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PostPosted: Tue Jan 12, 2010 11:35 pm
by peter
Hi Guys.....Anyone got a couple of spare nacelles laying around...I've been doing a little testing with 6.5 hp 4 strokes this winter, and I'd like to buy a couple of ser 3 nacelles to mount them on, rather than swap out my rotaxes....The bench test results are real encouraging so far...but I don't want to tie up the rotaxes in case I get a chance to fly off the snow....
Thanks .....Pete

PostPosted: Wed Jan 13, 2010 7:46 pm
by Shannon
Hi Pete, any pics of the engines. What type ? I'm guessing Chi-Com Blue Max's. Year back a guy was talking about powering a Series I with some Honda GX-160's or 200's ? Never heard anything more about it. I recall the guy saying the engines could be lightened somewhat by modifying the case, pull start, muffler..ect.

PostPosted: Thu Jan 14, 2010 2:31 am
by peter
Hi Shannon...You guessed right..the motor I'm working with is a 6.5 hp honda clone...If you go to NR Racing it's the yellow clone package 1, with a honda jet and the fuel pump package only....the prop I'm testing it with is a 31x12...the same size that I'm using on my ser 3....the 185's turn them 5200-5400 tops...I first started testing with a new 6.5 clone...139 bucks from Princess Auto, and by just taking out the gov. only, I was getting 4550 rpm or so....that's about my cruise power showing 42-43 on the Halls...and then by putting on a strait pipe the revs increased to 4800....Just today I got the new racing motor going and after a half hour or so of running, a couple of short shots of full throttle brought the tack up to 5050...didn't hold it full power, but it looks like it is capable of maintaining at least 5000.rpm. I have a couple of 34x12 props ordered from GSC..150ea. Can....the static thrust calculator ( it) shows I should get about 4300 rpm at 8.5 hp giving me 71 lb thrust and an est. flying speed of 48 mph.....This is all quite encouraging, because according to my figures I'll be able to fly quite well, providing the main bearings can stand the load...I'm pretty sure the stock rod and flywheel are up to the far I have put 14 hrs. on the other motor, all at full throttle, and nothing has broke yet....I weighed the little yellow clone...28 lbs. and the prop and hub at the way, the engine will run 1 hr and 25 min. on a full tank ( 3.6 liters ) at full throttle....if these mikuni pumps can lift the fuel out of the main tank, a guy could get quite a piece from home on a full tank ha ha....some P.P. guys in England are experamenting and flying with these beefed up Eggmotor for some interesting entertainment....I'll keep you posted.....Best wishes to all in the New Year....Pete

PostPosted: Fri Jan 15, 2010 10:21 pm
by Chappy
FYI, I've run one of the Chinese made 5.5 hp Robin Subaru clones WOT at full load for over 25 hours (after a one hour break in) with no problem. Seemed to get stronger as it ran. It's attached to a 2" trash pump. I just bought a similar 6.5 hp engine (as in it looks identical) from Horrible Freight on sale for $100! Cheaper than rebuilding a old crummy Tecumseh engine I have. Too bad it weighs over 35 pounds. I would guess mounted up on a nacelle with prop would put it at around 50 pounds...or about twice what a Rotax 185 set-up runs.

With it's peak power atleast 1500 rpm lower than that of the Rotax, it would buy you some additional prop efficiency (but unfortunately a heavier prop).


PostPosted: Fri Jan 15, 2010 11:30 pm
by peter
Hi Chappy...I think I was telling you at the UPAC convention that I was going to see what a 6.5 clone could do...I got my new props today (34x12) and got one mounted on the N R racing engine, and was actually surprised to see the rpm settle down at a bit over 4400....The static thrust calculator says it is producing over 75 lbs thrust which is exellent and about 9.4 hp and around 50mph....I'm going to take it off the stand and take the fan out and I'll weigh it again but I'm sure the prop and motor won't weigh more than 32 lbs.and thats the exhaust too .....It appears the 34x12 prop at 4400 is about 20% more efficient than the bi props Although a lot of guys kind of roll their eyes at these Chinese motors, the karting boys think they are one tough little engine.....It would be nice to think that these motors could be an alternative to the 185's....Chances are I'll be flying down to UPAC this Aug. on honda power...Hope to see you there again Bob.........Cheers Pete ciggi 899

PostPosted: Sat Jan 16, 2010 12:51 pm
by gdewsbury
Pete showing his test stand to Lynn and Lorne.
Looks promising Pete.

