It is very easy and relatively inexpensive to add hardened valve seats to a set of heads during a reconditioning.
Also, depending on how many times the heads have been re-done, you may have to do this to get a good valve job.
For all of the 66 and older engines with the 1.6" exhaust valves, converting to the later 1.74" exhaust valves will help performance with no real modification to the engine and slightly mitigate the cost of the hardened seats with the less expensive and bigger valves.
----- Original Message -----
From: sosmi@xxxxxxxxxxx
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: Re: IML: Ways to improve milage?
Date: Mon, 09 Oct 2006 01:40:22 +0000
Just to add another point, propane ( MAP) gases, don't have additives for non-hardened valve seats, which were pre-72. I'd say: save the propane, for steaks on the bar-be. Thanks, Dave.-------------- Original message --------------
From: "John Harvey" <50scars@xxxxxxxxxxxx>
> The cost of converting to propane is prohibitive to amortize over a normal
> driving year. Propane is not exactly cheap, either, and it has much less
> BTU/Gallon than gasoline, so you get even worse MPG. Propane works OK for
> fleets who buy bulk, drive a whole lot of miles, and have to figure the cost
> of maintenence as well as the cost of fuel, but if there is much propane use
> in road vehicles, prety soon the states are going to demand road taxes on
> you too, which will finish wiping out any cost advantage propane may have
> offered.
>
>
> John
>
>
>
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Fred Joslin
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