RCGF "B" Line of Engines

[Al Lewis]

	Quote: Originally Posted by Tired Old Man
	Al, How did they lay out the cylinder ports? I'm suddenly seeing a lot of cylinders with open shaft port designs with ultra sharp short term radii at the top of the ports. Hopefully they haven't taken the 1970's port design route. Every engine maker doing this would realize a sudden and tremendous performance gain if they changed to a closed shaft port and addressed the bend radius. Costs more but gives more.

Pat, Here are a couple of shots of the ports. They are open shaft design but they have obviously taken some time to radius the top edges of the ports and remove the sharp corners, shiny edges. On a side note, I just checked the exhaust port layout and the prop bolt pattern and both are the same as the DA/DL 50s.

[Al Lewis]

Well we took it out of the box, bolted it up, and we ran it and Oh Boy!! I would have to say that this is the smoothest running and idling engine I have tested. If you don't believe that then just watch the video of the engine running. This thing is smooth and has plenty of power. At one point we thought the Hawk 22X10 prop was going to blow the stand over with the gas tank on it. This is definitely a keeper and I can't wait to get it into my Extra!! Keep in mind that this engine is straight out of the box. For $340.00 and free shipping this is definitely the way to go if you have a 30% with a lot of lead in the nose or just want to kick your thrust up for 3D. Judging by the thrust I would say the Hawk 22X10 "A" prop will be on the Extra.

YouTube - RCGF 62cc B Engine First Run

[Super08]

Al what was the rpm with the 22x10? I couldn't make it out.

[Al Lewis]

When I first looked at it it looked to be at 6800 but the sun was making it difficult to read, and video. I can tell you that standing behind it, it was definitely putting out some thrust. I'll do a thrust test once the engine is on the plane. I definitely think the 22X10 is the way to go with this engine.

[MODE 1]

Not being critical just merely stating. The transfer ports look like they've been addresses well at the factory. Doesn't look to be much polishing needed to bring em up to a high spec if needed. I've seen some that looked like they were dragged up and down the freeway a few times. Not sure about the exhaust port though cant see too well but then the intake and exhausts ports are always easily accessible.

6800 should go to 7000+ after a few gallons. Looks like a winner there Al

Pete

[Al Lewis]

I agree Pete. Once the rings have seated in this thing it should make my Extra a rocket! I have to admit that I was worried about the vibration factor inherent in big thumpers but this thing doesn't budge. It's just as smooth as silk. If you look at the edges up close it's very evident that they've been worked.

[MODE 1]

The 3W 70i which I have is a smooth single compared to the 85xi I also have. There must be a point where after a certain capacity it just loses that smoothness. And yet engine wise pound for pound they are the same externally.

So when do you think the 60 will be ready for the air?.......LOL ....tomorrows lookin good
I'm real keen to see how that puppy performs. I still have some data on the 70i which was / is a stump puller for its size.

For a low cost 60 it's beginning to put the Zenoah to shame.

[Al Lewis]

Not as keen as I am but I'm afraid I have to go back to work tomorrow so it will be next weekend or latter, depending on the weather. I know what you mean about the thumpers having ridden a Yamaha 400 IT in the day. I know of at least a couple of guys that sold their 85s because they shook their planes apart. You can see on the video that this thing doesn't move. Not even a shiver. For the extra performance it seems to be the perfect balance of cc's versus shake. I have a tall gear on my Extra and I have a strong feeling that that, combined with this engines power, are going to make take-off rolls VERY short! LOL I just can't believe what they are selling for.

[Al Lewis]

I have to tell you guys that when I find an engine like this I get excited, can you tell?? The reason is that I know there are a lot of guys out there looking to move up but don't have the money to do so. Engines like this 62cc for $340.00 are their way up and I feel really good about bringing that opportunity to them and I know that Ron feels the same.

[MODE 1]

Now there's something interesting. It was said earlier about the cylinder being similar or the same as the Zenoah 62.
I would be interested in seeing what the differences where in port timing and volumetric size between the two, if in fact they are the same part. Maybe Pat or Ralph or even yourself have the specs for the Zenoah.

[Al Lewis]

	Quote: Originally Posted by MODE 1
	Now there's something interesting. It was said earlier about the cylinder being similar or the same as the Zenoah 62. I would be interested in seeing what the differences where in port timing and volumetric size between the two, if in fact they are the same part. Maybe Pat or Ralph or even yourself have the specs for the Zenoah.

I have no doubt that Ralph has them. Maybe we can get him to chime in on this.

PM sent.

[flatspinjim]

I was curious too about the stroke and bore between the two.