Cross-threaded spark plug hole - pull heads or not?
Thread Starter
Launching!
Joined: Jun 2016
Posts: 285
Likes: 55
Cross-threaded spark plug hole - pull heads or not? My LS1 turned out to be a piece of garbage. But rather than rebuilding it, I just decided to upgrade to an LS2 from a GTO instead. Unlike the LS1, it came with all accessories, a wiring harness, and an ECU. It also looks clean enough inside to eat off of. And I don't have to worry about that stupid LS1 smog gear. But it DOES have one flaw - a cross threaded spark plug hole. I looked into the Time Sert kit to repair the threads, and they claim it can be used without pulling the heads. Doing it without pulling the heads would certainly be easier and save LOTS of cash (although I WOULD like to stud the heads, I could do without the expense of studs and gaskets right now). On the other hand, you hear mixed messages about the effect of metal shavings on the motor. Some say anfew flakes of aluminum are nothing to worry about, while others will say they will kill your motor. What do you think? Should I pull the heads or just do the job with the motor together?
TECH Fanatic
Joined: Sep 2005
Posts: 1,584
Likes: 23
From: NYC
I would buy a thread chaser (Summit Racing has low cost thread chasers), grease it and try to repair the threads before I pulled the head. If it works, you're good to go. If you can't repair the threads, then you will need to pull of the head and use a Time-Sert thread repair kit. Always put a small amount of anti-seize on spark plug threads and thread them in with your fingers (only).
Thread Starter
Launching!
Joined: Jun 2016
Posts: 285
Likes: 55
I would buy a thread chaser (Summit Racing has low cost thread chasers), grease it and try to repair the threads before I pulled the head. If it works, you're good to go. If you can't repair the threads, then you will need to pull of the head and use a Time-Sert thread repair kit. Always put a small amount of anti-seize on spark plug threads and thread them in with your fingers (only).
Last edited by StorminMatt; Jun 11, 2017 at 07:47 AM.
If half of the threads are still good you will probably be Ok. I would try to repair before pulling the head. What is there to loose?
As mentioned above a little bit of anti-seize on the threads will help and hand starting is key. My TA has had probably a dozen plug changes with anti-seize and no issues. We always use a torque wrench to make sure the plug is correctly tightened to 11 foot pounds.
As mentioned above a little bit of anti-seize on the threads will help and hand starting is key. My TA has had probably a dozen plug changes with anti-seize and no issues. We always use a torque wrench to make sure the plug is correctly tightened to 11 foot pounds.
Air Pressure in Combustion Chamber Hi, my method in to make the Intake Manifold and Combustion Chamber a "higher" pressure than the SPH.
The air is then flowed into the BAD chamber at LOW volume.
I have used Time-Serts often, their kit works well.
You will NEED to remove both Valve Covers.
Then find the "open" Intake Valves, remove those Rocker Arms.
Next "fit" a LONG push rod on the intake valve of the Repair Chamber.
You ONLY need to "crack" the valve open, watch for lifter bleed.
I use my shop air with a regulator set to five PSI with the chosen valve open AND a small air report from the repair plug hole.
The "home" air supply could be as simple as a Lawn Blower, just watch your max PSI.
Lance
The air is then flowed into the BAD chamber at LOW volume.
I have used Time-Serts often, their kit works well.
You will NEED to remove both Valve Covers.
Then find the "open" Intake Valves, remove those Rocker Arms.
Next "fit" a LONG push rod on the intake valve of the Repair Chamber.
You ONLY need to "crack" the valve open, watch for lifter bleed.
I use my shop air with a regulator set to five PSI with the chosen valve open AND a small air report from the repair plug hole.
The "home" air supply could be as simple as a Lawn Blower, just watch your max PSI.
Lance
