Deandome

My Feedback: (1)

I have a new T-Maxx w/about a gallon run thru it.

If I were to buy a pack of 10 glow plugs on e-bay, would I want McCoy # 59 or #9??

I know one is "hot" & the other "cold", but does that refer to the PLUG's temp or what ambient temp condition that the plug is good for?

Is there ONE plug that will work well al the time, or do I want a few of each for hot & cold days?

BTW, I'm a casual basher, not a racer, and I run a LITTLE rich to save the engine (no need to squeeze every last bit of power, it's PLENTY fast as is!). So far, the plug that came with my Maxx is going strong, but I read somewhere that I'm supposed to change it after break in, regardless of it's efeectiveness (is this true?).

Thanks for the help!

Dean Smith

nmtr13

My Feedback: (6)

Im pretty sure cold plugs are for hot weather, and hot plugs are for cold weather. So during the winter you would use a hot plug. Am i rite or wrong?

flatlander_14

eh kinda(as far as i know). i dont think cold plugs work all that well in small block engines witha few exceptions. i used a mccoy mc59 in my 2.5 when it was still alive. it worked well. i found it was a bit easier to tune that the stock plug. go for it.

Razoo

My Feedback: (2)

I use MC-8's in my 2.5 with no problems.

scale only 4 me

My Feedback: (158)

Sorry Bud, has nothing to do with the weather


LOL,
Cold and Hot Refer to the plugs ability to stay glowing
A colder plug is for Higher nitro 30% or Higher
a medium plug is for 20% or so nitro
a hot plug is for low nitro 10-15%

If you use a Hot plug with High nitro sometimes you get pre ignition, giving the engine less power, A cold plug with low nitro has a week glow also robbing potintial power.

Finding the right plug for the nitro% and compresion of you engine is important, as an engine gets older it starts loosing compresion forcing the need for a hotter plug and or higher nitro.

If you have a .21 and are running 30% and your eingine is in good condition MC-9 is the better choice, its the "Cold" plug for higher nitro.

if you're running a .15 on 20% the MC-59 might be better it's the "Hot" plug for low to medium nitro.

I run the MC-59 in my.12 engines on 20% nitro, it works well.

I scanned the chart for ya

BUGGIES_R_US

Yea hes right. Time to rate his post

Ididnt know that the MC-9 was a cold plug!!! I thought it was pretty equal to the 59.

SO MANY PEOPLE seem to think that they are. Some reliable souces have been wrong about this!

Guess now I know! Thanks for that little picture!

ram

Kuma

My Feedback: (1)

Hot plugs for cold weather, cold plugs for hot weather? HAHA, kind of silly...scale is right on the money, but I should also add that it usually helps to use hotter plugs on .12's and sometimes .15's, but .18's and .21's benefit better with cold plugs (in my experience). I use McCoy 9, and Rossi R5 in my .21s.

Monster Flip

as for the weather, you might want to richen it on hotter days and on colder (winter) days, you can choose to lean it out a little.

ZipZap

Exactly what flores4 said, except opposite!

COLD day=dense air; dense air=more air/stroke. More air needs more fuel. RICHEN

HOT day=less dense air: less dense air=less air/stroke. Less air needs less fuel. LEAN

Or, just bash and keep the temps under control.