The V8 Owners Forum -

Hi guys may end up making a whole new section for this,.
Im still pondering which oil to run in the 4.6,

For running in im going to use some chaep 15w/40 supermarket oil as the 20w/50 will be to thick for the oil pump,

So been talking to Lucas oil regarding engine oil and Zinc content,
they informed me they no longer use Zinc as its not allowed in oils now days due to the enviroment etc.

I said Oh, my engine needs Zinc he said yup we know, we now do a zinc substitute you add to your oil when you do an oil change thus putting the zinc or the equivilent back in,
http://www.lucasoil.com/products/displa ... 9&loc=show

He also said they now do a semi synthetic 15W/40 ideal for the later style crank driven oil pump rv8 engines,

Any recomendations or ideas?

I have a 4L cross bolted Rover V8 and had the same problem working out what was best.

After long discussions and a phone call to a chap called Holly (RPI's engine builder) I decided to use a 'classic 20/50'.

RPI use Valvoline 20/50 - I ended up with Halfords classic 20/50.

It runs smoother than the 10/40 that was in there, and doesn't leak now either. There is some sort of additive in it to stop leaks

which oil pump you using?
dizzy driven or crank driven mate?

I use Valvoline 20w-50 for two reasons:-

1. Its a 50 grade which is good as my lump gets quite a trashing!
2. It has a high zinc content.

The slight problem is that being a 20 the oil pressure is quite high when its cold, my solution is not to rev the lump above about 2500 RPM until its thinned down. (Thrashing a cold engine is bad as I'm sure you all know anyway).

My 4.6 uses an old SD1 front cover and dizzy driven pump. I've modded the pressure relief valve, its now adjustable, it runs at around 35 PSI at 850 RPM when hot. I don't ever let the pressure ever go above 60 PSI

Most of the bods on the Cobra forum run valvoline 20w-50

Pete

cheers mate,
the dizzy driven pumps use a 20w/50 grade oil anyways mate so your on the right track,
the prob i got is i use the later style front end with crank driven pump,

thev8kid wrote:cheers mate,
the dizzy driven pumps use a 20w/50 grade oil anyways mate so your on the right track,
the prob i got is i use the later style front end with crank driven pump,

Will a crank driven pump not pump a 50 grade then? (I thought that my setup was the weaker one in terms of pumping a thick oil and thus loading up the drive gears)

I guess the grade of oil has to suit the pump and the bearings, I can't see that the bearing tolerances will be any different in your engine to mine.

Tony,

Good subject that does require some definitive answers.

One of the other problems is that the requirement for bedding in the rings and breaking in the cam seem to have different requirements.

The rover engine definitely needs a high ZDDP content for it's oil, otherwise the cam will suffer prematurely as most of us are aware,but the debate goes on about which is the best viscosity to use.

In my last engine a 3.5 with dizzy driven oil pump I used Duckhams 20/50 which has the correct level of ZDDP but falls behind modern oils in repect of other areas of engine protection.

As I'm about to change the oil in new engine I look forward to hearing other peoples recommendations.

Kevin.

with my old dizzy driven pump kevin i used the Lucas 20W/50 plus Race oil it was a fully synthetic oil,
and quite a few on here used it too (not sure if they are still now though)
think it was a high zinc content too,

sidecar wrote:I use Valvoline 20w-50 for two reasons:-

1. Its a 50 grade which is good as my lump gets quite a trashing!
2. It has a high zinc content.

The slight problem is that being a 20 the oil pressure is quite high when its cold, my solution is not to rev the lump above about 2500 RPM until its thinned down. (Thrashing a cold engine is bad as I'm sure you all know anyway).

My 4.6 uses an old SD1 front cover and dizzy driven pump. I've modded the pressure relief valve, its now adjustable, it runs at around 35 PSI at 850 RPM when hot. I don't ever let the pressure ever go above 60 PSI

Most of the bods on the Cobra forum run valvoline 20w-50

Pete

Me to.

Castrol 20w50

Ian

Here in Australia, I use Penrite HPR30, which is a 20W-60 engine oil.
Penrite is the official supplier to Land Rover here in Australia.

The oil has ample quantities of the necessary zinc and phoshorous needed for camshaft longevity.

My 4.6 runs an SD1 timing cover and the distributor driven oil pump gears.

Ron.

thev8kid wrote:which oil pump you using?
dizzy driven or crank driven mate?

Dizzy driven.

Why does the oil need Zinc?

ppyvabw wrote,..

Why does the oil need Zinc?

It is an anti wear additive..

http://www.penriteoil.com/uk/nextpage.p ... ine%20Oils

Ron.

I should point out that I am in no way connected with Penrite, either now or in the past.

Oil always seems to come up both here and in many other motoring forums. There is an interesting topic about semi synthetic oil on a bike forum I am a member of. Basically a few members who are actually in the industry have put evidence on saying that semi synthetic is a complete waste of money. Some of the other interesting stuff about basic oil is also the fact that the way oil is made (long chain molecules cracked to make shorter chains, base stocks and stuff) 20/50 keeps its properties approximately twice as long as 10/40. The tests showed that 10/40 in a New York taxi was pretty much done by 1500 miles where 20/50 was ok to 3000 miles. This was true whether it was semi synthetic or basic mineral. The fully synthetic oil was good to 6000 and because it is synthetic it doesn't mater the grade. Nobody was saying your engines going to blow up if you don't change your 10/40 at 1500 miles but some damage is being done inevitably leading to shorter engine life. I will have a dig through the threads and post links with all the stuff later so if your interested you guys can have a read.
As to using 20/50 in the crank driven pumps, yes you can. If you look at the oil charts for any engine its grade against temp. The warmer your climate the higher the grade which is why 20/50 or 60 is still common in the Souther states and like OZ. In the Northern states they have to change grades between summer and winter since NY is hot in the summer but very cold in the winter. I cant remember what it is for the RV8 but its something like above 5C you can use 20/50 so if say you only use the car in the summer 20/50 is good to go. I would be tempted to still take it easy till things warm up a bit though.