Is this rotor reusable?

Sharingan 19 · 04-17-2011, 03:53 PM

A few months back a friend and I found a great deal on three 13b engines. We broke them down, scrapped the parts that were obvious garbage and cleaned up the parts that were in good shape. I ended up w/ almost an entire S5 engine worth of parts. There were only 2 rotors that appeared usable...

As all the hard seals were intact and there didn't seem to be any fluid leaks we suspected a spun bearing might have been the cause of failure. My friend them proceeded to press out bearing in the front rotor....with his thumbs :scratch:

It looks fine but something tells me that one is destined to become a clock

The other rotor (don't recall if it came from he same engine) Looks fine, there is a little copper showing in one small spot however (see last pic). Would this bearing need to be replaced?

N.RotaryTech · 04-17-2011, 06:05 PM

Replace both bearings.
Send them to a rotary builder to get those bearing replaced, If your not experienced with that.

Btw, you left the oil control rings and some side seal springs in there.

Sharingan 19 · 04-17-2011, 06:57 PM

Both?
I was under the impression that the only thing holding the bearings in was the friction between the bearing and the inner diameter of the rotor, and that they are/should be a beast to install or remove.

If the bearing in the first rotor was able to be removed by hand, I have to image that would be out of spec......

NoDOHC · 04-17-2011, 10:52 PM

I doubt that the rotor is damaged, probably just the bearing (the circumferential lines are probably deposited bearing material, not removed rotor material). You can probably replace the bearings ($25.00 each) and have the rotor bearings good as new.

As to the rest of the rotor, you will have to check all the groove tolerances per the FSM. If the rotors match the specs, they will make compression.

Make sure that the rotors are within one letter of each other (2 letters if you are sticking with the stock rev limiter) and as long as they are both the same compression ratio and series, you are good to go.

It might not hurt to clean them very thoroughly and weigh them on a gram scale. If one is an s4 rotor, you will notice a significant weight difference (although you should be able to tell the s4 and s5 apart by the machined (s5) or as-cast (s4) appearance of the combustion chamber).

N.RotaryTech · 04-18-2011, 09:16 AM

You could probably get away with just replacing the obvious bad bearing, and save some money.
The good bearing does look reusable.

But sometimes with components like that you should replace both. It's just good insurance.

04-17-2011, 03:53 PM	#1
Sharingan 19 Rotary Fanatic Join Date: May 2010 Posts: 138 Rep Power: 16	Is this rotor reusable? A few months back a friend and I found a great deal on three 13b engines. We broke them down, scrapped the parts that were obvious garbage and cleaned up the parts that were in good shape. I ended up w/ almost an entire S5 engine worth of parts. There were only 2 rotors that appeared usable... As all the hard seals were intact and there didn't seem to be any fluid leaks we suspected a spun bearing might have been the cause of failure. My friend them proceeded to press out bearing in the front rotor....with his thumbs :scratch: It looks fine but something tells me that one is destined to become a clock The other rotor (don't recall if it came from he same engine) Looks fine, there is a little copper showing in one small spot however (see last pic). Would this bearing need to be replaced?

04-17-2011, 06:05 PM	#2
N.RotaryTech Home-brew Rotary Join Date: Feb 2008 Location: GooseCreek SC Posts: 552 Rep Power: 18	Replace both bearings. Send them to a rotary builder to get those bearing replaced, If your not experienced with that. Btw, you left the oil control rings and some side seal springs in there. __________________ '89 RX7 GTU, half-Bridge-port S4/S5 NA, E6K, Full RB exhaust, weekend warrior. '83 RX7, The "this might take awhile" project. '87 RX7 GXL, Rest In Pieces. '98 Subaru Impreza Outback-sport, rx7 rescue vehicle, down for repair. '94 Ford Ranger, daily.

04-17-2011, 10:52 PM	#4
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	I doubt that the rotor is damaged, probably just the bearing (the circumferential lines are probably deposited bearing material, not removed rotor material). You can probably replace the bearings ($25.00 each) and have the rotor bearings good as new. As to the rest of the rotor, you will have to check all the groove tolerances per the FSM. If the rotors match the specs, they will make compression. Make sure that the rotors are within one letter of each other (2 letters if you are sticking with the stock rev limiter) and as long as they are both the same compression ratio and series, you are good to go. It might not hurt to clean them very thoroughly and weigh them on a gram scale. If one is an s4 rotor, you will notice a significant weight difference (although you should be able to tell the s4 and s5 apart by the machined (s5) or as-cast (s4) appearance of the combustion chamber). __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic) Last edited by NoDOHC; 04-17-2011 at 10:59 PM.

04-17-2011, 06:57 PM	#3
Sharingan 19 Rotary Fanatic Join Date: May 2010 Posts: 138 Rep Power: 16	Both? I was under the impression that the only thing holding the bearings in was the friction between the bearing and the inner diameter of the rotor, and that they are/should be a beast to install or remove. If the bearing in the first rotor was able to be removed by hand, I have to image that would be out of spec......

04-18-2011, 09:16 AM	#5
N.RotaryTech Home-brew Rotary Join Date: Feb 2008 Location: GooseCreek SC Posts: 552 Rep Power: 18	You could probably get away with just replacing the obvious bad bearing, and save some money. The good bearing does look reusable. But sometimes with components like that you should replace both. It's just good insurance.