The lifters(push rods) in an american 26 engine seem to have a dimple in the top exactly the same size as the valve.The valve stem fits right in. This engine has all standard size parts no under or over size. Are these dimples original and if so how did they adjust the gap between lifter and valve stem. I am confused. I was ready to start grinding all the lifters flat. Do I or Dont I.
The dimples are worn into the lifter. They should be flat. Adjusting the valves cannot be done properly with dimpled lifters.
Grinding them flat means you'll need longer valves. Ok, it's a good plan to replace old stock two piece Ford valves since they're prone to break, but most restorers buy adjustable lifters too when changing the valves. Available from all the vendors (Snyders, Lang's etc.)
Thanks for the responces. My first thought was that the lifters should be flat but these had a small tit in the centre as if it was machined so I wanted a second opinion. I have reamed the valve guides oversize and have stainless valves and I also have adj lifters but I was considering using these lifters as there seems to be no wear. I will try to include a picture.
Bumped it up because I am still wondering why they all seem so even
John, Those are scrap metal. No reason to consider using them. They're worn evenly due to being from the same engine, running in the same conditions (dust, dirt, heat and oil conditions)and all made from the same material. They may have not been heat treated properly on the stems. Lot's of things cause the wear. They never would have had a dimple machined in them. Let them go
I just added two full sets of lifters identical to those to my scrap pile. They're junk.
Junk is in the eye of the beholder. They are typical 90 year old original Model T lifters. They could be used as is by timing the valves with the K.R. Wilson piston travel method. You could grind them off flush and square and use them by setting clearances. Adjustable lifters make valve adjustments easier and I have used them.
Engine performance depends on the camshaft. If you have an original well worn camshaft you will not get the best performance out of your engine. A new one, or a reground one can be bought, but a local shop may be able to regrind yours quite economically.
John, they are all so even because they were uniform originally and have been doing the same job for 90 years. If you really want a good running Model T engine you need to address the camshaft.
Thanks If I use them I will grind them off. Thanks for the helpful information. I'll take a look at the cam also
They wear in a circle because the lifter turns. That's why they look machined. The lifters turn while the engine is running. This is designed into most engines so the valve doesn't hit the seat in the same place all the time or wear a slot in the head from the cam. If you look at the head, it will have a circular pattern also.
I would suggest that you also replace the camshaft, cam bearings, both timing gears and if it has a generator, the generator gear as well. And if the valve seats are worn, place with insert seats. This will cost you some money, but is well worth it for a smooth and quiet running engine with maximum power and long life.
Thanks all, John
i use lifters like that after grinding them.
Were (and are) Model T lifters case hardened? If so they would be hard as hell for a few thousands of an inch and then been fairly soft. I have seen dished lifters in engines I have torn down but never seen them like the pictures above.
Yes, original Model T push rods were case hardened. Try drilling through the side of one sometime. The case hardening is less than .015" deep. The dimples that one sees is really from compressing the softer metal under the case hardening. Grinding off the dimple is almost certainly going to grind off the case hardening on the top of the push rod. The new flat surface on the top of the push rod will not last long in service.
There are really only two good options: 1. Replace the old push rods with new, preferably adjustable push rods, or 2. As suggested above, continue to use the old push rods, but time the valves the way KR Wilson recommended by measuring piston travel. Either way will work. It depends on your willingness to spend time or spend money.
Trent Boggess - still in Beijing for a couple more days.
Weld the center to fill them in and grind them flat and use them.
Had not thought of that
Or...back in the day you just capped 'em!
They are junk.
I had lifters in my Model N that were made like that on purpose. The recesses were filled with little discs of red fiber material. Apparently to create a quiet valve train. The question is, who would know if the valves were quiet over all the transmission noise?
I've never seen recesses that deep! I have a fixture for grinding off the ends, a few thousands perhaps, but I wouldn't do it with those.
What does the cam contact area look like? I guess I've been really wasteful by scapping the old lifters. I'll start keeping them to bring to swap meets...not.
The cam contact looks OK however I am taking it to be reground tomorrow.
If the lifter bore fit is still good, cut the ends off and drill and tap for an adjuster in the lathe
Those look deep enough I could use them for my Chev overhead valve conversion! Bet the foot need some work too IF they did get reused.