L78 Dyno

[Salvatore]

hardened valve seats really necessary?

[earntaz]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: [email protected]</div><div class="ubbcode-body">hardened valve seats really necessary?</div></div>

It's a toss up -- I've read pros/cons. If you will be running the livin' hell out of the motor for extended period of times -- hardened seats are a must. But if you're just cruzin' with occasional jumping on it you probably don't need to install.

Valved seats back in the day were induction hardened -- but if the valve seats are ground below this &quot;hardened surface&quot; erosion may occur.

I'm sure others will chime in on this ...

TAZ

[Salvatore]

doubt if either of these guys are going to run their car that hard. both will probably use a lead additive or some racing gas anyway. Don't like cutting into stuff that can cause problems later. Not necessary just like floating wrist pins arn't really necessary for street motors IMO.

[JRSully]

I put hardened seats in my 70 291 heads on the 70 L78, didn't want to deal with lousy gas issues and the engine gets hammered on regularly. My engine dyno'd at about 428hp at 5600 rpm, dead stock except roller rockers, pertronix and headers, orig intake, compression, 4557 holley, stock heads, nos 143 cam. You need somebody experienced to do the valve seats right, have to watch the water jackets

[Kurt S]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: [email protected]</div><div class="ubbcode-body">hardened valve seats really necessary? </div></div>
If it sees a sustained hi-output duty cycle. That would be a tow vehicle where it's running high temps for long periods of time.
Not for a street or race car.