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Converting from a hand prop to electric start Varieze


Fleal68

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Greetings,

 

So my Verieze prodject started with a complete airframe but no engine, due to limited funds I ended up with a C85. Previously it was built with an O235 but was taken off from another home builder that just wanted the engine and mount for his project. It was originally built without a starter and was hand propped but for my own safety I went with the sky tech starter. Originally the battery it has is only a small motercycle 12v battery and is not sufficient to crank the engine. Another problem i foresee is the added weaight of the new cables, celinoids, and larger battery.

 

I'm open to any suggestions, or someone who has been there done that to move forward with my project.

 

Other sudgesstions on my project is,

 

Can I use the previous installed poropeler and how do I time it to avoid exhaust ? Also how far does the prop need to be from the trailing edge of the engine upper and lower cowling?

 

Fabricating new exhaust pipes and adding a heat exchanger for carb heat.

 

Trying to match all the OT/OP tachometer CHT/MT sensors or just go with a new engine monitoring system. Which system is best for type design and is sold at a reasonable price.

 

Engine baffles, I have two sets of plans, one plan boxes around the engine and the other is with the plans of the plane. Traditional design.

My airframe does have the P51 scoop intake.

 

Any suggestions are greatly appreciated.

Thanks,

Felipe

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No experience with Variezes myself but I have watched guys hand-prop them quite safely and easily.  I hand-propped a Cozy III/O320 for a while and it wasn't too bad.  The high position of the prop is good for that.  It's just a matter of getting used to your engine, how much to prime it and how much throttle it needs.  Do that with a helper until you get used to it.  I had a chock-on-a-rope that I would use to keep the airplane from rolling as I climbed in, then pull the chock up.

 

I eventually went to a Skytec starter on the Cozy but with a Varieze, I think I'd try hand-propping that little airplane.   A starter requires a bigger battery and solenoids so you add weight there.  Then If you put the battery back near the engine you will likely have to add ballast in the nose--more weight.   Battery in the nose means a long run of copper cable.  

 

You can try the propeller but it will probably overspeed since it was designed for less HP so you have to be careful with the throttle.  Clock it near vertical with the engine at TDC.  The prop only needs to clear the cowls by an inch or so.

 

If you want to use an older engine monitor system.  Used round-dial EGT, CHT and other instruments are everywhere on ebay these days.

http://www.ebay.com/sch/Aviation-Parts-Accessories-/26435/i.html?_dmpt=Motors_Aviation_Parts_Gear&_pcats=6028%2C6000&_rdc=2

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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Thanks for the reply, one idea I've got is to keep the current battery setup and run some short cables to the back seat area and put a jumper jack to jump start it with and hand held battery pack. The starter has its own solonoid , just need to run a wire to a momentary switch in the cockpit somewhat close to the throttle levers. Not sure what amperage those units put out, but should do the trick. Still fabricating the exhaust and connecting the sensors but I'm just trying to get ideas. I actually ran one cable from the front to the back but yeah, that idea is getting too heavy and don't think I can squeeze in the second cable. I'll probably pull it back out and use it to fish in the starter switch cable along with a Hobbs time cable.

 

As far as the prop goes, the original engine was rated 115 hp and the engine I have is only 85 hp. I'm sure the pitch is not going to work but was wondering if I can use it to test run the engine. My clearance should be good on the back section unfortunately my top cowling is making contact with the top spark plugs, so will need to do some modifications to the top. Anyone with a similar situation and figure out a workaround. Let me know.

 

Any other suggestions are greatly appreciated.

Thanks,

Felipe

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those lithium ion booster packs are said to have enough capacity for multiple starts on a big engine and there is some advantage to recharging them where they won't burn your airplane up but i think you are fretting too much about hand-propping a rather small engine. Put your manual primer back near the prop, give it a shot and swing the prop. No big deal. Guys do it one-handed.

 

Not sure 85 hp is enough, though. You will have to ask some Varieze fliers. Join the Canard Aviators group. More Varieze owners there.

 

Cowl mods are pretty easy but making pretty cowl mods is more work.

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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Guys do it one-handed.

 

.... at least they do it one-handed now. LOL

Seriously, Kent's right. Once you have someone show you the proper technique it's pretty easy and a nice skill to acquire.

I do like the Idea of a lightweight starter and one of those anti-gravity batteries.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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