Quantcast

440CC Honda clone , anyone using any of the big singles for Ultra light?

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

sigrana

Well-Known Member
Joined
Oct 19, 2010
Messages
63
Location
Australia
Ahh, but the Duromax aren't a Chinese company making clones. They are an American company making clones.

Don't believe what you read until you do your own research.

Extracted from the XP18 manual:

Rated Power (KW/rpm)
9.0 kW (18.0 HP) @ 3600 rpm
Compress ratio 8.5 : 1
Max Torque
19.55 ft. lb. @ 2500 rpm

Now, max torque is quoted as 19.55 ftlb. If it still had that much torque at 3600rpm, it would have 13.4hp...
9 KW = 12 HP . Who is stupid enough to believe the given specifications? I would NEVER put one of those engines on any vehicle and certainly not on any aircraft.
 

Protech Racing

Well-Known Member
Joined
Jul 10, 2020
Messages
184
I started the thread knowing that these engines are on planes and air boats. Thinking that someone would share a prep template. As it appears that the guys actually flying them dont visit this site. Probably too busy flying . The result is a lot of conjecture about how bad this idea is ,based on desk top calculations and no real world experience.

FWIW using more RPM will result is lower operating temps at the same power level. More cool Air in , less cylinder pressure per revolution etc. The redrive allows this. Direct drive may work OK at reduced power output. Ilike the 103 planes and the direct drive is less optimal for slow flight. None of these engines are designed to have a large Gyro hanging off one end or the other.
I like electric start. I will keep some sort of flywheel to accommodate it and some charging system .
My time frame is about one year . I will start with the best deal i can find on either the big single or the baby twin. The twin shows really nice on the front of an old AC tho.
I can direct load my dyno load cell for reference against a known good value . That may be the Hirth 389 @ 30HP or the Cuyuna 430 @ 37HP.

For the guy inverting his engine . really nice research BTW. Most inverted engine struggle to control the oil ring drain. The oil is supposed to drain from the bottom of the piston. Inverted makes it very hard to get rid of the oil. You will need a large drysump pump to vacuum the case, or the oil burn will be too much to tolerate.IMHO. Thats one reason why the big radials burn oil .
 

Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,378
Location
AMES, IA USA
I started the thread knowing that these engines are on planes and air boats. Thinking that someone would share a prep template. As it appears that the guys actually flying them dont visit this site. Probably too busy flying . The result is a lot of conjecture about how bad this idea is ,based on desk top calculations and no real world experience.

FWIW using more RPM will result is lower operating temps at the same power level. More cool Air in , less cylinder pressure per revolution etc. The redrive allows this. Direct drive may work OK at reduced power output. Ilike the 103 planes and the direct drive is less optimal for slow flight. None of these engines are designed to have a large Gyro hanging off one end or the other.
I like electric start. I will keep some sort of flywheel to accommodate it and some charging system .
My time frame is about one year . I will start with the best deal i can find on either the big single or the baby twin. The twin shows really nice on the front of an old AC tho.
I can direct load my dyno load cell for reference against a known good value . That may be the Hirth 389 @ 30HP or the Cuyuna 430 @ 37HP.

For the guy inverting his engine . really nice research BTW. Most inverted engine struggle to control the oil ring drain. The oil is supposed to drain from the bottom of the piston. Inverted makes it very hard to get rid of the oil. You will need a large drysump pump to vacuum the case, or the oil burn will be too much to tolerate.IMHO. Thats one reason why the big radials burn oil .
=========================

There really isn't a need to reinvent the Wheel. Engines for Part 103 probably need to be under 65 lbs Complete ( Motor, Redrive, Exhaust, Electric Start). For the most part that means Singles. Some of the Small Block V Twins 470-627 in Direct Drive could also work. You're never going to appease all the Arm Chair Mechanics, the hate mongers. You have very valuable Data to look at on these Go Kart Sites on what they did to make these engines almost Bullet Proof! Almost all of these Part 103 and Small Kit Planes their MTOW fall into the 540 lbs (32.8hp) to 660 lbs (40.1hp).

Based off the 460 Dyno Sheet 37.37hp@5000rpm, 458cc/37hp = 12.4cc to make 1hp.
Spec's: 34mm Carb, 11.0cr, 307 CAM, 40/32 Valves, K&N, Tuned Header!

Based off the 420 Dyno Sheet 33.4hp@5000rpm, 420cc/33 = 12.7cc
Spec's: 34mm Carb, K&N, Tuned Header!

I would use 12.4cc as a base and make up a chart. Very few Planes will use less than a Honda GX390 (389cc) 389/12.4 = 31.4hp@5000rpm since most Planes need a minimum, 25+hp. 40.1hp being the Max any Part 103 would need, 40.1 x 12.4cc = 497.24cc (500cc) Engine needed.

While you can CUSTOM Build any Engine up to a (100mm x 86.5mm) 679.6cc, it's going to be easier, faster, cheaper, to just upgrade the most common off the shelf Engines, like GX390's 420's, 440's, 460's. Which you can buy at Harbor Freight, Home Depot, Lowes, eBay, Amazon, NH Northern Tool, etc.

