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MK4 Engine swap


25 posts in this topic

Posted

Im ready to upgrade the 582. I think it was the Yamaha Apex that got me excited about something different. After tons of research the Yamaha looks better and better, until you add up all the cost. What starts out as a look at this cost effective Rotax 912 replacement, ends up being well it has more HP and is a little lighter. The used 912 market is very attractive, many GOOD  FWF 912's for under 8k. Im working on a deal for a 912 as we speak. The main reason for this post is im looking for the other threads about the 912 swap. What engine mounts and hurtles other have overcome. I try the search engine but i cat get the darn thing to do squat. I know i have seen other document there swap. Please share advice and knowledge gained with your experience.

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Posted (edited)

The Rotax Rick 670 is a viable alternative, and a drop in. I uses the 582 mount and fits like a glove, produces 91 HP and starts and runs great. It costs about $3750 plus your old 582 for a zero time 670.

The whole story:  http://avidfoxflyers.com/index.php?/topic/5734-new-rotax-670-install/

 

Rick's pricing page:  https://rotaxrick.wordpress.com/pricing/

Edited by nlappos

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Posted (edited)

I have a 670 of the appropriate year with the case already machined. It still needs to be overhauled and converted. The 912 im looking at comes with everything but the engine mount and is less the 5k delivered. If the 912 deal does not not pan out i may revisit the 670. Plus my 528 only has 10hr since a Leaf rebuild with everything new, pistons,crank.ect... Hard to bring my self to trading it in for parts.

Edited by aschlem
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Posted

I flew my Kitfox 4 with 80 HP about 3.5 hrs today, and burned right at or just under 4 gph.  Cruise was at 5200 on average or a bit less, speed was 90-95, prop pitched more for climb then cruise.  Didn't burn any oil that I could tell on the stick.  I really am liking the 912.  And another thing is there are more of them for sale all the time, which makes the used price come down.  I would have  a hard time looking elsewhere for an engine.   JImChuk

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Posted

I agree they are plentiful and the price of used one are starting to reflect that. Maybe not the most powerful option but a well proven one. Even the used accessory are becoming affordable. 

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Posted (edited)

I've sure been happy with my 912. You will need to put the battery in the tail, or better yet put a small door and carry some tools way in the back of the plane and save the weight of running big battery cables.. You will need 5-15 LB back there depending on your build. I have a little access cover where I keep 10Lb of weight. If I do a camping cross country trip, I remove the 10Lb because all the baggage for camping ends up making the CG about the same as the weight in the tail.

Of course your build may end up different.

If your made of money, one of those big cool hydraulic spring tail wheels with a giant tire might be just about right to offset the bigger engine too. :-)

Edited by ChrisBolkan

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Posted

Where did you guys get your engine mounts? Were there any special accessories needed? My 912 is on its way...

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Posted

Are you getting the oil tank, voltage regulator, exhaust system , radiator, OIL COOLER, air filters and etc with the engine?  Dual throttle and choke cables work best IMHO AVAILABLE from McFarland or ACS.

You might be able to get a mount from Kitfox. Or have someone local weld one up for you.  The Kitfox and Avid mounts are not that pleasant to use, if I needed a mount I would have somebody build a bed style mount like Zenith uses.

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Posted

Where did you guys get your engine mounts? Were there any special accessories needed? My 912 is on its way...

Kitfox mount will not work on an Avid.  Not without a bunch of remodeling anyway.  Leni made a jig, I think, but it seems he doesn't want to quit his day job to go into the airplane supply business.  Wise man most likely!  JImChuk

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Posted

Yes, it is coming with the oil tank, voltage regulator, exhaust system , radiator, OIL COOLER, air filters and etc. The exhaust is for a pusher unfortunately. Why the bed type?

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Posted (edited)

I like them because they are less complicated and if properly designed easier to get the hoses threaded around.  The ring mount would be my second choice if you find a used one but then you still have to build a mount for that.  Once again this is just what I Would do, not necessarily the best way for everyone, just my own personal bias. I have a friend that built one, I’ll see if I have a picture. 

5B556835-2F2F-4DAF-B6F4-F3E5F06C97B6.jpeg

Edited by wypaul
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Posted (edited)

Paul,  I wonder how you get the muffler on with that style mount.  I would like to see the finished product all set up.   Not saying you can't, just wondering how you do!  JImChuk

PS  I just looked, and there is a ring mount for $370 including shipping.  It's from Israel, but he does sell stuff on ebay all the time.  Probably stuff from their drone program   ROTAX 912 914 ENGINE ORIGINAL886-561 SUSPENSION FRAME. | eBay

Edited by 1avidflyer

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Posted

I believe he has the exhaust on it now, if I get out to his hangar (another airport) I’ll snap a picture.  This is obviously not a KF OR Avid.  I think I have a picture of the Zenith Cruzer mount I will add to this post.  Oops a Long Ear Bat resting for the winter here in a Wyoming cave.

