Printable Version of Topic

Posted by: yellow914 Jun 11 2009, 10:04 PM

I few weeks ago i posted that my 914 sounded like a harley...with little power. i have now discovered why. I found the spark plug still coonected to the plug wire floating around beneth the fuel injection system?...I tried to reinstall it but nope!...no bite in the threads. Is there a cheap easy fix...or dare I say it...a larger diameter plug I could make work until i can re-do it?

Posted by: Derek Seymour Jun 11 2009, 10:09 PM

Helicoil


It is temporary though. You will need to take your head to a machinist or replace it eventually.

Posted by: sww914 Jun 11 2009, 10:35 PM

I had to fix one at the racetrack once. My dad had cross threaded it the day before but didn't really say anything. At the track the plug blew out as I was full throttle on the front straight.
It was loud.
I hauled butt to the nearest auto parts store and bought a time-sert kit. A time-sert is like a heli-coil but it's solid, not a spring. I spread a thin layer of grease on the tap and tapped the hole, installed the insert, and ran the engine for a couple minutes with the spark plug out to blow any chips out the hole.
It was still loud.
I put the plug back in and it ran fine. I rebuilt the engine a couple of years later and there was no sign of any scoring or damage in that cylinder. The time-sert was good enough that the machinist that built those heads told me to just go ahead and time-sert the other 3 holes myself. It's been 8 years and they are still good.

Posted by: zymurgist Jun 11 2009, 10:45 PM

Go with the Time-Sert. It's a much better piece than a Heli-Coil. I had a Heli-Coil let loose on my John Deere head and it tore up the threads.

Posted by: Jake Raby Jun 12 2009, 06:12 AM

.....and the reason the plug blew out was more than likely because of the crack that you'll find in the chamber leading up to the spark plug hole.

Posted by: jmill Jun 12 2009, 07:49 AM

I blew 2 plugs once on my VW when a heater hose blew off. I overheated the head and both plugs shot out. I did the Time-Sert. Worked great. I would look at why it blew. Cracked head or cooling issue?

Posted by: yellow914 Jun 12 2009, 10:20 AM

I was thinking about the reason......anything I do will just be a bandaid. Might need to look for another motor as I have no idea what this one has been through.

Posted by: HAM Inc Jun 12 2009, 12:55 PM

If it has 1.7 heads it may be cracked. If it has 1.8 or 2.0 914 heads I'd bet a Varsity dog it's cracked!

Posted by: Derek Seymour Jun 12 2009, 01:05 PM

That's why I suggested the Helicoil as a temporary fix. They are usually half the price of a time-sert kit and there's no reason to spend extra $$$ on something that you are going to replace anyway. I had this trouble on my 71 Super Beetle and used a time-sert to fix it. But that also blew out. When I took my head off... yep... cracked.

Posted by: kwales Jun 12 2009, 09:56 PM

Only time I've seen an insert work is when somebody cross threads a spark plug into a head and when the plug is removed, the threads come with it...

Worked for me on my bug. The dealer had a small round plate with a threaded insert on it, They tapped the hole, threaded the insert into the hole until the plate was against the head, and punched a dimple or two into the plate and the head.

Car ran fine for 250K.