Valve Shims
sweller
I need various valve shims to fit a 1965 Jaguar 3.8 XK type engine.
However, they need to be a lot thinner than those normally available.
The required dimension is a diameter of 17.5mm in a range of thicknesses
from 1.92mm to 2.30mm (0.076"-0.090")
Is it possible to buy shims "off the peg" or does anyone know of a car
that uses the same size in that range of thicknesses.
I'm led to believe the SAAB 900 (old shape 8v) uses the same diameter
shims - does anyone know if this is the case?
Thanks.
--
Simon
Rob
Its cheaper to have the valves ends done. You can have the shims
ground - they hold them on a magnetic chuck and surface grind.
Whats caused the need for thinner shims? have the valves sunk into the
seats? Unleaded petrol, in a leaded engine?
If its the SAAB also Triumph and think Marina for shims. There is still
a limited size range.
r
sweller
> > I need various valve shims to fit a 1965 Jaguar 3.8 XK type engine.
> > However, they need to be a lot thinner than those normally available.
> Its cheaper to have the valves ends done.
...but this would require the head to be removed?
> Whats caused the need for thinner shims? have the valves sunk into the
> seats? Unleaded petrol, in a leaded engine?
It actually needs thicker shims than it's got but still slimmer than the
available range.
I suspect the valve seats have been over cut at some point in its 45 year
life and 'homemade' undersize shims have been fitted as a result.
I believe XK heads are ok on unleaded and the valves don't seem to have
receded as the tappet gaps haven't closed up - quite the opposite, hence
the need for new shims. It's a healthy engine, good compression and it
returns 24mpg (good for an S type!).
> If its the SAAB also Triumph and think Marina for shims. There is still
> a limited size range.
From my research the SAAB shims are available in the sizes I require but
I need to confirm the diameter - does anyone know the diameter of the
Triumph (which model?) or Marina ones?
--
Simon
Dave Baker
"sweller" <swe...@mztech.fsnet.co.uk> wrote in message
news:xn0gsgcx...@news.individual.net...
You need to check that diameter which I don't recognise. As far as I'm aware
most of the old Imperial engines like the Jag, Lotus, Imp etc used 5/8"
(15.875mm, 0.625") diameter shims. Aftermarket suppliers then made these as
15.55mm diameter shims to allow them to also fit other engines including the
Saab 99 and 900, Maestro and Montego 1.7 and 2.0, and Rover 2.3, 2.6
engines.
The Saab ones are available down to 1.77mm. However if yours really are
17.5mm diameter these would very loose in the valve cap, not that this would
actually stop them functioning.
Shims can be ground thinner within certain limits. They are generally case
hardened with a case thickness of about 10 to 15 thou which you don't want
to grind right through. That means you can take about 5 thou a side off.
0.25mm total.
Your other two options are shortening the valve tip which is fine as all OE
valves are through hardened right down to below the collet grooves and using
lash cap shims which fit over the top of the valve stem and don't use the
valve cap for location purposes.
--
Dave Baker
Puma Race Engines
--- news://freenews.netfront.net/ - complaints: ne...@netfront.net ---
Mrcheerful
or if you are a real animal you can take a little grinder and grind the end
of the valve in situ. I saw this several times in the early days of the
Suzuki GS engine which had shims. Even worse is that the owners claimed it
had been done by a motorcycle shop.
JB
chucks in our toolroom at work.
Drop me an email if you want them done.
cheers,
JB
jmbyrne_AT_greenyonder.co.uk (changing colour to BLUE
obviously).
Rob
The Triumph Dolomite ones available are 090" to 114" can't find my
bucket full or I would have measured the diameter. (Saab is the same motor)
What you have to watch is the the edges, some have square edges whilst
others ( I thing marina???) have rounded edges. The round edge type tend
to sometimes jump out of the cap.
Your cheapest way is the measure what your requirements are then have
them ground.
I would measure the clearance - remove them - measure the shim - and see
if you can swap any around.
then have the rest modified to suit. or source new ones.
BTW have you asked at a JAG place if they have any to swap at a charge?
r
Adrian
they were saying:
>> If its the SAAB also Triumph and think Marina for shims. There is still
>> a limited size range.
> From my research the SAAB shims are available in the sizes I require but
> I need to confirm the diameter - does anyone know the diameter of the
> Triumph (which model?) or Marina ones?
The "B-engine" in earlier 99s was developed from the Dolomite lump - but
heavily so in all bar the very earliest 99s - and by the time the 900 had
come along it was even more heavily so.
Charles C
Hi,
A bit late ... I found the sims from my 8v 900 heads + spares bought at
the time.
Measuring the diameter of a couple (with calipers not micrometer), I get
15.6 and 15.65mm.
I remember me grinding them with my fingers (and my fingers too) on
emery paper till they got to the right thickness. Anyhoo, they lasted
another 8 years in the car (sold by then) when the flies took the
body-work away.
Charles
sweller
> If you need them ground, we have several precision surface grinders
> with mag chucks in our toolroom at work. Drop me an email if you want
> them done.
Cheers JB - local engine recon place sourced and ground some XK shims for
me. For the same price as the usual suppliers ?3 ea.
Put it all back together today - look out for posts on how to straighten
bent valves....
--
Simon
sweller
> lash cap shims which fit over the top of the valve stem and don't use
> the valve cap for location purposes
I couldn't find any of these in the UK - could you point me in the right
direction - thanks!
--
Simon
sweller
> > From my research the SAAB shims are available in the sizes I require
> > but I need to confirm the diameter - does anyone know the diameter of
> > the Triumph (which model?) or Marina ones?
>
> The "B-engine" in earlier 99s was developed from the Dolomite lump -
> but heavily so in all bar the very earliest 99s - and by the time the
> 900 had come along it was even more heavily so.
XK engines have larger shims but the general view is the smaller dia ones
will be ok.
I managed to source and have ground, cheaply, XK shims - which was handy.
--
Simon
Grimly Curmudgeon
drugs began to take hold. I remember "Mrcheerful" <nbk...@hotmail.co.uk>
saying something like:
>or if you are a real animal you can take a little grinder and grind the end
>of the valve in situ. I saw this several times in the early days of the
>Suzuki GS engine which had shims. Even worse is that the owners claimed it
>had been done by a motorcycle shop.
Fucking heathens.
I've had to grind a couple of shims, but never the valve ends.
Rob
Valve ends get ground all the time, but this becomes a problem when the
collett's become higher than the valve stem:)
Mrcheerful
yebbut, think of the grinding dust inside the engine!!
Rob
No - at an engine reconditioners when a valve has been serviced the seat
and the stem. Rockers hitting stem end will show signs of wear.
Valve refacing machines have a wheel to face the valve angle and the
other side you face the stem,
r