The muffler is just in view in the Cruzer mount.

1008B520-1ED1-4A1C-BDBA-59B1E7B53879.jpeg

C856EF10-4464-4085-A442-0366A5A13255.jpeg

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Posted

The 582 is purring and flying season is here. I start planning the swap every time i look at the 912. I still need a exhaust system. Maybe i can modify the dual can pusher setup it come with. I have a rotax suspension ring to build from but i don't want to start until i remove the 582 and mount and use them to build the fixture. Im hoping for minimum modification to the cowling. Man its hard to take apart a flying airplane......I know once i get her open this mod will spread like wild fire, new firewall, panel update, ect.. and I have the wing extension kit coming soon also. I guess not flying now is better than freezing my can off huddled in front of a torpedo heater this winter. Like any junkie would say one more flight and i will start.

avid.jpg

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Posted

So it seems like you figured a way to fit in the plane?   How is the plane flying?  As far as looking for an exhaust, maybe run a want add on barnstormers and all the forums you can connect to.  There is one out there for sure, you just have to find it.  JImChuk

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Posted

I sewed a sling seat that does the trick. I would still like more room may try a aluminum seat pan

 

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Posted (edited)

The 582 is purring and flying season is here. I start planning the swap every time i look at the 912. I still need a exhaust system. Maybe i can modify the dual can pusher setup it come with. 

 

The Exhaust system can be a real tough thing to overcome.  If you have a dual exhaust system it could be easy to modify.  (Easy is a relative term)  I used an exhaust from a SeaRay that I modified when I put a 912 on my KitFox.  It never really worked the way I wanted so this year I had some extra Covid time and decided to rebuild the entire exhaust.  I got 450hrs out of the old system but it was basically a straight pipe system.  The secret to the new system is the Ubend pipes I bought off Amazon.ca 

https://www.amazon.ca/gp/product/B000S0I9MS/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1   This is an 1 1/4 pipe and I cut it as necessary to fit in place.  The muffler is also custom built to fit in place because I used a bed mount and had to do something different.  With the dual cans you may be able to build a nice little system.

20210228_110348.jpg

Edited by JustNorm

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Posted (edited)

  As far as looking for an exhaust, maybe run a want add on barnstormers and all the forums you can connect to.  There is one out there for sure, you just have to find it.  JImChuk

Ebay is another place to look.  Also, there is a guy near Chicago, Art Sclorinski or something like that who buys up wrecked planes and parts them out.  If you can connect with him he can maybe give you a heads up if he comes across one as well.  If I run across one of his adds, I'll pass it on to you as well so you can get his contact info.  JImChuk

PS  did a bit of digging and found one of his adds.  I got the Art right....

VIKING 130HP ENGINE • $4,900 • FOR SALE • Complete VIKING 130 HP engine 421hrs TT with exhaust , fuel pumps and computer. • Contact Art Skolinski , - located Naperville, IL United States • Telephone: 630 854-0780 • Posted March 17, 2021 • Show all Ads posted by this Advertiser • Recommend This Ad to a Friend • Email Advertiser • Save to Watchlist • Report This Ad

Edited by 1avidflyer

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Posted

Yes, it is coming with the oil tank, voltage regulator, exhaust system , radiator, OIL COOLER, air filters and etc. The exhaust is for a pusher unfortunately. Why the bed type?

Hey Norm, I was wondering if you still have the "pusher" configuration exhaust? If yes I might be interrested. Can you post a picture?

Thanks

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Posted

No I chopped it up to make the first exhaust I used on the Kitfox.  The new one is much nicer and quieter

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Posted

I sent Art Skolinski a email, waiting on a response. In the mean time i went for another flight. LOL just not ready to take her apart. Maybe this weekend...

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Posted

When I read about header fabrication some keep all the pipes the same length, Rotax and others don't seem to worry about this with the 912. Any thought why? Vetterman and other do it and keep it under the cowling. Is the juice worth the squeeze?

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Posted

I wouldn't pull the plane apart till you have everything you need in hand.  Sure enough, you will be waiting for some part, and wishing you could fly.   And as far as the exhaust pipes being the same length, maybe that is more important when the four pipes go into a collector that connects to one pipe.  On the rotax, they go into a large muffler.  And it seems to work pretty good on thousands of 912s.  JImChuk

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Posted

No worries i put 3hr on it since i said it was time for the swap. I have my eye on another project, may have to keep this one flying for now.

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Posted

No worries i put 3hr on it since i said it was time for the swap. I have my eye on another project may have to keep flying for now.

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