High Performance Cox tools by Bob Oge

Here's Bob's adjustable piston "truing" tool that laps the piston completely square. It's made from a piece of steel which everyone told him would not work.
Well dang!  It does work & works well!

Here are Bob Oge's chromed crankshafts. Bob sands the stock crankshaft down a bit then chromes it back to size.
When done right, they fit real free in the c/case.

Bob claims that his method of determining if a piston is worn is by turning the motor to top dead center & looking for bubbles coming off the piston.
If bubbles are evident, the piston is worn.  However, Bob feels that if the piston sticks much below TDC, then it will not be a "fast" one...
INTERESTING!
By applying a thin layer of chrome to a (bead blasted) clean cylinder bore, Bob can resurrect most any cylinder and that
gives the rebuilt motor a much longer service life. Bob shut down his chroming service & no longer offers it to modelers unfortunately.  

That's pretty neat. How many RPMs did these mods increase in the engine performance?

Jason_WI wrote:That's pretty neat. How many RPMs did these mods increase in the engine performance?

You know, I'm not sure if they add all that much extra RPM to a perfectly set up standard engine. HOWEVER, they sure do add to the RELIABILITY & LONGEVITY of the engine.
If you can control piston to cylinder fit, you have a much better chance of going consistently fast also.

Truly, the proof of the pudding is really in the flying. Sadly due to the horrendous rainfall, mouse race had to be cut from the events roster & so we really don't know...

I would also be interested in performance figures, although longevity is probably much more important as long as the engine is competitive. Sorry you got rained out.

Thank you for sharing Paul that was interesting.

Paulgibeault wrote:Here's Bob's adjustable piston "truing" tool that laps the piston completely square. It's made from a piece of steel which everyone told him would not work.
Well dang!  It does work & works well!

Very interesting tools. Thanks for posting.

I wonder if I understand its function correctly: to e.g. reinstate piston roundness after a balljoint resetting went wrong and resulted in a trumpet in the piston crown? (What else would impact roundness other than a wrong resetting?)

balogh wrote:

Paulgibeault wrote:Here's Bob's adjustable piston "truing" tool that laps the piston completely square. It's made from a piece of steel which everyone told him would not work.

Very interesting tools. Thanks for posting. I wonder if I understand its function correctly: to e.g. reinstate piston roundness after a balljoint resetting went wrong and resulted in a trumpet in the piston crown? (What else would impact roundness other than a wrong resetting?)

YES, I believe that is correct. Some (softer) pistons get out of round easily. Others seem to hold shape better.

Red paint drops or Blood in the piston photos?

Bob did 3 LA.25's for Phil Cartier, they just run like no other LA .25's that I have seen. I have a piston liner from Bob for my Fox .15 BB. I haven't run it yet.

Thankfully....stray paint!

fredvon4 wrote:Red paint drops or Blood in the piston photos?