350x engine retaps

[jcraig]

has anyone had to retap the holes on the 350x engine for the cylinder head cover. there are a couple stripped out on mine and i was wondering what size bolt i should/could go up to.

[rally4x4racer]

have a machine shop do it if you dont have the tools.. probably cost you 10-20 bucks. next size up - but a drill press is preferable.

if you want stronger threads - have the threads roll tapped (or thread formed). cut taps suck - and thats what you would be doing if you have a tap-die set. your cut threads and roll threads start with a different hole diameter. to make the same thread.

there are threadforming bolts that would tap the hole as they go in but I would be cautious if you do this. it works fine on alloys such as 360, 383, etc - not sure what alloy the head is.

[oldskool83]

helical coil may work, take it to a machinest, this way if they mess up you are not to blame.

[dreadhed]

What is roll tapped? One of those thread repair(thread straightening) taps?

[johnny's X]

I would put studs in all of them, If you have to get back into it you will be alot happier.

[Dirtcrasher]

I would put studs in all of them, If you have to get back into it you will be alot happier.


If you put studs on them you may not be able to get the cover on and off with the engine in the frame. Just a thought, it may work fine but check it out.

Roll formed threads are when the tap doesn't cut the threads it actually forces the hole in the metal to change shape and become threads. I don't think I'd be worried about roll forming them as there are allot of those bolts holding it down and there not a common Honda failure point.

I'd helicoil them all and they are a 6mm x 1.0mm thread. You can do it yourself but it would be so much better to clamp that cover onto a Bridgeport milling table and just cruise around drilling and tapping everything perfectly straight. May cost you 100$ from soup to nuts unless you have a old school machine shop or a friend with one.

[dreadhed]

Roll formed threads are when the tap doesn't cut the threads it actually forces the hole in the metal to change shape and become threads. I don't think I'd be worried about roll forming them as there are allot of those bolts holding it down and there not a common Honda failure point.

I'd helicoil them all and they are a 6mm x 1.0mm thread.

Right on that is what I though he was talking about.

I would helicoil them too. I have the same problem on one of my Xs & I am just going to helicoil it. I think the motor will have to come out though.