melly-g
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| posted on 27/8/14 at 04:19 AM |
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Oil again
I have just changed the oil in my pinto, the motor factors sold me 5/30 grade oil?
I didn't think about it until pouring it in I could hear it dribbling into the sump! Is this too thin for my old pinto?
I'm sure I used 15/40 last time.
I don't want a smoke screen behind me.
What do you all think?
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snapper
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| posted on 27/8/14 at 05:25 AM |
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What's you oil pressure like hot?
I still run 20/50 in mine, it leaks less that way
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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ian locostzx9rc2
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| posted on 27/8/14 at 05:55 AM |
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5/30 is too thin for a pinto 20/50 or as you say15/40 is a better grade .
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melly-g
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| posted on 27/8/14 at 06:08 AM |
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I haven't ran it yet, yes I think I'll drain it again and put 15/40 in!
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britishtrident
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| posted on 27/8/14 at 06:31 AM |
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5w/40 or 10w/40 semi-synthetic it is probably best not to use a fully synthetic because it acts as a detergent and will loosen 30+ years of sludge
inside the engine.
20w/50 mineral oil is a camshaft killer, the main reason the Pinto had such a poor reputation for eating camshafts in the 1970s. It depended on huge
amounts of Zinc additives to protect the wearing surfaces, the current SAE standards have forced oil manufacturers to remove most of the Zinc
additives from oil because it slowly kills catalysts and is bad for the enviroment.
At the cold end of the viscosity range you want a thinner oil to ensure the camshaft gets lubricated quickly.
At a 100c there is not much difference between in viscosity between a 5w/40 and 20w/50. Once over 100c a good 5w/40 synthetic can actually have a
higher viscosity than a 20w/50 mineral oil.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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melly-g
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| posted on 27/8/14 at 07:10 AM |
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So Britishtrident do you think 5/30 is any good?
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Brian R
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| posted on 27/8/14 at 09:35 AM |
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quote:
Originally posted by britishtrident
20w/50 mineral oil is a camshaft killer, the main reason the Pinto had such a poor reputation for eating camshafts in the 1970s. It depended on huge
amounts of Zinc additives to protect the wearing surfaces, the current SAE standards have forced oil manufacturers to remove most of the Zinc
additives from oil because it slowly kills catalysts and is bad for the enviroment.
We use this in our crossflow race engines because of the above reason. Never had one fail yet. (he says reaching to touch some wood!)
http://www.burtonpower.com/parts-by-category/sundries-miscellaneous/additives-petrol-oil/oil-additive-for-classic-engines-zddplus.html
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mcerd1
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| posted on 27/8/14 at 09:48 AM |
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quote:
Originally posted by melly-g
So Britishtrident do you think 5/30 is any good?
I guess it might be worth a try if its really good stuff - what kind of 5/30 did they sell you ?
good quality semi synthetic or a decent full synthetic in either 10/40 or 15/40 look like the best options to me - my plan was to run one for a bit
and see what the oil pressure was like when hot....
-
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britishtrident
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| posted on 27/8/14 at 11:27 AM |
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5w/30 is best left for engines with hydraulic tappets, 5w/40 or 10w/40 semi-synthetic is fine if you want spend more you can find 5w/50 or 10w/60
oils.
Oil pressure is a bit of a red herring, if you have an engine running brand X 20w/50 and the oil pressure drops you have cause to investigate,
however if you swap to say a 5w/40 it is normal for the oil pressure to be lower.
The oil pressure generated by the oil pump is not what keeps the bearings from metal to metal contact, pressure of the oil film within the bearing is
many times that generated by the oil pump.
The critical factors are that the bearing is supplied with a copious supply of oil to cool it and that film strength within the bearing is sufficient
to prevent metal to metal rubbing.
With a lower viscosity oil although the pressue is lower more oil is being pumped through the bearings so bearing cooling is not an issue. Modern
multigrade oils which have a wide viscosity range will be at least semi-synthetic.
Synthetic oils have much greater film strength than mineral oils and don't depend on additives. One of the reasons synthetic oils have better
film strength is unlike mineral engine oils all the molecules in the oil base stock are of the same length. The viscosity of an oil is largely
determind by the length of its' molecules.
With a mineral oil the required grade is created by mixing oil from a vareitry of base stocks with different viscosities and molecule lengths.
As a result in a synthetic oil the load is shared more equally between molecules and the oil film is stronger and more effective.
Mineral oils breakdown in norrmal running resulting in black tars and brown varnishes being deposited in the engine.
Even the cheapest supermarket synthetic oils don't form significant deposits in normal running.
The main argument against using fully synthetics in engines dating back to the 1980s is synthetic oils act as solvents a nearly all of these older
engines will have substantial amounts of internal crap that could become dislodged and block oil ways.
There used to a issue with oil seal shrinkage in pre-1960's engines when using fully synthetics but semi-synthetic have enough mineral oil
content to prevent this.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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melly-g
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| posted on 27/8/14 at 12:39 PM |
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yeah I've gone a got some semi-synthetic 10/40.
I don't trust the other stuff, cheers for the replies.
[Edited on 27/8/14 by melly-g]
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