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#1
IP: 162.219.70.239
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Oil pressure question
Hi all,
The Maintenance Manual describes in winter layup that one should warm up the engine nicely, drain the oil, and replace with a quart of MMO. And this also “facilitates recommissioning in the spring when you only need to add enough new oil to bring the level to the full mark.” I have followed this procedure for the last two seasons and my oil pressure has been on the lower side compared to when I ran with no MMO in the oil. Previously I would get 60 lbs on start up and 40 when warmed up. Now I get 40 lbs on startup and it sags to 30 when warmed up and down to 20 at idle. Do you folks change the oil in spring to remove the MMO? Will the MMO evaporate as time goes on and I will then top up with regular oil? The exhaust smells lovely (MMO in fuel too) but not as nice as castor oil that I used to smell at the race track. Engine started beautifully this spring and runs like a top. Am I being a Nervous Nellie? Appreciate your wise advice! Peter |
#2
IP: 138.207.177.95
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I have never done anything like that. I just change the oil in the fall and use that oil until the next fall or 100 hours, whichever comes first.
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#3
IP: 162.245.50.230
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Peter, when you changed the oil did you always use the same "weight and grade" of oil? And did you always have the same percentage of MMO in the oil upon your start up?
The numbers are not bad at all, at least nothing to worry about. Frankly I do not and have not used MMO in my oil ever. The MMO is a hi-detergent type of oil and was good 75 years ago when there was nothing available in "detergent oils" like today. There are far better lubricants today for top oils in the fuel too. It is good for soaking rings if there stuck which seldom happens with todays "modern" and superior detergent oils unless there was water encroachment. IMHO Dave Neptune |
#4
IP: 162.219.70.239
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Dave,
My notes are not careful enough to answer that question I am afraid. Maybe just for fun I will change the oil mid season and see if the pressure pops up. Thanks! Peter |
#5
IP: 138.207.177.95
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Quote:
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#6
IP: 67.184.216.83
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I too have never added MMO to oil, fuel yes - oil no. I have had for the last 45yrs a 1966 early model that has never needed rebuilding. It is a short season in Chicago and I usually clock about 25 to 30hrs a year engine time with the longest run being about 6 hrs each way to and from yard ...a lot of shorter runs entering/leaving harbor. I was an engineer and not a chemist but recommend and do change oil mid season and just prior to haul out for winter layup. I use any quality 4qts 10w-30 or 30 with some STP added at spring launch. My layman's understanding from an old mechanic friend is that besides some viscosity thickening it contains extra zinc which aids in improving lubricity and resists corrosion. Oil pressure at start up is about 45psi and settles down to about 35psi and about 25psi at idle. To some [and manual] this may sound a little wasteful but for about an extra $15 and half hr of time I like the idea of clean oil in a non filtered engine. Just my thoughts- hope this helps.
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#7
IP: 73.35.200.244
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echoing the same as guys above. my climate is pretty mellow here in the PNW compared to some. just an oil change for me in the spring before the season. every 100hrs after that. No MMO in fuel or oil.
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'69 Newport 30 MKI Hull #20 |
#8
IP: 165.225.20.162
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Quote:
https://www.moyermarineforum.com/for...ead.php?t=3333
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Surcouf A nostalgic PO - Previously "Almost There" - Catalina 27 (1979) |
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Peter (06-21-2022) |
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