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  View original topic: Is it possible to replace valve seats? 65 1200
StiffGizzard Mon Aug 20, 2018 9:40 pm

So I finally pulled the valves off and started lapping and noticed that exhaust valve seats 1&3 are fucked.

The valves sit flush with the top of the guide and never mind the leak down, I can see LIGHT through one side like the guide is ovalized :(

Any idea why 1&3 would be in the exact same shape while all the others are solid?

parker007 Mon Aug 20, 2018 9:43 pm

can be fixed by good machine shop. but sometimes cheaper to find used good head. when seat lose machine shop has to make new seat, true pocket and install then grind, expensive.

StiffGizzard Mon Aug 20, 2018 10:45 pm

Is it possible to just run an over sized valve that would sit on the top of the seat like the rest?


... or am I just fucked....



Any idea how much it would be for two replacement single port heads?

parker007 Mon Aug 20, 2018 11:07 pm

that head look like fixed before by hacker, no cant just change valve. problem is gases going between seat, plan new seat with full rebuild or new head.

glutamodo Tue Aug 21, 2018 1:34 am

Valve seat replacement is a high specialty job - one that most general purpose machine shops are not going to be able to do.

It was with the change to square boss heads during the 1965 model year that VW changed to a higher quality valve seat, pretty much "unleaded quality" seats began then. Before that, valve seats could and would erode away with modern fuel. I know, I've seen it on my own engines before I changed to square boss heads. (Not that I haven't seen heads form after this time also have horrible valve seats)

rcroane Tue Aug 21, 2018 4:54 am

glutamodo wrote: Valve seat replacement is a high specialty job - one that most general purpose machine shops are not going to be able to do.

It was with the change to square boss heads during the 1965 model year that VW changed to a higher quality valve seat, pretty much "unleaded quality" seats began then. Before that, valve seats could and would erode away with modern fuel. I know, I've seen it on my own engines before I changed to square boss heads. (Not that I haven't seen heads form after this time also have horrible valve seats)

Andy...did the replacement "F" heads also have the higher quality valve seats, or was it just the square boss heads? Thanks.

glutamodo Tue Aug 21, 2018 8:58 am

Oh, good point there. I think they did, but I never saw any kind of service bulletin saying so.



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