Shorty Spark Pluigs

[cngordon]

I've got a 440 with Edelbrock 84cc heads and a set of headman headers that came off of the 383 I replaced. The 383 plugs had a 3/8" reach inside the head, but the Edelbrocks require a 3/4" reach inside. This makes the plug longer, and I have to remove the header to get #6 plug installed.

I am using a set of Accel 786 plugs for the other 7 holes and an Accel 416S plug for the number 6. My supplier tells me the 416s is the "shorty" (thus the S) but there does not appear to be much difference in length.

Anyone out there figured out which brands or models are shorter than others ? Is there a true "shorty" plug ?

 

[khryslerkid]

I can see the difference between the two plugs in your pic. The thing I would be worried about would be the "heat range" between the two. The depth of the electrode into the head is important. You don't want that to be too short. Any chance of modifying the header at that plug? (Hammer and a round punch)

 

[440roadrunner]

It has been a VERY long time since I've paid any attention to spark plugs, other than ones I need. But in the world of small engines, chain saws, garden tractors, and other oddball engines, there's a whole new world of special and compact plugs. You need to find, either on the www, or a good parts guy, who has a numerical plug list that can equate long reach (3/4) plugs with special hex and insulators. There might be one, don't know

Another question (not familiar) are you sure the Ed heads use the standard 3/4 reach, or do they use a tapered seat plug?

Here's one a little shorter:

http://www.speedwaymotors.com/champ...4mm-13-16-hex-750-reach-colder-alky,5490.html

http://www.speedwaymotors.com/spark-plug-14mm-reach-th.html

and


http://www.speedwaymotors.com/autol...ex-gasket-seat-14mm-3-4-reach-cold,28494.html

 

[cngordon]

Any chance of modifying the header at that plug? (Hammer and a round punch)

I think if/when I had to pull this engine again for any reason (such as replacing it with a mustang eating stroker) I would look at new headers. I installed a mini starter but that was next to ridiculous hard to do. I almost had to hire a side show circus performer with triple jointed fingers and 4 elbows on each arm to install that thing. I do not think you could replace that starter without lifting the engine again. There must be a better way to run a header.

 

[benno440]

tti headers man i have no problems with spark plugs or starter motor, ia do now have a tubular k member though so no torsion bar interference