KRE heads and spark plugs
 

I changed the plugs on my car today, had these heads since 2010, the plugs are auto lite 3924 with the crush washers,.

I always start them with a rubber hose over the plug to get them started, then i put my socket on them to turn till snug against the head.

This is where i seem to get confused, says hand tight till snug, then another 1/4 to 1/2 turn..................ok got that.

But as soon as i put the wrench on, and only using one hand to not overtighten the plug, they seem to spin quite a few more turns with really no effort, then they will get someone tight, then i go maybe a 1/8 to 1/4 turn..........im assuming the crush washer is crushed.

My question is when the plug is tight with the socket by hand, why does it seems to turn quite a bit more before becoming a little more than snug.......

I see no damage in any of the threads inside the motor...........the motor is on a stand now so easy to see .

Rich

That’s perfectly normal. No worries.

Also according to Murphy’s law if you put a plug back in a aluminum head that is hot, then chances are that when the head cools the plug will be loose.

Hey, thanks guys................just wondering would it pay to run a spark plug chaser thru the heads.............never done that before.................Hey Gach, first the oil pump shaft issues, now spark plug issues.................im hoping to get this car running soon before i get a foot in the grave.........

Rich

I wouldn’t Rich.

Wait a minute now!
Do the KRE heads use a 13/16” plug with a flat washer?

Are they machined for that type or only a 5/8” type with a taper seat?

When installing these plugs into the heads I coat mine with a bit of cooper coat to prevent galling. Like mentioned the crush washer has to crush which will seat the plug. Tighten then up a bit. I use to run the Auto lite in my KRE heads, but I like the NGK plugs. R5671A-7

https://www.ngk.com/ngk-4091-r5671a-7-racing-plug

5/8” type with a taper seat

Then how the heck are some folks trying to get washer / gasket type plug to work?

Gach.............i wasnt talking about a tap................i thought you could run a chaser/cleaner in the threads............thought they were supposed to just clean the threads, not damage them.................think i"ll just leave them alone.

Rich

It's my understanding that KRE recommends gasket /washer plugs.

Autolite 3924 plugs are 5/8 with gasket.

I gotcha

I just looked at my set of KRE heads and there is no taper on the spark plug holes.