Stopped by the shop the other day to check headwork progress: (SURPRISE!) Since my guy has had some bad luck in the past with screw-in/spring type guides coming out, he went with the newest solid bronze alloy inserts (VERY hard!?).

Question: (TED?) Is it routine with Y-blocks to cut a spiral oiling groove in the solid inserts, or are the oil-retention/anti-friction characteristics of the new alloys adequate with stainless valves?

6 VOLTS/POS. GRD. NW INDIANA

I’ve never had an issue with the screw in bronze inserts once they have been installed.  But any of the bronze guide liners are expected to be compatible with stainless valves as long as adequate clearance is maintained.  Bronze guides do require more stem clearance than iron.  Haven’t seen the need for an oil groove as a positive type oil seal will effectively cut off most oil anyhow.  But this is something to talk to your own machinist about as He may have some more specifics on the particular guide liner He’s using.

Lorena, Texas (South of Waco)

Thanks Ted,



Since positive seals WILL be installed, I won't worry about it. It's only because when I whined about the unexpected change from the spring-type guides I had originally specified (one of the reasons I chose them was better oil retention), he offered to attempt cutting a spiral oil groove for me. I could tell though, he wasn't enthusiastic about the idea since he went on about how hard the new alloy was. I also decided that regardless of the success YOU have had with the screw-in liners, if HE had a history of problems with them, whatever the reason, I was not going to force the issue!

6 VOLTS/POS. GRD. NW INDIANA

Ted: Can you elaborate on the use of guide liners as opposed to bronze guides. What is the reason for using them in some cases?..  

Paul

I’m far from being the expert on the differences in many of the available guide options but will give what I know based on raw experience.  The guide liners are less expensive than guides but are prone to coming loose or becoming dislodged much easier than an installed guide.  Guide liners are also not an option if the original guide is heavily worn or damaged.  On the flip side, boring for replacement guides can break into the water jackets in the guide area but not a problem as long as the replacement guides are adequately sealed.

Any one else with other experiences or knowledge is welcome so just feel free to chime in.

Lorena, Texas (South of Waco)