Thanks very much for your thoughtful and well produced video! I'm working on my first flathead engine and potentially first valve job. As usual, I do a lot of research to learn tools and techniques before diving in. While watching the ridiculous old school method of back and forth spinning a hand tool on multiple videos I thought there must be a better way and contemplated buying a standard set with 4 suction cups and mounting them on 5/16ths dowels to chuck in my drill. Now you've pretty much confirmed my thought process so that's what I'll do first. I can control my drill right down to almost a standstill very easily and just as easily either reverse direction (which I actually see no need for) or simply lift and drop as necessary to get more lapping compound on the seating area. If all else fails I can go back to the old fashioned way because I'll have the wooden hand tools stored.

When you're drilling the valves back in with the suction tool, you wanna drill back and forth; a few seconds clockwise, then a few seconds anti-clockwise, and repeat, until you no longer hear the grit. This is better than just continuously rotating the valves in a single direction. Just a pointer.

I I have probably lapped well over a thousand valves. I gave up years ago trying to get them stupid suction cups to work LOL. I had brass teeth made for my drill and all I do is check the valve stem up in the drill and from the other side of the head I do my lapping .so much easier. You can use any drill, if you want to take the time to put some duct tape on the end of your valve. you'll be good to go. The guy that made this video knows what he's doing he was at the right speed and used the right amount of compound.

Nice useful tips, thank you

Had the same trouble with the suction cups popping off. I super glued mine on the stick. Been good ever since

Thanks for the video! I'll be doing a SBC soon.

thanks for a really well done video and explanation.

Use an old Bit Brace chucked up to the valve stem and start turning. That way you won't have to fight hearing over the drill motor. Works like a charm

😂 it took me the entire day with that old tool, slipping badly. Next time i will do likewise. Thanks mate!

Thanks for the helpful videos I don’t know if I missed it but how do you clean the heads so well before paint I have some that are pretty rusty can I use evapo rust remover?

I just had a dumb idea. Would it be OK to use a paint cutting compound after you finish regular valve lapping to get a nicer, smoother finish? 🙂

put the drill on the stem, pull back gently, go in BOTH directions.

Hello friend, put the rubber on a short shaft, and put a spring between valve and seat, and you will see that it works better.

How did you find this worked when the engine was built back up? This looks like a far more agreeable way of lapping the valves in!

Gas hose on the valve stem and then into the drill. Works a million times better than anything.

I've always just attached a vacume line to the valve stem and attached the vacuum line to a dril and then used my finger to control how close the valve is.

what year it is that we are laping the valves ? O_o ... 60's?

im sorry but how do u expect the suction to stick with it not being wet?

So, can a person do this type of Lapping on a 3-Angle Valve Job? I ask because that's what I have. 🤔

Bruh that lapping handle got bout 10ft of run-out iiiiight precision 👌

The reason your hand lapping hasn't gone well is the fat diameter of the wooden bit , you need to stick it in the lathe and thin it right down to a concave section where your hands would use it , the thinned section will increase the speed , sit your valve seats level , using the biggest sucker on your valve is best , those suckers almost look plastic-ey as they get older and well used they soften and work better .

It's the back and forth motion from your hands that makes a better seal.

I just spit on my tool and it usually sticks like glue

You should go in both directions

It doesn't stick because the valve isn't flat.

Put water on the suction cup. It will stick better

Seems like you need to clean those valve guides up. Looks a little stiff

Just chuck the drill on the tip of the valve stem

You're using an excessive amount of grinding compound. That much is not needed. The trick is to just coat the surfaces grind it until gone and do it again.

Practice makes perfect, The old school why is much better. You can't feel your work as you progress with a drill.

I dunno why everyone has such an aversion to lapping valves the correct way. It's really not that hard.

You should have cut your valve seats first at a 3 angle cut. Why using this tool with the drill if you could just put the drill on the other side and pull and damage this way your valves? 😁 Buy a 25$ valve grinding tool which does the left right turning perfectly. Anyway, your valve seats were anyway out of specs.

You really should have the valve facing straight vertical, and you shouldn't use a drill. To be honest, you just shouldn't be lapping valves in the 21st century, it's not that expensive to have your local machine shop cut your seats on a Serdi and grind your valves if you've disassembled and cleaned the heads yourself. I'm a trade-qualified automotive machinist.

I used a drill a long time ago as a shortcut, and it ruined the seats and valves. Not something I would do again, but hey, if it works for you, crack on.