inertia of the spinning prop...all six, cleanly sheared off.
Looking at the engine when I got home, I noticed that the starter looked like it was cocked up. Then I saw the bulge in the crankcase half. The force of the internal damage had bent the rod up to where it pushed a portion of the crankcase up, tearing a hole in the 'case. Taking the head off, I saw that the con rod was bent nearly 180 degrees...enough that the pin end was laying right over one of the two rod bolts. The piston pin was split end-for-end, and I found one piece laying in the cylinder bore, along with chunks of the piston. I later found another long piece of pin in the exhaust megaphone. I haven't found the rest of the piston pin yet...probably in the pan.
No word yet on the prop, but we visited the folks who saw the plane coming down and saw the prop go off on it's own flight plan. They said they'd look for it, a I posted a $100 reward if they can find it...another object for my man cave. :)
The man who came over to help shot a video, and sent it in the local channel 10 news, and it was on the air within a few hours of the incident. Oh, by the way, we were at 1100 feet agl at the time of the failure.

Lynn

[Esser]

Glad you are safe and sound Lynn. Any communication with Jabiru?

[Lynn Matteson]

Not much point in talking to Jabiru, as I've got 1698 hours on the engine, and this is WAY beyond the point where any help would be forthcoming from them. I'm just going to chalk this up to experience, and move on. Hell, they were of no help when I broke a timing gear at 500-some hours.
Lynn

[avidflyer]

Glad things went well for you Lynn with the engine out. At least you have a plane to hang an engine on to. I'll bet a 80 HP 912 would do wonders on you Fox, but that of course is up to you. Jim Chuk

[DesertFox4]

Great save Lynn.

Best of luck on the Rotec install.
Here is some visual insperation.

11366

[efwd]

Yeh, Thanks Desertfox4. Man, the Kitfox never looks better than when a Rotec is up front. Im jealous Lynn. Glad to hear your safe. The Kitfox with the Rotec on the Kitfox website is what provoked my Kitfox purchase however Im trying to keep it inside the LSA parameters so Im spending more but going Rotax 912is. I wish the Rotec were lighter. I know I will be doing a lot of solo flying but I would certainly be over 1320# with someone along for the ride and that beautiful engine up front.
Eddie

[Lynn Matteson]

Glad things went well for you Lynn with the engine out. At least you have a plane to hang an engine on to. I'll bet a 80 HP 912 would do wonders on you Fox, but that of course is up to you. Jim Chuk

Thanks, Jim...I've just never been a big fan of the Rotax...too many horror stories of shaking, carbs falling off, radiator placement, etc., when I first got into Kitfoxes. I know there are thousands of them flying all over the world, but once I got "a bad taste in my mouth" it was hard to let go of that notion.
And I really didn't like the notion of a high-revving engine with a geared prop...so what do I do, but order the Rotec radial, with a moderate speed engine and a geared prop...go figure. :)

Lynn

[Lynn Matteson]

[QUOTE=DesertFox4;58221]Great save Lynn.

Best of luck on the Rotec install.
Here is some visual insperation.

Thanks...what I'm looking for is engine mount dimensions for the Model 4. I live about 4 miles from an under-construction Model 7, with a Rotec 2800. But the mount dimensions are different between the 4 and the 7, and I'm not sure just how much stuff will get in the way down near the footwells. I could tell the mount-maker to space the engine out a bit, but that's not a good approach from a CG point of view. Also, I'm not sure how low to mount the engine from a thrust-line point of view. Was hoping to hear from somebody who has a Model 4, like Joe Meyers. Maybe I need to give John McBean a call, and ask if he has any advice.

Lynn

[cubtractor]

Glad you got down safe Lynn. The radial will be awesome.

