Cuttin' seats

a.woodrow, Dec 11, 8:39pm
89 Mazda familia, twin cam 16 valve. needs valve seats cut, been quoted $196+ for cutting, $39+ for decarb. is this dear! never had to pay someone to do this before. I have stripped the head down so valves etc are already out. thoughts! tempted to maybe spend longer just lapping the valves in cos I'm tight lol
purple666, Dec 11, 8:47pm
If your time is your own then I would be doing it myself, depending on just how bad the seats were.
a.woodrow, Dec 11, 9:00pm
it is and I would, just my valve seat cutter shaft is too big! They are bad enought, after a quick lap I see the valves are only touching on one side of the seat, before pulling to bits the engine had no/low compression
the-lada-dude, Dec 11, 9:17pm
you'll need tungsten carbide cutters and the highspeed steel ones wont cut as the seats are hardened because there is no lead in the petrol to help stop seat wear. grinding stones will do the job.
does that price include refacing the valves !
a.woodrow, Dec 11, 9:32pm
to be honest I didn't ask! the valves are good though, they just need lapped in. the seats are a little off I would say as the head was overheated. Think I'm going to try and mickey up something to use the cutter I've got, price seems just a bit steep to get them done
the-lada-dude, Dec 11, 10:16pm
it might pay to hardness test the head 1st
the exhaust seats are the one that have to be pretty good, you'll soon see if there any good as lapping will leave a witness mark. just get the ex val done if necess
a.woodrow, Dec 11, 10:38pm
yep its the exhaust valves that are the problem. head has been hardness tested and ok, is also still flat.
the-lada-dude, Dec 12, 12:21am
say$8 / ex seatx 8 seats= $64
if you have'nt got the right gear you'll end up making a mess of it !
go on let the man do it !
a.woodrow, Dec 12, 5:01am
I reckon I'll do it myself, have enlisted a friend to make up a smaller shaft for the cutter :)
mrfxit, Dec 12, 8:52am
There are ways . but only the good bushmen know them ;-)