All of my lifters are worn slightly concave, and a couple of them have more serious wear patterns on them that concern me. I haven't priced new lifters at AGCO but I doubt they're cheap.

I'd like to think you could take parts from 4-5-6 engines, mix and match and Frankenengine would start right up an last 30-40-50 years.

Sure it'd be nice if evrything was 'within spec' but... reality is things wear over time and STILL perofrm reasonably well. I KNOW that a certain lil English Austin never had all the 'head parts' put back 'in order' and it ran GREAT.... dang that was 1/2 century ago.

I will not be putting a new/reground cam in this tractor and valve springs will be stock. However, I should mention that this tractor will get some hours on it since I have about 20 acres of tillable I plan to mess around with. Sounds like I should just find the best looking used lifters I can and go with them.

I think I read a DickL post somewhere that said the lifters should actually be slightly convex?

WC/WD/WD-45 lifters should be concave when new?

Most automotive examples I looked up have a convex surface. Mine from my WD are all slightly concave and definitely showing various levels of wear... If they were originally concave that would make me feel slightly better.

Any way you'd have the part number somewhere? I've searched NAPA's website with no luck for anything tied to a WD. The only new ones I can find are from Reliance and they're in the $50 each range.

On my 20-35 rebuild, we originally used the original worn cam, with resurfaced lifters.  That is what people told us we should do, and we didn't know any better, so we did just that.

That was NOT the thing to do!

After minimal running we pulled the engine side covers to inspect, to find the edges of several of  the lifters chipped up and you can guess where those chips go.

Long story short, we SHOULD have had the cam ground as well as the lifters.  The old funny worn cam was putting pressure on the edges of the new lifters and making them fail.  Maybe it was a fluke, but I don't think so.

Tore the engine all back down to have the cam ground, and new lifters AGAIN.  Clean out entire engine.  Very frustrating.

Take the time and $ and have both reground.  It really doesn't cost that much compared to fixing the carnage when something goes wrong.  Now you know how I know.

That would be slick. I have a Sioux 645L and it came with the rocker arm grinding attachment, but it doesn't look like they even made anything for lifters - at least for that model.

I was trying to think of a way to rig it up but I'm not sure I could accurately do much other than grind the bottom of the lifter flat.

That flat grinds the surface, or gives you a slightly convex surface?

I guess if these were flat from the factory I could handle that with my valve grinder.

Awesome. I guess that makes sense... They start out convex, eventually get worn flat, and then wear in to concave. By at least making them flat they're probably at least half as good as new, and way better than what they look like now.

These are samples of the ones I'm working with out of my WD. They're concave by 0.002-0.003 in the centers. Some have some pretty ugly wear patterns from the lobes at 90 degree angles which tells me they weren't or haven't been rotating at some point in their lives. Those spots are worn in a little deeper. I'll play around with grinding them flat on the valve end grinding attachment on my Sioux. No Bridgeport unfortunately but I can try hand finishing them.

Thanks Tom. I should price AGCO ones but I doubt they're much if any cheaper than the Reliance ones at $50 each. I wonder if the ones you got from NAPA were from Reliance or someone like Mahle, Sealed Power, etc. but I can't find them available anymore. As you are hinting at it might be worth stopping by a local NAPA in case they have a better way to look them up.

well... a guy could chuck them in a cordless drill, clamp it in a vise, duct-tape the trigger ON, and use a fine, well-worn flap-disk in a 4" grinder...

Or better yet, put a cheap speed controller on the 4" grinder, dial the speed way down, and smear the worn-out flap disk with some fine valve grinding garnet mixed with axle grease.... 

making them convex and PRECISE is simply a matter of having a radius to work on...

If you were a Kiwi, you'd cut a broomstick off at whatever that convex radius is, mark a spot on your shop floor just below where your cordless drill chuck spins, and use that as a 'swinging radius' rest for your 4" grinder as you made that dressing pass...

..If you were a Scotsman, you'd find a much harder way to do it...

...and if you were Russian, you'd mix some vodka with the grease, and post a how-to video on Youtube!!! 

(This, by the way, is a tip-of-my hat to all the Kiwis, Scotsman, and Russians out there who live amidst, and solve real-world problems and are NOT encumbered by the Proper Gentleman's Rules Of Machine Rebuilding Propriety (PGROMRP)

I had a B&S Vtwin Intek apart the other day and gee, when you consider it runs at 3600RPM for hours, weekly, the 'valve train' is well..kind of a joke compared to a 'tractor'.

I'm thinkin you could 'mismatch' a tractor valvetrain and never notice anything chuggin along at 1500-2000 rpms....

While it would be nice to properly rebuild and get it 'tight' and up to 'factory specs', overall, it probably doesn't really matter....

In most cases today for sure. 10 hours a day on a plow or fitting ground in making a living with a tractor that is less than full power would make a difference and make for tiring days.   

Turns out they don't, but I lucked out and my dealer has a NOS one at a different location that I'm supposed to pick up next week when it comes in.

This engine wasn't making any odd noises and ran pretty well. I think it must have had almost no oil pressure or got a bunch of junk in the cam area at one point because in addition to the worn lifters, the camshaft journals were also very worn.

I have to admit I'm not ballsy enough to try any of these, which may mostly be me overthinking it combined with not having enough nice ($$$) equipment... I sure couldn't meet the radius that is presumably specified on the print from AC. Or, it could be too much German in me vs. the Scottish. We will see what the new part looks like when it arrives and I'll proceed from there.

Certainly spinning the lifter while removing material is the way to go. The chuck on my valve grinder won't quite open up enough to fit these. I've been drill press shopping for other reasons already.

I picked up the new lifter today and it is actually very flat - not at all convex. Unless AGCO changed this more recently for service parts, I assume this is how they came from the factory for at least the 201 engines. As Butch said these engines should be happy with flat lifters - that appears to be how they were designed. I will use the valve end grinding attachment on my Sioux and clean up my old lifters with a nice flat surface and be able to sleep at night.

I am thinking that I will call around and ship my camshaft out to have the lobes reground. Jacob's right - not worth risking it at this point with the rest of the money I am putting into the engine. A couple lobes have enough pitting that they definitely need attention. Hopefully it will be good for 40 or 50 years.

I will stand corrected! I received the convex information from the shop that did my crankshaft grinding.  

 Good information! Thanks for sharing. It is nice to have the real part in your hand to get good data from. 

Nice picture! Get that old cam tuned up and you will be good to go. Hey I way over think stuff too. Then have to get a reality check when I actually have the items in my hand and the work needs to get done! German and Swedish on this end.:)

 Regards,

 Chris

Well, that's not to say that the B/C/CA engines didn't have convex lifters, but I would be surprised if they were any different. Convex lifters seem to have been very common in automotive engines which is probably why the machine shop said that.

No problem Chris. I wanted to solve this mystery. Thankfully they should be easy to clean up.

Very worn lifter as removed from the engine:

Showing the attachment that holds the lifter, which is rotated up and down in and out of contact with the grinding wheel. Then you slowly turn the red wheel in the lower RH of the picture to feed the lifter closer to the grinding wheel with each pass, to take more and more material off of the face.

Here you can really see how the lifters had worn so that the face was concave - the freshly machined surface is a high spot only around the outer edge, where there is no wear from the cam lobe:

And done: