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I have a 22nd 327cu...

I am having my engine rebuilt. I was running a lead additive prior to rebuild. (the block cracked due to an unseen previously welded crack that failed again) I am trying to determine whether or not to have the seats hardened.

Some people have told me to do it, and some have said just to run the additive. ...some have said with that low of compression, it's a non-issue. I do plan on running a 288cu head on the 327.

What do most people run with un-altered engines?

Thanks,

Mark

These flatheads run very low valve spring pressures and don't turn too fast so it is not an issue. I have several hundred thousand miles on various flatheads from Kaiser to Stude to Packard with unleaded fuel, no additives, and no problems.

While your engine is apart, be sure to check the fit of the exhaust valves in the guides as this is a common wear area and heat transfer out through the stem is important to keep the valves happy.

I'll agree with the advice of Ross 100%. However u mentioned a cracked block that had been repaired but did not indicate WHERE the crack repairs is. Assuming the crack repair is not in a valve seat then no seat inserts should be necessary. IF seat is cracked then a seat insert mite very well be a good idea.

Another potential problem with seat inserts is that they can come loose. UNless a seat is cracked i would avoid inserts Regardless of the type of valves used.

I mite add that u refered to "... have the seats hardened". I'm not real sure what u mean by that. I assume that means hardened seat INSERTS that require a machining process to install them. IF u were told by someone that the EXISTING cast integral iron seats as they came from factory could be hardened as opposed to a maching process to replace the seats then i would sure like to know what that hardening process is. I've never heard of simply hardenenig an existing valve seat.

S8 I'm not sure.

V-8 for sure hardened exhaust seats. I have previously posted a chart that says that if you cruise at 60+ for extended periods, then your non-hardened seats will be beat down. I personally experienced this. Since I replaced the V-8 heads & with hardened seats, I've had no problems and that's been about 10 years at extended high speeds, of which the V-8s are more than capable.

For an example, see KevinAZ's 1955 400 turning "back to zero" odometer whilst cruising at 80+MPH on the last PackardInfo.com meet to/from 900 mile trip. His engine has hardened inserts on the exhaust seats, so he should be able to do that high speed cruising for years and 10's of thousands of miles.

Craig

To be clear... The block that cracked is the one that I used the additive in. (however, I am not attributing the crack to that). That block had previous water jacket corrosion that caused the re-crack. I mentioned that block but didn't finish my thought... When I pulled the head, there was alot of oily buildup in the cylinders. I'm wondering if it was the lead additive. I don't really feel that it was oil, but I could be wrong.

The block that I am rebuilding is in good condition and is at the machine shop. The machinist and I were discussing the installation of hardened seat inserts. ...not actually flame hardening. He doesn't have the equipment to do it.

The previous poster brings up a good point about sustained highway speeds. I will probably do some highway driving, so I may use the additive then.

Sorry for the confusion!

Mark

BTW... I had bought the replacement engine from Mike Dulinski. The engine turned out to be in great rebuildable shape. Thanks again Mike!

D-train, Craig's comments were mostly about the V-8s, which can have valve troubles with the new fuels if driven at more than moderate speeds. He posted a very interesting graph depicting speed v wear. It is worth viewing if you can find it here. You should be fine with no hardened seats and regular grade modern gas. Get a good precision valve job with care to how the valves fit in the guides. The S-8s are low stressed in the valve area as compare to the V-8s. Good luck either way.

(o[]o)

Added comment: You should not have any need for lead additives or supplements. The big problem with modern fuels and the vintage S-8s is vapor lock in warm weather.

I don't know if this is the same chart that Craig and JW are referring to, it's been around the hobby for years and I know I've posted it here before.

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Owen_Dyneto Quote:

That's the chart. The gray line from 60 to 90MPH at 19 Spec-Wt is my 1955 Patrician. You can see that sustained driving at 85MPH is "Very likely" to cause valve recession. I can vouch for the accuracy of that! Of course, this chart only applies to non-hardened (original) exhaust seats.

Craig

In my experience with running Packards at high cruising speeds with unleaded petrol ( over 60 mph), is that you should use an anti valve recession agent. It is almost unnecessary if the engine uses a bit of oil as this tends to protect the exhaust valve seats. I still use it however just as an upper cylinder lubricant if nothing else. I fit hardened exhaust seats to any Packard engines which I overhaul as the fuel quality is getting worse all of the time and it is cheap insurance. PT

When the 327 straight eight was designed gas was low lead, low octane. It should run on today's regular gas with no problems.

The only possible exception would be, the last year or 2 of production when they had over 8:1 compression. One of those might run better on hi test. You would have to try them and compare, if the engine runs well and does not knock on regular there is no advantage to using hi test.

Hardened valve seats should not be necessary.

If you like, you can add some upper cylinder oil to the gas. Redex, Bardahl, or your favorite brand. It can't hurt especially for hiway driving on a hot day.