Losing Compression On Dyno, Any Ideas?
05-02-2004, 08:11 PM
#42
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Join Date: Feb 2003
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Originally Posted by Badog' date='May 2 2004, 10:54 AM
Wow. Bad news. At least you got some good people scratching their heads over it.
Sounds like the merging of results of multiple variables over time.
Sounds like the merging of results of multiple variables over time.
05-02-2004, 08:16 PM
#43
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Join Date: Aug 2002
Posts: 502
Originally Posted by Badog' date='May 2 2004, 10:54 AM
Wow. Bad news. At least you got some good people scratching their heads over it.
Sounds like the merging of results of multiple variables over time.
Sounds like the merging of results of multiple variables over time.
05-02-2004, 08:26 PM
#44
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I would like to add that "ccarlisi" has been invaluable. This is not a one man job and Chris has taken his time, driven up from Boston and spent many hours of his time researching and working on my car at no charge. Many in the rx7 community have also given of thier time as mentioned above. I could not have done this alone. Thanks Chris, Sean, Steve, Judge ITO, and Demitrious.
There are people who I am probably forgetting but everyone has been helpful. I am confident all these great Rotary minds will help me solve this issue.
There are people who I am probably forgetting but everyone has been helpful. I am confident all these great Rotary minds will help me solve this issue.
05-03-2004, 07:36 AM
#45
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This problem we are having with Mike's engine is a serious pain in the ***. Before Mike brought me the engine the car was being worked at KDR and had some engine problems over there. I built this nice engine for mike and KDR installs it. I tell mike to bring me the car over so I could go over it(check ignition timing) sure enough the trigger wires to the crank angle sensor was inverted and the engine timing was too advanced causing problems with his other engines. I fix that problem and told mike to break his engine in. Before when the car was at KDR the engines were breaking apex seals from detonation(timing was to advanced from inverted sensor wires) this time on my engine the apex seals warped. Basically the seals overheated and curled up in the center and looses connection to the surface of the rotor housing causing a loss of vacuum and compression.
Later after some more searching into mike's car I found a problem with the secondary injector harness. I fix that problem, rebuilt the engine and again after some dyno tunning the apex seals warped. I do some more research. I blue print the engine. I mean I measured every single part of the engine for bad rotor houisngs bad rotors and fine every single part with in specs. In my years I have seen apex seals warp and curl up when the engine is running super lean and creates more internal combustion temperatures then what the apex seals are built to take. If the apex seals heat up past a point they will warp.
Know addressing warped apex seals. I talk to Steve kan and he told me that the engine seems to be needing more fuel then normal and that the front rotor was running leaner then the back rotor. some corrections was done to the power fc and the balance between rotors was better.( this could have been the cause of a bad primary injector) Steve told me that the tunning was very weird, that other cars with this type of fuel being pumped into the engine would not even run but mike's car was fine. clearly there is a fuel problem but where?
I talked to JIM Mederer from Racing Beat to pic his brain, and he told me a couple of scenarios.
1) fuel mixture to lean will cause high exhaust gas temperatues(we already know this)
2) not enough pre-mix(bad metering oil pump)
3)oil temperature to high and will not cool off the rotor's and transfer heat away from the apex seals.
4) after market secondary injectors may have a fuel spray pattern that will not flow in a suspended state into the intake manifold. If the wrong sencondary injectors are used the intake manifold walls will get saturated with fuel and cause a lean condition and elevate combustion temperatures.
All I could say is that I have tuned and seen engines run at 15 to 44lbs of boost and apex seals are not warping like mikes engine at 13 to 15lbs of boost. In mikes car we have a serious bug and I feel is fuel related. (not enough fuel via bad injectors high or low impedance problem with the power FC) I too want to get to the bottom of this problem and learn from it. I will not want this to happed again. The power FC is in question now.
And yes the rotor housing exhaust ports are beveled. Let's not forget I started that whole thread.
