Thread chasing

[ctrout]

I need to chase the threads in the thermactor holes in the front of my heads. A 5/8-11 tap is like $22 +shipping and I'm having a hard time finding one locally. I have read that people plug the rear ones with a spark plug so I thought of just using a spark plug hole thread cleaner (a $6 item) but they all seem to be metric thread. Is there any such thing as a 5/8-11 spark plug thread tool? Are there really spark plugs with that thread pitch or is everyone just forcing metric plugs into those holes?

 

[Addermk2]

the people who thread spark plugs into the heads, have done so because of a VER VERY incorrect How-To over on AllFordMustangs. I have sent countless messages to the admins and moderators over there.. and they refuse to fix it.

Spark plugs are not 5/8"... One option you might want to try is getting hold of a grade 10 5/8-11 bolt, and grinding a couple notches in it. I used a similar method to clean up the threads in my GT-40's when I plugged my thermactor system. Just remember to work the bolt back and fourth, slowly letting it go deeper.

 

[d_punch]

as adder has said above the spark plugs don't work.

and sometime ebay is your friend

http://shop.ebay.com/i.html?_from=R40&_trksid=m570&_nkw=5/8-11+tap


but if you can find a bolt in that size locally you can try and make your own tap. just don't forget to use some lube

 

[ctrout]

Thanks for that clarification. For guys like me who are just getting their feet wet with these cars, this kind of information is helpful in keeping us from making expensive mistakes and screwing stuff up.

 

[modo]

DO NOT use a tap as a thread chaser... get a thread chaser.

http://www.sears.com/shc/s/p_10153_...o=2&blockType=G2&prdNo=2&i_cntr=1307564132595


chaser will clean the threads where as the tap will remove material and thin out the threads that already exist or cut new and cross thread... also make sure you use plenty of oil on the chaser

 

[modo]

also goto a ford dealer or order these. don't use a bolt or spark plug

http://www.summitracing.com/parts/PIO-PF580-4/

 

[castine917]

4.25 through here vs 8.99 there. i bought mine through napa for 2.50 or so.

http://racerwalsh.zoovy.com/product/RWA7800/thermactor-plug-Each.html

 

[rz5.0]

Cheaper here http://www.store.partsdinosaur.com/product1521.html

 

[Paul]

Spark Plugs are M14 x 1.25 thread. Thermactor is 5/8-11 as has been stated above. People who think they're the same are retarded.

Buy a thread chaser. Use lots of lube. (snarf snarf)

Paul.

 

[rz5.0]

KY works great and when your done just take it back inside.