[avidflyer]

I have no experience with the radial engine. Was just emailing back and forth a week or so ago about someone who wanted to put a radial on their Kitfox. That prompted me to go look at some videos on utube of the radial in Kitfoxes. Just out of curiosity I counted how many seconds it took to get off the ground in these videos, and some were around 12 seconds. That did not seem impressive to me at all. I don't know the what the weight or density altitude was and that would make lots of difference, but I was surprised it didn't do better. One video is the Kitfox factory plane when it had the radial on the nose. Wonder what the John Mcbean's comments would be. Great sound no doubt, I wonder about the performance. Aren't they supposed to be making 130 HP? Not trying to sound critical, I was just surprised by what I saw. If you're flying floats, all the more reason to be concerned about takeoff performance. Jim Chuk
https://www.youtube.com/watch?v=97dO-pq03Qs
https://www.youtube.com/watch?v=TL1kVB7e7FE

PS did a bit more checking and see there is a 110 HP model radial engine. That is probably what is being used on these planes. I looked here:
http://www.rotecradialengines.com/0RotecR2800/R2800.htm
it says the engine is 224 lbs dry (almost 100 more than the Jabiru) fuel burn is 5.82 gph, although it doesn't say what the rpm is for that fuel burn. Again I'll say this, I'm not trying to bash this engine, just mentioning what I found out. YMMV

[DesertFox4]

Lynn, Kitfox Aircraft has the firewall forward kit that might save you time and money even if it is for the model 7. You will need longer gear to have enough clearance to swing a big enough prop to put that 130 hp to use. Battery goes in the tail and I beleive the wings were swung forward for C. of G. considerations on Bill's model 4 in the photo I posted.
Go back and look at the Kitfox of the Month for June 2010 " Little Red". Bill may have been the first to go through this process.
11374

As to performance, I was the one taking the video in the 2nd youtube video that Jim posted. You do not firewall this engine like you might a Rotax. It has a fair amount more torque and on those longer gear P factor is prevalent. I counted 8 to 9 secounds and Bill was very easy on throttle application. I know that engine will set you back in the seat even with a smooth steady roll in of power more than my 100 hp. Rotax could acheive. Climb out was evey bit as good as my 912 uls or better with two guys and full fuel. I think Rotec is right on with their 130 hp claim.

Be aware Lynn that this engine is no jump in the Kitfox and hit the starter go fly kind of engine. It is a real radial requiring all the fussing that those engines demand. Draining oil from the bottom cylinders is an unavoidable routine start up necessity. It marks it's territory everywhere it sits for any period of time.:)
Best of luck with the project.

[Danzer1]

Okay, I'm going to chime in here. Like Jim and many others, I have been on a quest for finding alternate engine choices.

I will preface this by stating:I am a proponent of documentation of claimed performance (dyno charts) and abhor anecdotal and hearsay claims. I also could care less about HP numbers, but do care where peak torque occurs and what the rest of the torque curve looks like. I also care about fuel consumption and total weight.

I to was enamored with the sexy round radial look and in 2013 investigated the R2800 as far as I could. Jim is spot on with weight - it is a heavy engine!

In my quest, I contacted the factory and asked for a copy of the dyno test results so I could see for myself the HP/Torque curve and associated fuel burn.

In response, I got a lengthy email from the owner, pretty much touting all the testimonials by users, that can all be found on their website. Which by the way hasn't been updated since 2014. I did however glean a few "facts" from him. I say "facts" in quotes as he refused to share any dyno charts. He did state though, they dyno'd it once in 1999.

He stated: it produces "110 HP at 3600 rpm" which equates to 160 Lb.ft. of torque at the engine with a 3/2 reduction or 240 Lb.ft. at the prop. Pretty good!

However, he stated, "it consumes 32 liters/hr" doing it (WOT) with the Rotec TBI (optional). That's a hair under 8.5 gph - not so hot!

The only other "fact" I could glean was that he says it consumes "around 20 liters/hr at cruise" (again with the Rotec TBI). He did not state the power level or rpm that occurred at, but that still equates to 5.28 gph - also not so hot.

Besides that info, what turned me off was:

If the engine performs as claimed, why not share the dyno results?

