[6cylcecil]

My V8 project has a set back. After adjusting the rockers, I noticed a puffing from the number one spark plug on my new heads.

The odd thing is the AC/Delco R44T plug will thread in straight ( but loose ) and tightens up but does not seal.

Messing with it has caused it to go from a puff to a audible hiss. The threads look messy but not cross threaded.


I've never used a helicoil. My guess is this is not something done in the car even with the room afforded with the number one spark plug position.

Thanks for your help.

[Molly's 70]

I have installed more helicoils & other types of thread repair inserts than I can remember.
If it were me I would put the part on the work bench. Some people put grease on the helicoil tap to prevent metal shaving from falling into the engine. I would never do this, but that's just me. You just need to drill a good straight hole & use plenty of cutting oil on the tap. Some use other types of lube for tapping, but I prefer cutting oil. I insert the new coil w/ red locktite. Take it easy when starting the new insert & knock off the tang. It's really very easy. Good Luck!

[BillK]

Cecil,
The "normal" helicoils really will not work with a taper seat plug like the R44T, there will not be a surface left for the plug to seat on. You either have to use the Helicoil "solid" plug inserts http://www.sjdiscounttools.com/hel5334-14.html or I prefer Timeserts http://www.timesert.com/ but they are not as easy to find as helicoils. I have done the Timeserts on the car quite a few times on aluminum heads, but not sure if I would want to try it with cast iron. The aluminum filings from the tap dont seem to do any damage if you dont get them all out, but I dont know about cast iron.

I do know that plenty of repair shops use them and get away with it. I use a shop vac with a piece of 3/8" vacuum hose to suck out as much of the residue as possible, then start the engine without installing that one plug, that blows most of the rest out.

[6cylcecil]

Thanks for the replies, John and Bill, one of the things I did not know about the solid Helicoil is this statement in the listed features from the first link you provided Bill

"No drilling necessary and perfect alignment of tapped hole due to reamer tap."

Drilling a hole square to the plug seat seems like the entire job to me, if the tool is able to solve that, that's great if I decide to do this my self. On the other hand, how much should this repair cost if a machine shop does it?

[bad66427]

the shop i work at uses the heil coil plug inserts and do it on car cast or aluminum the trick is to ues a shop vac on blow and set the cam so you can feel air though the plug hole then proform the work.

[BillK]

Cecil,
If you brought the head to me, I would put a timesert in it. It would be $50

[Molly's 70]

Hey Bill, I agree the time sert is the way to go in this case. Do they make an insert for spark plug thread repair w/ the tapered seat for the plug? Sounds like a winner to me.

[BillK]

Originally Posted by Molly's 70

Hey Bill, I agree the time sert is the way to go in this case. Do they make an insert for spark plug thread repair w/ the tapered seat for the plug? Sounds like a winner to me.

Yes,
If you look at the link I posted it shows the inserts.