Spark Plugs
Spark Plugs Ok. I know im beating a dead horse when it comes to the basic question, "Spark Plugs". My question is; Do I need a colder plug for higher compression setup? Im asking this because I am currently running NGK TR5's Gapped at .40. Ive been recently having Misfires on multiple cylinders, P0300 code. Ive checked everything, wires, coils, injector firing with noid lite, etc. All seem to be fine, never thought about the plugs cause I only have like 3k miles on build. I took one out and it seemed to reduce gap to less then .10. I was like HOLY CRAP! So i took another 3 out, all the same, .10. My setup is PRC 5.3 Heads, torquer V2 cam, ls7 lifters, manley pushrods, stock rockers, headers, etc. Also have cometic .040 gaskets to get to that 11:1 compression. Pushing 425 rwhp. Would the compression/Heat drive the gap to reduce? I just ordered a set of TR6's and by reading other forums, its a colder plug and may be what I need. Also I hate to ask, Did the pistons come up and hit the plugs causing the reduction? I dont here and noise and when I first got the car tuned and it was fresh, it ran like a raped ape. This seems to be a endurance problem with the plugs I think. ALSO, do i need the spark plug washers for them too? Do to the spacing between the block and heads? Alot of info, but anything helps.
First things first, the plugs gap should not get smaller in 3k miles (I have seen plug gaps get larger on high mileage plugs but never smaller). Secondly i would go to NGK.com and start reading. When you increase compression and power you need a colder plug to better dissipate the hotter cylinder temps. You should probably be on a #7 plug.
NA / Nitrous
stock ls1 -tr55 @ .055-.060 / br6ef @ .035 up to 150 shot
bolton -tr55 @ .055-.060 / br6ef @ .035 up to 150 shot
cam/bolton-tr55 @ .050-.055 / br7ef @ .030 up to 150 shot
H/C/I 11:1 -tr6 @ .040 / br7ef up to 100 shot, br8ef @ .028 up to 200 shot
stock ls1 -tr55 @ .055-.060 / br6ef @ .035 up to 150 shot
bolton -tr55 @ .055-.060 / br6ef @ .035 up to 150 shot
cam/bolton-tr55 @ .050-.055 / br7ef @ .030 up to 150 shot
H/C/I 11:1 -tr6 @ .040 / br7ef up to 100 shot, br8ef @ .028 up to 200 shot
Last edited by kinglt-1; Apr 23, 2011 at 11:34 AM.
You are making roughly 500 fwhp which is around 200 more than stock rating. Based off ngk.com you should be on at least a #7. I make roughly 50 fwhp less than you and I run #6s. Also take into consideration that my best NA times ever was run on a Br8ef which is 3 steps colder than stock. When it comes to keeping your engine happy you sometimes have to get out of the box.
Heat range
The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.
The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.
The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK. Some manufacturers numbering systems are opposite the other, for domestic manufacturers(Champion, Autolite), the higher the number, the hotter the plug. For NGK, the higher the number, the colder the plug.
Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single pre-calibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.
The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.
The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK. Some manufacturers numbering systems are opposite the other, for domestic manufacturers(Champion, Autolite), the higher the number, the hotter the plug. For NGK, the higher the number, the colder the plug.
Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single pre-calibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage
Ok so. I called advance and told them to put my plugs to the side. I was on duty so couldnt get there. The wife went in and they didnt have them put to the side and already charged my account. Also on top of that, they didnt have any in stock. So instead the wife picked up AcDelco Iridiums. Will the delco's out perform the tr6's? Will I be fine off?
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Verdad Gallardo Normally 5 is the stock heat range, hence "tr55". Going to a 6 is one step colder, then 7 is 2 steps colder,, and so on... Now refer back to the plug chart I posted earlier... with your setup you should run a number 6 heat range. No the plug does not have to be ngk, but thats what I suggest using... delco is good tho, just get one step colder than stock in those if thats all your local parts store has...or order a set from a sponsor here on the right lol---->
Last edited by kinglt-1; Apr 24, 2011 at 12:46 AM.
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Joined: Apr 2011
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Hi Folks
This might help everyone, it the official NGK symbol description from their site.
http://www.ngksparkplugs.ca/documents/partnumberkey.pdf
This might help everyone, it the official NGK symbol description from their site.
http://www.ngksparkplugs.ca/documents/partnumberkey.pdf
OHHH def was running 8 PIcs included Well I pulled out all the plugs after i got off duty. Looked up the plugs to see what I put in there, due to the facts it has been over a year. I put the R5724-8 Heat range 8. I gapped them at 40 when I got them and all seem to be less than .10. Whats the deal now? Im still getting the tr6's today but thats a warmer plug. I dont get it. Here are pics too!
