Big Block folks with headers: Spark plug boot clearence
Thread Starter
Safety Car
Joined: Mar 1999
Posts: 3,715
Likes: 1
From: VASS, NC, USA
Big Block folks with headers: Spark plug boot clearence
I have a set of headman headers on my BB. #1 and #3 spark plug boots are a major clearnance factor, even with the smaller plugs (not header plugs, but the auto lites Im now using as they are smaller than delcos. #3 is so tight, I cant even get a spark plug socket in there to change it. Ive ground down a socket, and even so, it is a VERY tight fit, and breaking spark plugs is very easy
Im using the spark plug hi temp "socks" that slip over the boots, but the boots are still so close to the headers they will still melt over time
anyone have spark plug boot clearence issues on thier BB headers?
Also, Im looking for the very small profile "header style" spark plugs made by Accel for my 502, which I beleive will really solve my clearence issues for sure, but I cant get a x reference for my 502. any source would be helpful
Im using the spark plug hi temp "socks" that slip over the boots, but the boots are still so close to the headers they will still melt over time
anyone have spark plug boot clearence issues on thier BB headers?
Also, Im looking for the very small profile "header style" spark plugs made by Accel for my 502, which I beleive will really solve my clearence issues for sure, but I cant get a x reference for my 502. any source would be helpful
Burning Brakes
Joined: Dec 2000
Posts: 962
Likes: 0
From: Carlisle PA
Re: Big Block folks with headers: Spark plug boot clearence (MELVIN)
I can't offer any words of wisdom, I had the same header and encountered the same problem on #1 and #3. Using Taylor's socks, I used Taylors (too knobby), Accel's (boots just didn't seem to last), finally went with MSD 8.5's (they seemed to last). That's my experiance.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Big Block folks with headers: Spark plug boot clearence (MELVIN)
I had the exact same problem. Burned #1 and #3 regardless of what I tried.
I ended up solving the problem by going to accel #276S spark plugs which are about 3/8th shorter then regular.
I also bought 2 JACOB'S ceramic boots. They are ceramic, good to 2000 degress and could lay right against the header without a problem although they are smaller then normal. I bought 2 90 degree ones complete with wire. Lifetime guarantee but no problems after about 3 years, None.
I also found them really nice to deal with and quick response.
Get 2 jacob ceramic boots and I also machined a bit off the socket so it fit fine.
I ended up solving the problem by going to accel #276S spark plugs which are about 3/8th shorter then regular.
I also bought 2 JACOB'S ceramic boots. They are ceramic, good to 2000 degress and could lay right against the header without a problem although they are smaller then normal. I bought 2 90 degree ones complete with wire. Lifetime guarantee but no problems after about 3 years, None.
I also found them really nice to deal with and quick response.
Get 2 jacob ceramic boots and I also machined a bit off the socket so it fit fine.
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
Re: Big Block folks with headers: Spark plug boot clearence (MELVIN)
Or you might want to dimple the header tubes. I did but still tight around #1 and #4, which I have the 'glass socks on. Oh, I've got MSD 8.5s and burnt up #1 2 months ago. I'm curious to see how long the new wires last with the sock on them.
Brett :thumbs:
Brett :thumbs:
Burning Brakes
Joined: Nov 2000
Posts: 948
Likes: 0
From: Johnston Iowa
Re: Big Block folks with headers: Spark plug boot clearence (Brettmc)
I have just a little more than 1/8 of an inch clearance between my boots on #1 and #3 and my header tubes on my big block.
I'm running Hooker super comp headers and side exhaust.
I have MSD wires and boots and so far have been ok.
I have not driven the car a ton yet.
I hope an 1/8 inch is enough to not start burning up boots.
I'm running Hooker super comp headers and side exhaust.
I have MSD wires and boots and so far have been ok.
I have not driven the car a ton yet.
I hope an 1/8 inch is enough to not start burning up boots.
