that looks more like a crack than a scratch... I would have them replaced... sorry bro.. looks like the only way out too... even if it is a scratch it looks too deep to be fixed... Just as a precautionary step you could try to re-seat the valves or grind the seats past the scratch and re-seat the valves... 3 or 5 angle valve job should do it...
dam my post was confusing... LOL sorry for that... try the valve job first... if its cracked then you will have no choice but to replace the seats...
The seats have 2 primary functions... first is the obvious one which is to seal the combustion chamber... second is to help wic heat away from the valves and into the head itself to help keep the valves cool
Its hard to tell from the pictures. But to me it looks like the crack isnt on the valve seat but rather in the head. So somebody has allready tried seating new valves and cracked the head. Inspect it proper if the crack is in the valve seat then you cant use it.
But if that crack is in the Aliminum of the head. Then trying to replace a good valve seat is only going to complicate matters.
Id just run the head and keep my fingers crossed if the valve seats are not cracked.
If you dont want to do that Id look for a fresh head to start with.
May be the cheaper better option.
thanks for the info. guys, seems to be on the seats, probably not worth fussing over. its my old a6 head i have had on the shelf for a few years, slowly messing with it. was gonna try to use it with a low budget build, but looks like it would be a waste of time; since i could get a z6 head for the price of replacing the seats, would most likeley be the best route.
the scratch looks like its on the its on the first angle which isn't the sealing angle, so like danz said if you lap them in and the seating angle shows 100% clean up, you'll probably be just fine.. However if it doesn't clean up after lapping you can choose to get them cut.
i have not priced them at a machine shop, but if i got the two seats repaired/replaced wouldnt i need to replace them all? In that case anything over 100 is not worth it, being that i have a 95 ex anyway, i would just pick up a z6 head to throw on my a6 block that hopefully i can start getting around to. thanks for looking at the pics guys i do apreciate it
just being an extra head, not sure if i want to foot the bill for a recut, its hard telling from the pictures, but the nick in the seats seem to be fairly deep and im not sure how much would be needed to be reground before it would just need replacement seats. thanks for the help everyone
I have a 1990 crx si with the original d16a6. I wont to build the original motor. The head has had a value job and has been shaved. Machine shop has stated that the block needs to be bored out at least .10000. What is the best bore to go with being I have to bore it? And what pistons and rods...
Hey guys I researched and found alot of controversy on this topic people not including full writeups and so forth and calling bs saying it cant be done or he/she is a liar cause of lack of proof but im here to say it can be done! And is pretty straight forward too.
1st. You gotta block your oil...