/diy/ - Do It Yourself

>>2652014
what would be the best method of filling in a port in a cast iron 2 stroke cylinder? As in completely filling it in, so that gasses are not able to flow into it, meaning the filler has to form part of the cylinder wall? Exhaust port specifically, not the transfer ports.

So far I've considered either filling the port with braze, or using an epoxy like jb weld. I don't think I'll be able to get the cylinder hot enough to bronze braze it with my current tools (MAP torch), so might have to find a roofing torch to keep the temperature high enough to locally heat the port area with the map torch. Maybe could use aluminium braze, and try to cover a large enough area that it acts as a heatsink so it can lose heat faster than the exhaust gasses in the cylinder can heat it up?

Not sure about epoxy, I would have though that it would have issues with heat, but I've heard of some guys who use it to fill in small holes in cylinders so might work? Anyone on here tried this?

>>2466410
I have a 2 stroke moped cylinder like picrel. I want to fill in the exhaust port, in a way that will hold up in a running engine (yes, i know that a 2 stroke wont run without an exhaust port), and struggling to think of a good way to do this. I'd like it to not wear out too much, I know a 2 stroke piston/rings would be able to hold up if it did but I would get blowby which I dont want.
The only thing I can think of is making some sort of blank that fits inside the cylinder, and pouring some bronze down the exhaust port, the problem would be the bronze "brazing" itself to the blank inside the cylinder. High temp epoxy would be easier but would probably wear quite a lot, Cylinder is cast iron so welding is a no-go, at least for something like this. Don't want to just put a blanking plate on the outside of the port, again due to blowby.
Any ideas? I don't have access to too many fancy tools (lathe, mill, etc), but could probably melt down some soft metal, etc to get this done