What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Gap the BR8EIX with a P-Mag?

WingnutWick

Well Known Member
Hello all,

I am just curious about whether or not people have been gapping their BR8EIX plugs when used with P-Mags to the .030-.035 that the manual states? I was told that these are pre-gapped however and don’t require. Is this the case?

Also any argument over using BR8ES vice the EIXs?

Thank you!

Charles
 
Hello all,

I am just curious about whether or not people have been gapping their BR8EIX plugs when used with P-Mags to the .030-.035 that the manual states? I was told that these are pre-gapped however and don’t require. Is this the case?

Also any argument over using BR8ES vice the EIXs?

Thank you!

Charles

I've tried both but went back to the ES. Lots cheaper and I just throw in a new set at condition inspection. On gapping the ES, I'm not real scientific about it but they've always passed my gap test. I'll be laughed at but I use a piece of .032 aluminum to check the gap. Probably most important thing for either plug is to check the resistance before installing the new ones.
 
Hello all,

I am just curious about whether or not people have been gapping their BR8EIX plugs when used with P-Mags to the .030-.035 that the manual states? I was told that these are pre-gapped however and don’t require. Is this the case?

Also any argument over using BR8ES vice the EIXs?

Thank you!

Charles

I use BR9ES stock gap with a pumped up engine, otherwise the BR8ES.

DAr Gary
 
NGK

I’ve bought maybe 60. I change em often. Have only found one with a gap that looked too small, maybe .020. Opened it up to .035. Rest appeared to be .035. No problems leaving them as bought. I use solid tip 3961
 
So is it no big deal to leave their stock gap?
Even though they seem to be close out of the box I will always check it to make sure. I'd feel pretty silly (or worse) if I didn't and there was some Q/A lapse and it's way off, resulting in a problem.
 
.029 - .030

Pretty much all of my BR8EIXs are right around .029 - .030 .... these aren't the easiest to gap. You guys think it's fine to leave them here?

Thanks
 
Pretty much all of my BR8EIXs are right around .029 - .030 .... these aren't the easiest to gap. You guys think it's fine to leave them here?

I'm not an expert on ignitions so I'll leave it to others to say whether .029 is okay. However I don't find them hard to gap, I use a piece of .032 AL to check it and some smooth jaw needle nose pliers to tweak the gap.
 
I'm not an expert on ignitions so I'll leave it to others to say whether .029 is okay. However I don't find them hard to gap, I use a piece of .032 AL to check it and some smooth jaw needle nose pliers to tweak the gap.
I guess I am the only old guy that worked on cars when you had to gap points and plugs, and thus needed a couple sets of wire feelers, as well as a set of flat blade feelers to set valve clearances. A flat piece of metal will work if the plug ground electrode is flat metal beyond the center electrode, but round wire is better, since the electrodes rarely wear to be exactly flat. However any electrode that is parallel to the center electrode, like aircraft plugs requires a wire gauge. Also, using aluminum, it will get thinner after checking a number of plugs, since the electrodes are a far harder steel alloy.
The gap needs to be proportional to the voltage the ignition generates. That is why plugs with magnetos use .016-.018 gaps. Most '60s cars with distributors and a single very big coil used around .028. Modern electronic ignitions generally use around .032-.045.
Difficulty in gapping is indicative of how hard the alloy is. Iridium, platinum or similar plugs will be more difficult than straight steel.
 
I guess I am the only old guy that worked on cars when you had to gap points and plugs, and thus needed a couple sets of wire feelers, as well as a set of flat blade feelers to set valve clearances.
Ha ha you are certainly not the only one! But I lost my old feeler gauges when that tool box got stolen and then for a while the only plugs I was gapping were aviation plugs, so I have the thinner wire gauges for that. Then I put on an Emag and now I'm messing with automotive plugs again - go figure!

But this brings up another question... iridium or not for the auto plugs? I did some searching and based on some other threads and the E-mag recommendations I'm sticking with the regular ones. The gist is, there doesn't seem to be better performance and the plugs break down for other reasons than just the metal on the tip. And E-mag says to replace them at 100-125 hours regardless of type. So for 3-4 times the price, it doesn't seem worth it to me.
 
I use BR9ES stock gap with a pumped up engine, otherwise the BR8ES.

DAr Gary

So at what point does an engine move from standard (BR8) to pumped up (BR9). Is it compression ratio (say, below 9 or 9 or above)? Or is it ram air induction, turbo charging or overall HP? Curious minds as I have an IO-360 with 9:1 pistons that dyno-ed at 198hp.
 
If you are using 8ES and plugs load up with lead and the gap opens up between checks then it may be worth considering the 9ES. When I switched I found the gap stayed much more consistent. That was with a carb'd 160hp 320.
Pete
 
Back
Top