Apparently maximum power is achieved from the engine by running with the oil temperature at around 90C. To achieve this the water temperature should be no more than 80C. Most TVRs I have driven operate with a normal water temperature of 90C. I was wondering if anyone has any experience of the engine in other vehicles e.g. Range Rover and if so, what temperature they use.
The book claims that modern lightweight oils are unsuitable for the engine because since it is a relatively low pressure lubrication system at 30-40 psi, the pump can't deliver enough oil with a 5W50 oil. I have always thought that a modern synthetic oil such as Mobil 1 should be OK in any engine, but now I am not so sure, particularly with some tales of high camshaft wear at low mileages recently. The book says that a single grade SAE3O or 40 oil should be used. Also a standard engine e.g. Vitesse or Range Rover uses a pressure relief valve on the pump, limiting pressure to 35 psi. The oil pump drive is not very strong, it is perfectly OK for the standard pump at this pressure but not practical for an uprated pump without modifications
Another problem with the lubrication system is that at high cornering speeds on a race track oil surge occurs, causing oil starvation and wear in parts ofthe engine. To prevent this the Group A SD1s used a complex sump with baffles, compartments and trap doors. They were not allowed to dry sump the engine, which would also solve the problem, because of homologation reasons.
One real weakness in the engine is the distributor drive which wears exponentially with engine speed. Although there isn't too much information about this, it does say that at 5,500 rpm the wear rate is 'alarmingly high' - perhaps enough of a reason to restrict playtime to a limit of 5,000 rpm.
It is common knowledge that Rover had a lot of success with the
engine in motorsport, particularly in the SD1 Group A saloon car,
and of course the TVR 42OSEAC was so fast it was banned after
a singIe season, but did you know that the Rover V8 block was
used to win a Formula One world championship for Jack Brabham
in the 1960s? If anyone has any knowledge of the technical points
with regard to what TVR may have done to alleviate the problems,
I would be very interested.
Steve Powell
Sep 96
TVR started by recommending Mobil 1 from new for the Griffith
and Chimaera, but changed to using a mineral oil (mobil XHP 10W40)
for the first 6000 miles. A lot of owners believe that something
like Valvoline Racing 20W50 (developed in the US where hydraulic
lifters are more common) is much better for this engine, but I
wouldn't like to argue the point with TVR if I had a warranty
claim. Respectable oil pressure is about 15lbs at tickover and
30-40lbs at normal running speeds. Oil consumption should, very
roughly, be 1000 miles per litre on 400 and 430 engines and perhaps
500 miles per litre on the 500.
Internet Mailing List Jan 97
My dealer says the same thing, but I think it depends a lot on
how hard you drive the car. My Chimaera uses less than half a
litre between services, and my old MGB V8 at 100,000 miles was
doing about 2000 miles per litre, but most of my driving is pootering
along motorways at under 90 mph. I don't trust the dipstick markings
on V8s, and if you're putting too much oil in it will burn off
very quickly. This normally produces clouds of smoke the first
time you put your foot down, but it might be worth checking the
dipstick reading after an oil change (when you know the engine
has a measured amount of oil in it) just to eliminate this possibility.
If the car's running ok I wouldn't worry too much about it. Bear
in mind that this lump is 1950s technology and cars in that era
did use a lot more oil.
Peter Beech
Internet Mailing List Jan 97
That's not bad really. When you get through a gallon in 100 miles
you want to get worried! At your rate it's probably getting burnt
when the engine is cold.
Blocked breathers cause the oil to leave via the crankshaft oil
seals, it drips out of the front below the pulley, and the back
out of the hole in the bellhousing. You can sustain quite a high
rate of leakage with no problems. Stick a pin in the little breather
hole in the rocker cover on the passenger side from time to time.
The breaher on the drivers side unscrews and can be washed out
with petrol, same with the hose. Occasionally the tube into the
plenum that this hose joins gets blocked (try blowing through
it). This is a right pain to clean out, as it has 2 corners. I
managed it by blowing a cotton thread through it. To the thread
was tied some string, and to the string some rag. Pour in petrol,
and pull it back and forth a few times.
Adam
Internet Mailing List Jan 97
My 4.0 Litre Griff gets through about 1 litre per 1000 miles.
My local dealer said that it still sounds 'sweet' and not to worry.
