- Joined
- Dec 16, 2000
- Location
- home
The other day at work I was removing a set of bronze valve guides from a set of 18degree aluminum "bowtie" heads (the same cylinder heads used on many Chevy Winston Cup cars.). I have a special way of removing valve guides. I have a short piece of hose, with a fitting on one end for attaching it to a tank of propane, and a piece of brake line on the other end. I invert the tank (so liquid propane exits the tank rather than gaseous propane), stick the brake line in the valve guide, and open the valve. When the propane evaporates from a liquid to a gas, it instantly cools the valve guide to some -125F, and it shrinks and falls out of the head. It occurred to me that the propane fridge in my RV works the same way, but it burns the propane off afterward. Someone needs to give this a shot on there CPU!