His 2nd to last paragraph asked if I was ready to put down a 20% deposit and asked for me to do so at the upcoming Copperstate Fly-in. Kind of presumptuous seeings he wouldn't provide any hard documentation!

And lastly, his last paragraph killed it for me. He referred to the additional 6 pdf testimonials he attached to the email and stated (and I quote): "if there is still not enough evidence here to convince you to buy our R2800 engine, then I hate to say it, but you ain’t ever buying a Rotec!"

Well guess what? I guess I "ain't"!

Cheers, Greg FWIW

[DesertFox4]

In my previous post I typed 130 hp when it should be 110 for the 2800.
Apologies for not catching that. :o

[Lynn Matteson]

[QUOTE=DesertFox4;58221]Great save Lynn.


Thanks.....I used to hear that all the time when playing goalie on an ice hockey team....now I hear it too often while flying....:)


Best of luck on the Rotec install.
Here is some visual insperation.

[jmodguy]

Lynn
Go for it! There will always be naysayers and some that say this or that. It is known that the Kitfox will fly with the radial. That should be enough. If you like the sound of a radial then go for it! I was considering a Rotec until I decided on an IO-340. Got some negative feedback here and then Kitfox posted some pretty neat info on their website... An O-340 on a Kitfox SS.
Hmmmm :rolleyes:
DO IT! I triple dog dare you!!
Jeff

[HighWing]

Lynn,
I do remember the olden days. I think you have proven that you can make things work. I'd just say - Go for it.
Lowell

[Dave S]

Lynn........ Highwing's comment "I do remember the olden days." came back to rest on my shoulders today as my wife and I got back to the home 'port with our Kitfox to find some radial powered warbirds (AT-6's) practicing up for their July 4th formation and overflights & smoke they do in conjunction with our liberty celebrations. Had to stick around and watch & listen...particularily thinking about how these engines powered the many craft which had a lot to do with why we celebrate our days of patriotism such as this weekend.

There really is nothing like the sound & fire of these engines starting up and taking off. I'll agree....it's a lot of nostalgia mixed with testosterone poisoning that really thrills a person at the sound of a radial. I don't have one but am grateful for those who do.

You know.....as a group, we are really about trying things and experimenting with what strikes our fancy; and thank heavens we don't all do the same thing:) That's what keeps it interesting.

There is grace, gratitude and satisfaction in persuing our dreams and I seriously doubt that any of us would rest on our deathbed when we are 110 years and say: "gee I wish I hadn't built the plane I always wanted" - not gonna happen.

Persue you dreams....:)

[Lynn Matteson]

Lynn
Go for it! There will always be naysayers and some that say this or that. It is known that the Kitfox will fly with the radial. That should be enough. If you like the sound of a radial then go for it! I was considering a Rotec until I decided on an IO-340. Got some negative feedback here and then Kitfox posted some pretty neat info on their website... An O-340 on a Kitfox SS.
Hmmmm :rolleyes:
DO IT! I triple dog dare you!!
Jeff

I've got plenty of naysayers around here, but that just spurs me onward.
I'll take that triple dog dare...now where's that frozen flagpole? : )

Lynn

[Lynn Matteson]

Lynn,
I do remember the olden days. I think you have proven that you can make things work. I'd just say - Go for it.
Lowell

Hi Lowell-
The last time I took on a challange, it was the floats....and they sort of worked (if I could have got the flight instructor out of the plane, they would have worked better :) )
Now this idea has been proven so I have no doubt that the radial will be lots of fun to play with.

Lynn

[Lynn Matteson]

Lynn........ Highwing's comment "I do remember the olden days." came back to rest on my shoulders today as my wife and I got back to the home 'port with our Kitfox to find some radial powered warbirds (AT-6's) practicing up for their July 4th formation and overflights & smoke they do in conjunction with our liberty celebrations. Had to stick around and watch & listen...particularily thinking about how these engines powered the many craft which had a lot to do with why we celebrate our days of patriotism such as this weekend.

