http://forum.teamfc3s.org/showpost.php?p=5...p;postcount=399



B

interesting. how to the grooves in the rotors spec out?

I haven't measured them. Thanks for reminding me.



I'm also curious why the corner seal springs on the front rotor were all flat (well, almost all of them).



B

the motor that came out of my old gsl-se was like that, spotless, but the corner seal springs were pounded into the rotors... that motor saw a LOT of high rpms, everyone who borrowed the car would say the same thing



them: donuts/drifting etc are so easy in that car, you just rev it up to the limiter



me: it doesnt have a rev limiter

Here's the actual post from TeamFC3S.org along with the link to the pictures:



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The motor is torn all the way down. Here's the low-down:



- Front iron's inner water jacket o-ring (an RA teflon-encapsulated ring) was beginning to split on its teflon jacketting on the combustion side

- 5 flattened corner seal springs on the front rotor

- Two small cracks on the upper dowel land on the front iron plate. Rear iron was fine.



Photos are uploaded. They start from here: http://bdc.cyberosity.com/v/ProjectC...bly/?g2_page=2 at image 5246 onward. Got 23 of them uploaded.



For a motor that was built in Mid 2004 and having been run daily since up to the point of breaking in Dec 2006, it is remarkably spotless. There was an extremely small amount of carbon build-up left on either of the two rotors. The rotors are nearly carbon-free with the exception of a few small spots. Also, all of the seals and springs were carbon-free. In the above-linked photos, you can see one of the side seal springs in one of the photos -- it's 100% carbon-free. I believe the alcohol had this profound effect on the internals as nothing else can explain it. The motor had run for 2 years as a daily prior to the introduction of alcohol. In the short 5-odd months or so of running alcohol, and only having it engage in boost, is what I believe cleaned the internals of the motor. The intake ports are spotless as were the exhaust ports along with all of the seals and springs (excluding the oil control ring springs). Simply amazing. The removal of any carbon deposits is a benefit as it removes potential for hot-spots to develop that might cause some other kind of pre-ignition or detonation. The rotors are so clean that I won't have to dunk them in the cleaner bucket. That has never happened once since I started building RE motors.



My plans on this motor are to replace the 12 corner seals with newer, updated solids, the 6 RA apex seals and springs with 3mm Atkins 2pc seals and stock apex seal springs, the 12 corner seal springs, all 12 side seals w/ new Mazda ones, the oil control ring springs, as well as the oil control ring o-rings. I am also reverting back to the use of stock coolant jacket and dowel pin o-rings and dumping the RA ones. Not replacing any of the crankshaft bearings as I did this 3 years ago. I'm replacing the two outer irons w/ replacement S4 turbo ones and hopefully having them pocket-pinned for additional shear strength. I'm also removing the RB oil pressure regulator and upgrading to an FD3S regulator. Not sure if I'll have to restrict the oil pressure going to the turbo. Since the oil control ring scrapers are finally getting old, I may go ahead and replace those as well.



A couple other things I'm doing -- Replacing the oil pressure feed line to the turbo with a hand-construct -4AN unit, extending a portion of the modified RB oil filter stand, constructing -4AN lines for the wastegate and dumping the blue silicone hoses, as well as replacing the Turbonetics 60-1 HIFI w/ 0.96 A/R P-Trim turbo I had (since now sold) with a Master Power T70 w/ 1.32 A/R P-Trim turbocharger. I've also since upgraded the Alkycontrol nozzle output to use twin M10gph nozzles while replacing the single M15gph one. This will yield 25% more alcohol output as I believe the turbo I'll be switching to will add atleast 20% more power to the motor. I hope to crack 550rwhp and over 400ft/lbs torque on 93 octane/Methanol combination.



Did I mention the seals, springs, and rotors were spotless?



B

Link didn't transfer over properly:

http://bdc.cyberosity.com/v/ProjectCars/BD...mbly/?g2_page=2



B

i think its gonna like the new turbo. old turbo must have been tired or something, it was dynoing kinda low

Anyone want to talk about misfires? It'll be fun.. https://www.nopistons.com/forums/pub...DIR#>/cool.gif

sure, i'd love too. how do you detect em before the engine fails?

5 gas sensor, if the sampling rate is high enough on wideband it will work, pressure sensor, also torque readout on dyno, if you have instaneous output.

Even if you did detect one, you've got very little time to do anything before something bad happens, if the engine is an older block, I think.



B

yep, less room for error on the older ones

That is true, but its part of the tuning process, to slowly roll into your tune, thats how you buy engine life, as John Cleese so aptly said, you just dont go stampeding for the clitoris, you start with a simple kiss..

Some things just happen, while others are avoidable, running really rich mixtures, weak ignitions , bad wires etc etc, that stuff is avoidable..

Typically though misfires will show and you can back out, 99% of the time its not where its a totally one shot happening that destroys the motor like detonation. Sometimes you cant even hear the misfires especially at rpm, but it will show with the tools I listed previouly, and contrary to popular belief it will show as a small torque drop then a large torque rise and the back to the mean output. But do it repeatedly and even an FD engine will succumb to misfire damage.

I know nothing of boosted engines, but isn't a flattened apex or corner seal spring, often evidence of a cycle of detonation?



I cracked out a front dowel hole years ago in a NA 12A with a cross fire. If you have a misfire, does the fuel air unspent and entering the turbo make the turbo more effective long enough to see the boost increase you have now?



I have misfires in NA 12A bridgeport any time the plug gap gets above .012". I set them at .010" before the race. This is with a MSD-6AL on both leading and trailing, with no split at all.



Another thought: in the definition of detonation is the part about "remote from the spark plug"........the split timing fits right in there.



Is there a possibility that the waste gate piping is seeing some harmonic in the primary pipe that is impeading flow and replicating a closing waste gate?



At the RPM where you are having this problem, the rotor face is moving very slowly. (compared to a piston moving over TDC) or dwell time. The time the rotor is at TDC is adequate for complete combustion and then some, with very little ignition advance.



The hair on the back of my neck is telling me that the boost spike is jacking the effective compression ratio up into the range where only a few degrees of advance can be tolerated.



Is there knock sensor in that data stream?



Lynn E. Hanover

i agree its either detonation or misfires, or possibly a little of both...

i hate flattened corner seal springs.. always a good indication of detonation.. engine looked flawlessly cleaned for a 2 year build..

Detonation as per the text-book definition of a second flame front post-spark event? That could be I figure as I was running well past 10:1 AFR's when it happened. My guess was that it was spark blow-out that created misfire then the shake-the-hell-out-of-the-motor thing.



B