Possible Spark Plug Thread Problem

[RussMcB]

I know this has been discussed quite a bit. I've read past threads and gotten some good advice. I'm just checking to see if anyone might have some timely suggestions.

My #8 plug came out okay. I don't remember it having extra resistance, but when I went to screw it in (using a short piece of rubber hose), it seemed to stick very early, as if it was cross threaded. I backed it out, tried again with the same results. It was late at night so I decided to stop and think for a while.

I'll probably try brushes first (but not expecting that to do much), then maybe a thread chaser, hoping it might be a burr in the top of the threads.

My biggest worry is I might not be able to get a good, straight shot at the threads due to the A/C box obstruction (but I did read someone said it has provisions for moving out of the way).

I'm also leaning towards a long lasting spark plug (instead of the less expensive A/C Delcos), and maybe not worrying about changing it for many miles. Any good suggestions for a spark plug that might stay in place for a long time?

TIA.

[Jim Nolan]

I use a spark plug socket and it drops in dead center every time. I also tape 2 wigglers together with the socket and tighten it in.

Jim

[RussMcB]

I use a spark plug socket and it drops in dead center every time. I also tape 2 wigglers together with the socket and tighten it in.

JimThanks, Jim. Yeah, the spark plug socket I've been using doesn't have the rubber insert, so the plug "drops" in if I just use it. So, I've been starting the plug with the rubber hose, which now I realize wasn't ideal (doesn't insure a straight shot into the hole).

I'll buy a new socket today. That should help, but I'd like to make sure the threads are good first.

Did I read earlier somewhere here that our aluminum heads have Helicoil-like inserts (from the factory)?

[Dynomite]

Number 8 Spark Plug Removal

1. Blackhawk 5/8 Spark Plug Swivel Socket 3/8" Drive :thumbsup:

If you have ever had an issue finding just the right spark plug socket for that number 8 cylinder that is too close to the temperature controller on the Heater and A/C Housing....here is the answere and these 5/8 inch swivel sockets come with a nice tight rubber insert :cheers:

If you use a 3" x 3/8" extension, lube the rubber insert in the Spark Plug Socket to make sure the Spark Plug Socket lets go of the Spark Plug before the extension lets go of the Spark Plug Socket when installing plugs :D

Blackhawk 5/8" Spark Plug Swivel Socket 3/8" Drive
http://i287.photobucket.com/albums/ll142/dynomite007/D%20Engine%20LT5/44a79c6a-500f-42c2-8e71-028e1072c81b.jpg

Number 8 Spark Plug Removal and Test Drive with Jeff Gordon (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581827106)


I'll buy a new socket today. That should help, but I'd like to make sure the threads are good first.


2. PM me your address and I can send you one Blackhawk 5/8" Spark Plug Swivel Socket 3/8 Drive ;)

[1991ZR1]

I had one time the extension kept coming off the swivel socket. I had to unscrew the spark plug to get the plug an socket out. Now I tie a string to the swivel.

[Hib Halverson]

First, never attempt to install/tighten a plug in an LT5 using a straight plug socket on an extension coming in at an angle due to obstructions.

The right tool assembly to use for plug numbes 6 and 8 in an LT5 is as follows.

A ⅝-in, ⅜-drive magnetic plug socket with a built in universal joint.
A one-inch extension
A ⅜-drive universal joint.

I built this with Mac Tools but other name brand tools, such as Gear Wrench, Craftsman, Snap-On, will work fine.

I also use this tool on the end of a 2-foot extension with a T-handle. That rig prevents overtightening and, if you've been to the drag races, makes changing plugs on an LT5 kinda like doing it on a Top Fuel motor, where you break 'em loose then spin the plugs out and back in with the T-handle.

If you like antiseize always use a non-metallic antiseize.

As for plug type...I use the Denso IT-22 in my LT5. Their durability is pretty darn good.

[Jagdpanzer]

I've had good results using a 3/8" drive limited access spark plug thread chaser like this:

http://www.summitracing.com/parts/WMR-W83193

http://static.summitracing.com/global/images/prod/small/WMR-W83193_s.jpg
liberally apply tune-up grease on the threaded end to help capture the debris as you screw it in.

[rkreigh]

I've had good results using a 3/8" drive limited access spark plug thread chaser like this:

http://www.summitracing.com/parts/WMR-W83193

http://static.summitracing.com/global/images/prod/small/WMR-W83193_s.jpg
liberally apply tune-up grease on the threaded end to help capture the debris as you screw it in.

pulling the ac panel also gives a straighter shot and is so worth it!

Phil gave me a hand with this at carlisle when #8 blew out and for sure the threads needed to be chased with the tap. we were luckly and the tap we found had a 3/8 square hole in the end which I though was great!

Phil had a steady hand and the head was just fine!!! sure sounded funny.

lucky it was a very easy fix, especially with talented guys like phil doing all the heavy lifting!!!

dinner and brews on me phil, can't thank you enough!