PostPosted: Sun Jan 17, 2010 7:27 pm
by Shannon
I've been watching development of these engines for a while now. It's starting to get interesting......

Day before yesterday I was test running a low time 185 on the stand with wood P-tip. Man that sucker was just flat-out getting it at 100% ! Smooth and strong ! Looking at it objectively the 185-P-tip combo is just SUPER SWEET all things considered ! 34lbs complete, super reliable, extremely durable, and good fuel burn too.

PostPosted: Sun Jan 17, 2010 10:37 pm
by peter
Hi Shannon....I'm having an interesting winter so far playing with these motors...I'm familiar with what Jay from Silver lining has been doing, but I wanted to dodge a redrive if possible...what encouraged me most was a site from England that I stumbled upon called Eggmotor...couple of PP guys trying to get airbourn with 6.5 hp clones
I don't have anything against the 185s, in fact mine are now in top bearings and seals, and electronic ign. and have real good power, and likely good now for maybe all the flyin I have left in me, but I think a guy with a crapped out engine looking for an inexpensive alternative, this could be an option....I think 500 bucks would do the engine and put the new prop and hub on it also....this engine will likely run a ptip up to speed too,but I opted to drop the rpm down to the early 4000' will spin a 31x12 at 5050 rpm.
I've not flown with the p tips but I've heard them run and they sure are sweet...the props I have on my rotaxs are 31x12 wood made by John Clark in Tottenham Ont....They are noticably quieter than the bi props and a fair bit more efficient too.
I don't think the weight of the 6.5s is going to be an issue ...the bare motor is 28lbs on the br scale, then the hub and prop and whatever kind of muffler I'm going to put on...I'm getting the engine mounts finished tomorrow...3 or 4 lbs maybe, and then the nacelle what ever it weighs....Don't think it will be over 40lbs hope not anyway....I'll weigh it for sure and let the group know.
My son shot a short clip of the NR Racing motor this morning that he was going to put on utube.....everhill69....that shows the engine might be interested in having a look...............Cheers Pete

PostPosted: Thu Jan 21, 2010 7:04 am
by Shannon
Hi Pete, looks pretty good so far. Holding the weight down and increasing RPM is pretty critical with the project I'd think. Really don't want to end up with the weight of 20hp JPX's with a lot less power. Tyler what do the JPX's weigh and what thrust numbers are you getting ?

One thing I noticed on the GX 200 page was a Tillotson carb. Now that would maybe be the ticket. Could that be used on your clone motor with a V-stack ? ... Code=GGPP5

Also looks as though the motors can be purchased with different degrees of modification to up the horsepower. Would a guy in the end maybe be better off to start with an already modified Genuine Honda. $400 gets a basic modified Honda.

The Package 3 Clones are boasting 12+Hp and 6500rpm are only $450 too. Why not start out with one of these. Is it simply a matter of testing with a cheap engine and later upgrading to the engines with upgrade parts and increased power-revs.

Things have come a long way fast with these engines. Definitely surprising what they can do !

Do you have a link to your thrust calculator ?

PostPosted: Thu Jan 21, 2010 12:49 pm
by JPXman
wow, an optimistic message from shannon about new lazair engines? i knew it was cold in hell lately but didn't know it had frozen over!!!!!!!!!!!

seriously though, if you can't find a nacelle to buy i will loan you one for your testing, just let me know.

My JPX weighs 45 pounds loaded up with nacelle, exhaust and all - it puts out 85-90 pounds of thrust measured by spring scale on groovy test stand daffy built.