Suggestions on when to do a rebuild

Sephitrask · 05-06-2011, 04:50 PM

Well, I was going to post this in the 8 forum, but I figure the information is prolly universal. And I did attempt a search on this, but didn't come up with anything constructive.

So the question is this: I have a 05 rx-8 with 90k on it, original motor. I have premixed since about 70k, and have used only 20w 50 since I got the car. Currently there does not seem to be any issue with the motor; It idles fine, and performed like a champ at DGRR. From what I have heard, when it comes time for a rebuild, at least one item (rotor, housing, etc) needs to be replaced, depending on the failure mode. So what I am wondering is, would it be beneficial to tear down the motor and rebuild it BEFORE it failed? I would assume it could potentially save a bit of cash doing it this way. If anyone else does this, about what mileage would be suggested?

Thoughts?

N.RotaryTech · 05-06-2011, 06:28 PM

I would not rebuild it until something gives way, coolant / oil seal or compression seal etc.
Unless I wanted to upgrade the internals. Porting, etc.

Just take care of it and it should go a long way.

NoDOHC · 05-06-2011, 11:36 PM

If you are running non-turbo, they will typically give some indication of age before they let go. With a Turbo, you could destroy a new engine as easily as an old one, so there is really no major advantage to a rebuild there either.

If compression is good, you are probably Ok to keep running it. It will probably start flooding and idling a little rough long before you have any actual failures.

***TitaniumTT*** · 05-07-2011, 12:12 AM

These men speak the truth. N/A's can and do go a loooooooooooooooooooooooooooong time. If it ain't broke, don't fix it.

The problem is, with the mileage you're at, and the fact that you've only been pre-mixing for 20k, those housings probably aren't reuseable anyway, at least not highly useable if that makes any sense.....

project86 · 05-07-2011, 12:23 AM

ya my fc had 140k on it when i tore it down. after looking over alot of the parts im surprised at how well it ran... corner seals were f***** i had gouges in rotors and gouges on the leading edges of ports. i was getting some smoke but i think it was primarily from premix.

05-06-2011, 04:50 PM	#1
Sephitrask BOILED PEANUTS!!! Join Date: Jun 2010 Location: Jacksonville, Fl Posts: 257 Rep Power: 15	Suggestions on when to do a rebuild Well, I was going to post this in the 8 forum, but I figure the information is prolly universal. And I did attempt a search on this, but didn't come up with anything constructive. So the question is this: I have a 05 rx-8 with 90k on it, original motor. I have premixed since about 70k, and have used only 20w 50 since I got the car. Currently there does not seem to be any issue with the motor; It idles fine, and performed like a champ at DGRR. From what I have heard, when it comes time for a rebuild, at least one item (rotor, housing, etc) needs to be replaced, depending on the failure mode. So what I am wondering is, would it be beneficial to tear down the motor and rebuild it BEFORE it failed? I would assume it could potentially save a bit of cash doing it this way. If anyone else does this, about what mileage would be suggested? Thoughts? __________________ www.rotarycarclub.com *"The way a Rotary engine makes power is ferocious, much like having a chainsaw under your right foot."*

05-06-2011, 06:28 PM	#2
N.RotaryTech Home-brew Rotary Join Date: Feb 2008 Location: GooseCreek SC Posts: 552 Rep Power: 18	I would not rebuild it until something gives way, coolant / oil seal or compression seal etc. Unless I wanted to upgrade the internals. Porting, etc. Just take care of it and it should go a long way. __________________ '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.

05-06-2011, 11:36 PM	#3
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	If you are running non-turbo, they will typically give some indication of age before they let go. With a Turbo, you could destroy a new engine as easily as an old one, so there is really no major advantage to a rebuild there either. If compression is good, you are probably Ok to keep running it. It will probably start flooding and idling a little rough long before you have any actual failures. __________________ 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)

05-07-2011, 12:12 AM	#4
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son Posts: 4,581 Rep Power: 10	These men speak the truth. N/A's can and do go a loooooooooooooooooooooooooooong time. If it ain't broke, don't fix it. The problem is, with the mileage you're at, and the fact that you've only been pre-mixing for 20k, those housings probably aren't reuseable anyway, at least not highly useable if that makes any sense..... __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

05-07-2011, 12:23 AM	#5
project86 Can't.Make.Up.My.Mind. Join Date: May 2009 Location: Murfreesboro, TN Posts: 1,377 Rep Power: 18	ya my fc had 140k on it when i tore it down. after looking over alot of the parts im surprised at how well it ran... corner seals were f***** i had gouges in rotors and gouges on the leading edges of ports. i was getting some smoke but i think it was primarily from premix. __________________ '90 GTUs Stay up to date with my photography '06 Toyota Highlander Hybrid '10 Toyota Prius "Initial Success or Total Failure"