Valve guide installation

Uncle Josh

Should the guides be inserted with a little dowel grease or dry?



Bang em in or press em in?



Warm the block and cool the guides or both at ambient temp?



"Nothing should ever be done for the first time"

Unknown

do you have a valve guide driver?

i make mine in the lathe .001 smaller than the internal diameter of the guide,and bang'em in dry.

Uncle Josh

I really thought more people had experience doing this. Now I have some and will share it.



Being a toolmaker by training, I have an aversion to banging things If I can avoid it.



Therefore, I pulled the old valve guides in my 308 out with a long grade-8 5/16 bolt, assorted washers, and a long 1 3/4 nut (connector) which allowed me to hold it from turning and still ride up in the bore with the guide. After an initial 'snap' they pulled quite easily. I used anti-seize for lubrication of the threads.



Wanting to insert them from the top the same basic way, I tried a length of 5/16 threaded rod from below the lifter thru the guide bore, which I promptly pulled in two on the first one. A stainless threaded rod was a little more expensive but held together for all 12 guides.



I used a 1 3/4 in long 5/16 connector below the lifter bore, then a washer, and a 5/16 std nut to center the rod in the bore. I used a grade-8 washer above the guide, then a connector nut to spread the thread load, and turned it with a deep 1/2 in socket. Pulled them in as nice as can be. One of them tightened up pretty good before it was quite in place, so I just gave the socket a solid tap or two with my 16 oz whompin tool, with the pressure on it from the nut. I used anti-sieze liberally on the washer and nut threads.



I put the guides in the fridge so they were cool, but not sure if you need to. I used a little motor oil on the guide to prevent galling in the bore. Pretty tight press fit so they're not going anywhere.



Now, on to grinding a couple of bad seats.



As Cousin Jim says, "Ya never know what ya can do 'till ya try"

[Deleted User]

Can they be driven out through the bottom with the lifters in place? Norm

Geoff

The shop manual for '34 -'39 models shows them being driven in with a special tool, and a hammer. Now I don't have this special tool, so I use a suitable bolt with a brass collar under the head. I drop this into the guide, so the brass is acting as a cushion, instead of the hard head of the bolt. I then drive the guide out using a short handled 5 pound hammer, and an old water pump shaft as a drift against the head of the bolt. You have to use a heavy hammer to give it some inertia. Using a light hammer is useless, as you have to use more force on it and it can bounce and miss and do all sorts of damage. The '52 shop manual says "Valve guides can be removed upward through the valve seat opening with a suitable puller", so they may not come out underneath with the tappet in place, but this should be easily measurable. You may just have to take the adjusting bolt out. However, it again shows the guides being driven in from the top, and there is no mention of any lubricant. I have always driven them in dry.

Geoff.

Unknown

I'm pleased with what I've learned here and on the thread that I started about boring out and relining valve guides. I'm curious about one more thing, though. I can recall someone else talking about reaming out valve guides. Under what circumstances would this be necessary? Do they sometimes they distort when being pressed in?

Geoff

The only reason for reaming that I can envisage would be if you were fitting valves with oversize stems. Sometimes guides get gummed up with carbon, but you would be unable to ream this out, it would soon wear the edge off any reamer. You can get special valve guide cleaning brushes, which are barrel shaped spiral wire . You need a liberal dose of lacquer thinners to help wash the carbon off and abrade it with the brush attached to an electric drill.

Geoff.