Using a drill to Lap in the Valves on an old Austin A40 Devon head

Notice how the valve is lifted slightly to allow the grinding paste to flow down behind the valve face. A steady slow speed is best.

Category:

Autos & Vehicles

Tags:

• Austin
• Valve
• A40
• Devon
• Motor
• Engine
• Lap
• Lapping
• Morris Vave Grinding
• Grind
• Paste

[prophaniti1]

Using a drill is a surefire way to socket your valve seats not good. :-(

[whitebusfamily]

@prophaniti1 Fiddlesticks! This method was used by old timers for years! In New Zealand we use sensible methods... Practice, not theory makes the world revolve! Start living in the real world and you will see that some people don't live with a nose in a text book! :P

[micky2900]

You do not grind valves this way, leads to bad compression, using the drill method you get circular lines around the lap, this forms bad seal.

Hand only in both directions is best.

[whitebusfamily]

Sorry my friend but you are sadly mistaken. You do NOT get circular lines around the lap. By using a fine grinding paste and lifting and dropping the drill to allow the paste to flow below the valve, you prevent any lines naturally! As for bad compression, we are talking about cars from a different era. Maybe junky modern cars have the problems you speak of, but not old classics. We have used this method for 50+ years without issues. Thank-you!

[muszyngr]

why is everything in the auto industry such a debate, what oil to use, what tires to run, what spark plugs are better, ask 10 guys how to do a valve job and you get 11 opinions, I don't know who to believe the old timers who've done it for 50 years or the guys throwing around big words and 4 letter acronyms, lol

[Nugsport]

@muszyngr exactly what i was thinking, every video i watch the comments are allways the same, "you don't do it like that or yes you do", the real question would be, the guys throwing these big words around do they actually or have they ever done the job they are commenting on!

[ted850760]

@cosast54 do you honestly beleive he's lapping ti valves

[cranelift]

Hey micky, why the heck did they make all those valve laping jigs back in the day? BECAUSE THEY WORK And on newer engines as well. Thirty plus years in the buisness

[1989jadex]

thats just a fucking poor effort

[sesamestreetsquad]

@muszyngr I've wondered the same thing myself..I usually go for consistency, start a job with one person, and finish the job with the same person, instead of switching to someone else midway, yuh know..

[jims72]

@whitebusfamily i use this method and would chose this method over hand lapping any day.way more accurate and dependable than lapping by hand.

[Mitsugejl]

@whitebusfamily I have recently done this (approx. 7 months ago) in the same manner on my '91 mitsubishi and i works just fine. Compressiontest is only microns from being exactly the same on all 6 cylinders :) So it works on "modern" cars as well, i guess it has something to do with the rpm on the drill also. And as a last treatment, i used a fluid named Slipol, it is a fluid with very fine grade of polish in it and it gave the valves and seats a nice, mirrorlike surface :D