Water outlet holes

[2speed]

I have stripped water outlet holes, most likely from a bad engine stand job. Are these helicoilable? Enough meat? Depth? Is it better to go 7-16-14?

 

[Big hammer]

The water outlet is on top of the engine at the head, the side outlet is the inlet. Yes there is enough meat for the next size bolt, but a helicoil is a better choice. I had one engine that had a larger bolt

 

[oldspert]

If you go Helicoil, Be sure the tap has been ground off to go the full depth. If you drill deep enough to install even one diameter helicoil, the tap will not thread to the bottom.

 

[Kurt in NJ]

Another way that can work is to get bolts take are longer with threads all the way, thread on a nut,tighten the bolt into the last of the threads in the bottom of the hole,then tighten the nuts, cutting off the heads of the bolts is optional

 

[Gene F]

Is this a block, or the engine in your car?

 

[2speed]

My mistake, inlet holes.


It's an assembled engine outside the car. I was going to mount to an engine stand so I can pull the pan and inspect things and that's when I found the stripped threads.


Going to attempt to helicoil it, just nervous about break through and keeping things straight.

 

[Dan in MI]

I had the same problem with a block last year. Use a stop on the drill to keep you from going too deep. For alignment I made a block to help with this. It was just a 1 1/2" thick piece of aluminum. First I center punched two holes the same distance apart as the holes in the water inlet. Then I drew an arc at this distance. Then I drilled (on my drill press to get as straight as possible) 2 holes the same size as the Heli Coil Drill. Then on the arc away from the first hole I drilled a second hole the same size as the Heli Coil Tap. Loosely bolt the block on the inlet pad with the hole that is away from the 2 holes next to each other. Then I put a transfer punch down into the block and into the threads in the head to help center the block. Hopefully you can tighten down the block. Drill the hole for the Heli Coil, using a stop. Then loosen the bolt and swing the second hole over the hole. Now you can tap the hole for the Heli Coil. Remove the block and insert the Heli Coil. Now turn the block round so you can drill and tap the second hole.

 

[2speed]

Thanks, I have a generic tap jig for tapping straight, but the drilling I needed to figure out, but that block idea is great.

 

[nkaminar]

When using the water inlet threaded holes to mount an engine stand, use grade 5 bolts that go the the bottom of the holes and if a trifle longer than needed use some flat washers to make sure the bolts get tightened.

The helical inserts, Heilicoils or other brands, are a good idea. As others have said, just make sure they are inserted in the correct location and perpendicular to the surface. And, as others have said, use a bottom tap for the threads for the inserts.