Backcountry Pilot • Bought a Zenith CH701 full kit

Bought a Zenith CH701 full kit

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Re: Bought a Zenith CH701 full kit

It's busy with all 'dem numbers
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Re: Bought a Zenith CH701 full kit

S-12Flyer wrote:There is a 701 with a 914 at a private strip close to me. The thing is an elevator. They hang 0-200s and 3300s on the 701's and they are way heavier than a 914. Horsepower is your best friend on high DA days in the backcountry.

Check out this turbo prop on a 701.
http://www.zenithair.com/stolch701/pic1 ... llage1.jpg
Well that's encouraging. I've seen the turboprop but I don't know where you would put enough fuel for more than a flight around the patch. :D
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Re: Bought a Zenith CH701 full kit

Emory Bored wrote:
S-12Flyer wrote:There is a 701 with a 914 at a private strip close to me. The thing is an elevator. They hang 0-200s and 3300s on the 701's and they are way heavier than a 914. Horsepower is your best friend on high DA days in the backcountry.

Check out this turbo prop on a 701.
http://www.zenithair.com/stolch701/pic1 ... llage1.jpg
Well that's encouraging. I've seen the turboprop but I don't know where you would put enough fuel for more than a flight around the patch. :D

Randy has the extra wing tanks in his but he rarely uses them.
That turbo prop in flat black and no markings would sure look stealthy. Oddly enough, several people have done the turbo prop set-up.
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Re: Bought a Zenith CH701 full kit

The firewall, forward fuselage and nosewheel of the 701 was not really meant for the weight of a stock O-200. Something like 240 pounds with the OEM starter and generator. If you really lighten it up, by liberal use of Dr. Seuss' Calculatus Eliminatus, then maybe.

But the handling of a small and light airplane will be seriously affected by the weight, even if you got the weight down to 200 pounds. That is why the CH-750 has a different firewall and forward fuselage than the 701.

If you want light weight and power on a 701, take a tip from our recently lost friend Dirtstrip (who had this airframe/engine combination) and start looking into the Simonini 110HP 2 stroker, with some sort of EFI upgrade for reliability. 52 kilograms (114 lb.) with integral PSRU, starter, electronic ignition, alternator... and 110 HP. The combination of 110HP, geared prop for max acceleration, and 100 pound less empty weight would make this a rocket. Emory Bored once told me he's on the light side, so he could potentially win some free beer off of the nearest Carbon Cub owner :twisted:

The mfg's CLAIM is less than 3 gallons an hour at cruise. So let's chalk up a couple of gallons an hour extra for "brochuremanship", and we still get under 5 gallons an hour. Yeah, I know... it's a 2 stroke. Gotta learn how to operate it, learn it's language, learn how to not piss it off, etc. etc.

http://www.simonini-flying.com/victor2super_eng.htm#
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Re: Bought a Zenith CH701 full kit

EZFlap wrote:The firewall, forward fuselage and nosewheel of the 701 was not really meant for the weight of a stock O-200. Something like 240 pounds with the OEM starter and generator. If you really lighten it up, by liberal use of Dr. Seuss' Calculatus Eliminatus, then maybe.

But the handling of a small and light airplane will be seriously affected by the weight, even if you got the weight down to 200 pounds. That is why the CH-750 has a different firewall and forward fuselage than the 701.

If you want light weight and power on a 701, take a tip from our recently lost friend Dirtstrip (who had this airframe/engine combination) and start looking into the Simonini 110HP 2 stroker, with some sort of EFI upgrade for reliability. 52 kilograms (114 lb.) with integral PSRU, starter, electronic ignition, alternator... and 110 HP. The combination of 110HP, geared prop for max acceleration, and 100 pound less empty weight would make this a rocket. Emory Bored once told me he's on the light side, so he could potentially win some free beer off of the nearest Carbon Cub owner :twisted:

The mfg's CLAIM is less than 3 gallons an hour at cruise. So let's chalk up a couple of gallons an hour extra for "brochuremanship", and we still get under 5 gallons an hour. Yeah, I know... it's a 2 stroke. Gotta learn how to operate it, learn it's language, learn how to not piss it off, etc. etc.

http://www.simonini-flying.com/victor2super_eng.htm#

The 701 is a very draggy aircraft at cruise and the burn rates on Randy's 912ULS are a gallon or more higher than my S-7 at the same speed. To get much more than 75 to 80 mph you have to be fairly heavy into the throttle and that sucks down the fuel no matter what you're spinning up front. Most of the guys I've talked to with smokers in their 701s are not all that thrilled with them.
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Re: Bought a Zenith CH701 full kit

I just got a ch 701 kit that a friend was building but got cancer so I now have it and I am going to finish it. The one change I am going to make is to get rid of the leading edge slats and go with vg's. You increase your cruise and it has better control on STOL performance.
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Re: Bought a Zenith CH701 full kit

Congrats on finding a fun project. Keep us posted on your progress and I'll keep you posted on my efforts to relocate to Port Townsend. I think every airplane requires some fine tuning of the pilot. The important thing is to know the plane you are flying inside and out and fly within the limitations of the plane and your skill level. That combination should give you lots of happy hours in the 701.
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Re: Bought a Zenith CH701 full kit

Congratulations RudderBash. I'm still in the process of creating an airplane factory out of a garage that's full of too much crap. I'm hoping I'll have a clear floor by Thanksgiving and can get going on this thing.

I would encourage you to buy all the CD's available from Homebuilt Help and watch them. They are that good. I bought my kit from a fellow who had already built one from scratch and got the same advice from him. He glanced through the Zenith builder's manual but built his using the plans and the videos. Watch the video concerning your task for tomorrow and then go out to the shop and build that. Then watch the next segment. When you get to the end, stop, and go flying.

EB
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Re: Bought a Zenith CH701 full kit

Congrats on the purchase. I really enjoy flying my Savannah with a 912. Just make sure you have a friend like GroundLooper to carry your cooler for you when you go camping :lol:

How much baggage does the 701 hold? I have a 45lb and 15lb compartment that I've been able to stretch to more like 60lb and 20lb. No problem at sea level, but I did notice a difference in performance taking off from Smiley Creek at 7100' they sell a "belly pod" for the Savannah but Walter at ICP has been a little slow on getting the specs.

GroundLooper wrote:Congrats, EB!

After riding around in a friends Savannah recently, I think you'll be pretty happy with the performance. They don't carry a lot but boy they get off the ground fast and land short. I think you'll find it a to be a great and fun little airplane. Just keep it light on the build as much as possible.

I seriously doubt you'd be disappointed with the 912ULS and the 914 will add weight... you're research may say differently.
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Re: Bought a Zenith CH701 full kit

rudderbash wrote:I just got a ch 701 kit that a friend was building but got cancer so I now have it and I am going to finish it. The one change I am going to make is to get rid of the leading edge slats and go with vg's. You increase your cruise and it has better control on STOL performance.


Congratulations Rudderbash !

Again, IMHO contact John Bolding, he has the correct airfoil templates to use for building the wing without the slats. It is different than just leaving the too-blunt leading edge of the stock wing with slats removed... what you do is build a specific no-slat airfoil.

Have fun building, please let everyone know how you're doing from time to time.
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Re: Bought a Zenith CH701 full kit

I am planning on putting a A-80 Continental. Has anyone heard of any trouble with the extra weight?
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Re: Bought a Zenith CH701 full kit

EZFlap wrote:
rudderbash wrote:I just got a ch 701 kit that a friend was building but got cancer so I now have it and I am going to finish it. The one change I am going to make is to get rid of the leading edge slats and go with vg's. You increase your cruise and it has better control on STOL performance.


Congratulations Rudderbash !

Again, IMHO contact John Bolding, he has the correct airfoil templates to use for building the wing without the slats. It is different than just leaving the too-blunt leading edge of the stock wing with slats removed... what you do is build a specific no-slat airfoil.

Have fun building, please let everyone know how you're doing from time to time.

How do I get a hold of John Bolding and if I buy the wing kit is there changes or do I have to build the wings from scratch?
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Re: Bought a Zenith CH701 full kit

rudderbash wrote:I just got a ch 701 kit that a friend was building but got cancer so I now have it and I am going to finish it. The one change I am going to make is to get rid of the leading edge slats and go with vg's. You increase your cruise and it has better control on STOL performance.


Can I have your slats?? :mrgreen:
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Re: Bought a Zenith CH701 full kit

Find the Australian guy selling the Stolspeed VG's, he has worked with Bolding if I recall.

A stock Continental engine is a bit too heavy for a 701. It has been done several times, but it is far from ideal. I'm guessing the flight handling of the airplane suffers. The CH-750 is designed for a Continental and it has a beefier firewall for a reason. I believe that lightening up the Continental will make it do-able, but this means spending a bit of money.

I recommend the Light Speed Engineering electronic ignition. This costs a few bucks, but makes several improvements. You will get a 10 or 15% improvement in torque and horsepower. You will get a 10-15% reduction in fuel flow. These two things will pay for the ignition. Most importantly you will remove the weights of the magnetos, and will be able to remove the weight of the starter. Using the LSE ignition makes hand starting safer, easier and a lot less effort. This in turn will allow you to use a smaller battery and a much smaller alternator (or even no alternator).

So all of this can easily remove 30 pounds or more from the installed engine weight.

You will also need to forget about a metal prop and go with a wood or composite prop. If you are leaving the airplane as a nosewheel configuration, use a composite prop for sure... Ivo or Whirlwind or whatever is the big thing right now. This can remove another 5 or 10 pounds off the front end.
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Re: Bought a Zenith CH701 full kit

EZFlap wrote:I recommend the Light Speed Engineering electronic ignition. This costs a few bucks, but makes several improvements. You will get a 10 or 15% improvement in torque and horsepower. You will get a 10-15% reduction in fuel flow. These two things will pay for the ignition. Most importantly you will remove the weights of the magnetos, and will be able to remove the weight of the starter. Using the LSE ignition makes hand starting safer, easier and a lot less effort. This in turn will allow you to use a smaller battery and a much smaller alternator (or even no alternator).

Those power numbers sound generous, given the fact that at high power setting the timing difference between mags and EI is nonexistant.... where do they claim the 15% power increase comes from? Is there a non-promotional, independant document which verified that improvement? I have often wondered about that but never taken time to explore it.

I imagine any weight savings are offset by the need for an extra battery and possibly an extra alternator too, depending on your risk appetite. If you want the same redundancy an mags, I can't see how you can avoid duplicate alternators....

Sorry about the diversion from topic! #-o
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Re: Bought a Zenith CH701 full kit

Battson wrote:Those power numbers sound generous, given the fact that at high power setting the timing difference between mags and EI is nonexistant.... where do they claim the 15% power increase comes from? Is there a non-promotional, independant document which verified that improvement? I have often wondered about that but never taken time to explore it.


I do not have any independent study on those numbers. The owner of that company is a friend of mine, I've flown in his airplane with him, and I've seen the trophies he has won with this system in all the efficiency races. I trust him personally, but that of course does not mean that anyone's word is the gospel.
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Re: Bought a Zenith CH701 full kit

I have an A-65 that I am turning into an A-80 so There is no starter or charging system I belive in keeping it simple the engine will only weigh around 175lbs by the time I am done....
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