How come we never do valve jobs anymore?

Question

In the old days valve jobs were common. You never hear anyone say they had to have one anymore.

Answer 1

Gasoline had the lead removed which required a different grade of material to be used on valves and seats, so they last longer. There are also systems cleaners that will remove many deposits from the valves.
However some of us still do a valve job at 80 to 90 thousand miles because there has been a loss of performance.

Answer 2

Both the answers are partially correct. The biggest reason is modern engines have less valve dammage is due to much better fuel management fuel injectors that spray just the right amount of fuel for conditions. This also accounts for longer engine life pistons and rings wear less. But wait! now many engines have oil change intervals at 7,500 miles so we trade valve jobs for engine sludge. Or low speed driving intake valve deposits.

Answer 3

Most of the currant answers are correct, this just ads to them.
In my day, valve seats were part of the head and materials were softer thus wear caused irregularities which had to be corrected. Burning valves due to high wear and temperatures.
When they started installing steel valve seats (pressed in) they pretty much solved the problems. Also the heads have better cooling circuits now, than they had back then.......
45 years engine mechanic, all sizes...........

Answer 4

ok at the beginning... i for my area like cork gaskets, and would in no way positioned vaseline on them it in basic terms provides the oil a head initiate on inflicting a leak, we use cork gaskets on our race vehicle automobiles and in no way have a difficulty with them till they don't look to be tightened acceptable, so my first suggestion would be to ensure you're tightening them sufficient and not overtightening them... 2nd... sure oil can leak from an exhaust manifold if the valve seals are worn sufficient oil can certainly drip into the exhaust and take a seat on the area around the exhaust gasket and reason a leak to look 0.33... heres what you do to end this leak from the valve conceal... make optimistic there is not any previous gasket cloth caught to the suitable of the pinnacle floor and make optimistic none on the valve conceal itself, then make optimistic each and every of the bolt holes in valve conceal are flat (not dented upward" use a small hammer with a chunk of medal on underside and gently faucet and bolt holes that are raised down flat , then do such as you probably did formerly with the hi-tack spray to hold them to the conceal whilst tipped over, then make optimistic head floor is sparkling and dry, utilising a one million/4 inchcontinual ratchet and socket and extension positioned all bolts in formerly tightening any of them totally... as quickly as all put in and comfortable bypass around tightening them gently somewhat at a time till you are able to desire to apply a honest volume of torque to coach them anymore thencontinual the vehicle for an afternoon or 2 and bypass decrease back and verify each and every of the bolts lower back... i assure you would be waiting to tighten a minimum of a few of them in basic terms like yet another one million/2 a turn or so, then you definately shouldnt have from now on leaks from the covers in case you discover a leak around the exhaust nonetheless ...then you definately probable have very worn valve seals which isnt uncertain because of the fact the truck is 20 yrs previous now

Answer 5

Fuel injection has all but erased the carbon build up on valves.
When engines ran with a carburetor, the carbon build up was pretty bad.

Answer 6

improved metallurgy,multiple smaller valves,cleaner fuel