Some more ugly in my motor. Can any one tell me whats going on here? Sbc 492 casting. Opinions welcome
looks like the valve seat has been replaced, was common to use a small punch to 'stake' the new seat into place by deforming the head material around it.
some one installed valve seats in my 402 and one came loose and it dropped a valve ruined the head and cracked the cyl wall. You dont need hard valve seats and hard valves. Just one or the other. If you have hard valves your stock seats will be ok. I am guessing they machined the head too far and then punched it to tighten it up. I would not trust it.
What you need is another pair of heads. There's nothing left to work with there - milled a bunch, too.
Tenacious - What's been said. Time for another set of heads. Old Wolf - Completely incorrect statement... ""You dont need hard valve seats and hard valves. Just one or the other."" Mike
Ive been owning LP and distillate tractors for decades. The LP & distillate used hard valves and never have any valve or seat problems. Ive been running one 1944 tractor that was converted from LP on unleaded for decades. And it still runs great. It idles so slow and smooth you can see the fan blades. Its bits of carbon that stick to the seats or valves that erode the valve seats. A hard seat or hard valve will not allow that carbon to accumulate. A hard valve and a good three angle valve job will last forever.
So basically the machine shop cut every single valve seat to big! They are all like that on 1 head. I can't believe this motor didn't drop a valve Sent from my XT1526 using Tapatalk
Old... You said it..! LP fuel, runs at low rpms... That's NOT what car engines do..! I've rebuilt too many heads with receded seats and no valve problems to even close to agreeing with you. Unleaded fuel, soft seats and hard OR soft valves are NOT contingent to a long life...period. Interesting how none of the manufacturers agree with you either. Mike
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