I don't need any more engines, but...

andrew wrote:

batjac wrote:  Those I didn't need, but I did want.  ............

You have just described probably 80% of the posters on the forum.

Yup, I resemble that remark.

Mark, from what I understand, the OK Cub .059-R (think it's this and not an .049-R) is a decent reedie. Doesn't share the needle problem of the front rotor OK's, it's power peaks at around 11.5k, so perhaps trying a 6x5 prop might make it perform. Walt Musciano featured the OK Cub .049-B tankless with separate tank on a number of his cover photos for the half-A C/L kits.

The Testors "Pipe-Bomb" .049's for the RTF's, looks like you gained a complete assortment. Congrats on the buy!

GallopingGhostler wrote:Mark, from what I understand, the OK Cub .059-R (think it's this and not an .049-R) is a decent reedie.

Well, whaddaya know?  It is an .059 engine.  Do you know what the shroud around the cylinder ports is?  



I can't find a reference to it anywhere.  If a previous owner installed it, I wonder if that raised the cylinder and decreased the compression?  Also, the head is not the OK Cubglow head.  It is a Cox glow head with the "W" filament.  And it even glows brightly!  Any information on how compression of the Cox glow head differs from the compression of the OK Cub head?

The More Powerful Mark

The Comet plastic models were battleships and the engines used were not up to par. It was somewhat of a standoff between Herkimer and Fox. This is why the OK .059 was developed. Fox offered up the .07 which and during this period, Comet was going through major financial problems which Duke took took back all of his engines. This is why Duke ground off the Comet logo on his engines. This is why the earlier .049 and .07 have no markings. On some of the .07's it appears as if the backplate was made with a axe. This is because they used a hacksaw to cut the tanks off and used them as backplates. If one still has a Fox .049 or .07 with the Comet logo, it's somewhat of a rarity.

Some of the Comet tether cars like the Hornet also utilized OK engines later using Fox's. The aluminum piece you posted in the picture is a heat shield and it is a stock OK part. Essentially, you see these in the plastic models to distribute heat. Many times you see these engines, the flywheel or pull starts are associated with them.

The Comet plastic models were battleships and the engines used were not up to par. It was somewhat of a standoff between Herkimer and Fox. This is why the OK .059 was developed. Fox offered up the .07 which and during this period, Comet was going through major financial problems which Duke took took back all of his engines. This is why Duke ground off the Comet logo on his engines. This is why the earlier .049 and .07 have no markings. On some of the .07's it appears as if the backplate was made with a axe. This is because they used a hacksaw to cut the tanks off and used them as backplates. If one still has a Fox .049 or .07 with the Comet logo, it's somewhat of a rarity.

Some of the Comet tether cars like the Hornet also utilized OK engines later using Fox's. The aluminum piece you posted in the picture is a heat shield and it is a stock OK part. Essentially, you see these in the plastic models to distribute heat. Many times you see these engines, the flywheel or pull starts are associated with them.

The later OK engines utilized a one piece glow plug like Cox. I use both including the standard OK head which accepts long plugs. I'm certain there's measurable differences in rpm's between all of them and I've tried them back to back. Audibly, they sound similar. I really like them and I use them a lot for free flight models. One thing about a Cub is that the more nitro you throw at them the more they like it. Some have a dual bypass in the case, others don't. The rods are different in some as well. Cox engines were the nail in the coffin for OK.

Those Testor 8000 with the white tank are pretty strong runners. At least the one i tried out with a 5 1/4-4 Top Flite nylon. They like lots of nitro.
                         Mike1484

WooHoo!  All four Testors glow heads glow nice and bright.  4/4 is not my normal outcome.

The Lucky Mark

edit: All glow heads/plugs are good!

batjac wrote:WooHoo!  All four Testors glow heads glow nice and bright.  4/4 is not my normal outcome.

The Lucky Mark

edit:  All glow heads/plugs are good!

Ok.......NOW I am officially jealous!

batjac wrote:

GallopingGhostler wrote:Mark, from what I understand, the OK Cub .059-R (think it's this and not an .049-R) is a decent reedie.

Well, whaddaya know?  It is an .059 engine.  Do you know what the shroud around the cylinder ports is? I can't find a reference to it anywhere.  If a previous owner installed it, I wonder if that raised the cylinder and decreased the compression?  Also, the head is not the OK Cubglow head.  It is a Cox glow head with the "W" filament.  And it even glows brightly! Any information on how compression of the Cox glow head differs from the compression of the OK Cub head?

The engine used to be described on OK Cub's website, when the OK Company owner's son was building engines for sale and selling parts, from left over production years ago. They went off line, don't remember exact year, but may be about 5 years ago. I guess they were running out of parts and he was nearing absolute retirement (old age?).

Can't answer about differences in compression of the heads. Ken mentioned that the exhaust deflection collar was to protect the RTF plastic around the cowl from engine exhaust heat damage. I think this was an engineered manufacturing decision. They probably took it into account by milling the crankcase mount top down a touch to compensate. If you were to remove it, you would most likely need to shim the cylinder up then. I'd just carefully remove the bends and dents in it to restore it to its original shape. Who knows, it deflecting the hot Castor oil droplets may help to spare some wear and tear in the finish of the plane you mount it on.

And, It has the plastic resistance tab just above the tank that the needle screws through, it helps to hold the needle setting (replaces the spring), like mine. Seems you got a complete one. Regarding the missing 5-40 prop screw, it uses one but a little longer than the Cox one. Good is, the engine uses the Cox tank reedie bolt pattern, so you can replace a Cox tank engine with it, to test it out.