Hardened valve seats yes or no?

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JR

JR

Pissed off senior member.
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This seems to be just as big as an argument as oil/zinc.

Here is the back story...
I am trading my 53 for a 56 Olds holiday 88 4 door hardtop with a 324 and auto. The car is numbers matching and has 56,000 original miles but the head gaskets need replacing. The owner has new head gaskets and an extra set of stock 324 heads so it is no big deal. I am going to drop off the heads with my machinist and have them magged and tanked do you think that I should have hardened seats put in or should I leave them?
The car will just be a driver with a few "how fast will it go with this new intake, coil, alternator, hub cap, or air freshener installed?" runs down the freeway.
 
I talked with my machinist in rebuilding my2 340 and my 383 and he said with the iron heads u don't need them for a street motor so i say save the cash
 
superdart340 said:
I talked with my machinist in rebuilding my2 340 and my 383 and he said with the iron heads u don't need them for a street motor so i say save the cash
Click to expand...

That's pretty much what my builder said too. I made him do them anyway. The added cost wasn't too significant.
 
I've put a little over 20 K miles on my '66 Valiant since I bought her. Haven't even needed to adjust the valves yet, so I'm calling this one :bs: .....
 
Scamp, I will agree with the rest. My head guys said hardened seats weren't necessary. Mopar uses a high nickel content in their cast iron so the seats are halfway there already. A fresh valve job will last for years especially because we don't put many miles on our cars.
 
I think Olds used higher nickel too, atleast from what I've read.

Post pics of the car.
 
At some point, the seats will get worn out, likely due to sloppy guides. At this point you'd be replacing the seats or fitting larger valves anyhow, so do it then.

If its just a cruiser, iron seats will last a long time. Lots of freeway driving, or towing the upgrade makes sense.
 
JMO, do the seats on the exhaust side.

in 40-50k the exhaust valves [the center to back cylinders] will sink almost an 1/8

I ran around with no hard'nd seats in slant for 4yrs and had valves that were sunk over a 1/4 and the machinist and I were shocked it still ran, at that point it was big valves or get a new head, so save yourself some grief in the long run.
though if you never drive it more than 50 miles a year I'm sure it will be fine for plenty long.
 
Unleaded fuel is the root of the problem. The valves will wear into the heads. The edges of the valves will become razor sharp and start to drop particles eventually. Agreed it'll take 100K miles to wear that much. A stainless valve may wear the head more than itself.
 
those engines ran on regular gas,the lead additive lubricated the valves.now days we use unleaded gas,has higher combustion chamber temps,and no lubrication for the valves.this causes the exhaust valves to resess into the cyl. head.i would install new exhaust seats and not be sorry later.later engines from 1972 to now have harden ex seats for this purpose.
 
I will give it a tune up, check the brakes, clean any carbon off the valves and pistons, have the heads tanked and magged out then put the new head gaskets in and drive the piss out of it!

He is going to get me some more pics but he says that all the floors are solid, 324 rocket V8, auto tranny, front seat, rear seat and front door panels have been recovered and it has 56,000 original miles. He bought it out of Eastern Washington.

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360scampI will give it a tune up, check the brakes, clean any carbon off the valves and pistons, have the heads tanked and magged out then put the new head gaskets in and drive the piss out of it!----- Back in 95, I was ignorant to exhaust valve seats, and told my machinest naaa. Big mistake, the exhaust valves sunk bad in no time, ford 390. Your call:clock:
 
I'd do it. The exhaust vavles were sunk in my sunk '74 but I have no real idea how mileage there was on this RC or if the heads were swapped. I'm think the heads were as they were J's and it had a MLS gasket (not factory) and had .020 over pistons.

Nice car.
 
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