Needing Help on HKS 700 ENGINE...

[kyle.anderson]

Hi.
I’m Kyle Anderson, Studying Metallurgy and my research is about ultralight weight engines that are used in aerospace applications. As my research continued, HKS 700 series drew my attention (not surprising!) but sadly I didn’t found much on internet. Could you tell me more details about this great engine? My research is more about optimizing ultra-weight engines.
I’m looking forward to your reply

[Jan Olieslagers]

There is very little info about that HKS engine indeed. I suspect its creators regret their sidestep into light aviation and are purposely silent. One doesn't see it on any new designs, to my knowledge.

Allow me to suggest an alternative: an extremely light design, the MC30 Luciole, uses a B&S 4-stroke V-twin. I suspect you'll find better documentation about that engine, including the recommended modifications.

Good luck!

[Colibri49]

One such HKS engine that I know of in the UK has been experiencing problems with loss of compression in one cylinder and I'm told that valve seats receded into the alloy cylinder head. I'm also told that this type of engine doesn't have a happy track record in the UK, but after the manufacturer discontinued its production, there was an outcry in the USA where it is much better liked. Production has resumed after the introduction of modified cylinder heads, so I'm told.


https://en.wikipedia.org/wiki/HKS_700E

[Genghis the Engineer]

I test flew the (first and only) HKS700E engined X'Air. Wonderful was not a term I would have applied - it was basically a 4-stroke Rotax 503 - massively underpowered for the class of aircraft, with complications and extra weight that in my book made it a far less good weight than the 503. To be fair, it was very frugal on fuel, but I can't recall any other redeeming features.

IIRC, the first production HKS engined AX2000 kept blowing up CDI units, until they realised that a common earth through anodised airframe components wasn't conductivey enough for the job and just separately earth strapped everything together.

G

[kyle.anderson]

Thanks for your replies and good suggestions.
I will definitely search about it.

Originally Posted by Colibri49

One such HKS engine that I know of in the UK has been experiencing problems with loss of compression in one cylinder and I'm told that valve seats receded into the alloy cylinder head. I'm also told that this type of engine doesn't have a happy track record in the UK, but after the manufacturer discontinued its production, there was an outcry in the USA where it is much better liked. Production has resumed after the introduction of modified cylinder heads, so I'm told.


https://en.wikipedia.org/wiki/HKS_700E

Could I have more details about the reference of your statement? (One such HKS engine that I know of in the UK has been experiencing problems with loss of compression in one cylinder and I'm told that valve seats receded into the alloy cylinder head)

Originally Posted by Genghis the Engineer

I test flew the (first and only) HKS700E engined X'Air. Wonderful was not a term I would have applied - it was basically a 4-stroke Rotax 503 - massively underpowered for the class of aircraft, with complications and extra weight that in my book made it a far less good weight than the 503. To be fair, it was very frugal on fuel, but I can't recall any other redeeming features.

IIRC, the first production HKS engined AX2000 kept blowing up CDI units, until they realised that a common earth through anodised airframe components wasn't conductivey enough for the job and just separately earth strapped everything together.

G

Do you have any documentation about it?
( the first production HKS engined AX2000 kept blowing up CDI units, until they realised that a common earth through anodised airframe components wasn't conductivey enough for the job and just separately earth strapped everything together.)

[Colibri49]

Kyle. I don't know any more than I have stated already. You would stand as much chance as me of finding more on the internet. Your location is given as Colorida which seems to be in Portugal, but could just as easily be in the USA. If the latter is the case, then you are much closer than I am to better informed people regarding this engine.


The company "Green Sky Adventures" is based at Hawthorne in Florida and they are the agents for HKS 700E engines.


https://en.wikipedia.org/wiki/Green_Sky_Adventures


Good luck with your research and studies.

[Genghis the Engineer]

Not about that, no. I knew the engineer and test pilot managing the project quite well at the time, and this all came to me verbally.

G

[Corey Highsmith]

Torque for the this 700

Anybody know what the torque of the nut on the crank shaft that holds the main gear?

[Heavy Delta]

Do you mean the M10 Bolt that holds the Magneto flywheel and gear in place on the end of the Crankshaft?
This should be 50 kgfm and threadlocked