Template for All Singles and V Twins:
1. Disable Governor.
2. Disable Low Oil Sensor.
3. Install 34mm Carb for Singles.
3. Install K&N Airfilter.
4. Install Billet Rod.
5. Install Billet Flywheel.
6. Install Tuned Header.
7. Install Hi-Rev kit.
8. Install a Better CAM for peak hp@5000rpm.
9. Mill Head for 11.0cr.
10. Install Billet Needle Bearing Racker Arms.

For more hp.
11. Use Bigger Valves
12. Port & Polish the Heads.

Chart showing Approximate hp@5000rpm upgraded!
CHART.jpg
 

Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,378
Location
AMES, IA USA
9 KW = 12 HP . Who is stupid enough to believe the given specifications? I would NEVER put one of those engines on any vehicle and certainly not on any aircraft.
===============================

Apparently, some People are Smart Enough on how to upgrade these Cheap Engines with HD Racing parts. Stock GX200 is 6.5hp@3600rpm and with some Basic upgrades, 15hp@5000rpm. A Full Race GX200 Engine they can make 26hp.

My thoughts on the Honda Gx200's suitability to re-power the Lazair.
 

sigrana

Well-Known Member
Joined
Oct 19, 2010
Messages
63
Location
Australia
It is yuor and their life, not mine. I have been flying several types of aircraft for over 55 years, including
some of my own designs and construction and I would not touch any of the above engines, expecially not the modified racing version. Remeber, if they stop and you are too low......
 

Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,378
Location
AMES, IA USA
It is yuor and their life, not mine. I have been flying several types of aircraft for over 55 years, including
some of my own designs and construction and I would not touch any of the above engines, expecially not the modified racing version. Remeber, if they stop and you are too low......
======================

It doesn't matter if it's a Certified Airplane Engine, a Converted Auto Engine, a 2 Stroke Engine, or one of these Industrial Honda/Clone Type Engines, they All can Fail without proper Maintenace, and 99% of these Engine Failures is Human related.

Using the HD Racing parts makes them even more Durabil. Using them at 5000rpm to 6000rpm is normal for most 4 Stroke Engines. These Engines were rated at 3600rpm account that is the Industry Standard for running Industrial Tools, like Generators, Cement Mixers, Water Pumps, etc.

The leading causes of Small Commerical made Airplanes and Kitplanes is not Engine Failure, but:
1. Running Out of Gas!
2. Flying in known Bad Weather!
3. Flying with a known Mechanical Defect!

It's about 50/50 between Commerical Small Planes and Kitplanes for Accidents!

Off the FAA Site:
The Top 10 Leading Causes of Fatal General Aviation Accidents 2001-2016:

1. Loss of Control Inflight
2. Controlled Flight Into Terrain
3. System Component Failure – Powerplant
4. Fuel Related
5. Unknown or Undetermined (Carb Icing)
6. System Component Failure – Non-Powerplant
7. Unintended Flight In IMC
8. Midair Collisions
9. Low-Altitude Operations
10. Other
 

n3puppy

Well-Known Member
Joined
Jun 25, 2019
Messages
179
Finally had time to watch the Lazair/GX200 video - AND listen to the real world observations.

Narrator says of motor builder -- "Thinks they make 15hp - I think that may be a little optimistic"
Also says -- "I think about 10% more than the old straight 185's "
So GX200 at 10-10.5hp as flown based on observed performance.

Later narrator says will fly at 4000rpm and hold altitude
The original Lazair flys AND climbs on 11hp (5.5x2)
Seems the GX200s are being operated at about 5hp when throttled back to 4000rpm, so again around 10hp at full power.

GX200 6.5hp bumped to10hp could be viable. ( 35 hours at time of video)
Similar increase to the 440cc units might also be viable. (13 bumped to 20hp)
 
Last edited:

pictsidhe

Well-Known Member
Joined
Jul 15, 2014
Messages
8,812
Location
North Carolina
Those redrives and props will add a healthy amount of thrust. Those Hondas may not be any more hp than 185s. Someone claiming 15hp is unlikely to be an expert tuner. Keeping the stock torque at higher RPM is an accomplishment and would be 9hp.
The big takeaway here is that redriven gx200 work on Lazairs.
 

Protech Racing

Well-Known Member
Joined
Jul 10, 2020
Messages
184
I'm pretty sure that He flew those direct drive to start with. Caught flack for the tiny cranks.
 

wsimpso1

Super Moderator
Staff member
Log Member
Joined
Oct 18, 2003
Messages
7,249
Location
Saline Michigan
Extracted from the XP18 manual:

Rated Power (KW/rpm)
9.0 kW (18.0 HP) @ 3600 rpm
Compress ratio 8.5 : 1
Max Torque
19.55 ft. lb. @ 2500 rpm

Now, max torque is quoted as 19.55 ftlb. If it still had that much torque at 3600rpm, it would have 13.4hp...
One hp is 746 W, 9 kw is 12 hp.
 
Top