Installing split valve guide and Mushroom Valves

Joe KCMO

Joe KCMO

Senior Member
The last early flathead I rebuilt, I used one piece valve guides and straight valves. I assembled the valves and the springs were tight against the guide. They slipped into the engine and with the long valve tool, I set the horseshow clip.

With the split guides, after the valves are assemble, the spring is loose and the guides are slightly split. Is there any thing special in installing this type of valve. The steps described would be on great help.
 
It sounds like you have the horseshoe clips in wrong. Maybe in just one half of the guide. Make sure when you instal the assemblies, the 'split' of the guides is straight up and down, that way the horseshoe clips will hold both halves together.
 
My question rephrased is should the valves be assembled before they are put into the engine or do you assemble the valves in the engine. What is the preferred or best way to do the job.
 
Joe KCMO>>>should the valves be assembled before they are put into the engine >>>

Yes, this seems easiest. A bit of never-seez should be smeared on the split guides. Also, it helps to insert the block C-clip retainers by cocking the valve to the partially open position with a removable clip between the guide & valve stem ridge. This removable clip allows you to push down on the valve head to expose the C-clip slot in the guide. Once the temporary clip is removed, the C-clip will go up into its block recess.

Jack E/NJ
 
Jack E/NJ said:
Joe KCMO>>>should the valves be assembled before they are put into the engine >>>

Also, it helps to insert the block C-clip retainers by cocking the valve to the partially open position with a removable clip between the guide & valve stem ridge.

Jack E/NJ
Click to expand...


A little more information please. I know what the guide is, what is the valve stem "ridge".
 
Hi Joe:

There should be a protruding ring or ridge around the valve stem between the underside of the valve head and the top of the valve guide.

This ring sits on top of and covers the valve stem hole in the guide when the valve is in the closed position. The temporary homemade clip shown in the image below is clipped to the valve stem between this ring protrusion and the top of the guide. This props the valve open against the valve spring tension so that when you insert the entire valve assembly into the valve chamber it can be pushed down far enough to expose the guide's c-clip retainer groove inside the engine valley.
stemclip.jpg


You then insert the c-clip retainer in the groove and wedge the valve head open a bit more with a wooden or brass wedge so you can remove the temporary clip. Ease the wedge out and the spring will seat the valve and push the retainer up into the block recess.

I made the homemade clip by cutting a 3/8" length piece of 5/16" ID steel tubing lengthwise, slightly off-center, so that the open end of the resulting C-clip will be slightly less than the 5/16" diameter of the valve stem. As such, you need to push the clip onto the stem and the natural spring tension of the steel will hold it firmly in place. I silver-soldered a flat spring-steel rail from an old windshield refill to the closed end of the clip to aid in both inserting and removing the clip from the stem.

If you used never-seez during assembly, you can also use the clip to help disassembly by wedging the valve open and pushing the clip back on the valve stem between the ring protrusion and the top of the guide. Remove the wedge and tap the top of the valve head with a brass mallet until the c-clip retainer comes out of its block recess. Remove the c-clip and you're free to pull the whole assembly back out of the valve chamber.

Of course, the valve lifter should be resting on the heel of the cam during these procedures.

Jack E/NJ
 
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assemble the guide and intake "O" ring , the "O" ring valve guide seal will hold it together while you install the guide, but my advice is get rid of the split guides and mushrrom valves, the new one piece guides are much better and a lot easier to work with
 
I never had to do anything to hold things together while assembling. I always assemble the guide halves, sping, sping seat and retianer before installing. The guide occasionally may want to spread apart while working with it but it's easy to hold it together if properly assembled. You said the spring was loose after putting tje parts together? It sould not be loose and floppy. If it is, you either have something assembled wrong or something is missing. After the valve/ guide assembly is put together it's easy to hold it together as you stick it into its hole. Be sure the dividing line on the guide is straight up and down and stays that way when you put it in. The valve head should be up off it's seat if it fits snugly. Push down on the valve head until you can get your valve bar to grip the slots. Pull the assembly down with the bar, check to make sure you lowered both halves of the guide, check to make sure the guide parting line is still straight up and down, then install the horse shoe retainer. Be sure the retainer sits all the way into it's recess in the block. You may need to tap it in until it drops into the recess. It really is easy. Just costantly check to make sure everything is where it belongs.
The new replacement guides have provision for an "O" ring on the intakes. A light coat of Vaseline helps them slide ito the block. This is really an ingenious arrangement if you really think about it.

Edit: one more thing - be sure to check the guide to stem clearance before you put things together. Some of these replacement parts are too tight and need to be lapped before installing.
 
If you are using split guides, the parting line between the halves needs to be on a line facing up toward the intake and down toward the cam. This insures that the notches for the valve bar are facing in the right direction and the retainer will hold both halves equally. If the valve bar notches are not oriented right, you'll have a hard time getting it apart next time. This can cause an attack of very foul language. Of course, if you are using the late one piece guides, none of this has any bearing on anything. Good luck. :D
 
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