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Hole in Head Gasket Surface

Hi Guys!

Today, big drama in the garage: my valve spring compressor slipped!
(my ego doesn’t want to say that I missed the valve so yes, it slipped!)

I poked a small hole on what appears to still be the combustion chamber, not really the gasket surface. See the grandiose picture:

That’s my way of getting more compression I guess!

More seriously, how can I repair this? The valve seating surface is not damaged, it looks like it on the picture but it isn’t.

I doubt good ol’ JB Weld + sanding is gonna do the trick…


What about just getting a new head?

Take the head to a machine shop that can TIG weld and machine the head.


A new head is out of the question, my wallet (and wife) would not approve!

Machine shop sounds reasonable; I wish I could do something myself…

Thanks guys!

I had a channel in a piston wall that kept blowing through head gaskets, jb weld did not work, FYI

What would happen if you didn’t do anything, other than file the raised edges of the gouge down level? Just curious.

It would create a hot spot and melt the aluminum head in that area,


Hot spot, I kind of guessed. But it will melt the head? Yowsers. Did not anticipate that.

Thank you all for your comments and help!

I’m so pissed at myself, I was waiting for all parts to come for weeks and now I’m going to wait even more for a machine shop to work on it.

This head is from a motorcycle (04’ Honda CB600RR) but it doesn’t really matters…

Hard to tell in pic, is that a little hole at the bottom of the dent or just carbon?

If it’s a hole, no question it needs to be filled and smoothed.

Before I had a welder for this kind of thing I probably would have dressed the edges to flatten and round them and called it a day. There is crevice volume by the plug, head gasket and other areas. They just round it off to reduce hot spots. Depends on your tolerance for risk…

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Just looked on eBay. Bunch of heads for $75-100. 2 weeks beer budget.


Bikes like this are very high hp/cc, any irregular bump like this, even sanded down, could cause a problem. I’d see what a machine shop would charge to fix it the right way.

While you’re at it, you might get a price on a complete top end job. They will probably remove the valves and associated hardware before machining the head anyway.

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Yeah I found a head for $60 on eBay indeed! Cheaper than contacting a machine shop! Love the internet lol

I think a replacement head is the best option. Welding that hole up will quite likely distort the exhaust valve seat which is next to it. That will in turn lead to a burned valve/seat.
The only way around that is to perform a complete valve job after the welding is done.