Dissimilar metals used for spark plug thread inserts

I've decided that the motor will be coming apart to fix the stripped spark plug thread.( this helped ease the pain of having the CSR torn down for awhile ebay #190037205828 )

I will be using one of the "hi-end" methods to replace the thread. That means an insert, no heli-coils here.

My concern is over the material used in the insert. I'm not sure what "time-cert" uses, but I think it's steel. Will this be a problem in a high performance Al head motor? Does anyone make Al inserts?

Should I go ahead and do and insert on all 4 plug threads so they will all act the same, thermally?
Will an insert change my heat range on the plugs?

cary wrote:

My concern is over the material used in the insert. I'm not sure what "time-cert" uses, but I think it's steel. Will this be a problem in a high performance Al head motor? Does anyone make Al inserts?

You are putting STEEL spark plugs in right? Or have you found some special aluminum spark plugs?

I think the threads in the plugs are actualy plated - probably cadnium.
Galvanic corrosion can occur with some dis-similar metals. I think Aluminum and Iron don't work and play well together. But there are so many different types of steels... you need an expert.

Post edited by: ltdrider, at: 2006/10/04 12:59

put some anti seize on them if youre worried about it;)

Neither your bike nor spark plugs care what material the insert is made of. I am not a fan of Helicoil but the reason folks use Helicoil is price. Once you have priced a Timesert "kit" you will understand a bit better. A decent alternative is a NAPA insert as they are solid. Get the longer insert... think it is 3/4" (can't recall for sure but they have two lengths for plug thread) and cut it to length. The 5/8" insert is too short. Buy a new head gasket and remove the head. The tap they give you for the insert is a bear and difficult to start. You might need to open the hole up with a drill bit... Use ONLY the size recommended by NAPA if you use their stuff. Use Red Loctite to retain the new insert. NAPA gives you an anaerobic thread locker but it isn't as good as RED Loctite. Also... keep in mind that MOST insert companies will tell you that it is possible to put grease on the tap when cutting the thread to keep it out of the combustion chamber. I guess I am a nervous-nelly but the thought of dropping a blob of grease filled with metal shavings onto the top of a piston scares me. I just don't know how you could suck it out with a vacuum hose. I think if I HAD to do the job with the head on the bike I would rather do it dry and try and vacuum out the shavings dry. Anyway, don't fret so much about inserts... just use some anti-sieze compound on your plugs in the future.

is there any reason to do all 4, as far as heat transfer goes?

No reason to do all four. If you ever put an insert in, you probably wouldn't be looking for the work bwhahahaha It is a pain...

Everybody knows the only way to fix a buggered hole is with KRYPTONITE. It's the only metal that your bike will be happy with and you won't have to worry about Clark bike jacking you when he finally gets the kitty call from Lois.