Wanted: OS .30 Conrod

Does anyone have a new rod for an OS Max .30? I have an engine with a loose fit on the big end. I doubt it would run long the way it is. Does anyone know if this rod is used in any other OS engines? Perhaps the .35? Can't give you the dimensions--the liner is still stuck in the case.... What is the typical new condition fit between the crankpin and bushed rod? I might try re-bushing the existing rod....

Dave
LA_Flyer
"The difference between junk and a fine engine is a thin film of oil."

The Max-S 35 would be the same con-rod. Also hard to come by. I have several in need of bushing, as well as some ST 60 rods in need. Let me know if you find a source.
Once I heard that an ST 35 rod would fit but I checked and the ST was a different length.

Dave,
will get back to you on an OS rod. Already found a venturi (.257 bore). What else do you need?
Larry

hi
You may want to get all the parts out first and check for wear, lots of times the piston would wear as much as the top of the rod. I have seen dozens of these with oblong holes in the piston wrist pin hole.
If you do find a new rod it will help to drill a vent-oiling hole in it, and use a good fuel with 25 to 28% oil

I have tons of older max parts, not sure about rods but i have heads, washers, cases, backplates, screw - gasket sets, crankshafts , wrist pins, and other parts for the OS 30 35 S engines

If you don't find what you need I may have some parts to help you.

[email protected]

Randy (and others),

I pulled the liner, piston and rod out of my OS .30 over the weekend. After cleaning them up, it appears that the wrist pin fit in the piston is good, and the piston/liner fit is reasonable. The crank seems ok, but the lower rod hole is oversize (egg shaped). So replacing the rod would appear to get this engine back in the air.

If anyone has a new rod, let me know what you want for it. This rod is unbushed aluminum, with an oil feed hole on the lower end only.

Thanks!

There are 3 or 4 of these for sell on EBAY right now for $25 apiece. One is brand new. Hard to beat. Check it out.

Bill

HI Dave I sent you a list of parts i had there not cheap but they are new in pack

Thanks, everybody! I have located enough parts to get my OS .30 back in the air.

Good to hear Dave got the required parts, but I want to mention that it is not difficult to make a new rod from suitably hard aluminum sheet. A drill press to punch in the two holes, bandsaw to get it cut at least close, hand finishing with a file and/or hand-held grinder.

Dan,

Yeah, that was my backup plan. I have a little 7075-T73 stashed away for emergencies, but my drill press has the infamous Taiwan wobble. I've been trying to do a little CL Speed and CL Racing in addition to learning stunt, so every plane has a lot of custom everything in it. Bellcranks, horns, motor mounts. Starts to take over your life. For the engine I built up last Friday (for the race on Sunday) I had to find a different head, special plugs, lap the crankcase, new crank starting from an unbalanced blank, handmade starter spring (reed valve engines invariably start backwards more than 50% of the time....), drilled backplate, ad nauseum. The sales guy at the local RC shop thinks I'm a walking anachronism...with the nerve to ask for parts that can't bark (ARF, ARF.) I did buy an RC glow driver that's great for lighting up a Nelson plug.

And just for kicks, I always ask him if he's got a 9x4APC. This one puzzles him a bit. Apparently a 9x4 MIGHT be a real RC prop, so he thinks he should have one, but the box has now been empty four times in a row. This last time he was a little suspicious, thinking that I was asking for an illegitimate size perhaps to be used for archaic purposes....

Dave
LA_Flyer

PS-Did I mention the 9x4 was to try out on my iron piston OS .25FSR? Think of it as kind of a super .20!

Dave,

I like your style. Start asking the shop owner if he has APC 10-3s. He won't, but it might make him reconsider on the 9-4s.

Larry,

Thanks for looking for the parts. I had two .259" nylon venturi inserts. Got the engines reassembled last night. Can't wait to try 'em out!

When I baked the second OS .30 to get the liner out, I did the little Torpedo .09GH too. The bad news there is that the wrist pin is really bent. Must have suffered a hydraulic lockup....

I do have the .15GH back together and ready to go into my new (still not finished) Buster.

Best regards!