Hot Plugs and Carbs

[macssc911]

Presently running a neutral plug, WR7 DC+ Bosch . PMOS running a little rich, spoke with Richard at PMO and he suggested maybe a little hotter plug. Anyone out there tried, thinking WR8DC or NGK BPR5ES. Engine is hot rod, Pistons cams etc
Thanks

[JJ 911SC]

Contact NGK, give then your spec and they will recommend a plug. They answer within 30 minutes using their contact form: NGK Spark Plugs USA


For my stock 3.2 (no internal mod) with PMO EFI using Electromotive TecGT they recommended BPR6EIX 6637.

I was running rich using using the WR7DC+

Unfortunately, I won't be able to try them for another month.

[T77911S]

how do the plugs look when pull them?
are you fouling plugs?
how do you drive the car?

if fouling then run a hotter plug.
if racing run a colder plug.
if city driving or idling a lot run a hotter plug.

a "hot" plug is really only needed for idling and startup. if a car was only driven at hiway speeds you could run a very cold plug.

look at it this way, the temperature range of the plug is what keeps it clean. it has to stay clean to keep from fouling. if you are not fouling them then you are probably OK but this can also depend on my other questions and how they look.

hopfully this will help YOU decide on what you need

[john walker's workshop]

I've run both the plugs you mentioned on MFI and carbed hot rod engines. Prefer NGK over Bosch.

[JJ 911SC]

This may help as well;

How do I "read" a spark plug?NGK Spark Plugs USA

Why are there different heat ranges? NGK Spark Plugs USA

Heat Range: NGK Spark Plugs USA

[macssc911]

Originally Posted by T77911S

how do the plugs look when pull them?
are you fouling plugs?
how do you drive the car?

if fouling then run a hotter plug.
if racing run a colder plug.
if city driving or idling a lot run a hotter plug.

a "hot" plug is really only needed for idling and startup. if a car was only driven at hiway speeds you could run a very cold plug.

look at it this way, the temperature range of the plug is what keeps it clean. it has to stay clean to keep from fouling. if you are not fouling them then you are probably OK but this can also depend on my other questions and how they look.

hopfully this will help YOU decide on what you need

I do both DE as well as being a law abiding citizen wihen no one is playing attention, compression 98 . HP around 275 . Changing plugs next week and then going to look at accelerater pumps , No fouling just black plugs and AFM is not giving me Good ratio in middle range. Just work In progress a good part of the ownership experience
Thanks for you input

[JJ 911SC]

Originally Posted by macssc911

... No fouling just black plugs...

More like Dry Fouling (carbon) PLUG STUDIO / NGK

[snbush67]

NGK BPR5ES burn clean in my motor.

[T77911S]

fix the AFR. also could be timing. maybe not enough advance at that RPM

i dont think i would go hotter.