has any 1 played with the trailing plug hole size?

 

good question...

 

i'd like to know about that one... while i have my engine apart.. i want to do every thing i can to this thing... (looking at getting all performance machining for free...)

 

i feel there would be better flame front burn maybe if it were

 

mazda did and the larger you make the hole the more "blowby" you get

mike

 

the compression ratio would change also

 

that makes sense

 

No,no,no,no...please leave it the stock size!!!!
I had the same idea...i thought that the flame travel would be better.I made the hole 0.31 " (8mm)
BIG MISTAKE !!!

The compression was fine before i did it...afterwards it wouldnt start without the addiction of ATF..(100cc minimum).
It wouldnt idle below 1600rpm,and just died.It ran horrible,and had no power.

After opening the engine again,i saw when i turned it,that almost all the compression was lost,with the gas escaping past the apex seal through the hole.The stock hole size is 0.15 " (4mm) with 3mm apex seals.My housings are useless now,you cant fix it,seeing that when you wled it,the housing warps,and the apex seal eats away the spot that was welded in the hard chrome.

Please use my advise...leave it stock