Correct spark plug for Performer RPM Head

[Garys1969RR]

Will be replacing my ported 915 heads 2.14/1.81 with some performer RPM heads in a couple months. These are going on a 451 with 14cc dome Ross pistons. Edelbrock says to use the Champion RC12YC long reach spark plug. I believe it is a heat range of R. Does anyone know if this will be too hot a plug for a 12.5 to 1 C/R motor? Also, is there a shorty spark plug that will work if there is interference with the header pipe? Ok thanks

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I am anxious to see if these perform better than the ported 915s.

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Am also going to use the low deck Performer RPM intake manifold with this PERF RPM HEAD. Ports should align well.

 

[A383Wing]

long reach plugs are for small blocks

Accel makes a "shorty" plug for header clearance

 

[Garys1969RR]

long reach plugs are for small blocks These are the ones Edelbrock says to use. They are an angle plug head, and the threads in the head are longer than a cast iron head.

Accel makes a "shorty" plug for header clearance

Thanks for the tip on the Accel plugs.

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I understand that these heads require a long reach plug. The thread depth on these alum heads is longer than a cast iron head. The earlier iron heads originally used a J 11Y Champion plug. I used to use J10Y in a high compression motor, as they are a cooler running plug.

 

[440beep]

Don't aluminum heads generally use the 3/4 reach plug? For example the NGK BKR6E.

http://www.jegs.com/i/NGK+Spark+Plugs/739/BKR6E/10002/-1




Or is that only for big block aluminum heads?

 

[Kern Dog]

long reach plugs are for small blocks

Accel makes a "shorty" plug for header clearance

?????
Maybe you missed that the OP had switched to EDELBROCK heads.
I ran the suggested Champion plugs but at almost 11 to one CR, I had run-on quite often. I switched to RC9YCs because the 10s were hard to find. The run-on stopped with the colder plugs.

 

[bth0320]

Will be replacing my ported 915 heads 2.14/1.81 with some performer RPM heads in a couple months. These are going on a 451 with 14cc dome Ross pistons. Edelbrock says to use the Champion RC12YC long reach spark plug. I believe it is a heat range of R. Does anyone know if this will be too hot a plug for a 12.5 to 1 C/R motor? Also, is there a shorty spark plug that will work if there is interference with the header pipe? Ok thanks

- - - Updated - - -

I am anxious to see if these perform better than the ported 915s.

- - - Updated - - -

Am also going to use the low deck Performer RPM intake manifold with this PERF RPM HEAD. Ports should align well.

Hi Gary,

I have a similar set up with the rpm heads and with the angled plug design/dome pistons, I found those RC12YC's were just about to touch the piston as the angle design of the head puts that plug to the side of the piston dome and not in the recessed portion. I had to go with the RS12YC's which have a reach of .708. I can't comment yet on whether the heat range is correct as I have not run the motor much yet. I have TTI headers and had no issues with the length of the plugs interfering with the headers. I have those RC12YC's still and would be happy to send your way so you can try them....better yet, might be a way for us to finally meet up!

 

[GTX MATT]

Those Champions with the 12 heat range are technically the stock heat range plug. Champion no longer offers the stock heat range of 11, this supersedes it. IMO they work nice in a stock engine, but you should experiment with what works best for your engine. As mentioned the RC9s are the next step down.

Accel 0416S for a stock heat range and 0414S to go colder if you want a shorty plug that works with aluminum heads.

 

[Garys1969RR]

Don't aluminum heads generally use the 3/4 reach plug? For example the NGK BKR6E.

http://www.jegs.com/i/NGK+Spark+Plugs/739/BKR6E/10002/-1




Or is that only for big block aluminum heads?

Yes that is the same type of plug. 14mm X3/4 " reach. 5/8 socket. I would guess many if not all alum heads use them. Due to the fact that alum is a softer metal, and more easily stripped/damaged. I understand anti-seize lubricant must be used on the threads to keep the plugs from locking into the threads of the head.

 

[Herr_Poopschitz]

Yes that is the same type of plug. 14mm X3/4 " reach. 5/8 socket. I would guess many if not all alum heads use them. Due to the fact that alum is a softer metal, and more easily stripped/damaged. I understand anti-seize lubricant must be used on the threads to keep the plugs from locking into the threads of the head.

All aluminum heads I've experienced use these style of plugs, for what I'm guessing is the reason you mentioned. An alternative to anti-seize that I've used is just motor oil. Been doing that since the late-90's when I read it in some literature from Trick Flow. Never had an issue.

 

[lewtot184]

go to walmart and pick up 8 autolite 3923's. heat range is close to champion "10". stick a couple of plugs in the head and put a little play dough on top of the piston dome, gently rotate the engine, then remove the head and check the piston to plug clearance.

 

[Garys1969RR]

go to walmart and pick up 8 autolite 3923's. heat range is close to champion "10". stick a couple of plugs in the head and put a little play dough on top of the piston dome, gently rotate the engine, then remove the head and check the piston to plug clearance.

Lewto, would you recommend running these plugs as opposed to the Champions? Thanks

 

[440beep]

Yep, its funny that I run the same NGK plug in my Volvo inline 5 motor.

All aluminum heads I've experienced use these style of plugs, for what I'm guessing is the reason you mentioned. An alternative to anti-seize that I've used is just motor oil. Been doing that since the late-90's when I read it in some literature from Trick Flow. Never had an issue.

 

[lewtot184]

Lewto, would you recommend running these plugs as opposed to the Champions? Thanks

i like champions but i think the autolite is a better made plug. the real reason i mentioned the 3923 is that they aren't expensive and fairly easy to get. i like their finer tips better and as a resistor plug i think their resistance is lower than the champion rc12yc. the heat range is probably an ideal starting point. you can use them as a first step, and may find them to be a good general purpose street plug. i would recommend a step colder for strip use with your compression.

 

[A383Wing]

Champions & Autolites are made by the same company...just a different package

 

[Garys1969RR]

Hi Gary,

I have a similar set up with the rpm heads and with the angled plug design/dome pistons, I found those RC12YC's were just about to touch the piston as the angle design of the head puts that plug to the side of the piston dome and not in the recessed portion. I had to go with the RS12YC's which have a reach of .708. I can't comment yet on whether the heat range is correct as I have not run the motor much yet. I have TTI headers and had no issues with the length of the plugs interfering with the headers. I have those RC12YC's still and would be happy to send your way so you can try them....better yet, might be a way for us to finally meet up!

Ok I sent you a PM, so call me and we can meet up! Thanks