How to know when Valves are closed

[sub7m19]

Hi, I am looking to time-cert my spark plug hole that has degraded threads since my spark plug won't tighten. Moreover, is there anyway to know when the intake and exhaust valves are fully closed? I heard that getting chips in there or in the cylinder can be really bad. Any tips would be greatly appreciated!

[grannyknot]

You have to remove the cylinder head to do that repair properly.
If you drilled it out and installed the Time-sert with the head on and started the engine the chips would most likely be blown out the exhaust passage and not the intake.
The real danger is the chips getting caught in the compression ring, and scratching the cylinder wall, that would result in lower compression on that cylinder.

Take the head off.

[Chihuahua]

Originally Posted by grannyknot

You have to remove the cylinder head to do that repair properly.
If you drilled it out and installed the Time-sert with the head on and started the engine the chips would most likely be blown out the exhaust passage and not the intake.
The real danger is the chips getting caught in the compression ring, and scratching the cylinder wall, that would result in lower compression on that cylinder.

Take the head off.

+1, absolutely should take the head off to do any kind of machining, which in a sense is what you're doing. You'd be surprised how little debris it takes to completely destroy an engine.

[TheMidnightNarwhal]

Originally Posted by grannyknot

You have to remove the cylinder head to do that repair properly.
If you drilled it out and installed the Time-sert with the head on and started the engine the chips would most likely be blown out the exhaust passage and not the intake.
The real danger is the chips getting caught in the compression ring, and scratching the cylinder wall, that would result in lower compression on that cylinder.

Take the head off.

Can't you just vacuum out the shavings from the spark plug hole? Or have the intake valves open and snake the vacuum down the cylinder from there while you drill the spark plug hole.

[4JawChuck]

Have you tried to just clean the threads with a tap first?

You can coat the tap with heavy grease to catch any shavings from entering the cylinder.

An insert repair indicates completely stripped/missing thread's which is unlikely, usually they are just damaged and need restoration with a tap.

A helicoil or timesert repair should be done with the head off, too many possibilities of not catching all the debris.

[inTgr8r]

Originally Posted by grannyknot

You have to remove the cylinder head to do that repair properly.
If you drilled it out and installed the Time-sert with the head on and started the engine the chips would most likely be blown out the exhaust passage and not the intake.
The real danger is the chips getting caught in the compression ring, and scratching the cylinder wall, that would result in lower compression on that cylinder.

Take the head off.

100% agree!!!

[grannyknot]

Originally Posted by TheMidnightNarwhal

Can't you just vacuum out the shavings from the spark plug hole? Or have the intake valves open and snake the vacuum down the cylinder from there while you drill the spark plug hole.

That would be a pretty small vacuum hose, but I guess you could and if you very through you would probably get most of the chips.
I think it is just as likely that you would miss some and then you run the risk of scratching the cylinder walls.

If it were a beater I would probably take that chance but if it were my baby, no way. Or as 4JawChuck mentions a tap with some heavy grease on it, that is a great idea.

[sub7m19]

I don't think I have the experience to take the whole head out. I saw a couple videos on youtube and they did the insert on the block without having to take it off. They just super greased up the tap and vacummed it afterwards. Im pretty sure the threads are gone as it wont even hold the spark plug in place. If i remember correctly the spark plug blew up in that hole bc oil was leaking into it for a while hence why I ended up taking everything apart and redoing the valve cover gaskets