Straight 30 Weight Petrol Engine Oil.

tinkicker0

tinkicker0

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My Mercruiser has straight 30 oil recommended. Can't seem to be able to get hold of any.

I noted that the local chandlers had Morris Goldfilm 30 in stock, but reading the blurb, it is a low detergent oil. Not happy with this as I think filtration will suffer.

Otherwise, since the motor only seems to run about 20 -25 hours a year due to lack of time and decent weather over the summer weekends, and does no more than 6-7 knots, 1500 rpm, I think it would be better for the motor than the modern multigrades.

The oil from last autumn's oil change is still clean and clear on the dipstick and that is a multigrade detergent oil.

However, not an expert on oils and don't want a sump full of sludge. However I don't want bore glazing either.

What do you oil experts think about using this oil for 20 or so hours a year and draining; all at river type, low engine loads, or better still where can I get my hands on a straight 30 with an SF / SG rating?
 
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Thanks Kwacker.

Never thought of having it blended specially. We have several purveyors of oil locally, who will blend it to your own specification.

A straight 30 mineral oil with the usual additives ought to do it. No doubt the blender will be able to advise.

Rock oil, never used it. I was a Belray MC1 fan when I had the competition bikes and now use Motorex almost exclusively in the bikes at work.


I need to blag an empty 25 litre drum from work now for me oil. :)


EDIT

Had two PMs pointing me to the correct oil currently recommended by Mercury for all their inboard petrol engines and under all conditions, and its not 30 weight, it's a multi grade 25w40 :eek:

At least with the 25 - 40 weight spread its got more base oil and less VMs

Thanks again.
 
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tinkicker0 said:
Thanks Kwacker.

Never thought of having it blended specially. We have several purveyors of oil locally, who will blend it to your own specification.

A straight 30 mineral oil with the usual additives ought to do it. No doubt the blender will be able to adv :)
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No need for a special blend
Rock do a 'Classic' range.
30, 40, 50 etc
Really quite a reasonable price too
No need to go humping bloody big drums all over the place!

Plus if you do need advice on lubes of any sort.
Just ring em up, they will advise for nowt, nice family firm
 
tinkicker0 said:
Thanks Kwacker.

I need to blag an empty 25 litre drum from work now for me oil. :)

Had two PMs pointing me to the correct oil currently recommended by Mercury for all their inboard petrol engines and under all conditions, and its not 30 weight, it's a multi grade 25w40 :eek:

At least with the 25 - 40 weight spread its got more base oil and less VMs

Thanks again.
Click to expand...

I use Rockoil and it is supplied in 25 ltr drums so no need to go looking.

I have changed this year to 15-40 and was advised by Rockoil it would be Ok to do so. So far so good.

Tom
 
lovezoo said:
Other than cost, why aren't you just using Mercruisers own oil? Or is that the answer? :confused:
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That's what both PM's said. I used a 10w30 marine oil last year and saw an indicated 5 psi oil pressure drop over the original drum of 30 weight oil that the previous owner gave me with the boat. Even changed the oil pressure sender in case it was that that was failing.

Hence not happy with the runny multigrades.

The swindlers only seemed to stock Quicksilver runny oil for outboards running at full chat or the previously mentioned classic SAE30 for old gals, narrowboats and classic vehicles, without dispersants. However it did say that bore glazing would be eliminated, which made me prick me ears up.
Not an expert on oil, but I know enough that with a full flow filter you want dispersants and detergents in yer oil.

Looking down the rocker cover filler, the valve gear on my motor is the same colour as it left the factory and I don't want it turning black with sludge and varnish.

Some kind souls pointed me to the Quicksilver 25w/40 Inboard and Sterndrive Oil, stating they had no problems with a few years of low speed use using it and it is what Merc now recommend in 1990s GM based motors.

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So I ordered two gallons and two filters :)

Am happy now :)


Thanks again everyone for your replies. :)
 
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tinkicker0 said:
Some kind souls pointed me to the Quicksilver 25w/40 Inboard and Sterndrive Oil, stating they had no problems with a few years of low speed use using it and it is what Merc now recommend in 1990s GM based motors.
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Yes, that's the stuff I use. I can buy cheaper stuff in the supermarket, but don't see the point as its a once a year purchase. 8 years old and the engine still runs like a *******! :D
 
I use monograde X30 for my engines and its quite easy to get hold of.

Try googling a company called Wyko, who seem to be distributors for anything industrial. Ask them for a price for Shell Rimula X 30 Monograde. Last time I needed some it was £39.22 + VAT for 20 litres next day delivery.
 
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