Engine Oils. which ones???

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SuperV8
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Post by SuperV8 »

20/50 is what is used in the older engines or engines with the cam driven oil pump as they wont pump the thinner oil as well unless they are in top condition. You can get 10/50 5/50 but its expensive and fully synthetic. These are also old design engines with a lot bigger clearances (even the last 4.6) than modern engines so the thicker oil isn't such a problem in fact it could be argued its a benefit. You pays your money at takes your chances. There are probably more oil related posts on this and other car forums than any other posts.
I can see that being and older design with larger tolerances it would be happier with a thicker oil, a 50sae which is approx 18cst at 100degC

It's the 20w i'm trying to understand.

Oil is thicker when cold so at 0degC a 20w is over 2000cst in viscosity. A 5w is around 850cst which is still many times thicker than a 50sae at 100degC but if it's quite happy with a viscosity of 18cst than how is a 5w at 0degC too thin?

I've been reading up some articles on http://www.opieoils.co.uk/technicalinfo.aspx. Think i've been reading too much, just wanted to make sure the engine i've spent/ spending too much on has a well suited oil,
A big advantage of a crank driven pump is it runs twice as fast as a cam driven pump, this means starts producing pressure at half the engine revs of the cam driven pump
I know the cam runs at half engine speed but the cam driven oil pump uses a gear, doesn't it depend on the ratio of the gearing as to the speed of the pump? Maybe it's geared 1 to 1 in which case it would run at half engine speed. Just a thought.

I thought one of the advantages was the crank driven pump is its self priming. If the oil pickup picks up air it would re-prime and you might be ok (don't know how long the engine could be run at low to 0 oil pressure?) If the dizzy driven pump picks up air it won't self prime so more chance of damaging the engine??



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Post by Coops »

oh self priming, i wish,
we had to manually prime my crank driven pump as it would not self prime,
i think a couple of others had similar probs with the canck pump.
Regards Tony C (COOPS)
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SuperV8
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Post by SuperV8 »

Ah, ok,

Maybe the crank driven pump was cheaper for landrover to make???

:lol:

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Post by katanaman »

None of what your saying is wrong and I am not arguing but like I said to go to 5 or 10w you need to go to expensive fully synthetic oil. Most of the guys choose not to go this route. RV8 pumps virtually zero oil on the starter anyway so its not going to add to the stress of cold starting much. An advantage it surely would be but RV8's have been running for 30 years on 20w50 to no ill effect so most don't want to spend double or treble the money on oil.

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jimbob
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Post by jimbob »

I've used Mobil 20/50 for a few years, then went over to Valvoline from advice from Ray & Shaun, but after speaking to a few friends, they converted me to Castrol Edge.

Now I'm using Castrol Edge 20/60 sport, crank driven oil pump, cold oil pressures is around 57 psi, when the V8 is up to temp on idle sits around 30ish.

I've fitted the spring in spring mod on the oil relief valve, to give me the extra oil pressure

mx5v8
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Post by mx5v8 »

jimbob wrote:I've used Mobil 20/50 for a few years, then went over to Valvoline from advice from Ray & Shaun, but after speaking to a few friends, they converted me to Castrol Edge.
Been trying to get Valvoline as that was recomended for me to use but no one around my area seem to stock it or even be able to order it for me. Do you have to order it online?
Andy

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jimbob
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Post by jimbob »

mx5v8 wrote:
jimbob wrote:I've used Mobil 20/50 for a few years, then went over to Valvoline from advice from Ray & Shaun, but after speaking to a few friends, they converted me to Castrol Edge.
Been trying to get Valvoline as that was recomended for me to use but no one around my area seem to stock it or even be able to order it for me. Do you have to order it online?
Andy
Google Merlin Motorsport that have loads of the VR1 20/50 in stock, not a bad price.