The car has done 44k miles. The 450 SEACs tend to do about 1 litre
per 500 miles or less. Dave Lobb used to spend most of his time
filling it up!
Steve Marriott
Internet Mailing List Jan 97
Thanks for the response. I think what you're saying about the
kind of driving is a probably a big factor. When I first drove
the car up from Bath in December after buying it, at about 80mph
to preserve my licence which has too many points on it already,
it didn't seem to use much and its only really since I've thrown
caution to the winds and been going out on high speed night time
blasts with lots of full throttle work round the Edinburgh city
bypass that I've noticed big consumption.
Roger Slee
Internet Mailing List Feb 98
Question:
I seem to be getting through large quantities (2 ltr / 400 miles ) of Mobil 1, and my
oil pressure seems to have dropped to an all-time low even when fully topped up.
I know that the Rover engined Tivs use oil, but that much?
I get no oil puddle on the garage floor, and get no clouds of black
smoke from the exhausts, so there is no major leak, although the underside has got fresh oil on it.
I have been advised that it can be caused by a sticking oil pressure relief valve and failing oil pump base plate, on the underside
of the front timing cover. I thought maybe someone could de-code it for me!
A company called RPI Engineering supply a modified base plate for £45. Is this what I really need?
When I last had a session on a rolling road I was chatting to the guy about it as he had just been on a Slick 50 promo day at Snetterton. Basically the main thing they sell it on is that in the unlikely event that your oil should leave the sump the slick 50 will protect your engine for long enough for you to stop, they proved this by running two cars round the track, treating one then emptying the oil from both, needless to say the untreated car didn't last very long whilst the slick 50 one continued to lap.
As they also mentioned that he would get increased performance from the car he did some testing of his own. He dyno tested an MGB, treated it then dyno tested it again. Although the car felt much smoother and ran cooler there was no increase in power.
So thats one option. The other option is to use a product which
is an oil additive rather than a coating agent. I saw a test of
a product called XP-1 which consisted of a motor turning a wheel
in a bath of oil, then a metal rod with a newton gauge at the
end which you pulled down on to apply pressure to the wheel. With
standard Mobil 1 it would take say two seconds to stop the wheel,
when they added the XP-1 it took over ten. I know they could have
been using a footswitch to increase to torque on the motor but
I doubt it. However if you lose your oil you also lose you additive,
and your engine.
David Donnan
Internet Mailing List Sep 96
I bought some Slick 50 a couple of months ago, but I haven't got
round to putting it into the Griff yet because the oil level hasn't
dropped at all, never mind enough to put the whole bottle in.
I would like to know if anyone knows a good reason why I shouldn't
put it in.
The reason I want to use it is slightly different. Since the car
is only started at one or two week intervals the oil drains out
of the heads and the tappets are noisy for a couple of seconds
when the engine fires. All this noise means wear, and so I thought
it would be a good idea to use Slick 50 to limit engine wear on
startup caused by temporary oil starvation.
Steve Powell
Internet Mailing List Sep 96
I use Molyslip, which (it is claimed) will coat bearing surfaces
with a protective compound. My hope is that it will protect my
engine against any oil surge. It also seems to have helped cold-starting
but this could be psychological. There are two drawbacks to this
theory.
Firstly, when I talk to anybody knowledgeable the immediate question is "how much of it gets through the filter?" Apparently the particle size is large enough to get trapped so all you do is clog your filter.
Secondly, good quality oils have additives which do the same job.
Despite this, I reckon it's worth the peace of mind to bung in
a couple of quids' worth as insurance, it can't do any harm and
might do some good. Incidently, I gather that oil surge is a major
engine wrecker (even worse than cold starting or totally losing
oil pump drive) because the oil pump forces air into the bearings
so blowing out any oil that was clinging there. Having lost one
engine this way, I've no intention of losing another.
Peter Humphries
Internet Mailing List Sep 96
As a matter of course I add Slic 50 to my V8, and Molyslip to
the gearbox and diff. I haven't got any before and after rolling
road figures, though. I clocked up 60k miles on my previous V8
on one application of Slic 50, and it was only slightly smokey
at the end, but only when cold. That engine covered 140k in all,
and I usually explore the entire rev range quite regularly. The
gearbox was still going 40k after a rebuild with Molyslip in it,
and was showing no signs of failure, which for me was quite good.
