Clean the valve thoroughly and put a dab of maple syrup on the suction cup... push the suction cup down tight on valve and make it spin around on the valve to evenly spread the fluid.... should stay put
Interesting tip! I also saw a guy once gently warm the valves with a heat gun and jam a big glue stick on it and use that. Worked pretty well, but may not have been that practical for an every time thing.
I second this, but I've got glued directly to the tool but also to scrap broom handles or similar. Hot glue is easy to use and easy to remove when done.
@@gordocarbo I would love someone to explain the technicality of why this method is wrong. Yeah I've read about how it might cause it to grind the valve/seat unevenly. But how exactly if the guide and stem are true? In my mind the valve will 'wobble' just as much if done using a sucker. Either way, I'll still be using a drill. Never had any problems in all the years I've done it that way!!
I like the drill. I know so many say ots wrong but thats old thinking as long as you dont go crazy and you stay in line it works great and takes about 1:10th the time.
Same, been doing that way for years and never had an issue. Even on modern diesels it's worked out fine, I always get perfect looking valves and seats and never have any compression issues.
The suction cup ones used to be good (Pre 2000 year), but the market is now flooded with crappy chinese ones with this stiff type rubber. If you can buy a branded lapping tool with the more pliant rubber heads they work fine. Just don't cheap out.
Alot of new valve sticks are silicone rather than actual rubber, so they don’t stick well. You need to find a supplier who still uses rubber and they work 10/10
I go the hose and drill route and I put a hose clamp on it just for extra measure. I put a little dab of grease on the valve stem for the guide, again just extra measure. One of your comments mentioned pits, took me 1 to 1.5 hrs per valve to lap the pits out of the valves for the heads I'm working on, that's with the drill.
They were intented to be used after a proper valve job with stones or cutters. That would be plenty of time to check for concentricity or see where your point of contact falls. Lapping has become a multipurpose, like aforementioned or to conform mismatched valves and seats or old pitted non-sealing surfaces to get an old valve job sealing again with minimal investment and your up and running again. If your not worried about power potential or fuel economy it'll do.
PROBLEM SOLVED, here, dude. I remembered that I had some spirit gum that I had bought from Bargain Bins for about a quarter or 50¢. I put some on the suction cup and squished it against the valve which I had sanded. Then I removed it to let it dry some. It works amazingly well. The only thing is, I think I should have degreased the valve and cup first will anhydrous isopropyl alcohol or carburetor spray. It might have worked even better. The spirit gum is a "professional adhesive for applying prosthetics, bald caps, wigs, and crepe hair". It is a product of Mehron, Inc. in Chestnut Ridge, NY. It comes with a bottle of remover, but I might just leave it on and let it burn off. It DEFINITELY HELPS.
@@themotobarn702 Maybe, but it won't last long when I build a fire in those cylinders, especially on the exhaust valves. You can't burn it off your face, but off a valve face, yes, you can.
I've only actually seen this twice. What is the purpose of valve lapping? Is it about the sealing faces..? Does it actually have a measurable impact on performance?
It's a very common practice to ensure a proper seal between the valve face and valve seat. In my case, mine were heavily pitted and I was attempting to "restore" them without going to the machine shop. Long story short, I will be getting a proper valve job this time around, as the head required it.
Its only used to ck if its sealing or not. Quick lap no more. Doesnt substitue for a valve job. Vids of grinding the daylights out of parts with a dril are wrong wrong wrong. You can lose performance doing that. Valve job is the right thing to do if its not completely sealed
You could also let a maid clean your house. A landscaper cut you your weeds. An arborist trim your trees. A window washer wash your windows. A painter paint your house. A detailer wash your car. A dry cleaner wash your clothes. A food delivery service feed you A fuel truck pump your gas. And last but not least your wife could scratch the itch on the back of your head.
Best post!! Do it once, do it right .All these drill it hard videos are hackjobs and can lose them power. Maybe doing things right is called "old thinking" now. haha.
This...he needs to slow down and be patient. Lapping needs very little effort or time. These guys wanting to grind the pee out of seats using drills....drives me p the wall. More harm than good
i made my own tool. had to, no other way to grab a 15mm valve... just a piston in a lil cylinder of knurled aluminium with a drawbar/locknut, oring on the face. if there was a market i guess i would sell them. not many people grind valves anymore.
@@themotobarn702 😂😂 I just watched a valve lap job, and it was a clear point to lick the suction cup. Moisture is the trick. Lol. But nah, I’m sure these suction cups arent really good on old valves that aren’t clean even though they’re clean as mentioned.
@@themotobarn702 You should post up you got a valve job done..how important it is and let others know the drill hack job thing is wrong. Esp after guys port. PLenty of power to be gained with a V.J. I dont think many realize how much. Good on you for sprining and doing it right.
Thank you for such a wonderful comment. No misinformation, simply showing what I did and how it turned out for me. Already learned from a much nicer, informative comment that I should have wet the cup first, which slipped my mind. Have a great day.
@@themotobarn702... Also... You have to push every time you spin the valve so the suction cup is reseated each time you push anyway.... I like to rub the suction cup on my forehead just before using... The oils from your skin make it stick real good.
