RxParts apex seals warped twice
01-11-23, 10:33 AM
#51
Racecar - Formula 2000
theory is that the after market seals vary in length, so some people are fine, and some people are not. Mazda calls the rotor housing width to apex seal length measurement Delta S,
when you don't have enough clearance the aftermarket seal has nowhere to go when it heats up. kind of like a piston ring...
when you don't have enough clearance the aftermarket seal has nowhere to go when it heats up. kind of like a piston ring...
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j9fd3s (01-11-23)
01-15-23, 09:14 AM
#52
Rotary Enthusiast
IIRC, the RXParts seals are an imported/rebadged Australian seal, and I got wondering if the metallurgy or quality of raw material supply changed somehow. It wouldn't be a surprise given all the global disruptions. I had a set warp, but there were some mitigating factors. They were the first set of non-OEM seals I ever used. I'm on iRotary now, largely on the strength of them being developed by Dr. Ianetti, but if these **** the bed I'm going back to OEM permanently. Especially now with all the safeguards built in the my Haltech engine management, and the fact that the last set lasted for a decade of track use with just a PFC, they are tough to argue with.
01-15-23, 10:12 AM
#53
Rotary Enthusiast
Its my second motor and I too have PTSD, cant imagine three in a row.I've relayed everyone's points to my builder. At the same time I feel like I am chasing theories vs objective issues. I really hope this is the end of it. Changes this build:E&J apex sealsNew FFE trigger wheelNew center ironEmphasis on re-checking clearances as noted by Dave and others
I expected higher compressions, but looking back the builder never gave me the compressions to start with on a new crated motor. Large street port and seals were the only thing done by the shop.
01-15-23, 11:25 AM
#54
I still lean towards a metalurgy or process change (that perhaps RXParts isn't aware of, since he doesn't make them), because it seems like people used them for a while with great reviews, and some of those old builds still going strong, but lately there are a lot of failures. People didn't just suddenly forget how to build or clearance motors.
01-15-23, 12:58 PM
#56
Rotary Enthusiast
Gotcha. Anyway, that's what I am running (REC), but I could see a lot of issues right now considering how insane everything was and is in the world currently. I think if my compression goes south rapidly (which I don't expect) I will be going oem seals as I am chasing 325-380 rwhp and believe I have everything else in line.... so I think anyway
01-16-23, 01:06 PM
#57
Armen sorry I read through this a few times and didn't see it so I must ask. When you say the egts and afrs were closely monitored are you speaking throughout the life from new to warpage? Or you tuned it and everything was great let's put it out on the road/track and run it. I ask because I went through hell trying to figure out why I would have my car running with a perfect tune. I put it on the track or after multiple pulls it would start to slowly run lean. I probabky went through thousands of miles. Originally I thought it was my 2200 secondaries as there was record of them heating up and slowly not opening. Long story short I had an alternator that would heat up and start getting wacky. If I had a "pro" tune this car and not payed attention down the road it most certainly would have warped or popped a seal. I swapped to ID1700 and an ARD alternator. I have maybe close to 15000 miles on this build and compressions are acceptable at 110/102/101 on the lowest rotor and very. REC seals (which I thought RX parts were re branded REC). I run omp with a bit more flow than factory and 1oz per gal min premix. This is running between 12-14 psi on Hitachi "SP" twins.
I expected higher compressions, but looking back the builder never gave me the compressions to start with on a new crated motor. Large street port and seals were the only thing done by the shop.
I expected higher compressions, but looking back the builder never gave me the compressions to start with on a new crated motor. Large street port and seals were the only thing done by the shop.
I managed to get my hands on a new crate Mazda motor so the next build will be using all new parts with an added street port and E&J seals. Part of me still is considering OEM seals.
01-17-23, 07:18 AM
#58
Original Gangster/Rotary!
iTrader: (213)
One detonation event with OEM seals, and you're out a rotor and rotor housing combo (maybe two) and an EFR turbo. Not worth the risk for anything over low to mid 300s at the wheel in my opinion.
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01-17-23, 02:13 PM
#61
I used OEM 3mm seals in my TII as a "cake and eat it too" solution. Of course you have to use S4 rotors as well so detonation doesnt dent them.
On my 3mm OEM sealed TII detonation would flatten seal springs, crack corner seals and crack housings at the dowel, but the apex seal usually just "warped".
