man that is sad hope it all works out for you

You'll probably see a lot of dimensional changes, but assuming that it was allowed to air cool and not hit with water, it's probably OK. Cast does very poorly with rapid changes in temp, cracks very easy due to internal stresses.

Expect to do some machining, but should be OK. S/F......Ken M

Well if they are still there they didnt see 2000+ degrees, since cast is supposed to melt at 2000 degrees. I also bet they cooled slowly if the fire wasnt drenched with water after the fire was out.

Sorry about the fire./

My nephew was working that fire.He thought they would have to evacuate his house but the wind changed and he was OK.hes a Captain on the Colorado Springs FD.He worked a lot of overtime.My brother was there also as he went out for my great nephews graduation.Sorry about the house.Rocky

http://www.heat-treat-doctor.com/documents/CastIrons.pdf

This has a nice phase diagram of iron-carbon-silicon (grey cast iron). It shows a melting point near 2100 F. Here are some brief highlights from the text:

"Stress
relief is done at temperatures between 1020
and 1200°F (550 and 650°C) without significantly
lowering strength and hardness.
Heating at temperatures between 1290 and
1400°F (700 and 760°C) lowers the hardness
for improved machinability. Ferritizing (for the most ductile
microstructure) is done by austenitizing at
1650°F (900°C), followed by holding at
1290°F (700°C) to completely transform austenite to ferrite and graphite."

So, if the temps were low (not likely as the aluminum completely melted) then they would be merely stress relieved. More than likely the hardness has changed. I would expect them to be scrap unless they are rare and expensive blocks. You might be able to heat treat them back to a useable form if they are rare. Most likely would have to machine every critical surface.

I have no idea on the blocks, but man, do I feel for your Dad and you guys. I wish you the best of luck. Leigh.

Did the copper wiring melt? That goes at 1950F. Aluminum goes at circa 1100F, and sucks up heat quickly. S/F....Ken M

Thanks guys for all the great input, and also for the support. No copper melted, maybe the temps didn't reach 2000. I will probably take one of the blocks to a machine shop to check trueness.

I bet the blocks are OK.

Brother had a similar fire, he'd built a nice Pontiac 455 for his Goat, the carb was just a puddle. So he sold it for $100 or some ridiculously low number, was awfully surprised to see it on the road in a couple of weeks! Bummer!

I hope your stuff turns out as well.

R.

Bummer on the house and all... but you saved $250
having it stress relieved that way(I had to pay to
have it done)..good luck to you and your family

Cast grey iron will turn into cast white iron and a cetain temperature, I don't know correct number on it, sorry But once it does that it will be so hard you can not cut or touch it(leave a mark ) with a standard file I know a local shop that treid to weld a nut on the front of a older SB Chevy head, it turned into cast white iron before he was done, a old timer machinest told him about the changing of the metal afer he found out the hard way