Stumpalump

I never used index washers but instead just select a plug that winds up in a basic general direction. Typically the open end facing the exhaust valve or largest part of cumbustion chamber. I've never seen a head off of this motor and was wondering if one side of the cumbustion chamber was larger so I could point the plugs that way. 4 valve and center plug is as good as it gets but if you were going to point them then where would it be? This sand car goes from WOT to off throttle to back on as fast as possible over and over to control steering and front end height so it needs to fire perfect. High voltage coils and new plugs are in the mail to ease the flame out so I figured I should index the plugs as well.

Sharkey

iTrader: (1)

its not really nesessary to index a plug when it comed straight down into the cylinder. yes there are gains to be had in a typical ohv engine where the plug comes into the side of the chamber, albiet small gains.

Stumpalump

Best to point them if the head and piston favor a larger part of the cumbustion chamber. Is it symmetrical? Has anybody tried the new ZZP high out put coils and did you fool with wider plug gaps? ZZP High Voltage Coil Packs-LSJ

Staged07SS

iTrader: (25)

I have the zzp coils. They work as advertised.

Stumpalump

They worked good on mine as well. .040 gap on one step colder NGK Iridiums. ZZP recomended .045 but with the leaded fuel and bouncing around I played it safe. Biggest difference is top end smoothness. I hit the rev limiter more in 3 days after installing them than in the last 3 years combined. It just keeps pulling at top end. It does not seem to surge or hunt for idle after a prolonged hard run either. Thanks ZZP!

Staged07SS

iTrader: (25)

Glad they worked out for ya.

Yeah 0.045 is wayyyy too large of a gap. They are great coils but not 0.045 great, lol.

You were smart to not listen to that advice.