Drivetrain Why upgrade to colder range spark plugs?
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6th Gear
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From: Wyckoff, NJ
Why upgrade to colder range spark plugs?
Well, I did some testing with a 19% pulley and about 10 dyno runs with approx 1 minute between runs on the stock plugs to test longevity, here is what I found. The same test on colder plugs had no effect on the plug. This is the reason that we carry colder range plugs for people with upgraded pullies.
http://www.piloracing.com/shop/products.php?cat=23
http://www.piloracing.com/shop/products.php?cat=23
6th Gear
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From: NY NY
actually the reason is to protect everything else; the life of the plug itself is secondary. a hotter rated plug can turn into a little glow plug which is a sure path to detonation resulting in bearing, ring and piston failure. after those dyno runs cremating those plugs it would be a good time to pull your head and pan and drop in those new pistons.
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6th Gear
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From: Wyckoff, NJ
There were no bits that fell into the piston area.. luckily, we caught it prior to that, and verified that all the ceramics were accounted for on the spark plug. But, these are the findings of actual tests. The plugs just got to hot.
6th Gear
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From: NY NY
for your reading pleasure: from germanmotorcars.com
The higher the specific output (HP/in3) of the engine, the greater the sensitivity to detonation. An engine that is making 0.5 HP/in3 or less can sustain moderate levels of detonation without any damage; but an engine that is making 1.5 HP/in3, if it detonates, it will probably be damaged fairly quickly, here I mean within minutes.
The higher the specific output (HP/in3) of the engine, the greater the sensitivity to detonation. An engine that is making 0.5 HP/in3 or less can sustain moderate levels of detonation without any damage; but an engine that is making 1.5 HP/in3, if it detonates, it will probably be damaged fairly quickly, here I mean within minutes.
Detonation causes three types of failure:
1. Mechanical damage (broken ring lands, rod bearing failure)
2. Abrasion (pitting of the piston crown)
3. Overheating (scuffed piston skirts due to excess heat input or high coolant temperatures)
The high impact nature of the spike can cause fractures; it can break the spark plug electrodes, the porcelain around the plug, cause a clean fracture of the ring land and can actually cause fracture of valves-intake or exhaust. The piston ring land, either top or second depending on the piston design, is susceptible to fracture type failures. If I were to look at a piston with a second broken ring land, my immediate suspicion would be detonation
Last edited by jlm; Feb 7, 2005 at 12:32 PM.
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6th Gear
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From: Wyckoff, NJ
Originally Posted by jlm
for your reading pleasure: from germanmotorcars.com
The higher the specific output (HP/in3) of the engine, the greater the sensitivity to detonation. An engine that is making 0.5 HP/in3 or less can sustain moderate levels of detonation without any damage; but an engine that is making 1.5 HP/in3, if it detonates, it will probably be damaged fairly quickly, here I mean within minutes.
The higher the specific output (HP/in3) of the engine, the greater the sensitivity to detonation. An engine that is making 0.5 HP/in3 or less can sustain moderate levels of detonation without any damage; but an engine that is making 1.5 HP/in3, if it detonates, it will probably be damaged fairly quickly, here I mean within minutes.
Detonation causes three types of failure:
1. Mechanical damage (broken ring lands, rod bearing failure)
2. Abrasion (pitting of the piston crown)
3. Overheating (scuffed piston skirts due to excess heat input or high coolant temperatures)
The high impact nature of the spike can cause fractures; it can break the spark plug electrodes, the porcelain around the plug, cause a clean fracture of the ring land and can actually cause fracture of valves-intake or exhaust. The piston ring land, either top or second depending on the piston design, is susceptible to fracture type failures. If I were to look at a piston with a second broken ring land, my immediate suspicion would be detonation
6th Gear
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From: NY NY
FYI: the mini is about 100 cu in, so that it exceeds 1.5 hp/cu.in.
Pilo:
yes you were monitoring detonation; you obviously found this, albeit, after the fact: "...it (detonation) can break the spark plug electrodes, the porcelain around the plug..."
Pilo:
yes you were monitoring detonation; you obviously found this, albeit, after the fact: "...it (detonation) can break the spark plug electrodes, the porcelain around the plug..."
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6th Gear
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From: Wyckoff, NJ
Originally Posted by Helix13mini
Monitoring knock?
I've been looking for an application that monitors knock. What do you use?
I've been looking for an application that monitors knock. What do you use?
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6th Gear
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From: Wyckoff, NJ
Originally Posted by jlm
FYI: the mini is about 100 cu in, so that it exceeds 1.5 hp/cu.in.
Pilo:
yes you were monitoring detonation; you obviously found this, albeit, after the fact: "...it (detonation) can break the spark plug electrodes, the porcelain around the plug..."
Pilo:
yes you were monitoring detonation; you obviously found this, albeit, after the fact: "...it (detonation) can break the spark plug electrodes, the porcelain around the plug..."
That was not the case.
6th Gear
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From: NY NY
i think the clear message form the plug is you can have heavy detonation regardless of this method:
"I was monitroing the knock signal, and did not see a spike or any change really in the signal that would indicate detonation, and from the way that you described it above, the signal would have an obvious change"
"I was monitroing the knock signal, and did not see a spike or any change really in the signal that would indicate detonation, and from the way that you described it above, the signal would have an obvious change"
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From: los angeles
Originally Posted by jlm
i think the clear message form the plug is you can have heavy detonation regardless of this method:
typically done from very heavy detonation.
The broken ceramic is not the only sign of detonation, also consider the metal flakes missing on the and/or deposited on the electrodes....not good.
And why 10 back to back dyno runs on an MCS, it would be a heat soak nightmare
peter
Team M7
562-608-8123
www.m7tuning.com
6th Gear
Joined: Oct 2002
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From: Lansdale, PA
I pulled my stock plugs the other day, just to check their condition after 30k pulleyed miles and they look almost brand new. I'm planning to replace them with some good ol' fashioned single electrode copper plugs in the course of normal maintenance. 
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