ok, i have a 510 with a 13b 6 port in it.

i had a holly 600 cfm installed by the local rotary specialist.

he could never get it running right, basically saying "this carb is too big, it's running too rich".

well, the plugs were fouled so i bought four b7em's to install.

i removed the plugs that were put in by the rotary guy and i noticed the plugs were as follows-

upper left- br8eq
lower left- bur7eq

upper right- br8eq
lower right- bur9eq

would this make the car hard to start? or should it be no big deal?

also what spark plugs would you run?

 

wow an extra cold plug in rear leading chamber? who built this car / setup?

 

well, ummmm. the guy i bought the car from.

but, the guy that put the spark plugs in didn't build the car. he just installed the carb.

he then put these plugs in.

so, back to my question.

would this spark plug setup make the car hard to start? or should it be no big deal? or what?

also, what spark plugs would you use?

 

The Holley 600 cfm is too big for a street driven rotary.

A 7 heat range plug is too hot for an engine that you plan on driving hard; use a cooler plug like an 8 on the street, and then use colder and colder plugs (higher numbers) as you get more and more into hi-rpm racing operation. The high number plugs do tend to foul out in street idling and part throttle operation; that is why they make hotter 7 and 8 range plugs. An all out ported race engine will use 11 or 12 super cold plugs, but then those pure race engines are not operated below 6000 rpm.

The lower (leading) plugs tend to foul a little more than the upper (trailling) plugs. Sometimes people use one range hotter plug in the lower leading holes.