Oils and Oil Pressure

[Henry Harris]

The engine in my wedge appears to be a standard cross-bolted 4.6 litre Range-Rover engine. I am currently using Mobil 1, 15W-40. When thoroughly warm, oil pressure at tick-over is low, say less than 10 psi; at 2000 rpm varyingly 25 psi. When testing with an oil line, the pressures are 28 psi and 48 psi. Interesting. The oil pressure sender has a lozenge that may stick and I know of a modification to keep it free.

Comments.

[Number 7]

Henry Harris said:

The engine in my wedge appears to be a standard cross-bolted 4.6 litre Range-Rover engine. I am currently using Mobil 1, 15W-40. When thoroughly warm, oil pressure at tick-over is low, say less than 10 psi; at 2000 rpm varyingly 25 psi. When testing with an oil line, the pressures are 28 psi and 48 psi. Interesting. The oil pressure sender has a lozenge that may stick and I know of a modification to keep it free.

Comments.

Your oil is fine. The gauges, as you have discovered, can be unreliable. Is yours a serpentine engine Henry, with the oil pump driven off the crank rather than the end of the distributor shaft? It does make a difference to the resultant pressures. Not sure I know about the sender though. Do you mean the relief valve in the pre-serp oil pump covers, which are known to stick?

[adam quantrill]

Agree about unreliable guages, is 15W40 a little thin though, what mileage is your engine? I would stick with 20W50 personally.

[KelWedge]

After having a chat with RPI I would not be using Mobil 1, Gauges can be a pain, pressures seem OK compared to mine.

[Campbell]

I wouldnt be using moble1 in a rover if u paid me to. Not a good oil for that engine design, allows the engine to eat cams. Did in mine unless you were racing the car and running hih revs all the time to help with the splash affect.
Using a heaver grade of oil should left pressure.

Cambelt

[TVRleigh_BBWR]

I'm running a X-bolted crank driven 4.0 in my Tasmin Racer, and I run a 20w50 mineral oil, (changed every 500 miles) I have a £150 spar digital gauge linked to a data logger, and it stays at 55-60 psi when racing 3000-7000 rpm.

[ctsdave]

I'd also replicate not using Mobil1 - even for racing applications! The only engine failure we ever suffered with a full race 3.9 was at a time we used this oil (rocker snapped due to fatigue) and the result was quite outstanding - inside the engine was far worse than we expected! We ran Valvoline 20/50 racing oil prior to that with no problems with cams etc for years, and now run Castrol Edge Sport (10/60 iirc) and the inside of the engine is always excellent, and no cam wear! Expensive but very good!

[Number 7]

I get the impression from Opie Oils and elsewhere that the best oils are either Silkolene Pro or Motul 300V. I use the latter, 15W 50 Competition type.

[Transmitter Man]

...and you can add: http://www.holden.co.uk/displayproduct.asp?pCode=0... to that.

Phil
420 SEAC

[CarbonWedge]

And I use this,

http://www.lucasoil.co.uk/products.php?page=produc...

[simonwedge]

Valvoline VR1 20/50 for me!

[adam quantrill]

Unipart 20W/50 for me (historically) but they seem to have raised their prices alot recently so I'm not so sure now.

[wooly350i]

I used to use Mobil 1 in my old 3.5 but since transplanting the 5 ltr x bolted lump into the old boy i was advised by the engine builders not to use anything other than valvoline vr 1 or Millers 10/60 so ive gone with the Millers at around £62.00 for 5 litres,not cheap but cheaper than wrecking the engine,John

[Wedg1e]

simonwedge said:

Valvoline VR1 20/50 for me!

Snap. 10W/40 is for Jap bikes and modern car engines with tighter tolerances.

[ed_crouch]

I'm using Comma fully synth 5W50 in mine. Found oil pressure was a bit slow to build with Mobil 15W50. Pfff, see how we go; it's a PAO based synthetic that holds its viscosity well when hot, and isnt too glopy when cold.

Oil viscosity is one of the most hotly debated things I've seen since buying a TVR!

[Henry Harris]

Thank you for the comments so far on oils.

Any comments about real or perceived oil pressure?

[simonwedge]

At hot idle mine shows about 25psi (Valvoline VR1 20/50) and about 50psi at speed.

[Number 7]

Henry Harris said:

Thank you for the comments so far on oils.

Any comments about real or perceived oil pressure?

Henry,

I use a separate Racetech oil presure / temp gauge in my dash (where the clock used to be). With Motul 15W 50, hot idle (1K rpm) is 20 psi, hot at 2K+ rpm is 40 psi. TBH I found the standard gauge, which is still fitted and working, to be too vaugue to be of much use. How is the oil pump in your engine driven, because there is s big difference between the pre-serp and serp based systems, both mechanically and in the resultant pressures?

[Trickie Dickie]

simonwedge said:

Valvoline VR1 20/50 for me!

My mechanic only uses Valvoline VR1 20/50 in Rover V8 engines
and to qualify my mechanic he is ex World Champion F1 Stock Car racer Andy Turner
who prepared his own RV8 engines and still does many of the top racers

HTH

Trickie

[tempus]

It is a can of worms,when someone says I`ve always used brand X then they should be aware that the oil they used to use and the one they now use are completely different to the product they used to use,for us one of the most important parts of an oils makeup is Zddp an additive that cuts down on sliding contact wear,for us cam and followers,the powers that be have been making manufacturers remove it from their oils,plus it shortens the life of catalytic converters,Mobil get round this by making a motorsport oil which will say on the bottle/can for motorsport use, this allows them to use a lot more Zddp than for a road user based oil. I would not even pretend to know which oil is "best",we all have different criteria,but I would say check your Zddp content and compare it with others and our lumps may just thank us.