Spark plug helicoil advice please

[Slammed]

How do I prevent swarf going into the head when I'm helicoiling a spark plug hole? Any tips? Thanks

 

[Robert Parry]

I always put some grease on the tap, this catches most of the cuttings. You must cut the thread in one continuous cut, do not go forward and then back, Alluminum should always be cut like this and normaly dry. when done start the engine with the plug out and the rest of the debris will come out. Robert

 

[Slammed]

I always put some grease on the tap, this catches most of the cuttings. You must cut the thread in one continuous cut, do not go forward and then back, Alluminum should always be cut like this and normaly dry. when done start the engine with the plug out and the rest of the debris will come out. Robert

Excellent advice, thanks Robert.

 

[Robert Parry]

Have you done one before? If not do you have a scrap head to try a test one. I have just got back into building VW engines. I have not done one in situ for 20yrs, but I do remember that you have to shorten most helicoils so that when they are fully in they do not protrude at both ends of the thread. I think it is 4 turns, but if you have a head you can work this out, 4 turns is less than 4 threads on the helicoil. The other thing that comes to mind is to fit a plug spanner to the adajacent plug and this will give you the right angle to hold the tap at. All good fun, I could have done 2 in the time it has taken to type this, the worst ones were type 3. Good luck. Robert

 

[subheatadey]

I would use bigserts instead of helicoils

 

[Paul Weeding]

I use timeserts, as helicoils have a tendency to unwind with the plug when you remove the plug...