[Staowners] Oil Issues at High Revs

[Captain Ian L. Moist]

Gooday Rowan,

 

I too think that GTX II  is a great oil. and have used it also in all the
Sunbeams & Hillmans I have run.

 

It was fairly  common though, and a well known fact, that when  wound up for
prolonged periods,

the 2,267 cc Sunbeam engine  seemed to froth up the oil in the crank case
which then vented 

through the crank case breather  with exits low down on the left hand side
of the engine,

 

A few years back we came back overnight,  from Adelaide to Melbourne. The
car was driven hard: That is 

maintaining speeds of  70 - 100 MPH ( Indicated) all the way  for about 7
hours non stop except for fuel .The

car,  a Sunbeam Mk III without overdrive, was fitted with 175 x 15" Michelin
steel belted radials on Hawk rims,

so the engine was turning slightly quicker than standard anyway.

 

On arrival back in Melbourne the oil was nearly off the end of the stick,
but oil pressure and engine temperature

Were not affected during the run.

 

On examination, the entire underside of the car on the passengers side was
sprayed with the lube oil, right

back to  the rear axle casing. It had evidently blown out of the breather in
the form of an oil  mist.

 

One bloke in STAR (UK) many years ago, who drove a very nice Alpine Mk III
was known to carry  5 litres of

Oil  in the boot, as when going to meetings he liked to "open-up" the car on
the motorways. He would 

then top up the oil before going back home.  

 

I have not seen the type of oil breather pipe that curves upwards before
going down, but often thought 

that  it could have helped the problem. Using  multigrade oil  probably
doesn't help, whatever they say

about them, they are virtually as thin as water when hot, except for
penrite and other brands who produce

a heavier  mutigrade  Trouble with that stuff is that there is more load on
the starter motor when cold starting , 

and the engine does not spin quite  so freely as with a standard multigrade.


 

It's when you get up to 4,000 RPM  and over that the oil seems to froth. If
an overdrive is fitted with the correct

rolling radius tyres, you can cruise at 70 MPH  at under 3,000 RPM  and be
on the band of maximum torque,

and not experience oil loss.

 

 

 Ian L. Moist 

 

  _____  

From: staowners-bounces at sunbeamtalbot.info
[mailto:staowners-bounces at sunbeamtalbot.info] On Behalf Of Rowan Charrington
Sent: Sunday, 11 March 2007 11:04 AM
To: Staowners at sunbeamtalbot.info
Subject: [Staowners] Oil Issues at High Revs

 

Greetings All,

Just thought I would pass on my experience with my 1955 MKIII Sunbeam Saloon
regarding the emptying of it's sump oil when held at sustained high
revolutions.

 

I have only used GTXII oil (20-50 grade) in all of my vehicles since it came
on the market and continue to do so with the Talbot, even though the
specified oil is SAE30.  All my engines have been long lived and I am
convinced that GTXII was, infact, created on the 8th day by you know who.

On a recent drive with our club from Darwin to Katherine (Northern
Territory, Australia) I had the opportunity to stretch the old girl out on
our then unlimited speed Stuart Highway.  Most of the 300 km drive was at
90-100km/h with no problems.  However, when I took her up to 120-130 km/h
for about 15 kilometres, the oil pressure suddenly dropped away (from its
normal 50 PSI+) and the temperature rose rapidly.

On stopping I found oil all over the left hand side of the engine compatment
and engine and the dip-stick dry.  Radiator was full and no sign of any
reason for so much oil to have been lost.   After topping up the sump with
approx 3.5 litres, the motor started OK with no noise and normal oil
pressure and water temp again.  No sign of any oil leaking from anywhere on
the engine.  Drove on to Katherine at 90-100 km/h without further problems
and also on the return the following day.

I checked out compression (better than specified accross all cylinders), no
sign of oily plugs or exhaust smoke, everything as good as could be.

 

The only logical reason for the loss of oil is that the GTXII at its 50
grade viscosity is slower in returning from the side cover cavity to the
sump through the standard cast drain holes in the block.  This would be
exacebated by the higher revs in the standard top gear (NO overdrive is
fitted to my MKIII) causing the 50 grade oil at 50 PSI+ to exceed the
drainage capacity of the side cover cavity until it backed up to the
breather pipe level and then to flow, be blown or sucked out the pipe and
all over the engine compartment.   This problem would obviously be mitigated
by, 1) lower revs used when overdrive fitted, not driving at sustained high
speeds with a 50 grade oil in normal top gear, going back to 30 grade oil
(not for this Kid).  I have noticed that some earlier Talbots had side cover
breather pipes that were curved upwards before dropping down to the sump
level filter outlet so maybe this was an issue even with the 30 grade oils.

Anyway, just some food for thought.

Regards,

Rowan Charrington

 

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