High compression spark plug question...
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- nickpohlaandp
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Re: High compression spark plug question...
He just text me that he went and bought some Autolite 26's. I think... from what I can find on Google, that those will be too high of a heat range. Can anyone back up that thought?
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Re: High compression spark plug question...
nickpohlaandp wrote:He just text me that he went and bought some Autolite 26's. I think... from what I can find on Google, that those will be too high of a heat range. Can anyone back up that thought?
I can't find my book so I used and online book and it comes out WAY too hot. The plug he is talking about is a 10:1 pump gas plug.
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Re: High compression spark plug question...
That's what I was seeing too. I told him not to use them. Hopefully he'll listen.statsystems wrote:nickpohlaandp wrote:He just text me that he went and bought some Autolite 26's. I think... from what I can find on Google, that those will be too high of a heat range. Can anyone back up that thought?
I can't find my book so I used and online book and it comes out WAY too hot. The plug he is talking about is a 10:1 pump gas plug.
Never half ass two things... Whole ass one thing!
Re: High compression spark plug question...
You really need to state the plug gasket or taper and reach length to get a good recommendation. You could be comparing different size plugs ,causing the confusion of heat ranges.
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Re: High compression spark plug question...
.460 reach, tapered seatRCJ wrote:You really need to state the plug gasket or taper and reach length to get a good recommendation. You could be comparing different size plugs ,causing the confusion of heat ranges.
Never half ass two things... Whole ass one thing!
Re: High compression spark plug question...
Here's my "rule of thumb". Compression ratio has nothing to do with anything. It's all about HP per cylinder/plug. I only use NGK so my ranges are for that.
Your plug, .460" reach, tapered seat, non extended tip. R5673-x
-6 up to 75hp per cylinder
-7 up to 85hp per cylinder
-8 up to 100hp per cylinder
-9 up to 125hp per cylinder
-10 up to 185hp per cylinder
There are other things that matter, fuel type, endurance/extended EGT etc etc. These are good starting points.
Rockauto.com has these racing plugs for $1.36 each.
Your plug, .460" reach, tapered seat, non extended tip. R5673-x
-6 up to 75hp per cylinder
-7 up to 85hp per cylinder
-8 up to 100hp per cylinder
-9 up to 125hp per cylinder
-10 up to 185hp per cylinder
There are other things that matter, fuel type, endurance/extended EGT etc etc. These are good starting points.
Rockauto.com has these racing plugs for $1.36 each.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: High compression spark plug question...
Your buddy is exactly opposite! That guy is a hole in a piston waiting to happen. Start cold, work hotter. Too cold = fouled plugs. Too hot = detonation. Which would you rather have?nickpohlaandp wrote:I am more curious as to whether or not his buddy's claim of using a hotter plug due to it being a high CR engine has any merit. My first instinct would be the exact opposite. Seems a hotter plug would lead to the greater possibility of detonation.
Heat range is all about keeping the plug porcelain at the right temp to cook off deposits, not affecting how well the plug can ignite the mixture (unless it fouls so bad the spark suffers, of course). That Depends on cylinder heat, which depends on load conditions, power output, compression, fuel, timing, etc. If you need a hotter spark, then you need different ignition components, not hotter plugs.
Even if you don't become an expert at reading plugs for mixture, at least learn what the early signs of detonation look like, which is much easier.
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Re: High compression spark plug question...
Good info! ThanksIn-Tech wrote:Here's my "rule of thumb". Compression ratio has nothing to do with anything. It's all about HP per cylinder/plug. I only use NGK so my ranges are for that.
Your plug, .460" reach, tapered seat, non extended tip. R5673-x
-6 up to 75hp per cylinder
-7 up to 85hp per cylinder
-8 up to 100hp per cylinder
-9 up to 125hp per cylinder
-10 up to 185hp per cylinder
There are other things that matter, fuel type, endurance/extended EGT etc etc. These are good starting points.
Rockauto.com has these racing plugs for $1.36 each.
Never half ass two things... Whole ass one thing!
Re: High compression spark plug question...
Yeah the chart will get you in the area you need to be, I never saw a big issue with plugs except fouling cold ones. The head manufacture usually has a base line plug recomendation, Her is a chart that may give you an idea.nickpohlaandp wrote:I just found something interesting while Googling for heat range comparisons between manufacturers in regard to Autolite plugs.
"The last digit in an Autolite part number represents the Heat Range within a plug family.
For example, take the 254x plug series. Autolite has 2544, 2545 and 2546 available. 2544 is the coldest plug in that plug family, and 2546 is the hottest.
However, according to an Autolite reference chart, Autolite 86 has the same heat range as 2244 and Autolite 303 is a hotter plug than 2974.
Therefore, it is impossible to chart an Autolite Heat Range hierarchy, let alone a standardized comparison to other spark plug brands."
Seems like you could easily get screwed up trying to change over from one brand to Autolite, or vice versa.
Plugs I have run for racing NGK -8 and (-9 nitrous), Autolite 133 and AC Delco , 44...(43 and 42 nitrous)
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
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Re: High compression spark plug question...
GARY C wrote:Yeah the chart will get you in the area you need to be, I never saw a big issue with plugs except fouling cold ones. The head manufacture usually has a base line plug recomendation, Her is a chart that may give you an idea.nickpohlaandp wrote:I just found something interesting while Googling for heat range comparisons between manufacturers in regard to Autolite plugs.
"The last digit in an Autolite part number represents the Heat Range within a plug family.
For example, take the 254x plug series. Autolite has 2544, 2545 and 2546 available. 2544 is the coldest plug in that plug kfamily, and 2546 is the hottest.
However, according to an Autolite reference chart, Autolite 86 has the same heat range as 2244 and Autolite 303 is a hotter plug than 2974.
Therefore, it is impossible to chart an Autolite Heat Range hierarchy, let alone a standardized comparison to other spark plug brands."
Seems like you could easily get screwed up trying to change over from one brand to Autolite, or vice versa.
Plugs I have run for racing NGK -8 and (-9 nitrous), Autolite 133 and AC Delco , 44...(43 and 42 nitrous)
There is a big mistake on that chart. It's so simple that it should not happen. Makes me question what else is wrong.
Re: High compression spark plug question...
Maybe you could tell us what needs correcting instead of just making a statement!
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Re: High compression spark plug question...
GARY C wrote:Maybe you could tell us what needs correcting instead of just making a statement!
There is no such thing as a Champion plug with a 3/4 reach, 5/8 hex and an N designation.
If they missed that, what else did they miss? It's too simple to be a typo.
Re: High compression spark plug question...
I don't know? I wouldn't use a NGK chart to confirm a Champion plug, I would refer to their chart to get an understanding and then I would contact tech as well as racers using them.. Thats why I only commented on the ones I and others around me have run...The Champions I ran were the V59c.
Do you know if they are wrong on the heat range of that plug?
Do you know if they are wrong on the heat range of that plug?
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!