Note: its not warping, its a high rate of wear on the side that travels over the Leading plug thermal expansion hump formed from detonation heat.
Its usually the long angled end of OEM apex seals where they meet the corner assist piece that break off. I think we should try a localized annealing process there so they are less brittl at that spot.
On my 3mm OEM sealed TII detonation would flatten seal springs, crack corner seals and crack housings at the dowel, but the apex seal usually just "warped".
Note: its not warping, its a high rate of wear on the side that travels over the Leading plug thermal expansion hump formed from detonation heat.
Its usually the long angled end of OEM apex seals where they meet the corner assist piece that break off. I think we should try a localized annealing process there so they are less brittl at that spot.
01-19-23, 11:01 AM
#63
FWIW guys, I had an email thread going with Dr. Ianetti, so I asked about water/meth injection, and whether or not it had the potential to essentially "wash" the lubrication off and expose lube-sensitive seals like RXParts or iRotary. Particularly in prolonged high RPM scenarios like circuit use. So often, the stuff we use that is "track tested" means drag racing. FWIW, I had no WI on my RXParts motor (it had oiling problems), and do have it on my iRacing motor (fingers crossed).
He wrote me back and said he doesn't have much experience with it, but referred me to some guy named Howard at Coleman Precision Rotary :-)
Rather than a side convo, might as well reach out here for posterity. What are your thoughts @Howard Coleman ?
He wrote me back and said he doesn't have much experience with it, but referred me to some guy named Howard at Coleman Precision Rotary :-)
Rather than a side convo, might as well reach out here for posterity. What are your thoughts @Howard Coleman ?
Last edited by ptrhahn; 01-19-23 at 11:04 AM.
01-19-23, 12:06 PM
#65
Racing Rotary Since 1983
iTrader: (6)
Peter
a good question as to what extent AI works against prelube.
having road raced for 22 seasons i can truly appreciate the unusual challenges presented by sustained foot to the floor conditons on track. the last 6 seasons were rotary but NA... so NOTHING like turbo land.
i remember being in the pits w Roger Mandeville at the end of the 1982 24 Hours/Daytona. most of the piston engines could barely idle at the end of the 24 hours while all the rotary guys would purposely get out of their cars w the engines still brapping happily. quite diff w turbo rotaries.
i did do 4 Ferrari Club of America track events w my FD at Brainerd. top speed into turn one was 160. 20 minute sessions. race gas. no AI, back in the day stuff... around 2000. never any problems. drove my car from Milwaukee to Brainerd which is 470 miles each way.
i started AI (100% methanol) in 2003. i can tell you i ran one of the motors i built for 4 years at approx 500 hp, about 20 psi w a Garrett G4094r. after 4 years i disassembled it primarily to check sideseal gap. at the time it was continuing to gain compression. from around 385 to 435 mm Hg. the big question of course is i was just doing road romps although i did do two track events at Road America which has 3 long straights. this was all on 93 pump and about 900 cc of meth.
of course WM would be much easier on the prelube.
a good question as to what extent AI works against prelube.
having road raced for 22 seasons i can truly appreciate the unusual challenges presented by sustained foot to the floor conditons on track. the last 6 seasons were rotary but NA... so NOTHING like turbo land.
i remember being in the pits w Roger Mandeville at the end of the 1982 24 Hours/Daytona. most of the piston engines could barely idle at the end of the 24 hours while all the rotary guys would purposely get out of their cars w the engines still brapping happily. quite diff w turbo rotaries.
i did do 4 Ferrari Club of America track events w my FD at Brainerd. top speed into turn one was 160. 20 minute sessions. race gas. no AI, back in the day stuff... around 2000. never any problems. drove my car from Milwaukee to Brainerd which is 470 miles each way.
i started AI (100% methanol) in 2003. i can tell you i ran one of the motors i built for 4 years at approx 500 hp, about 20 psi w a Garrett G4094r. after 4 years i disassembled it primarily to check sideseal gap. at the time it was continuing to gain compression. from around 385 to 435 mm Hg. the big question of course is i was just doing road romps although i did do two track events at Road America which has 3 long straights. this was all on 93 pump and about 900 cc of meth.
of course WM would be much easier on the prelube.
01-19-23, 02:04 PM
#69
I don't know.
j9fd3s is good at getting to the bottom of these mysteries.
