is there any way to change timing on both rotors independently? the reason i ask is because my brothers motor is built wrong. his builder used one s5 housing and one s4 housing. the spark plug holes are in different locations by about 5*. so my idea is to try to retard one rotor only by 5* so it will be with the same time as the other motor. he knows that this might not be possible but its worth a shot before we have to tear the motor down to fix this bonehead mistake

 

... bleh ... even if ms could do that, I would still open that motor and get matching housings ...

 

heres what you do.. go over to the builders house.. and karate chop him in the head.. now tear the motor apart and fix it if you wish... k my logic may be off here.. but timing is not effected by the possition of the spark plug - well in this case at least. you see as long as the rotor is in the correct possition when a spark event is triggered then it will be the correct timing. i would believe that the possition of the spark plug would change how well the flame propagates across the rotor surface, influencing power, and has little effect on timing.

please correct me if im wrong..

 

Timing is not affected by plug position, but the flame fronts will be slightly different from one to another. You definitely don't want to be messing about with different timing to attempt to correct this. I'd suggest you ask in the more active areas of the forum to see if anyone has any practical experience with a similar mistake. I suspect in the big picture, it's not a serious issue, but that's nothing but conjecture on my part. Let's just hope that's the only mistake during the build!

 

i still say karate chop him!

 

On the S5 test car (the first rx7 that we originally megasquirted, also the first rx7 to run a fully stock ignition system with the megasquirt) we could consistantly run more advanced timing than on our S4s... in both cases we were running stock NA engines. The S4 would knock with timings similar to the S5 once load was increased.

Ken