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bclancy
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Post by bclancy »

Hi guys

I know this isnt quite V8, but I think there may be some parralels here. I used to build/run some very highly tuned Harley Davidson big twins. They were specified a 20/50, but due to VERY HIGH oil temps and some extreem cam profiles/loadings over the years we tried many types/grades of oil, heavy 50's, lighter 10/40's semi and full synthetics, castor, lots of addatives. We found (mainly through inspection stripdowns at various milages) that a good, non synthetic 20/50 changed every couple of thousand miles of so gave by far the best protection and was a very cheap method too compared to the cost of some of the 'racing' and high performance oils. One of the best was a cheaper Unipart 20/50 'Green' oil (the colour of the container) but not sure if its still about now? For dizzy driven pump engine, I'm going to look for a decnt 20/50 with zinc (or add a zinc addative) and change it every 2-2500 miles

Only my thoughts

Brian

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bclancy
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Post by bclancy »

Hi guys

I know this isnt quite V8, but I think there may be some parralels here. I used to build/run some very highly tuned Harley Davidson big twins. They were specified a 20/50, but due to VERY HIGH oil temps and some extreem cam profiles/loadings over the years we tried many types/grades of oil, heavy 50's, lighter 10/40's semi and full synthetics, castor, lots of addatives. We found (mainly through inspection stripdowns at various milages) that a good, non synthetic 20/50 changed every couple of thousand miles of so gave by far the best protection and was a very cheap method too compared to the cost of some of the 'racing' and high performance oils. One of the best was a cheaper Unipart 20/50 'Green' oil (the colour of the container) but not sure if its still about now? For dizzy driven pump engine, I'm going to look for a decnt 20/50 with zinc (or add a zinc addative) and change it every 2-2500 miles

Only my thoughts

Brian

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Post by Quagmire »

I'm using the green Halfords Classic 20/50 in my 3.5 pre-serpentine engine.

Changed every 3000 miles religiously, and after 15,000 miles or so since the engine went in it still looks nice and clean under the rocker covers.

Running LPG 99.999% of the time helps with that though :lol:

Normally it starts to sound a tiny bit tappy in the week running up to the change, and usually feels smoother after new oil- although i admit this may be purely my brain playing tricks on me

:D

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Muscle-Manta
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Post by Muscle-Manta »

Euro car parts LTD supply Valvoline VR1 Racing 20w50 @ £30.50 for 5ltrs.

Not listed on their web site as you have to search by vehicle make. Got mine at their Reading branch.

Will Reeve
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Post by Will Reeve »

Anyone use the Comma Vintage Car 20W50 oil, it has a zinc content of 0.07% no idea if that is high or low!
It's very cheap at £10 a 5l can, you can afford to change it every 2k miles!

http://www.commaoil.com/productsguide/view/6/262

For running in I was going to add a 1l bottle of Lucas engine break in additive...good idea?

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Post by Coops »

im using the engine breakin aditive with my lucas oil,
they recomend using it with every oil change.
Regards Tony C (COOPS)
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MS2 V3.57 Ecu mapable efi and wasted spark ignition.
Procharger D1SC supercharger and Cossie RS500 Intercooler @ 14psi of Boost. 416 RWHP, (boost leak)
Forged 4.8 V8 kitted out with the dogs Cajones of parts. :D
Sponsored by: www.v8performanceparts.co.uk, www.interpart.biz, www.caprisport.com & www.baileyperformance.co.uk

TVRleigh
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Post by TVRleigh »

I use Rockoil Strata Mineral oil 20W-50 in my 4.0 TVR Tasmin Racer

Email response from them on there ZDDP content.

All of our engine oils, including Strata 20W-50, contain Zinc in the form of ZDDP.


The Zinc content of Strata 20W-50 is a minimum of 1100 parts per million
Current V8 car TVR 400SE 240 BHP
Current Project TVR Tasmin Race, with 3.9 running at 230 BHP
Currently building a 4.6 300 BHP Xbolted Engine for it. Solid Lifters and Group A rockers, Stange 4 heads, Pocketed piston, fully balanced.

bakuuu
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Post by bakuuu »

hi there. here in Portugal all people say me to put 5w40 fully syntethic oil and i read in this thread, that you use 20w50 oil :shock:
for a 3.9i V8 rover engine, the 20w50 is the better oil?
at this moment i use 5w50 mobil1 oil
Range Rover 3 door 3.9i V8

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