Grinding valve stem to adjust lash?

I've done valve work before but had the machine to do this type of work. I no longer have a machine to grind valves or the valve stems but if I had to grind the stems now to adjust the valve clearance I would probably use my belt sander which has a 6in. sanding disk made on it and use 80 grit sandpaper disk to get it close and then use 220 grit to smooth the end of the stem. Use a V-block set at a 90 degree angle to the disk and you're good to go.
 
I use a black & deckervalve grinding machine. But that won't help the op. Not that I haven,t done it but Norton Clames you should never grind on the Side of a bench grinder wheel :dunno: . A belt sander or disc sander would be my first choice.
 
The fixture on valve grinding machines to touch up the face work excellent, the only fear is heat.

When building the race engines we had the machine but did not want the grinding dust in the assemble room. When you are setting the valves so they open at the exact timing, it may involve 10 walks over to the valve grinder... this is when we started doing it with the file. Almost all the chips stick to the file and there is no fear of them getting into a engine (with no oil filter or rod/main journal bearings).

As long as you get it close to square you will be fine.
 
Quick and dirty. Our jig is a simple piece of pipe welded to flat stock. The ID of the pipe is the same as the valve stem. This is then c- clamped to the
grinder on center (fine stone) just "nip" it while rotating. Actually we are doing this only on a V8 Ford and there is 16 of these. Although adj. lifters
way over priced is the way to go, there is a solution if you over grind. Called a cap with internal shims a racing item. The shims are little disks that
go in the cap; either add or remove these shims. Around $12 for 8 caps. Its done like this example= the lash calls for .010 you are at .004, the stem
is ground roughly to .018 thereabouts then add the cap- adding/ removing shims till you get .010. Way easier than running back and forth to the grinder,
and worst case regrinding the valve or cutting the seat again. Before starting, make sure you mic the cap (thickness) so your in the ballpark to shim.
This should help I know these caps makes my life easier. I assume Summit racing sells these I dont know, a local engine builder sells them to me.
sam
 
Take a small magnet and see if the entire stem is magnetic or just the tip or none at all. Many good valves have Stellite wafers welded for the tip, if you can figure out the thickness of this wafer you don't want to grind past it. Some valves are only heat treated and cannot handle more than 005 being removed, and some valves will be magnetic about halfway up the stem and non magnetic from the middle down to the head. These you can generally remove as much of the tip as you desire. If its completely magnetic stem to head you will have to cross your fingers, I rarely see those anymore in my work.

A V block with a freshly dressed stone to get a perfect 90 degree is the way to go. We dip in oil every 5 seconds or so of grinding to keep the heat down. If its a welded Stellite tip and you get one to fly off and hit you in the face like what happened to me once you will not go for the cherry look anymore..................

BTW - keep an eye on Craigslist for Sioux and Kwikway valve grinders, they are there for pennies on the dollar now. I picked up 4 grinders inside of 2 weeks for $700 combined and 2 were the desirable variable speed Sioux models. You can use a mixture of WD40 and 5W20 for the grinding oil, I quit buying the expensive stuff. Only time you need the expensive oil is for Titanium valves, and thats beyond what we are discussing here.
 
On old (pre war) Fords built in the UK the lash was set by grinding the ends. the valve grinder had a small v block for the job BTW the Valve ends where larger than the stems to retain the spring plate so the valve guides where split into 2 length wise, so you could fit them.the spring then held the guide in place.
Happy days!!
Brian.
 
I hate to dig up such an old thread, but I am facing this very same issue on my car. Lots of ideas here, but I don't understand them all.

I plan on getting a 6 inch harbor freight bench grinder and grinding from the side of the wheel. A v block with clamp seems like a great idea but i guess that I'd have to raise it to meet the side of the grinder or alternatively mount it to the side of the shield. Thing is, it might still be crooked.

Almost thinking of drilling through the side of shield, making a hole no bigger than the valve stem, and nipping at the stem tip. Don't see why that simple idea won't work. I'd like to keep this simple.

Thanks!
 
What kind of a car are you working on?

I doubt you'll get the results you want with a hole in the side of a thin sheet metal cover. Pictures are preferred for the best response.

Welcome to the forum :)

John

- Former racing kart engine builder....
 
Hi and thanks for the response and welcome. I am working on a Ford Focus SVT where all year (2002-2004) engine specs were identical. The issue is that the buckets were discontinued a while ago from Ford and I cannot find buckets nor can I get someone willing to sell me used ones. The vehicle uses bucket tappets which do not have shims. Regular Focus buckets are differently sized by a large margin. I purchased the vehicle thinking that this would be a zippy regular Focus but didn't realize that it would be a situation where parts are extremely rare. I am also thinking of machining the bucket as well. There is a guy who did that to his buckets using a dremel but he hasn't posted in a while (being cynical but maybe that didn't work out well). To me, it seems that machining a bucket is the easier option but some are claiming that only the tip of the bucket pedestal is hardened. I did end up swapping around buckets as much as I could but I still have 2 valves with this situation.

I have no real way to verify that either way though. One idea was take my Dremel 8220 and chance that the entire pedestal was hardened then purchase a Dremel Drill press workstation. Looking closer at it, it looks like I could turn it sideways and may have a v-block with a clamp meet the valve stem tip and the Dremel workstation.


It looks like this guy went this route with a regular drill press and a dremel aluminum oxide grinding stone. I don't know how long that would take though, if that would take longer with a dremel or a drill per say or if the aluminum oxide grinding stone might even be my best bet. Wondering about carbide bits which I used on a harbor freight grinder but have never seen that they can be used "straight on" in an application like this. I also own a Subaru with that engine so his approach has got my attention should this ever happen to me in the subaru world (far less likely since that engine was mass produced).


I'll see if I can find a spare valve to grab a picture of.

Thanks for pointing out my concern in that the sheet metal around it is thin which probably wouldn't do all that much better than me eyeballing it!

To me personally, I think that I am leaning towards machining the bucket as opposed to tipping the valve even though 2 people (1 vaguely) says don't do machine the bucket whereas one person says that he machined the bucket but cannot be reached.

I like that it is easier to see what I have done with the bucket each time as opposed to having to either hold the valve with one finger and put a few cam caps down or use low pressure springs and a keeper each time. It's much more convenient and less intrusive especially given that I am concerned about tearing the new valve stem seals I just installed.
 
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Just acouple observations you say the tappet button/shims are no longer available discontinued. If that's the case I would not be doing any modification to the ones you have. You mess up your done then. I could see grinding the buttons but NOT how that fella did. He scraped the inner wall of the shim every time he went to grind it. Those shims are ground OD, ID, and the ends for length. Scouring the inner sides will cause that shim to fail prematurely. Surface finish quality will count here.
I would assemble the valve train and do all you measuring. Take apart grind the valve stems and not the shims. Did you say you need to do only two or all? Surface finish on that button and valve stem end is crucial. Ruff finish will chew itself up and matting parts.
I've built a couple dozen motors in my life and have always used a bench grinder for the bulk keeping it cool. Then lay on its side and use a fine file followed with some fine emery. You do not want a choppy surface as flat as possible slight chamfer on edges. If I had to do it these days I'd throw on the SG put the valve in a spin fixture and go at it.
 
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