EF

Would appreciate your experience on some questions, as I have no experience with gas power:

1) The manual indicates a 17-8 as a most suitable prop.
I am thinking of using it on a CW Cub, so would an 18-6 be more suitable and still load the engine in the same way?

2) How powerful is this engine, compared to a glow egnine? what displacement glow engine would have similar power?

3) Would this engine suit a Sig 1/4 scale CW Cub? or should I use the 26EI? (significantly more expensive than the 20, where I am)

Thanks!

Zippi

My Feedback: (10)

EF,

The G20/EI would be more suited for a Prop in the 14 x 6 through 16 x 6 range, Benchmark Prop: APC 15 X 6 9500 rpm by Horizon Hobbies. I run the G26/EI and I run a 17X6 through 18x6 prop, 16X8 is good as well. The G26 is comparable to a 180 4 stroke so the G20 should be around the 150 4 stroke range I would think. I think I would use the G26 as it would be more useful down the road when it comes time to look for another plane. You always go bigger .

EF

Thanks! do you happen to know if the 20 and 26 have the same mounting holes?

Zippi

My Feedback: (10)

That I don't know. I've never had a G20.

Smacka

The Zenoah 20EI and 26EI have the same size mounting holes (4.2mm = ~0.1653-inches), however, they are not the same bolt hole pattern. I have listed the bolt hole centerline to centerline patterns below:

20EI = 70mm width x 50mm tall...divided by 25.4 = ~2.755-inches x ~1.968-inches

26EI = 94mm width x 62mm tall...divided by 25.4 = ~3.700-inches x ~2.440-inches

Match the bore and stroke below with a nitro engine and you have your other answer(s) BUT there will be a difference of power from nitro to gas, so it is only an approximation. Should be enough info to make the comparison that you are looking to make.

20EI
Bore = Diameter 32mm (~1.259-inches)
Stroke = 25mm (~0.9842-inches)
Displacement = 20.1 cm3 (~1.2265 in3)

26EI
Bore = Diameter 34mm (~1.338-inches)
Stroke = 28mm (~1.1023-inches)
Displacement = 25.4 cm3 (~1.550 in3)

Max Power (kW/rpm) and Max Torque (N m/rpm) is not shared by Zenoah.

Lastly, using an 18-inch range prop is okay with the 26EI BUT not with the 20EI. Use a 16x6 with the 20EI. Like Zip said, the benchmark prop is 15-inch range.

Hope this helps!

karolh

The G20 would make an ideal powerplant for the Sig 1/4 scale Clipped Wing Cub spinning a 16x6, 16x8 or 17x6 prop.

Karol

EF

Thanks, Karol do you fly this combination and if so are there any special characteristics to watch out for?

karolh

No I do not, but have been told that together they make a good combo.

Karol

rogue-RCU

My Feedback: (2)

I have a G20 on a 1/4 scale hanger nine cub and it is one of the best gas engines that I have ever had . Plenty of power for the bird. I am also using an evolution 16-8 prop on it. That combo works out great. This engine runs great right out of the box.

EF

Thanks Robert!
What size ignition battery are you using?
Did you consider a 6 pitch prop for the Cub? I thought maybe this kind of model would need a lower pitch higher dia. prop?
I am seriously thinking of choosing this engine.

rogue-RCU

My Feedback: (2)

I have a 2400mah nicad jr battery 4.8 volts. The kit came with a 16 oz tank. I usually fill it up one time while flying . It will fly 30 minutes on 16 ozs of fuel. The prop I use works great.

BsSmith

How much does this engine weigh?

Smacka

Total Weight:41.6 oz with muffler, ignition and mount
Engine (Only) Weight:33 oz

karolh

To keep the AUW to a minimum I use an 8 oz tank which gives approx. 20 mins of run time and Cermark's SPE 26 lightweight muffler which weighs only 2 ozs., yet gives quite an increase in rpm over the stock muffler.

Karol

EF

Where do you install the electronic ignition unit? is it OK under the cowl?
I read the manual and it mentions the unit can get very hot.

I've never used a gas engine, only methanol engines...hence all the questions.

Are there any radio interference issues (I use a Sanwa RD6000 Super)? or if following the manual I can rest assured that if ground range checks are OK I should not have any surprises?

Smacka

Yes, you can mount the iginition unit under the cowl (attached to the side or bottom of the engine box). There "can" be RF issues if you do not follow the manual. Do not have the iginition unit anywhere near the receiver. Keep a distance from the throttle servo, and do not have a metal to metal connection between the throttle servo arm and the engines throttle. It will act like an antenna and RF will travel down the push rod and into the throttle servo and cause problems.

Yes, by all means follow the manual for this engine...