Hardened valve seats are needed when driving on LPG (Liquified Petrol Gas)
Some MG's in the Dutch MGCC run on this nice fuel. Very cheep to run, clean
for the engine and very environment friendly
'71 BGT still with normal seats
----- Original Message -----
From: "Paul Hunt (T)" <firstname.lastname@example.org>
To: "David Macedonia" <email@example.com>; "MG Mailing List"
Sent: Thursday, January 08, 2004 10:16 AM
Subject: Re: Hardened Valve Seats
> When leaded when from Europe a few years ago there was much discussion on
> this topic. One input, reputedly from BMW, was that if an engine had used
> leaded for at least 40k and not had new valves or recut seats (grinding
> OK) there would be enough lead leached into the valves and seats to last
> 'the normal service life of the engine' (whatever that might be). This is
> known as lead memory. Lead Replacement Petrol has been available in the
> since then, which is said to be dosed with half the ideal level of an
> additive which has been proven to protect against recession. Why half?
> Apparently because if a car with a cat uses it it won't suffer damage,
> whereas with a full dose it would. Whoever said that didn't explain how
> got a big LRP nozzle into a little unleaded filler hole, but never mind.
> LRP is said to be satisfactory unless you consistently use the car at high
> speeds and/or heavy loads over prolonged distances. All of which tends to
> support the opinion that a classic car used for occasional cruising at
> moderate speeds, probably doesn't need it, especially when users can
> protection additives which they can use at the ideal dosage. 'Daily
> or not probably doesn't cover it, it all depends how it is used when it
> being driven.
> ----- Original Message -----
> From: "David Macedonia" <firstname.lastname@example.org>
> To: "MG Mailing List" <email@example.com>
> Sent: Thursday, January 08, 2004 2:54 AM
> Subject: Hardened Valve Seats
> > While we're on the topic of hardened valve seats, can someone tell me
> > necessary they really are? When I had the machine shop overhaul the
> > back in '97, the owner insisted that hardened seats weren't necessary if
> > car wasn't going to be a daily driver? What you all think?