Later after some more searching into mike's car I found a problem with the secondary injector harness. I fix that problem, rebuilt the engine and again after some dyno tunning the apex seals warped. I do some more research. I blue print the engine. I mean I measured every single part of the engine for bad rotor houisngs bad rotors and fine every single part with in specs. In my years I have seen apex seals warp and curl up when the engine is running super lean and creates more internal combustion temperatures then what the apex seals are built to take. If the apex seals heat up past a point they will warp.
Know addressing warped apex seals. I talk to Steve kan and he told me that the engine seems to be needing more fuel then normal and that the front rotor was running leaner then the back rotor. some corrections was done to the power fc and the balance between rotors was better.( this could have been the cause of a bad primary injector) Steve told me that the tunning was very weird, that other cars with this type of fuel being pumped into the engine would not even run but mike's car was fine. clearly there is a fuel problem but where?
I talked to JIM Mederer from Racing Beat to pic his brain, and he told me a couple of scenarios.
1) fuel mixture to lean will cause high exhaust gas temperatues(we already know this)
2) not enough pre-mix(bad metering oil pump)
3)oil temperature to high and will not cool off the rotor's and transfer heat away from the apex seals.
4) after market secondary injectors may have a fuel spray pattern that will not flow in a suspended state into the intake manifold. If the wrong sencondary injectors are used the intake manifold walls will get saturated with fuel and cause a lean condition and elevate combustion temperatures.
All I could say is that I have tuned and seen engines run at 15 to 44lbs of boost and apex seals are not warping like mikes engine at 13 to 15lbs of boost. In mikes car we have a serious bug and I feel is fuel related. (not enough fuel via bad injectors high or low impedance problem with the power FC) I too want to get to the bottom of this problem and learn from it. I will not want this to happed again. The power FC is in question now.
And yes the rotor housing exhaust ports are beveled. Let's not forget I started that whole thread.
05-03-2004, 11:39 AM
#48
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Join Date: May 2002
Location: California
Posts: 22,465
Originally Posted by Judge Ito' date='May 3 2004, 04:36 AM
This problem we are having with Mike's engine is a serious pain in the ***. Before Mike brought me the engine the car was being worked at KDR and had some engine problems over there. I built this nice engine for mike and KDR installs it. I tell mike to bring me the car over so I could go over it(check ignition timing) sure enough the trigger wires to the crank angle sensor was inverted and the engine timing was too advanced causing problems with his other engines. I fix that problem and told mike to break his engine in. Before when the car was at KDR the engines were breaking apex seals from detonation(timing was to advanced from inverted sensor wires) this time on my engine the apex seals warped. Basically the seals overheated and curled up in the center and looses connection to the surface of the rotor housing causing a loss of vacuum and compression.
Later after some more searching into mike's car I found a problem with the secondary injector harness. I fix that problem, rebuilt the engine and again after some dyno tunning the apex seals warped. I do some more research. I blue print the engine. I mean I measured every single part of the engine for bad rotor houisngs bad rotors and fine every single part with in specs. In my years I have seen apex seals warp and curl up when the engine is running super lean and creates more internal combustion temperatures then what the apex seals are built to take. If the apex seals heat up past a point they will warp.
Know addressing warped apex seals. I talk to Steve kan and he told me that the engine seems to be needing more fuel then normal and that the front rotor was running leaner then the back rotor. some corrections was done to the power fc and the balance between rotors was better.( this could have been the cause of a bad primary injector) Steve told me that the tunning was very weird, that other cars with this type of fuel being pumped into the engine would not even run but mike's car was fine. clearly there is a fuel problem but where?
I talked to JIM Mederer from Racing Beat to pic his brain, and he told me a couple of scenarios.
1) fuel mixture to lean will cause high exhaust gas temperatues(we already know this)
2) not enough pre-mix(bad metering oil pump)
3)oil temperature to high and will not cool off the rotor's and transfer heat away from the apex seals.
4) after market secondary injectors may have a fuel spray pattern that will not flow in a suspended state into the intake manifold. If the wrong sencondary injectors are used the intake manifold walls will get saturated with fuel and cause a lean condition and elevate combustion temperatures.
