What about the C-series 2912 engine :)? I just torm my head down and only
had carbon deposits to remove. Seats where still good. And yes it is an
original 1969 head.
Just my 2pennies.
Tad R.
Orlando, FL
69 MGC GT
74 RWA Midget
----- Original Message -----
From: "Dodd, Kelvin" <doddk@mossmotors.com>
To: "'Barrie Robinson'" <barrier@bconnex.net>; "Rocky Frisco"
<rock@rocky-frisco.com>; <mgs@autox.team.net>
Sent: Monday, December 31, 2001 3:08 PM
Subject: RE: Blown Head/now hardened seats
> When the US market changed over to Unleaded low octane fuel, British
Leyland
> was faced with longevity issues with the venerable B series engine.
>
> To reduce the possibility of valve recession the valve seats of US bound
> engines were induction hardened. This was a very expensive process and it
> is very unlikely that the factory would have chosen this direction if
there
> was no wearing issue. The original exhaust valves were retained, as it
was
> determined that the material was suitable for the more critical
application.
>
> After spending many years trying to source good usable B-Series and
A-Series
> heads for customers. I can state that both designs are subject to a high
> degree of exhaust seat wear. The combination of high spring tension, hard
> use and iffy fuel quality and mixture tend to aggravate this wear.
>
> Each Persons Mileage May Vary (EPMMV) but I go on record stating that
> exhaust valve seat longevity is a limiting factor in A Series and B Series
> engines. Correctly installed hardened valve seats do improve this area.
> Obviously I would not suggest pulling down a running engine to install
them.
> It's pretty obvious when they are needed, as the valve lash goes out on a
> weekly basis.
>
> Come to think of it, the argument seems rather academic. I don't think I
> have seen an original pre-75 head lately that had any exhaust valve seat
> left to quibble about.
>
> Kelvin Dodd
>
>
>
> > and is still smooth, lusty and pulls hard (sound like a girlfriend I
> > had).
>
> Barrie, thank you for this image. : )
///
/// mgs@autox.team.net mailing list
/// or try http://www.team.net/cgi-bin/majorcool
///
|