If I go to an over sized valve stem and hole, how do I keep the chips from going into the engine while reaming?
Short answer you don't.You could cut down on a few by holding a vacuum hose near the hole,but this is an out-of car-project .
How about magnetizing the reamer?
If it's a typical 1920's side valve model T engine.. when i do things like this i put rags in the valve chamber (particularly the oil return holes) and wash it out with kerosene before removing the rags.
After putting some rags in that area to keep the shavings out (especially around the oil return holes as pointed out above), you can then slip some cardboard under the valve guides and long enough to exit the side of the block. When you ream, the majority of the chips should hit the cardboard, slide down and onto the floor. Obviously you would / should remove the intake / carb for easier working around that area.
Dip the reamer tip in grease before you start. The grease will catch and hold quite a few of the chips.
Erich, excellent pictures.
I'm a little nervous about this whole valve thing.
I know I have the old two piece valves, what if I just remove the old valves and replaced them with new ones without reaming and buying over sized valves? Car runs good now should run the same or better right? Might have to lap new valves to old seats?
It's easy to ream the guides - all you have to remember is to never turn backwards with a reamer - it'll destroy it.
But maybe it isn't necessary to do a full valve job? First a dry, then a wet (with oil) compression test would tell if you have a valve problem, but to be certain about the valve and valve guide condition you must pull the head and the valves. Get new head and manifold gaskets to be able to replace it after the valve job.
Jonathon--I don't know what year T you are working on but I will tell you if it is a 24 or 25, you will not be able to ream the number 4 valves with the engine in place. I was not able to get the drill and then the reamer to go straight even with an offset drill. I am assuming you will drill first for an oversize valve and then ream.
The most commonly used reamer is only 1/64" inch over standard.
Factoring in already worn guides no drilling is required nor advised since a drill bit will surely make the hole more off center than it may already be.
Yes.......that last hole is a trouble maker.
The hardest part of reaming valve guides is reaming the guide perpendicular to the deck of the block, and that the reamed guide is the same diameter from top to bottom. It is very easy to ream the guide off to one side or another, or to ream the guide so the top of the guide is larger in diameter than the bottom.
The Stevens Company had a tool for this that can be easily copied.
I have used one of these tools and it makes a big difference in reaming a guide of uniform diameter.
Like I said, I want to change the "two piece" valve before they break. Can I just buy the .312 valves and go without reaming to the next size. What can it hurt? I don't quite have the confidence to remove material from the guides. Or the tools for that matter.
because you have the 2 piece valves still, one would then have to assume that the cam lifters are original and the un-ajustable type, so to fit a new valve you will still need the ability and tooling to set the valve clearance.
From what I see, the difference in length between old and new valves is only a few thousands. I could file that.
And, Jonathon, you should set the lash on the new valves by piston position. Might as well do it right, while your about it. Many threads on this.Will work provided your old tappets are not too badly worn/cupped out.Then a tear-down installing adjustable tappets,possibly oversize, is the order of the day. And lapping in that back exhaust valve with the engine in the car can be a real buggar for the first-timer.
I go slow and use an expandable tap holder. The one I have you can remove the handle and use a 3/8 ratchet to drive it. I would think a drill would go too fast unless of course you only have a chuck type ream. Mine taps have the square shoulder which is what you get from the supplier and are the piloted type.
If I decide to ream them 1/64 over, what size is the pilot on the reamer??
Wiggle your valves and get a feel go how sloppy the guides are or are not. Measure the stem diameter on your valves as there are oversize two piece valves. If your car was running fine then just replacing the valves should be OK. If your tappets are worn then you can not set the valves with a feeler gage but you will have to use the K R Wilson method. The tappets usually have a valve stem size recess from 80 plus years of valve operation.
Here's my suggestion: Leave it alone or do a mini in car overhaul with new adjustable tappets, new oversize valves and piston rings. If the cam shaft is worn then it would be good to have it reground.
Just stick a piece of plastic hose over the bottom end of the valve guide that extends past the valve chamber. It will channel the cuttings out on to the floor. When you are done reaming the guide, blow it out with the air hose.
Stan, that is BRILLIANT!