-edit- you probably already saw it, but both part #s you list are unavailable and mazda motorsports shows N3Y2-11-B10A as the supesession part # for them
j9fd3s is good at getting to the bottom of these mysteries.
-edit- you probably already saw it, but both part #s you list are unavailable and mazda motorsports shows N3Y2-11-B10A as the supesession part # for them
Last edited by BLUE TII; 01-19-23 at 02:11 PM.
01-20-23, 09:06 AM
#72
Racing Rotary Since 1983
iTrader: (6)
" its not warping, its a high rate of wear on the side that travels over the Leading plug thermal expansion hump formed from detonation heat."
your comment was interesting. while there clearly can be dynamic changes re the apex seal based on heat... (won't hot start but will cold start)... is a seal that shows a .003 air gap in the center warped OR is that crown area worn off the seal. the wear would be caused by spark plug mountain AND a lack of suitable lubrication. i asked Dr Iannetti and he provided a method to answer the question.
measure apex seal height at both ends of the inner spring recess and the center. normally i would use my 0 to 1 inch micrometer but it doesn't work well as the barrel rotates so i used my vernier caliper.
the seals came from a motor w Iannetti I-Seals. in this case the front rotor was PERFECT and the back rotor showed 62. the front seals showed no light between them and a laboratory grade straight piece of stainless steel. the rears showed light and measured .003 on all 3 seals.
just to be clear, this shows the seals weren't the problem as the fronts were perfect. something effected the rear rotor system.
i measured all 6 seals at the 3 heights and took the average for the front and rear rotor.
i found the average of the 3 front rotor seals at the 3 locations was .0148 taller than the rear. so, overall, there was more wear on the rear seals.
where it became especially interesting was i found an average .0049 less height in the middle of the seal compared to the outer beam. since i was using a vernier caliper i wouldn't bet my life on my number being absolutely accurate but no question the center of the apex seal showing light was due to WEAR not warpage.
yet the front had virtually no center wear.
i have posted about spark plug mountain... the fact that as it becomes hotter the metal boss around the spark plug must expand and part of this expansion is radial towards the crank. this lifts the apex seal off the housing creating a loss of compression. it also is the cause of chatter on the housings which is evil. colder plugs lower spark plug mountain. decreased knock levels lowers spark plug mountain. (there is always some knock in boost...anyone w a good knock system knows that..) AI greatly reduces knock levels whenever it is triggered.
my conclusion:
while i agree that seals can shapechange w heat most non functioning apex seals are WORN in the centers due to encountering spark plug mountain due to improper lube, timing or AFR. i agree w Blue TII
your comment was interesting. while there clearly can be dynamic changes re the apex seal based on heat... (won't hot start but will cold start)... is a seal that shows a .003 air gap in the center warped OR is that crown area worn off the seal. the wear would be caused by spark plug mountain AND a lack of suitable lubrication. i asked Dr Iannetti and he provided a method to answer the question.
measure apex seal height at both ends of the inner spring recess and the center. normally i would use my 0 to 1 inch micrometer but it doesn't work well as the barrel rotates so i used my vernier caliper.
the seals came from a motor w Iannetti I-Seals. in this case the front rotor was PERFECT and the back rotor showed 62. the front seals showed no light between them and a laboratory grade straight piece of stainless steel. the rears showed light and measured .003 on all 3 seals.
just to be clear, this shows the seals weren't the problem as the fronts were perfect. something effected the rear rotor system.
i measured all 6 seals at the 3 heights and took the average for the front and rear rotor.
i found the average of the 3 front rotor seals at the 3 locations was .0148 taller than the rear. so, overall, there was more wear on the rear seals.
where it became especially interesting was i found an average .0049 less height in the middle of the seal compared to the outer beam. since i was using a vernier caliper i wouldn't bet my life on my number being absolutely accurate but no question the center of the apex seal showing light was due to WEAR not warpage.
yet the front had virtually no center wear.
i have posted about spark plug mountain... the fact that as it becomes hotter the metal boss around the spark plug must expand and part of this expansion is radial towards the crank. this lifts the apex seal off the housing creating a loss of compression. it also is the cause of chatter on the housings which is evil. colder plugs lower spark plug mountain. decreased knock levels lowers spark plug mountain. (there is always some knock in boost...anyone w a good knock system knows that..) AI greatly reduces knock levels whenever it is triggered.
my conclusion:
while i agree that seals can shapechange w heat most non functioning apex seals are WORN in the centers due to encountering spark plug mountain due to improper lube, timing or AFR. i agree w Blue TII
01-20-23, 10:02 AM
#74
Racecar - Formula 2000
Howard, I really like following your detailed analyses of issues. If you aren't a mechanical engineer, you should be!
