True or False: all RX-8 engines are slowly being damaged…
11-05-2006 | 01:53 PM
#28
Self built and tuned...
Joined: Jul 2006
Posts: 81
Likes: 0
From: Long Island, NY
Here is some more input on the build of the Rx8 engines... This is quoted from a well respected Rx7 forum member...
"The side seals for example in my opinion have a major flaw. Just about every motor I have opened, all the side seals looked like they had over 300k miles on it. Excessive side seal clearance only leads to one thing period in a rotary motor. One that's going to beat itself to death in a very short time. Most of the motors are suffering from blow-by and lost of compression in very short periods. The motors are experiencing the same problems they did when Mazda tried the 'multi side port' experiments in the 70's and then they blamed the induction choice of the time which was carburation for leading to excessive carbon build up in both the intake and exhaust ports to the point where the ports would almost completly become blocked by carbon. I guess modern day fuel injection did not stop that from happenning.
Mazda had no choice to assemble the side seals in the rx-8 motor with excessive clearance due to the high rate of expansion from heat transfered from the exhaust port. The side seal clearance in the rx-8 motor at minimum would come up at 0.010 to 0.015 inches from factory. The excessive clearance is causing the side seals to hammer a groove into the corner seals which results in lower compression over a period of time not to mention a path for the exhaust gasses to escape back into the fresh intake mixture. Ever wondered why some of the rx-8's are experiencing worst fuel economy than what Mazda claims from factory or even what was experienced in the previous rx-7.
The above is just what I've experienced on a pesonal level. It's obvious that not all the rx-8s are experiencing the same problems but only time will tell.
__________________
crispeed"
"The side seals for example in my opinion have a major flaw. Just about every motor I have opened, all the side seals looked like they had over 300k miles on it. Excessive side seal clearance only leads to one thing period in a rotary motor. One that's going to beat itself to death in a very short time. Most of the motors are suffering from blow-by and lost of compression in very short periods. The motors are experiencing the same problems they did when Mazda tried the 'multi side port' experiments in the 70's and then they blamed the induction choice of the time which was carburation for leading to excessive carbon build up in both the intake and exhaust ports to the point where the ports would almost completly become blocked by carbon. I guess modern day fuel injection did not stop that from happenning.
Mazda had no choice to assemble the side seals in the rx-8 motor with excessive clearance due to the high rate of expansion from heat transfered from the exhaust port. The side seal clearance in the rx-8 motor at minimum would come up at 0.010 to 0.015 inches from factory. The excessive clearance is causing the side seals to hammer a groove into the corner seals which results in lower compression over a period of time not to mention a path for the exhaust gasses to escape back into the fresh intake mixture. Ever wondered why some of the rx-8's are experiencing worst fuel economy than what Mazda claims from factory or even what was experienced in the previous rx-7.
The above is just what I've experienced on a pesonal level. It's obvious that not all the rx-8s are experiencing the same problems but only time will tell.
__________________
crispeed"
11-05-2006 | 03:16 PM
#29
Registered User
Joined: Jan 2006
Posts: 196
Likes: 0
From: Walnut Grove CA
Wouldn't Mazda know this by now? And if so, why would they have extended our warrantees? Would you foresee them redesigning and replacing most if not all of our engines before those warrantees expire? And if so, wouldn't that spell certain financial doom for Mazda?
Originally Posted by AnthonyNYC
Here is some more input on the build of the Rx8 engines... This is quoted from a well respected Rx7 forum member...
"The side seals for example in my opinion have a major flaw. <SNIP> One that's going to beat itself to death in a very short time. <SNIP> The motors are experiencing the same problems they did when Mazda tried the 'multi side port' experiments in the 70's and then they blamed the induction choice of the time which was carburation for leading to excessive carbon build up in both the intake and exhaust ports to the point where the ports would almost completly become blocked by carbon. I guess modern day fuel injection did not stop that from happenning. <SNIP> The excessive clearance is causing the side seals to hammer a groove into the corner seals which results in lower compression over a period of time not to mention a path for the exhaust gasses to escape back into the fresh intake mixture. <SNIP> It's obvious that not all the rx-8s are experiencing the same problems but only time will tell.
__________________
crispeed"
"The side seals for example in my opinion have a major flaw. <SNIP> One that's going to beat itself to death in a very short time. <SNIP> The motors are experiencing the same problems they did when Mazda tried the 'multi side port' experiments in the 70's and then they blamed the induction choice of the time which was carburation for leading to excessive carbon build up in both the intake and exhaust ports to the point where the ports would almost completly become blocked by carbon. I guess modern day fuel injection did not stop that from happenning. <SNIP> The excessive clearance is causing the side seals to hammer a groove into the corner seals which results in lower compression over a period of time not to mention a path for the exhaust gasses to escape back into the fresh intake mixture. <SNIP> It's obvious that not all the rx-8s are experiencing the same problems but only time will tell.
__________________
crispeed"
11-05-2006 | 04:46 PM
#31
Self built and tuned...
Joined: Jul 2006
Posts: 81
Likes: 0
From: Long Island, NY
Originally Posted by 9291150
Well, if its quoted from a "well respected" RX7 member, that all I need to know...
...THE SKY IS FALLING THE SKY IS FALLING...MUST SELL CAR...
...THE SKY IS FALLING THE SKY IS FALLING...MUST SELL CAR...
Anthony
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