Oil Pressure for Rover V8 engines

Oil Pressure for Rover V8 engines

Author
Discussion

Henry Harris

Original Poster:

566 posts

178 months

Sunday 19th January 2014
quotequote all
There are some myths about the oil pressure for this engine. I recall one that suggests as long as the oil pressure light is working not on when the engine is running then that is sufficient. I am finding out that this myth is not consistent with the original specification. Also, over the life of the engine there have been pressure issues and the oil pump was redesigned and repositioned.

I have a better understanding now following some research. Does anyone have relevant information?

900T-R

20,392 posts

236 months

Sunday 19th January 2014
quotequote all
Personally I would start investigating if the oil pressure drops under 15 psi at warm idle and switch the engine off/get help the moment it drops under 10 psi - rather than relying on the idiot light (5-7 psi?).

Number 7

4,101 posts

241 months

Sunday 19th January 2014
quotequote all
Henry Harris said:
There are some myths about the oil pressure for this engine. I recall one that suggests as long as the oil pressure light is working not on when the engine is running then that is sufficient. I am finding out that this myth is not consistent with the original specification. Also, over the life of the engine there have been pressure issues and the oil pump was redesigned and repositioned.

I have a better understanding now following some research. Does anyone have relevant information?
Not sure what "relevant info" might be, but for TVR purposes, I thought that the only change to the oil pump system was upon the introduction of the serp. engines in about '94, changing from a drive from the distributor shaft to a crank driven pump. I am obviously ignoring the fact that TVR applications use a remote filter arrangement with a sandwich plate, and may also incorporate an oil stat and cooler. As for pressure, mine runs (hot) at 20 psi idle using a 15W 50 oil, and 40 psi over about 3k rpm - read from an after market pressure gauge, not the useless thing that TVR fitted. I think oil pressure lights only trigger at single figure psi, so that would certainly not be sufficient for engine survival. People do change or modify the springs in the relief valve to increase pressure, but there are limits to how much it should be increased by. Des Hammill's book How to Power Tune RV8 Engines is very illuminating on this aspect. For example, he quotes the following as being reasonably expected pressures from a rebuilt pre-serp road going RV8:
1000 rpm = 10psi
2000 rpm = 28psi
3000 rpm = 32 psi
4000 rpm = 38 psi
5000 rpm = 40 psi

adam quantrill

11,441 posts

221 months

Sunday 19th January 2014
quotequote all
the SDi bought in a bigger pump with deeper gears.

I have had many of these engines all the way through from P5 and P6 rovers.

At idle, with the older engines, quite often the oil light would flicker, nothing to worry about.

30 psi is healthy, at 2000 rpm, and anything over 45 sustained isn't recommended because it will wear out the camshaft drive over time.

jon haines

931 posts

225 months

Sunday 19th January 2014
quotequote all
Totally agree with you adam, these engines are a low pressure running engine and always have been and anything round 30psi is good and normal. I and my old man have had nearly a dozen cars with these engines and at tickover they are all very low but when reved they all achieve 30psi unless they are knackered. I have also been told by an engine builder that anything up lr above 40psi is more dangerous than low pressure.

Number 7

4,101 posts

241 months

Sunday 19th January 2014
quotequote all
Idle pressures are obviously also dependant on where you set the idle speed. I have always set mine at 1K on the basis that it is better to keep the oil pressure up a bit and the coolant circulating that bit quicker.

ElvisWedgely

2,704 posts

144 months

Sunday 19th January 2014
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It's not only the idle pressure that's of importance but how quickly it rises when the engine is revved. Sharpish move up indicates a healthy engine, a sluggish move up indicates a knackered one.

Tony. TCB.

mrzigazaga

18,494 posts

144 months

Sunday 19th January 2014
quotequote all
ElvisWedgely said:
Sharpish move up indicates a healthy engine, a sluggish move up indicates a knackered one.
Thats good to know...Mine sits at about half of the first quarter on idle..950rpm and rises to the half of the next quarter quickly when revved at about 2000rpm.

Today at a constant 70mph it was a tad under the 50 on the gauge..Probably around 47-48...Is that too high?...Cheers...Ziga

hallsie

2,184 posts

199 months

Sunday 19th January 2014
quotequote all
900T-R said:
Personally I would start investigating if the oil pressure drops under 15 psi at warm idle and switch the engine off/get help the moment it drops under 10 psi - rather than relying on the idiot light (5-7 psi?).
What he said!

A visual indication on the guage is far better than an on off switch for the light!

Stu

ElvisWedgely

2,704 posts

144 months

Sunday 19th January 2014
quotequote all
mrzigazaga said:
Thats good to know...Mine sits at about half of the first quarter on idle..950rpm and rises to the half of the next quarter quickly when revved at about 2000rpm.

Today at a constant 70mph it was a tad under the 50 on the gauge..Probably around 47-48...Is that too high?...Cheers...Ziga
Hi Zig. That sounds quite normal for a V8 Wedge. Next time you change the oil fit 20W50 as that is what these engines were designed for, and I personally am a great believer in adding an oil treatment at the same time such as STP or Molyslip as I believe these products do the engine a world of good as well as naturally boost oil pressure.

