In the process of porting a set of heads and several of the cylinders look like they were ready to puke the spark plugs. I am thinking it would be a wise idea to put helicoils in all 8 cylinders. Is there a disadvantage of doing this?? Finalyy who makes the best helicoils for these heads and does anyone have a place to purchase and price on the coils??

Rob

 

Maybe ib fast will chime in here. Last year he had a few plugs helicoiled the day before we went to the track. He was running low 12's with gobs of boost and everything held together just fine.

--Joe

 

The guy that ported my heads put inserts in also. I don't know if they'll last or not. It may be better than the 4 thread alternative. I had a plug blow out of the stock head...

 

I have heard that JDM lost a helicoiled plug last fall at Cecil... Second hand info so I really don't know if its true or not....

PEaCE...................

 

I know some people who have helicoiled exactly how easterisland picture is and they have recorded no problems from it so far. To me it looks like a great thing to do while the heads are off.

easter - would you happen to have the part number for those? I put the numbers down in my cellphone, but accidently deleted the last 2 digits

 

Yea if my heads are taken off, mine will be helicoiled also...

PEaCE..................

 

I don't think they are heli-coils. Here is the web address of the guy that did my heads. He could probably tell you.

www.mohrperformance.com

edit: Here is what he had to say, "The threaded inserts used in your Lightning heads were "Perma-plug" brand. Installation is critical. It requires the fabrication of a tool to keep the drilled and threaded hole parallel and concentric with the original spark plug hole. There is little room for error if you machine it crooked. We machine down through the spark plug hole. We do NOT machine from the combustion chamber side, although it is possible with proper fixturing."

So I guess they are a solid insert.

 

Easter.

I believe these are what you are looking for:http://www.timesert.com/

 

easter - looking by those pics, they look like these things called "save-a-thread helicoils" (thats what was on the package) that are available from napa.

The part number I have is: 770 32??

 

Helicoils come from Shelton, CT ya know. So does the wiffle ball. -Mat-

 

Do not use the Sav-a-Thread type of insert. Do not use a solid style of insert. Use only a Heli-Coil wire type insert. Heli-Coil P/N 5523-14 is a complete install kit. You will also need addition inserts P/N 137-43. The kit comes with 6. Do a search on Heli-Coil I have posted some info in the past.

 

i think someone said that helicoiling might screw up the heat range on the plugs

 

Exactly why not?

I've seen solid inserts placed into different heads before. If you have 4 threads like our heads do, and you drill/tap them out and replace them with a solid insert wouldn't that be better then 4 threads? I'm not saying it would be better then the coil type, but wouldn't a solid be better then what we have know?

 

Nope you still only have 4 threads. The plug will thread into to more threads but the solid insert (OD) will only have 4 threads of engagement. A wire insert disburses the torque stress across all threads of engagement a solid insert does not. The test I did was I took a junk head, added the Heli-Coil and torqued a plug until it broke off. After the plug broke I was able to unscrew the broken portion and re-install another plug and repeat the test. I sent the head to Heli-Coil Applications Engineering and they repeated my test in the remaining three holes. I do have just a little experience with Heli-Coil. I have worked as their Rep for the last 15 years. Try www.emhart.com for more Heli-Coil information. Heli-Coil makes both types (solid & wire) inserts. Solid inserts have their place, just not in these heads. Heli-Coil trivia: A Boeing 747 has over 250,000 Heli-Coil inserts in each plane.

 

Not true,
What happened was they stripped the thread the night before Cecil were not going to go, but decided to anyway.Put a heli-coil in and when they made there run they realized the plug did not seat all the way down.
The plug was still in tact after the run.


VINNIE