Buy a plunger stick thingy, any auto parts store should have one. Then, use GREASE mixed lapping compound.....not water mixed, it sucks. Use it sparingly, and don't overdo it b/c too much lapping can actually harm the face of the valve. Just slowly rotate the valve back and forth a few times. When you're done, be sure to clean off all the compound from the valves and the seats. The contact area should look grainy, that's perfect. :bglasses:
I think you can buy valve-lapping compounds in a kit or you can just buy the compound pre-mixed and ready to go in a little and round tub thing. If you can get a kit, that should include a few lappers(the plunger looking objects), and the compound itself. And like joe said, don't over do it, ya just wanna do it untill it is nice and grainy looking, only takes a few minutes per valve(2-3 minutes max). Good luck :TU:
yep, thats how ive done it before, just didnt know if their was a different method. and yes, that damn water based paste sucks! the first time i did it on some sbc heads i left the paste on the valve and it rusted to the seat!!!!
I reccomend Clover Brand.... comes in a little green tin. I'm new here and an OLDS guy but have used this stuff for about 30 years. I like it that you guys don't think those orange motors are the greatest thing in the world........ :grin: This is a nice site.............
Actually, most of us do like oldsmobiles on here, I know I do. Do you by chance own an olds toronado? :bglasses: Welcome to the board!
I never liked the orange paint on an engine!! Even on Chevy engines that I've done, they've either been black.......or Buick Red. :Brow: :grin: As for lapping valves......I know it gets done, and in a pinch it's better than nothing. But......I don't like it. Guess that's just the machinist in me. I know guys that would take a perfectly machined 3 angle FLAT valve job and grind a trench into the face of the seat & valve!?! If you have a 45* valve face and a 46* seat face, you need to take into account how the 30* cut changes where and how much of a margin you have between the top of the 45* and the edge of the valve. If you only have the 45* angle past the top of the valve, you're looking to burn a valve and/or seat up!! Not to mention, a lack of flow with that now very wide seat.
I agree 100%. I never lap valves & seats anymore. 1* difference between the seat and the valve, "engineer blue" colour to see the contact point, and the valve/seat are perfectly "hammered" in the first seconds after start-up. Per. :beer
When I grind small engine seats and valves I grind both angles at 45*......I have an old machine, and how do I really know the angle markings on the machinery are accurate? Also, newer small engines have stellite seats which are very hard. I don't always have good luck with blue ink, but when I lightly lap I can see the contact area very clearly on the face of the valve. My equipment is designed for small engines, so I sent my 425 heads out and I never asked how they did the angles....but I still very lightly lapped them before assembly and checked each one. I too figure if they're off a little they'll "hammer in", but I still like the idea of a precise fit better. :Smarty:
Thanks, and yeah I do......'66 Toronado......it's my latest project and this time the 425 is going back in the Toronado! Sorry for the double post, I'm not the most computer literate guy around