Tony. TCB.

mrzigazaga

18,494 posts

144 months

Monday 20th January 2014
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I do believe it has 20/50w in it as the oil & Filter was changed just before i bought it...I might use
Penrite HPR15 fully synthetic 15W-60 next time....Ziga

Trickie Dickie

2,399 posts

213 months

Monday 20th January 2014
quotequote all
mrzigazaga said:
I do believe it has 20/50w in it as the oil & Filter was changed just before i bought it...I might use
Penrite HPR15 fully synthetic 15W-60 next time....Ziga
I may be wrong Zig - but I am sure you shouldn't use Fully synthetic on these engines

Someone knowledgeable will no doubt be along shortly to confirm

Cheers
Trickie

DEKE

224 posts

179 months

Monday 20th January 2014
quotequote all
All
When I started car V8 today noticed that the oil pressure went straight up of the scale. turned off at once and gauge slowly went down, turned on ignition only and pressure gauge shoots straight up. I would assume this would be an electrical issue. Any one have any pointers what and where to look,
Thanks
Deke

chapperssx

753 posts

150 months

Monday 20th January 2014
quotequote all
V8 Developments use 20/50w so that's what will be going back in when it's serviced biggrin

mrzigazaga

18,494 posts

144 months

Monday 20th January 2014
quotequote all
DEKE said:
All
When I started car V8 today noticed that the oil pressure went straight up of the scale. turned off at once and gauge slowly went down, turned on ignition only and pressure gauge shoots straight up. I would assume this would be an electrical issue. Any one have any pointers what and where to look,
Thanks
Deke
Could be a dodgy earth mate..Especially if it goes straight up without the engine running...Ziga


Trickie Dickie said:
I may be wrong Zig - but I am sure you shouldn't use Fully synthetic on these engines

Someone knowledgeable will no doubt be along shortly to confirm

Cheers
Trickie
Maybe stick to the Valvoline VR1 then....Cheers...Ziga

Edited by mrzigazaga on Monday 20th January 17:37

350zwelgje

1,815 posts

240 months

Monday 20th January 2014
quotequote all
mrzigazaga said:
I do believe it has 20/50w in it as the oil & Filter was changed just before i bought it...I might use
Penrite HPR15 fully synthetic 15W-60 next time....Ziga
As mentioned before 50 is good, 60 is too thick and won't do your engine any good: oil pressure will go up when the engine is at its running temperature, if there is 50 now in it.

Was running 15W40 in the past, but it is using a bit of oil then, changed back to 15 or 20W50 valvoline mineral.
Healthy engine with 180000km on the clock. Even with 40 it is nearly at 2 bar (30psi)/2000rpm when hot, but with idle it goes too low for my liking (no flicking of the light). So 50 for me and idle is also a little increased for ease of mind with being at at least 1 bar (15psi) when the engine is idling after being pushed or stuck in traffic.

Rob

keatsie

326 posts

143 months

Monday 20th January 2014
quotequote all
Zig, a good mineral based 20/50w. The Rover V8 is an old girl designed to run on proper weighted oil, I would recommend sticking with something like valvoline or millers.

Oil pressure, high flow low pressure so the pressure is naturally quite low couple this with old pressure sensors and wiring, means you can't trust the oil guage. The only real way is to measure with an inline pressure sensor independent of the tvr guage.

V8 Fettler

7,019 posts

111 months

Monday 20th January 2014
quotequote all
DEKE said:
All
When I started car V8 today noticed that the oil pressure went straight up of the scale. turned off at once and gauge slowly went down, turned on ignition only and pressure gauge shoots straight up. I would assume this would be an electrical issue. Any one have any pointers what and where to look,
Thanks
Deke
Mine has done this for 5 years plus, I assumed it was a gauge check! Gauge works OK after a few seconds of running. From a cold start, you can hear when the oil pressure has increased substantially (light goes out as well!). Someone did mention that this is an electrical issue, so it's on the list to do. But not very high on the list.

Important to use an oil filter with a non-return valve, I've been testing a few after my local supplier could no longer get Fram. I'll post findings when I get off my backside to find the photos. From cold, filter with non-return valve extinguishes light after 3.5 seconds, filter without a non-return valve takes up to 9 seconds (panic!).

TVR gauge and light are indicative only, need a mechanical gauge for accuracy, but RV8 will continue to run OK on low pressure. More important to change the oil frequently (petrol contamination), also no short journeys and use oil with zinc additive (VR1)for that camshaft

Trickie Dickie

2,399 posts

213 months

Tuesday 21st January 2014
quotequote all
mrzigazaga said:
Maybe stick to the Valvoline VR1 then....Cheers...Ziga

Edited by mrzigazaga on Monday 20th January 17:37
I used to use a mechanic that builds RV8 engines for the top F1 Stock Cars
(and used to be World Champion when he used to race with his own prpared engines)
and he always said Valvoline or Millers was all he would use on these engines

HTH

Rich

griffdude

1,761 posts

227 months

Tuesday 21st January 2014
quotequote all
OP- In my experience the amber warning light shouldn't be treated as a soft warning.

Another vote here for Valvolene VR1 20/50, often a good deal to be had on 'eurocarparts'.

I've got one of these pumps from John Eales on my RV8

http://www.johnealesroverv8.co.uk/3.html

Just don't go looking at the bottom of that page as it is potentially wallet damaging…….