RCGF "B" Line of Engines

[cap232tain]

The "B" stands for second run. The first run the aluminum was too soft.

[Al Lewis]

Okay, so here's what I got measuring the clyinder and piston with a CMM. Margin of error is ±.0002".

RCGF 62 B
Bore is round within .0006". Diameter at top is 1.8712" at bottom is 1.8717.
Bore is perpendicular to the flange by .0009". Hub run out on OD is .0075" and on the face the TIR is .0012. Piston diameter at top is 1.8671" and at bottom skirt is 1.8675". Double rings on piston. Forged rod and crank with oiling holes in both the top and bottom rod journals. Cylinder base is flat within .0009". Case is machined aluminum.

RCGF 50 B
Cylinder is round within .0006. Top of bore is 1.6947" bottom is 1.6944". Top of the piston is 1.6891, bottom is 1.6910. Bottom face of the cylinder is flat within .0008". Looks like it may have a slight skirt rubbing issue. We'll see. Ventilated top journal on the rod for lube and drilled bottom journal. Rod and crank are both forged steel. Case is machined aluminum. Haven't checked the hub run out yet but I have enough tenth indicators here at the house to do that.

[cap232tain]

Jody at Valley View RC has done some testing on them. At least the first run. I think he was sent improved aluminum to replace the soft!

[rcign]

Looks like the Chinese could use some machining training...the cylinder SHOULD be round and straight, at least slightly larger at the bottom...

[Al Lewis]

That's the sort of input I'm looking for so I can check on the "B" engines I have to make sure they have been fixed.

[rcign]

I turned a GT80 about 11,000 one day...with a 15-8 prop...

[Al Lewis]

	Quote: Originally Posted by rcign
	Looks like the Chinese could use some machining training...the cylinder SHOULD be round and straight, at least slightly larger at the bottom...

Yep but compared to some of the other Chinese bores I've looked at these are near perfect! LOL Most are octagonal.

[Tired Old Man]

Ralph,

You had an opportunity to get rather intimate with the first version of the 100 as well. Thanks for the machine work you did on that one for me

[Al Lewis]

	Quote: Originally Posted by rcign
	I turned a GT80 about 11,000 one day...with a 15-8 prop...

Yeah, I really wish that guy had listed what prop he was running. I'm going to throw a Vess 22A on the 50 and a 23A on the 62 and see what I get. May not be the right props but at least I'll have a base line to compare to.

[MODE 1]

The unknown aspect of testing will be how it stands up over time. Thats the main reason I've always shy ed away from cheaper engines.
When did the B series come out?

Pete

[rcign]

The old Horner twin was the absolute worst I ever saw...It took about .002 to just clean up the bore...It was cast iron...Same company made the 100 and 125 sold by ISC....

[MODE 1]

Al the info for the 15cc is on the site of the guy you posted
RCGF 15cc Gasoline engine. Tried with various props, 14 x4(wood), 14 x7(wood), 14 x 7(MAS) , 15 x 8(wood), 16 x 4W(APC), 17 x 4(APC). However the best combination for 3D flying is 15 x 4W(APC). If one choose to fly pattern, an APC 15 x 6 would be the best!!!
http://www.youtube.com/user/umranrc

Theres a RCGF 50cc twin here

YouTube - RCGF 50cc Twin

and here is the info for the 50cc B >> http://www.youtube.com/user/umranrc#p/u/15/Qy3GuohtvDU
RCGF 50cc-B, the crown jewel of the 50cc class gasoline engine in the market today! Without adjustment, initial test run using 22 x 8 prop, this engine spin at 7300rpm! a super duper engine i must say.


Pete

[zoomer260]

	Quote: Originally Posted by Nelly
	Before I crashed I had a RCGF 50 and I really loved it. From a female's point of view it was really easy to start, it ran great and had plenty of power for my 27% Edge!!! Also, I flew the crap out of it and never had any problems with it overheating. I couldn't have asked for a better engine.

Sorry to hear you lost the Edge Nelly. I am a front pager as far as forums go so I must have missed it.

[MODE 1]

more info here
http://www.umranrc.com/forum/viewthr...537#post_77537

[Al Lewis]

Picture shows the prop to be a 22X8. Not sure of the manufacturer but that sure seems like a good rpm for a 22X8. However, in his post he lists a 22X10 before posting the video. Nope, video is a 22X8. With regards to the other engines, Ron has tested and carries the 20, 50, and 62 only. I don't even know if they still make the others. I'll be busy enough testing these two. LOL