Fitting a .051 piston to a worn .049 cylinder?

G.O. Stang Wed Jan 29, 2014 6:44 pm

This may sound odd, but hear me out. I've got an early thin wall unmarked #1 cylinder. Problem is, any piston I try in it is too small. It won't make compression. I've tried various heads also. I've come to the conclusion that the cylinder itself is worn. A quick measurement with my calipers says it is slightly larger than my other .049s so that confirms it being worn. My question is, there is a seller on eBay who sells .051 Killer Bee pistons. Can they be made to fit inside this cylinder? I mean, if it physically fits and goes smoothly, shouldn't it work?

It would just look a lot better than the thick wall black widow #1 on one of my RR-1s.

WingingIt74 Wed Jan 29, 2014 6:54 pm

well... if it fits and has compression... I guess??? I have a cylinder that's larger then .051..... Affraid or WOW!

G.O. Stang Wed Jan 29, 2014 7:06 pm

WingingIt74 wrote:well... if it fits and has compression... I guess??? I have a cylinder that's larger then .051.....

Well I went through my cylinders and decided I'd throw an unmarked #2 on it for now since it's to cold to run anything right now. Either way, they're looking good.
Fitting a .051 piston to a worn .049 cylinder? C3B6E9B3-6D41-4E52-A03E-C79147032A8C

Fitting a .051 piston to a worn .049 cylinder? C3B6E9B3-6D41-4E52-A03E-C79147032A8C

WingingIt74 Wed Jan 29, 2014 7:10 pm

Man I really want a silver one......

G.O. Stang Wed Jan 29, 2014 7:22 pm

WingingIt74 wrote:Man I really want a silver one......

I want one of these....
Fitting a .051 piston to a worn .049 cylinder? 7A90027E-B21A-493B-BE42-61503A4661C3

Jason_WI Wed Jan 29, 2014 8:30 pm

The ungrooved RR-1 is pure unobtanium. I'm all out of unmarked thin wall #1 cylinders also.

**Cribbs74** Wed Jan 29, 2014 8:37 pm

Probably wouldn't be too awful hard to make one if you had an RR1 donor.

**Cribbs74** Wed Jan 29, 2014 8:40 pm

GO,

I am sure with some work you could fit the piston. Some hand lapping will be required once you get the fit close.

It would be a lot easier/genuine to just find the correct cylinder though.

It's also possible to enlarge pistons though I have never done it myself.

Ron

G.O. Stang Wed Jan 29, 2014 8:46 pm

Cribbs74 wrote:GO,

I am sure with some work you could fit the piston. Some hand lapping will be required once you get the fit close.

It would be a lot easier/genuine to just find the correct cylinder though.

Problem is, it is the correct cylinder. And if it wasn't for the piston being the 3-piece, it may have been possible reset the rod and get some "mushroom" effect to get the compression up.
The thin wall #1s are just so hard to come by. I've only got two. This worn one, and the other is on the other RR-1. I have decided to just put it on my spacebug. I probably won't ever run it so it'll be happy there. Still gotta find another at some point though. Haha

**Cribbs74** Wed Jan 29, 2014 8:51 pm

If I had one I would give it to you. At this point in the collecting game you might want to set your sights on parts lots. Lot's of interesting things can be found in those due to the amount of swapping that went on over the years. Having ready spares will certainly come in handy.

Ron

G.O. Stang Wed Jan 29, 2014 8:57 pm

Oh trust me. I've gotten. Few lots already. In my search for thin walls, I think I've gotten 6 or 7 #2s. One of which has a 3-piece piston also. Various other cylinders also. Got many crankcase, metal backplates, tanks, I think 7 or 8 w-filament glowheads(in fact, I seem to find these more than regular ones..) and many other parts. But I guess I'll start looking for some more lots. It's just so hard not to buy another engine on my list instead. lol!

**Admin** Wed Jan 29, 2014 9:03 pm

The 290 series engines used a #1 cylinder, these engines can usually be had for less than $20.

Here's a lot that contains one, not sure if its original though.
http://www.ebay.com/itm/Cox-049-Product-Airplane-Engine-Parts-Lot-049-/271384501331?pt=Radio_Control_Parts_Accessories&hash=item3f2fc6dc53

This one looks to be original, will need some cleaning up.
http://www.ebay.com/itm/Vintage-Cox-049-Engine-with-3-Blade-Prop-1960s-1970s-Used-2-of-2-/161211355667?pt=Radio_Control_Parts_Accessories&hash=item2588f21213

Here's another one
http://www.ebay.com/itm/Vintage-Cox-049-Engine-with-3-Blade-Prop-1960s-1970s-Used-1-of-2-/161211356164?pt=Radio_Control_Parts_Accessories&hash=item2588f21404

The 290 series engines also used fine thread needle assemblies too, would be good for project and performance engines.

G.O. Stang Wed Jan 29, 2014 9:09 pm

Hmmm. I did not know that. That's certainly good information!

Sponsored content

Fitting a .051 piston to a worn .049 cylinder?

Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?

Re: Fitting a .051 piston to a worn .049 cylinder?