HKS engine conversion

[Mnflyer]

Hi all I converted my Kitfox III from a Rotax 582 to a HKS 700E 2 1/2 years ago I now have 229** hrs on the engine and really like it I would never go back to the 582. I did not have any really problems with the 582 flew it to 297 hrs, but I never truly trusted it, didn't like the semiannual ritual of carb adjusting in the spring and fall but I really disliked the low TBO of 300 hrs.
The HKS has a 800 hr TBO burns 3 gph the preformance is so close to what I was getting with the 582 except for cruise which increased by 5 / 7 mph.
Operating cost for the HKS is 1/2 of that of the 582 about $12.00/hr VS $24.00
for the 582.
An update: HKS Japan says they will announce an increase in the TBO to 1000 hrs later on this year.
** 291 hr TT 9/18/08 GB

[mclayton]

Thanks for the post on your experience with the HKS engine installation. I am rebuilding a Model II badly damaged in an accident. Part of the rebuild will involve replacing the rotax 532 with a 4 cycle engine. For the Model II, it looks to me as though the HKS 700E is the best option out there, in terms of fit, price, and performance.

Could you share your experience with the conversion...that is what help you had, where you got it, where you purchased the engine, how was your experience overall, and so on. Would be greatly appreciated.

[RandyL]

Mnflyer, here's an area where a Photo Album could be very useful to other builders. If you have some pics please consider it. To create an Album first make sure you're logged in (check the upper right corner for your login status). Once you're logged in go to the 'UserCP' (user control panel), click on 'Pictures & Albums' and follow the instructions to start an album for yourself. You can create up to ten albums with 50 pics in each. Upload any size photo, the software will automatically resize it so as to manage server storage space. Once you create an album please let Moderators know so we can add a link to it in Photo Albums directory.

Steve Kellander's albums are a good example, click here to check them out.

Cheers,

[Mnflyer]

Hi mclayton, I got my engine and engine mount from the guys at Lost Hill Aviation in Mo. the conversion requires some modification of the round cowl to make room for the cylinder valve covers. Using the Lost Hill Av. engine mount the carbs are located aft of the cylinders its a close fit but it works, the oil cooler is mounted at the bottom of the firewall. Overall the change out went very good, a number of new instruments are needed 1. the HKS tachometer 2. an oil pressure gauge 3. an oil temp gage 4. dual CHT gauge 5. dual EGT gauge, on my Kitfox I installed a carb air temp gauge as I don't have a carb heat system at the present. I'll be installing and electric carb heat system this winter.
I now have 291 hrs on the engine and the only maintenance has be to change oil & filter every 50 hrs, spark plugs at 246 hrs and two (2) carb mount flanges (there is a Service bulletin on the carb mt flanges) the left flange has cracked on the engine twice the second one was defective and replaced under warranty.
I'll post a few pictures in the albums section.

[mclayton]

Thanks for the reply on your experience with the HKS. It pretty well describes what I suspected would be the case.

You mentioned that your cruise speed had increased. Any ideas on why? Did you change props? Is it due to the flat torque characteristic of the HKS? I am coming to the conclusion that with the HKS, it might not be a bad idea to go to a 68 to 70 inch prop.

[Mnflyer]

Hi Mike, yes I believe the increase in cruise was do to the HKS torque. Originally I used the 66" GSC Tech III prop I used with the 582, but have since changed to a 68" 2 blade Warp Drive Prop. The 2 blade prop is an improvement over the 3 blade GSC. Yes a 68" or 70" prop will work but if going with the Warp Drive square tips then a 2 blade is all the HKS can effectively use.
A 68" 3 blade tapper tip WD would work. Many are using the Power Fin prop with the HKS but I really have no experience with the Power Fin but I understand its an excellent prop and very esay to adjust the pitch setting.
I really believe that an inflight adjustable prop would be very good on the HKS but not the IVO, I tried a 68" 2 blade quick adjust IVO and the performance was the same as the GSC prop and I had hight CHT's with it installed after only 30 min.

[Mnflyer]

Hi, I'm getting about 80 mph IAS at a cruise RPM setting of 5600.

[rawheels]

Gary, did you consider reusing the original 582 mount when you did your conversion? Just wondering if it would be possible, because it looks like it is about the same heigth as the Lost Hill version.

BTW, I finally got someone to answer a phone at Lost Hill. They no longer make engine mounts, and the guy seemed pretty uninterested in even talking about it. No plans or fixtures either.

[Mnflyer]

Hi Ryan, no didn't really consider redoing the 582 mount as I purchased kind of a firewall forward from Lost Springs. I don't rally think it could be done easily but it probably could be used to get measurements tubing sizes etc. The wt of the 582 and the 700E are close to the same mine ended up about 5 /7 lb more when all said and done. Yea I know they kind of just got completely out of the HKS engines and mount business (Lost Spring) too bad they won't pass along / sell the information on the mount.

[rawheels]

It would just be really nice if somehow you could reuse the existing mount with a different plate. However, if it was that easy, I'm sure it would have already been done by now.