Engine block tick braze

[Paulbarrett]

Hi

I’ve cocked up a drilling into an engine block I’m working on. It’s for a custom Opel 16v build I’m into.
Basically these are posts that hold the timing chain guide from a different engine. My jig wandered and consequently the hole and tapping is all off.
I also manage to break through into an oil way.

My thinking it to completly braze up the whole area also build it up to allow a platform for the post with plenty of thread, an m10 rather than m12x1.25 also to allow enough braze to keep it strong.

Do we think it’s possible to get enough braze down this hole now?

 

[Popcorn]

You might be better of drilling it out to take a piece of brass rod that will block the oil way as well.
Then drill and tap it for the stud and re-drill the oil way, which you'd need to do anyway if you brazed it.

 

[Paulbarrett]

I did think about boring it out and inserting a press fit lump of bronze then. tapping that for the post. I am worried it may come loose with heat and dissimilar metals.

 

[Popcorn]

That's why I said Brass, it will always expand more than the surrounding metal, so won't come loose.
Another option would be to drill it out and then tap it, then use a piece of threaded steel bar and Loctite.
But it will be harder to drill out the oil way afterwards, with more risk of a wondering drill again.

 

[MattF]

I am worried it may come loose with heat and dissimilar metals.

Do cast iron & brass/bronze have differing expansion rates? Could the plug risk cracking the cast?

 

[Popcorn]

No look how many brass plugs are used in standard engines, especially in the coolant galleries.

 

[brightspark]

Do cast iron & brass/bronze have differing expansion rates? Could the plug risk cracking the cast?

yes they do brass and bronze expand more than cast iron but it wouldnt crack a block theres tens of thousands of bronze bearings in to cast

 

[addjunkie]

If your happy with the threaded hole, would an epoxy type repair into the oil way be sufficient

 

[Paulbarrett]

If your happy with the threaded hole, would an epoxy type repair into the oil way be sufficient

That I’m also considering just for the oil way repair area.

 

[Rrobson]

Tig weld with nickel, that would make a permanent repair. 100 - 150 degree c preheat in the local area and lay a couple of small runs to fill the hole.

For the threaded hole, fit an insert and redrill in the correct place.

 

[Popcorn]

Only places I've seen epoxy work is in dry area's, if liquids there it's always failed.
Despite what the Manufactures say on the tin.......

 

[Turbo]

Tig weld with nickel, that would make a permanent repair. 100 - 150 degree c preheat in the local area and lay a couple of small runs to fill the hole.

For the threaded hole, fit an insert and redrill in the correct place.

If you weld it with nickel would it create a very hard alloy that will be difficult to drill and tap.

 

[Paulbarrett]

I think my route is going to be-

braze up the oil way and tghreasdloivk an insert into block

 

[Paulbarrett]

So to update.
Tried to conjure up a way to get the block o to the mill for some more accurate machining.
Trimmed the head back up after it move form the old workshop to here.

Tried it one side no joy, then with a bit of luck the other side it just about worked out. Very scratchy with the turret out so far and a lot of weight hanging from the bed one side, but kept it tight to the knee.

Went to fit up the boring head and that needed the threads chasing out, couldn’t actually believe I had the correct tap considering I only use metric.
Came from paul hollands bits I’ve kept! Result thanks paul, looking after me from somewhere.

Go things bored out and decided upon.
Found a piece of bronze bar end that works lovely. Nice just tight enough press fit with some loctite 270.

Now my pan is to make another post with a large base to fill the gap and cover the ‘accident’ to the oil way. Will use some gasket seal and thread lock the thing in. Then drill out the oil way once set.
Hopefully pics show what I’m up to.