High powered setups dying of old age

sa22c · 05-28-2012, 07:51 AM

My built 12A started out at 97/102 compression. Its now all the way down to 85/94. Tested low cost piston engine tester. Its possible the front rotor has 2 weaker faces but can't be 100% on that.

Don't think I've ever had knock 3000rpm/part throttle. I would guess the usage around 80000kms/50000miles since rebuild. This includes years worth of cruising more than 150-200 1/4mile passes, some high rpm action >9000rpm years ago when it was nonturbo and lately >120kpa boost(operating at 170kpa atm) boost. Side plates, shaft and gears now have ~185k miles / 300k kms on them. Rotors ?kms bought used unknown km. Rotor housings and all other internals ~80k kms.

I'm in 2 minds about whether to pull it apart, build something more powerful and more refined. Or just leave it be. I would guess I use the car for ~240 1hr trips a year in its current usage + shops/gym when I need to.

For all these years I've never had an EGT on it so don't know if I could be flattening the springs or warping the apex seals.

If I cracked it open and the housings looked good. I would be up for minimum based off what I already 'know'

#1 Side Housing grind + lap + renitride
#2 12x FD3S corner seal springs + 12x Corner seals+ rubber plugs
#3 4x inner+4x outer rubber oil seals
#4 12x Side Seals
#5 Replace any out of spec/flattened springs

? Apex seals
? Rotors
? Rotor housings NLA
? Metal Oil seals

If it could still be good inside I'd be happy putting ~$1kUSD through it if it came back above 105 even on both rotors. Scored/Damaged Rotor housings basically leaves my 12A rebuild dead in the water, I have high standards.

It is still making good power. I think it is getting harder to start since I started racing on >120kpa boost. Also the fuel consumption has degraded, but then again I use the power whenever I get a chance.

05-28-2012, 07:51 AM	#1
sa22c The Newbie Join Date: Jan 2012 Posts: 21 Rep Power: 0	High powered setups dying of old age My built 12A started out at 97/102 compression. Its now all the way down to 85/94. Tested low cost piston engine tester. Its possible the front rotor has 2 weaker faces but can't be 100% on that. Don't think I've ever had knock 3000rpm/part throttle. I would guess the usage around 80000kms/50000miles since rebuild. This includes years worth of cruising more than 150-200 1/4mile passes, some high rpm action >9000rpm years ago when it was nonturbo and lately >120kpa boost(operating at 170kpa atm) boost. Side plates, shaft and gears now have ~185k miles / 300k kms on them. Rotors ?kms bought used unknown km. Rotor housings and all other internals ~80k kms. I'm in 2 minds about whether to pull it apart, build something more powerful and more refined. Or just leave it be. I would guess I use the car for ~240 1hr trips a year in its current usage + shops/gym when I need to. For all these years I've never had an EGT on it so don't know if I could be flattening the springs or warping the apex seals. If I cracked it open and the housings looked good. I would be up for minimum based off what I already 'know' #1 Side Housing grind + lap + renitride #2 12x FD3S corner seal springs + 12x Corner seals+ rubber plugs #3 4x inner+4x outer rubber oil seals #4 12x Side Seals #5 Replace any out of spec/flattened springs ? Apex seals ? Rotors ? Rotor housings NLA ? Metal Oil seals If it could still be good inside I'd be happy putting ~$1kUSD through it if it came back above 105 even on both rotors. Scored/Damaged Rotor housings basically leaves my 12A rebuild dead in the water, I have high standards. It is still making good power. I think it is getting harder to start since I started racing on >120kpa boost. Also the fuel consumption has degraded, but then again I use the power whenever I get a chance. Last edited by sa22c; 05-28-2012 at 08:06 AM.