All I could say is that I have tuned and seen engines run at 15 to 44lbs of boost and apex seals are not warping like mikes engine at 13 to 15lbs of boost. In mikes car we have a serious bug and I feel is fuel related. (not enough fuel via bad injectors high or low impedance problem with the power FC) I too want to get to the bottom of this problem and learn from it. I will not want this to happed again. The power FC is in question now.
And yes the rotor housing exhaust ports are beveled. Let's not forget I started that whole thread.
Later after some more searching into mike's car I found a problem with the secondary injector harness. I fix that problem, rebuilt the engine and again after some dyno tunning the apex seals warped. I do some more research. I blue print the engine. I mean I measured every single part of the engine for bad rotor houisngs bad rotors and fine every single part with in specs. In my years I have seen apex seals warp and curl up when the engine is running super lean and creates more internal combustion temperatures then what the apex seals are built to take. If the apex seals heat up past a point they will warp.
Know addressing warped apex seals. I talk to Steve kan and he told me that the engine seems to be needing more fuel then normal and that the front rotor was running leaner then the back rotor. some corrections was done to the power fc and the balance between rotors was better.( this could have been the cause of a bad primary injector) Steve told me that the tunning was very weird, that other cars with this type of fuel being pumped into the engine would not even run but mike's car was fine. clearly there is a fuel problem but where?
I talked to JIM Mederer from Racing Beat to pic his brain, and he told me a couple of scenarios.
1) fuel mixture to lean will cause high exhaust gas temperatues(we already know this)
2) not enough pre-mix(bad metering oil pump)
3)oil temperature to high and will not cool off the rotor's and transfer heat away from the apex seals.
4) after market secondary injectors may have a fuel spray pattern that will not flow in a suspended state into the intake manifold. If the wrong sencondary injectors are used the intake manifold walls will get saturated with fuel and cause a lean condition and elevate combustion temperatures.
All I could say is that I have tuned and seen engines run at 15 to 44lbs of boost and apex seals are not warping like mikes engine at 13 to 15lbs of boost. In mikes car we have a serious bug and I feel is fuel related. (not enough fuel via bad injectors high or low impedance problem with the power FC) I too want to get to the bottom of this problem and learn from it. I will not want this to happed again. The power FC is in question now.
And yes the rotor housing exhaust ports are beveled. Let's not forget I started that whole thread.
secondly, you may want to check the oil temps, maybe the thermostat in the oil cooler died? i know ive never seen that but you're now looking for wierd stuff, imo
05-03-2004, 01:43 PM
#49
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Join Date: Nov 2002
Location: Honolulu, Hawaii USA
Posts: 925
The pics above look like the apex seals were rocking in the grooves.
This is typical of too much clearance on the apex seal groove (highly unlikely), inadequate apex seal lubrication (are you running pre-mix or stock OMP?), or detonation (causes the seal to chatter along the rotor housing surface)...or all of the above.
-Ted
This is typical of too much clearance on the apex seal groove (highly unlikely), inadequate apex seal lubrication (are you running pre-mix or stock OMP?), or detonation (causes the seal to chatter along the rotor housing surface)...or all of the above.
-Ted
05-03-2004, 04:49 PM
#50
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Join Date: Feb 2003
Location: NewHampshire
Posts: 100
We have been using 3ohm resistors on the secondairies but we have mixed opinions about them. Some say they use them with the PFC some say they dont. Some say the resistors can cause a lean condition that happens so fast the Wideband wont pick it up. Also that the 1680cc inj change thier current needs as they warm up. All very confusing. I understood that you needed the resistors as to not overheat the inj driver (chip) in the PFC.
RETed, Thanks for the reply. I had hoped to get your input.
The clearance on the motor was done by ITO and i believe the tolerances might be a little greater but i dont know on what parts. Maybe Ito can answer this one. Is this whats meant by Race clearancing? Also i would like to add I get massive fuel in my oil and the crankcase is being pressurized by the cumbustion pressure.
RETed, Thanks for the reply. I had hoped to get your input.
The clearance on the motor was done by ITO and i believe the tolerances might be a little greater but i dont know on what parts. Maybe Ito can answer this one. Is this whats meant by Race clearancing? Also i would like to add I get massive fuel in my oil and the crankcase is being pressurized by the cumbustion pressure.