pd_day

iTrader: (6)

I have read on some of the threads that by cutting the washers off the spark plugs, the plugs would go into the housing more and in turn less volume for the a/f to compress, which = higher compression. Have anyone successfully done this?

Audiofight

From what I have gathered, Mazdaspeed7 (sorry if the handle is misspelled, no offense) has done this and it works.

The housing have a deep enough chamber for the spark plugs that the rotors clear it even w/o the rings on the plugs.

Haven't tried this myself, might want to wait for a more definite response.

pd_day

iTrader: (6)

I have checked the washerless sparkplug in the housing and indeed it does clear. I am just wondering how much power is harvested, and if higher octane gas is needed to avoid detonation.

Thanks

tims

the gap filled by the spark plug would not make a dramatic affect on the compression ratio. the increase in power is more likely from a more complete burn of the charge in the cumbustion chamber. without developing a new rotor there is no way to increase the compression if you are already using the 89 and later N/A rotors. I have thought about a spray metal treatment to an existing stock rotor, but this is a very expensive experiment and has not been tried yet.

rx7_ragtop

Hmmmm... IF you know someone who could weld cast iron... and you had a few extra rotors laying around... you MIGHT try filling the dish in the rotor face in slightly. Chances are you would simply destroy the rotor in the process... and even if you were able to do it successfully... you would then have to make sure the volume and shape of the dish on all 3 sides on both rotors was identical... and then also have to remove metal from another area to return them to stock weight. NOT a simple process. The rotors are cast iron, and would have to be heated evenly to a high enough temperature to prevent them from cracking when welded due to uneven heat distribution. What a headache.

Brad

SuperchargedRex

What if you had someone with a CNC machine first measure a stock rotor, and then cut a new one with the measurements for the dish modified? I'm guessing it'd be expensive, and you might end up screwing up the the flow and burn dynamics of the chamber when you change the shape, but what if you just made the dish a little shallower?

ROSHX7

Hmm, maybe I should try this and see!

Green

haha I'm going out with my hack saw tommorow, I'll let ya know how it works out hahaha... Without professional equip, Lots of research.. tossing numbers around... you will most likely end up breaking lots of stuff

I'm sure mazda has prototype's for much higher compression rotors.. maybe the engine didn't last long so they decided not to use them...

Shrug.. My guess

supergoat

So the rotors WILL clear the sparkplugs even if you cut the washers off?

tweaked

iTrader: (4)

I thought about finding someone with the equipment to cut some new rotors, Then I thought about Billit rotors!!!
But I thought $$$$$$$ so I droped it.
'It would be easy to cut new rotors if you had one to measure, as long as the measuments were exact. However, finding someone that would want to do this at an affordable price would be imposible. If any body finds this person let me know.