The Stovebolt Site Forums The Shop Area Engine Shop Valve Guides 53 Blue Flame 235

Does anyone know what material the valve guides are made from? I read that most engines have cast iron guides for the porosity and oil lubrication.

Iron

They can be bronze, brass, CI. What color are the old ones?

Ed

The old ones appear to be steel or cast iron, not bronze in color.

They are cast iron, bronze are nice but costly.

A competent machinist can install any kind of guides you want in a stovebolt head. Bronze guides are nice, but not really necessary. The original equipment guides are cast iron, mostly because they were, and are cheap to manufacture.
Jerry

Thanks for the info!

I number of years ago I had I head I was redoing that, for whatever reason, we were having a very difficult time getting the original guides out for replacement with new. Ended up using just a little too much pressure and broke the casting, instantly turning a perfectly good head into a boat anchor. From that point on I have opted to have bronze liners installed into the original guides and then finish the guides to a proper clearance with respect to the valve stems. It’s slightly more expensive, but I think yelds a better end result with respect to oil control on the stems.

Removing guides without boring them out to a thinwall shell is risky business. Once the guide wall is around 1/16" thick, a simple driver mandrel in an air hammer pushes them out easily. I learned that trick while rebuilding air cooled Volkswagen cylinder heads, but it works well on any engine with removable valve guides.
Jerry

Well you both gave me more good information to consider; unfortunately I already pressed the old ones out- but with no issues. It took 8-12 tons on the press gauge to get them out. So far so good. I am making the new ones so I can determine the press fit and clearance etc..

I hate to be the cold water, but with that much force I would put the head on a lathe bed, run a dial indicator along the gasket surface to check for flat. If you haven't pressure tested it consider it an investment - better to find out now then when it's assembled.

Unless you supported the area around each guide as you did the pressing, you've probably got a boat anchor. Ditto on the pressure test, and at least get the head gasket surface milled a little to be sure it's flat. Situations with long pieces of cast iron and ham-handed methods seldom end well. Straightening a bent cast iron crankshaft is done with a big lead hammer- - - - -not a press. Why are you making guides? They're available ready-made by the hundreds.
Jerry