OS 37 bearings

[bgymr]

I bougth a rebuild kit for my NX4 at ircha: ring, sleeve, connecting rod but the bearings were too expensive. I probably don't need all those but they were at my fingertips. After some discussion with guys around the pits they said that there were better bearings than OS offered. I just ordered a set from RC bearings. The ones you will need are:
607aa which is teh front bearing.
2513 is the rear

I called the owner of rcbearings.com just to pick his brain. Really nice guy. I asked if I should go with the ceramics. I said "what would be the difference?" He replied "just price". lol Gotta love the honesty.

[Hot Apple Pie Guy]

I've got an OS55hz in a Trex 600n that I've been flying for 3.5 seasons... I typically just replace the bearings and ring about once a season... And the thing is still pulling strong!

As long as you replace them before they fail, you'll save a TON of money in engine rebuild parts/costs...

And yes, my first engine I leaned it out too far learning to tune and HAD to replace piston/ring/ liner and bearings... Ever since, just bearings and ring.. I've gotten to the point now that I can rebuild an engine at the field with a pocket torch in no time...

For bearings... I've tried the ones with metal retainers, some kind of plastic retainers(the part that holds the ball bearings in place), and found that if you just plan to rebuild it a few times more often... Buying standard/cheaper bearings is just the way to go... Think I picked up a set off thE Bay for $6.99...

For break in... I give it a good 20 sec hover to make sure it's put back together right... Spend a tank doing fff and big loops, then next tank give her hell and start tuning for power! Lol.

Now that I've got the nx4 gasser... My methods may not work the same... But I'll talk to the guys in the 'know' and get my gaui airborne! Super excited for the flight times and cheap costs to fly!

[LegndarySaiyan]

Hey Serg, I've been using the stainless bearings from rc bearings for years on all my rebuilds. Not only are they cheaper than the o.s. bearings but they last longer. I would recommend the ones with the plastic bearing crown. When I run bearings too long it's usually pieces of the metal retainer cage that come through the combustion chamber and ding the piston and head. The plastic retainer doesn't have this problem.

[bgymr]

I can't edit the original post, but the front bearing size is incorrect, and it's incorrect on the RCbearings site as well. The right size is a 699zz

The rear bearing is listed correct.