Replacement castings for engines

I've been having some fun getting a head casting done. The original was kindly supplied by a fellow list member and is much the same type as a 2HP horiz rosebery (F&J 1 1/2) i.e. a dry head that would be much easier to cast than a water-cooled head.

It took the foundry 4 goes to get a good result. The first 3 were done with SG (nodular?) iron and the last (successful) was Grey iron. I got the head cast solid by patching up all valve/port/bolt with wood dowels etc The First attempt had a significant sag in the valve seating area. This was caused by the moulder using the valve ports as the runners (molten iron filling). The second attempt was no good (I didn't see it). The 3rd had a small pinhole near the valves that on poking showed it to be a near golf ball sized cavity.

At that stage I sopke to an 80 y/o pattern maker. He said 1. Avoid the sag by pouring at the valve seat face (not the in/ex ports) 2. Use grey iron NOT SG (because SG has no conraction-whatever that meant.

The final result - real good.

So, I'd use grey iron from now on I think, it's what the original parts were anyway.

Hope this helps

Graham in Oz ozengine@yahoo.com.au