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Neutron (01-20-23)
01-20-23, 11:10 AM
#75
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" its not warping, its a high rate of wear on the side that travels over the Leading plug thermal expansion hump formed from detonation heat."
your comment was interesting. while there clearly can be dynamic changes re the apex seal based on heat... (won't hot start but will cold start)... is a seal that shows a .003 air gap in the center warped OR is that crown area worn off the seal. the wear would be caused by spark plug mountain AND a lack of suitable lubrication. i asked Dr Iannetti and he provided a method to answer the question.
measure apex seal height at both ends of the inner spring recess and the center. normally i would use my 0 to 1 inch micrometer but it doesn't work well as the barrel rotates so i used my vernier caliper.
the seals came from a motor w Iannetti I-Seals. in this case the front rotor was PERFECT and the back rotor showed 62. the front seals showed no light between them and a laboratory grade straight piece of stainless steel. the rears showed light and measured .003 on all 3 seals.
just to be clear, this shows the seals weren't the problem as the fronts were perfect. something effected the rear rotor system.
i measured all 6 seals at the 3 heights and took the average for the front and rear rotor.
i found the average of the 3 front rotor seals at the 3 locations was .0148 taller than the rear. so, overall, there was more wear on the rear seals.
where it became especially interesting was i found an average .0049 less height in the middle of the seal compared to the outer beam. since i was using a vernier caliper i wouldn't bet my life on my number being absolutely accurate but no question the center of the apex seal showing light was due to WEAR not warpage.
yet the front had virtually no center wear.
i have posted about spark plug mountain... the fact that as it becomes hotter the metal boss around the spark plug must expand and part of this expansion is radial towards the crank. this lifts the apex seal off the housing creating a loss of compression. it also is the cause of chatter on the housings which is evil. colder plugs lower spark plug mountain. decreased knock levels lowers spark plug mountain. (there is always some knock in boost...anyone w a good knock system knows that..) AI greatly reduces knock levels whenever it is triggered.
my conclusion:
while i agree that seals can shapechange w heat most non functioning apex seals are WORN in the centers due to encountering spark plug mountain due to improper lube, timing or AFR. i agree w Blue TII
your comment was interesting. while there clearly can be dynamic changes re the apex seal based on heat... (won't hot start but will cold start)... is a seal that shows a .003 air gap in the center warped OR is that crown area worn off the seal. the wear would be caused by spark plug mountain AND a lack of suitable lubrication. i asked Dr Iannetti and he provided a method to answer the question.
measure apex seal height at both ends of the inner spring recess and the center. normally i would use my 0 to 1 inch micrometer but it doesn't work well as the barrel rotates so i used my vernier caliper.
the seals came from a motor w Iannetti I-Seals. in this case the front rotor was PERFECT and the back rotor showed 62. the front seals showed no light between them and a laboratory grade straight piece of stainless steel. the rears showed light and measured .003 on all 3 seals.
just to be clear, this shows the seals weren't the problem as the fronts were perfect. something effected the rear rotor system.
i measured all 6 seals at the 3 heights and took the average for the front and rear rotor.
i found the average of the 3 front rotor seals at the 3 locations was .0148 taller than the rear. so, overall, there was more wear on the rear seals.
where it became especially interesting was i found an average .0049 less height in the middle of the seal compared to the outer beam. since i was using a vernier caliper i wouldn't bet my life on my number being absolutely accurate but no question the center of the apex seal showing light was due to WEAR not warpage.
yet the front had virtually no center wear.
i have posted about spark plug mountain... the fact that as it becomes hotter the metal boss around the spark plug must expand and part of this expansion is radial towards the crank. this lifts the apex seal off the housing creating a loss of compression. it also is the cause of chatter on the housings which is evil. colder plugs lower spark plug mountain. decreased knock levels lowers spark plug mountain. (there is always some knock in boost...anyone w a good knock system knows that..) AI greatly reduces knock levels whenever it is triggered.
my conclusion:
while i agree that seals can shapechange w heat most non functioning apex seals are WORN in the centers due to encountering spark plug mountain due to improper lube, timing or AFR. i agree w Blue TII