Jdrift

DOne a few searches and a ton of reading, and thus far I haven't turned up anything to give me a solid awnser to my question.

Basicly when I pulled the engine from my 88 GXL ( na of course) I tore it down in hopes of being able to do a rebiuld. Afte the tear down I found an Apex seal broke off and jammed up the rear housing resulting in a useless housing and rotor( Of which I plan on making a clock and a fish tank out of for the hell of it.

My question is this. The trailing sparkplug hole is merely a pin hole in compairson to the leading plug hole. Not looking for any power gains and more for a cleaner burn. Would it be plauseable to machine the hole to be a little bigger to allow the spark to enter the chamber more readily. ( I'm assuming I would probably need to run a stronger ignition system to give a stronger spark.)

Just wanna hear the thoughts on it.Yes, no and the reason for it. I figured if a rebiuld was being done if that would be a step that could provide a little more stability in idle and perhaps a small gain of power due to a more complete burn. Thanks.

Go48

iTrader: (7)

My thought is that the leading plug hole can be a failure point in the housing with cracking over time. (Check out some rebuild threads with pics to see what I mean.) So, for that reason, and because the power gain would likely be very small if at all, I would avoid opening up the trailing hole. Just my opinion.

I will be very interested in other opinions, however.

Jdrift

Never really heard of housings' cracking, other than due to extreme heat. Honestly I'm not that worried about that.

Like I said before, i'm looking to help keep carbon biuld-up in the chambers to a minimum by allowing a more complete burn. ( Which is the main failure point in Rx-8s Renesis)

Thank you for the input thus far.

j9fd3s

iTrader: (3)

you should head over the foxed.ca and dl the book "rotary engine" its written by mazda, goes into great detail about how and why the engine is designed.

but in a nutshell, the trailing plug is in a spot where there is a big difference in pressure between the two chambers. if you put the apex seal right on the trailing plug hole, one chamber is in its intake stroke, and the other is in the compression stroke.

so basically the trailing plug hole needs to be small to limit leakage between chambers.

tweaked

iTrader: (4)

That's the way I understand it.

RotaryRocket88

iTrader: (7)

Something else that's mentioned in that book is the effect on compression ratio. Enlarging the opening for the trailing plugs would effectively reduce compression ratio by a small amount.