There really is nothing like the sound & fire of these engines starting up and taking off. I'll agree....it's a lot of nostalgia mixed with testosterone poisoning that really thrills a person at the sound of a radial. I don't have one but am grateful for those who do.

You know.....as a group, we are really about trying things and experimenting with what strikes our fancy; and thank heavens we don't all do the same thing:) That's what keeps it interesting.

There is grace, gratitude and satisfaction in persuing our dreams and I seriously doubt that any of us would rest on our deathbed when we are 110 years and say: "gee I wish I hadn't built the plane I always wanted" - not gonna happen.

Persue you dreams....:)

One of the sad things about "lunching" ny engine is that I can't take part in the local fly-overs celebrating the holiday.

Yes I agree...leave no stone unturned, even the heavy ones. : )

Lynn

[efwd]

Just curious....how does one address the need for a forward sweep that's needed when putting the heavier engine up front. My manuals says I had to decide on the engine type before I set up for drilling the spar where it connects to the airframe. I assumed I could never go to a continental or Lycoming after I've set up the wing for the lighter engines.

[DesertFox4]

Lynn, I just talked breifly with Bill Prokes (builder of the model 4 photo that I posted as "inspiration").
Bill said he designed the motor mount for his model 4 and sent Paul at Rotec the drawings. He mentioned Paul made the motor mount and Bill said he did a great job.
If I recall, Paul mounted a radial on a model 3 he was building.

[Lynn Matteson]

Just curious....how does one address the need for a forward sweep that's needed when putting the heavier engine up front. My manuals says I had to decide on the engine type before I set up for drilling the spar where it connects to the airframe. I assumed I could never go to a continental or Lycoming after I've set up the wing for the lighter engines.

In my case, the plane was already flying, so if I have to sweep the wings, I'll drill off the original tabs that are attached to the wing spar, make new ones, and transfer the spar rivet holes to the new tabs, then sneak up on the 5/16" clevis pin holes, after establishing the new wing location. Then, the butt rib must be made to assume the new angle of the root rib...again, the present rivets will need to be drilled out and new hole locations made. At least this is how I envision the job. But I'm wondering if this sweep is really necessary.

Lynn

[Esser]

I don't think you need to...

http://www.teamkitfox.com/Forums/showthread.php?t=6556

[Lynn Matteson]

Lynn, I just talked breifly with Bill Prokes (builder of the model 4 photo that I posted as "inspiration").
Bill said he designed the motor mount for his model 4 and sent Paul at Rotec the drawings. He mentioned Paul made the motor mount and Bill said he did a great job.
If I recall, Paul mounted a radial on a model 3 he was building.

Thanks...I'm having Paul/Rotec make my mount also, but I need the firewall-to-engine dimension to clear an air cleaner. If I already had the engine, I'd design the mount myself, as I have all the dimensions but that one. But Rotec sent me a drawing with blank dimensions, and I filled in all the "blanks" but one. I have asked them to review other Model 4 mounts that they have built, and see what those folks used for the missing dimension.
I have access to a friend's Rotec 2800 and I was able to measure his engine/mount combo, and I think I'm reasonably close to what I will need. Now to wait for them (Rotec) to get back to me...do they observe July 4th over in the land of Oz? : )

Lynn

[Lynn Matteson]

I don't think you need to...

http://www.teamkitfox.com/Forums/showthread.php?t=6556

I hope not. But I just removed two Odyssey PC680 batteries (one was for the Electroair ignition...overkill, but when one battery[probably the main] would go belly up, I'd buy a new one, use it in the ignition position, and switch the present ign. battery to the main location. The thinking was to use the freshest battery in the all-important ignition position, and if the other couldn't start the engine, no big deal, I could always swap 'em back.

All this to say I've got 30 lbs. of battery ready to position over or near the tailwheel if/when the radial engine requires it.

Pretty sure this hasn't much to do with the swept wing topic, but I thought I'd throw it out there.

Lynn