The diff on the Tasmin probably needs no protection, but any friction
reduction helps I guess. I also use moly grease in the propshaft
and driveshaft UJ's. Oil pressure seems a bit lower while the
Slic 50 is in the current oil, and is quite temperature dependent,
but recovers when you change the oil. I usually use the Green
Lucas 20W50 in mine - it's cheap (which means you can afford to
change it twice as often) and maintains good pressure even with
a high mileage engine. Obviously you shouldn't use Slic 50 in
a new engine (<12k) so the piston rings can bed in, nor use
Molyslip in an LSD.
Adam Quantrill
Internet Mailing List Sep 96
The merkins call these additives "snake oil" and if
you point your browser at http://www.tfb.com/sdmc/oil.html
there you will find a wealth of info about these products - Slick
50 is specifically mentioned (as one of the ones containing PTFE).
The research was compiled from reports and studies by the University
of Nevada Desert Research Center, DuPont Chemical Company, Avco
Lycoming (aircraft engine manufacturers), North Dakota State University,
Briggs and Stratton (engine manufacturers), the University of
Utah Engineering Experiment Station, California State Polytechnic
College and the National Aeronautics and Space Administration's
Lewis Research Center. - so they probably know what they are talking
about. The general summary is that most oil additives make zero
difference, some increase the standard oil specification and some
actually reduce the standard oil's performance. The last
line just says use the standard oil.
Andrew Guy
Internet Mailing List Sep 96
OK, I'm convinced after reading this lengthy article in full.
If anyone still believes it works after reading the extensive
and damning evidence to the contrary, do they want to buy some,
or shall I put it in my lawnmower?
Steve Powell
Comment
I tried to find this page on the web in mid October and it wasn't
there. The search did, however, locate a fascinating article about
carving decoy pigs. Wonderful things, computers.
Peter Beech
Internet Mailing List Sep 96
As I remember it, the manufacturers claim that you run the engine
up to temperature, pour in the Slick 50, then keep the engine
running for a while. At the end of this process they claim that
there will be a layer of PTFE inside your engine which will reduce
friction. According to the 'experts' (I believe one of the guys
worked for DuPont who trademark PTFE as Teflon) this is impossible.
Primarily, it is very difficult to put PTFE onto anything (it
is non-stick after all!). PTFE was around for a long time before
it appeared in frying pans because no-one could figure out a way
of getting it to stick to the metal.
The net effect of this is that (the experts claim) you're just
putting a few litres of gunge into your engine which will settle
in areas where oil moves slowly. I also seem to remember that
the test where a car has its oil drained and then does 50 miles
on just the Slick 50 is a con; believe it or not you could drain
the oil out of most cars and do 50 miles. Of course, you might
have a hot engine at the end of the 50 miles. After looking at
both sides of the argument it just didn't seem worth the risk
of using Slick 50. As an aside, the oil companies spend a fortune
on hitting the correct formulation for engine oil, and despair
when people put in a product that could totally screw up their
work.
Gary Walsh
Internet Mailing List Oct 96
I think a while ago I reading a car mechanic's type magazine that
Slick 50 caused slight pitting on the metal surfaces. I cannot
remember much about what else the article said. If the pitting
held the Slick 50 then that would be okay I imagine.
Ian Collins
Internet Mailing List Oct 96
I have used molyslip before, in a Nova 1.3SR, and found it gave
about 2-3mph extra top speed (and you need every mph!). I also
used the gearbox moly, which comes in a giant syringe. It quietened
down the box well, which had tended to whine previously. My boss
swears that Slick 50 saved his 110,000 Cavalier from seizing recently
when a suspected sticking oil pump bypass resulted in no oil pressure
(some would say it would have been a mercy killing).
I have recently put into my Wedge a Redex product which is molybdenum
disulphide based, but with a "binder" so that it is
not lost with the oil, and lasts 50,000 miles. I felt that as
there is a good metallurgical reason for the low friction properties
of moly., and that moly-grease has been around a long time, this
was a better solution than the Teflon in Slick 50. Does anyone
agree/disagree? Cost was £36 for enough to do the 3.5 engine,
with enough left over for my hack car. I decided to put this in
after seeing a fellow East Mids member run the big ends on his
Vixen at a trackday, due to oil surge. I had also suffered an
oil hose failure (350i has a remote oil filter), and lost a lot
of oil, so felt that the additive was a wise insurance.
Neil Porter