I've noticed a lot of FE motors have issues with burnt valves, mine included, and I've wondered, how come? They're pretty solid engines, but what happened with the valves?

Sam

 

Out of the 10 or so FE's that I have had around here, only one had any burned valves, it is my sons. It did not have hardened seats in the heads. It was run alot at harder than the others.

 

Valve jobs used to be common. Our '66 burned a valve at 41,000. I had just started driving, and I thought I used to run the wee out of it. But I figured out the rpms based on the axle ratio and tire size, and the most I ever turned it was maybe 4000 rpm....it just wouldn't go much more that that with the stock single exhaust. Usually, no more than 3800 rpm.

That was with leaded gas. Unleaded is death to old engines if they are run hard at all. D2.. heads have hardened seats, but that can wear through also.

As for the valve material, they are not stainless valves, and not sodium cooled valves either.

Another thing could be the valve train geometry. If your heads or deck have been machined and you have the same length pushrods, that might lead to a valve not seating properly sometimes or all the time--that'll cause issues.

 

Makes sense, my motor is out of a 71, that was right on the cutoff for hardened seats wasn't it? It's a regular pile of parts too, so who knows what it all has in it. Sounds like it's time to take them to the machine shop for a grind and some hardened seats then?

The blowby is so bad on this engine when I pull the breather cap and rev it, as it revvs down I can hear the blow by coming into the valve cover!

I never ran my engine very hard, but what Ive done to it probably doesn't make much difference, I'm pretty sure it had burnt vales when I got it. It never has run quite right, always misfired.

Sam

 

73 was when the engines really started getting hardened seats and 76 is the year the fuel nozzle restictors and cats came out.