Re: [FWDLK] NON STELLITE SEATS-Its an idea

I’m not an expert, but this is what I have heard:

On an engine that has been run on leaded gas for a long time and never had a valve job, the lead gets imbedded into the seat and continues to protect the seat from wear, even on unleaded gas, for a long time. Problems occur after a valve job.

Valve seat recession occurs much more often on engines that work hard. Typically tow vehicles and performance cars with higher lift cams.

Aftermarket lead substitutes work, but not as good as lead, and they do not embed themselves into the seat as well as lead, for longer lasting protection.

When the hot exhaust valve crashes down onto the seat, a few atoms of the seat material can stick to the valve. This happens about a million times every 600 to 700 miles. Lead acts as a barrier and cushion, and prevents the material transfer. Modern hardened seats are hard enough to also prevent material transfer. I’m not sure if a 2-stroke oil will be up to the job at the temperatures and pressures involved.

Hydraulic valves will automatically adjust to compensate for the change in valve height, until the recession is sever and the lifter runs out of adjustment. Solid lifter valves will actually get quieter as the clearance adjustment diminishes, until such time as the valve will not close tight. Then it will burn rapidly and loose compression.

Since valve recession does not affect the valve guide clearance or seal, there should be no change in oil burning.

One way to compensate for valve recession is to use a modern oil that lacks a sufficient quantity of ZDDP (recently reduced to below an effective level in new oils). This will allow the lifter to grind down the cam lobe, thus increasing clearance while valve recession is decreasing clearance. But once the cam lobe is ground flat, the valve will no longer open and the engine will no longer run. This is a plot by the EPA to get our old gas guzzling, non-PCV, non-catalytic converter, non-computerized, non-fuel injected, non-methanol tolerant, non-aerodynamic, non-seat belt, non-air bag, clunkers (their opinion, not mine) off the road.

Dave Homstad

56 Dodge D500 (with hardened seats and unleaded valves)

-----Original Message-----
From: Forward Look Mopar Discussion List [mailto:L-FORWARDLOOK@xxxxxxxxxxxxx]On Behalf Of jrawa@xxxxxxx
Sent: Monday, July 05, 2010 6:35 PM
To: L-FORWARDLOOK@xxxxxxxxxxxxx
Subject: Re: [FWDLK] NON STELLITE SEATS-Its an idea

2-stroke oil sounds like a good idea. i just dont buy the whole non-lead issue... after successfully clocking 65,000 miles [from sept 01 till now] officially on my last trip up to philly with my 59... no head problems, not a hint of tap, smoke, etc.... thats 65,000 miles on top of the 47xxx orig miles on the 67 383 that went in it...

-----Original Message-----
From: DOLORES ECKERSON <eddee@xxxxxxxxxxxxx>
To: L-FORWARDLOOK@xxxxxxxxxxxxx
Sent: Mon, Jul 5, 2010 10:35 am
Subject: [FWDLK] NON STELLITE SEATS-Its an idea

HELLO MEMBERS
-Just passing something along that should work for you or atleast help the sutuation.

With non-leaded fuels today,,,,,if one will be using their classic for any road trip,, the word was to have the stellite exhaust seats put into the heads.
It is TRUE that after a period of useage (especially high speed) that the stock cast iron exhaust seats will literally wear away. If not caught early it will destroy the heads.

The problem is simply haveing 'lubrication' to the cast iron exhaust valve seat!
Lead did that!

I have a suggestion that should ALMOST take care of that withouit the stellite seats.

I am using 1 oz/gal of top grade OUTBOARD MOTOR OIL in the gas.
At this small amount there is absolutely zero smoke , plus it keeps the carb internals nice and 'lubed'. When low throttle or idylle--enough 'fuel' (with the oil) gets to lube the seat during valve overlap.
I do NOT take road trips but have all stock cast iron seats.

I THINK one could up this to 3 oz/gal for road trip protection with out any smoke. You may see a hint of smoke at idylle, but the new outboard oils are ashless and almost smokeless.

Its all just educated conjecture--but it wont hurt
ED ECKERSON
LI NY

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