HD OIL?
- Thread starter 32carv
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SAE 30 HD is fine. It has more dispersants and detergents, and slightly higher levels of anti-wear additives.
I spoke with Crusader quite a few years ago and asked the question why not multi viscosity oil such as 10-30 or 10-40. They advised me that the multi viscosity is now fine. For the older boats they originally did not recommend the multi viscosity oils because they thought they would break down faster as the additive would loose it's effectiveness with, use and the oils would become too thin with time. They changed their position indicating that the more modern oils no longer have that issue.
If you use the boat in cooler weather, I would use a good grade multi viscosity. Last year I used Mobil Delvac Diesel oil which has good additives.
If you use the boat in cooler weather, I would use a good grade multi viscosity. Last year I used Mobil Delvac Diesel oil which has good additives.
Our SBC (signature) has 1300 hours. I was using SAE 40 HD as suggested by mechanic. That being hard to find, I tried 20-50, and it uses less of that oil between changes than the 40. Go figure. The engine has flat tappets so I get a bottle of ZDDP break-in lube and add about 1/4 of it to the oil per oin change.
I woudn't use a non-detergent oil like 30ND in any engine I have. Maybe somebody can explain why it's still even available. Your shop Oil Can?
I woudn't use a non-detergent oil like 30ND in any engine I have. Maybe somebody can explain why it's still even available. Your shop Oil Can?
imspacemancraig
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So is there a chart somewhere that can show you what to convert to? I am using SAE 30 as well on my Crusaders. I have been getting it from NAPA, so hasn't been a problem to find, but converting would make things easier to find better sales.
imspacemancraig
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This is going to sound dumb, but average temperature year round or for the boating months. I am in WI, from March to Oct. I would say the average temperature is above 50, but the rest of the year, not so much. But, I wouldn't be boating at that time either.
I wish I had my manual handy (up on the boat). In it they give temperatures for the straight SAE 30 vs. 40.... might be better to compare that with this...
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My manual ('87) for the 270 says straight 40wt. About 4 years ago I had to start ordering the oil as it was impossible to find on the shelf. I now have a guy getting me Pennzoil Marine 40 HD. I guess as long as I can get it I will stay with the straight 40 but it good to know the multi viscosity are ok. I just got back my oil reports for 2013 and all was good
Niles
Niles
It depends where you live but I don't understand why one would not take the recommendations from the latest manufacturer web site rather than stick to a 20 year old manual. Crusader told me a long time ago that their previous objections to multiple viscosity oil due to product improvements are no longer valid. I was never comfortable with starting my engine on a cold fall day at 45 degrees with 30 or 40 weight oil.
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I recall reading that this also depends on if the engine has an oil cooler. Without an oil cooler I'd stick with either a straight weight or the Merc 25/40 oil. If it does then the 15w/40 should be fine.
One true test is to run it on plane for a good run and then bring it back to idle and look at your slow hot idle pressure reading. If its low then you need a higher viscosity oil for sure.
One true test is to run it on plane for a good run and then bring it back to idle and look at your slow hot idle pressure reading. If its low then you need a higher viscosity oil for sure.
Lou,
I don't follow the logic of the oil cooler.
15-40 likely has a better viscosity as the oil temperature is raised than straight 30.
The risk of straight 30 at lower temperatures is that it is too thick and may not provide sufficient lubrication especially under load.
The multiple viscosity oils are designed to have a flat viscosity curve keeping viscosity relatively constant at a wide range of temperatures.
I don't follow the logic of the oil cooler.
15-40 likely has a better viscosity as the oil temperature is raised than straight 30.
The risk of straight 30 at lower temperatures is that it is too thick and may not provide sufficient lubrication especially under load.
The multiple viscosity oils are designed to have a flat viscosity curve keeping viscosity relatively constant at a wide range of temperatures.
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While oil companies try to present facts to show the multi vis oil will have the same visosity as a certain straight weight at a certain test temp, when this is achieved with viscosity index improvers, it is a known fact that such oils can shear down to lower grades after sustained high rpm use such as you have in boating. Oils that do not have v.i. improvers such as straight weights and the Merc 25/40 oil will be much less subject to this effect. An oil cooler that keeps oil temps lower also helps in this regard. You can see this for yourself, look at your cold idle oil pressure and then look again hot. The hotter oil has lower pressure, if it was truly higher viscosity at the higher temp the pressure would reflect that. If Crusader recommends 15w/40, I'd want to know if they fit oil coolers as standard on engines that are supposed to use that oil. If so then that tells you something. If not then maybe its is true that the oils have improved enough that you don't have to use a straight weight. I have used straight 30 and even 40 and never had starting problems even down to 45* F. Most boating use is at temps above 60*F so the straight weights should not cause a problem. And in fact, if you look at Merc's recommendations, they recommend the 25/40 first, but if that is not available, they do recommend straight 30 up to 50* and straight 40 over 50*. Now if this was a 4 cycle snowmobile engine that would be a different story.
I use the Merc oil now because its one of the few oils that is actually tested for use in inboards.
The other thing you can do is run an oil analysis with your current oil and see what it tells you. You will know for sure if it sheared down or not and if its protection level is high enough.
Edit: just for the heck of it I looked at some Crusader parts manuals on their website and their engines do use engine oil coolers.
They recommend 15w/40 above 50*F and 5w/30 below but that is with an engine oil cooler.
So if you have a typical sterndrive engine with no engine oil cooler you might want to stick to straight weight oils if those are recommended, or use the Merc stuff which at least is thoroughly tested for inboard use.
I use the Merc oil now because its one of the few oils that is actually tested for use in inboards.
The other thing you can do is run an oil analysis with your current oil and see what it tells you. You will know for sure if it sheared down or not and if its protection level is high enough.
Edit: just for the heck of it I looked at some Crusader parts manuals on their website and their engines do use engine oil coolers.
They recommend 15w/40 above 50*F and 5w/30 below but that is with an engine oil cooler.
So if you have a typical sterndrive engine with no engine oil cooler you might want to stick to straight weight oils if those are recommended, or use the Merc stuff which at least is thoroughly tested for inboard use.
Lou,
I posted this before and will repeat. I talked to Crusader folks years ago (probably 15+)and they said at that time that the concern about VI improvers breaking down was no longer an issue. In fact the manuals for the current engines call for multi viscosity. I have owned 5 Crusader engines from 283, 327, 454, and 502's, they all had oil coolers, I never had an engine failure.
Engine oil technology has advanced considerably since 1985.
I would suggest looking into using Mobil Delvac 15 40 which is intended for Diesel Engines and has excellent additives. It can be used in gasoline engines.
I used it this year in my 502's
http://www.mobil.us/USA-English-LCW/heavydutyengineoils.aspx?WT.srch=1
I posted this before and will repeat. I talked to Crusader folks years ago (probably 15+)and they said at that time that the concern about VI improvers breaking down was no longer an issue. In fact the manuals for the current engines call for multi viscosity. I have owned 5 Crusader engines from 283, 327, 454, and 502's, they all had oil coolers, I never had an engine failure.
Engine oil technology has advanced considerably since 1985.
I would suggest looking into using Mobil Delvac 15 40 which is intended for Diesel Engines and has excellent additives. It can be used in gasoline engines.
I used it this year in my 502's
http://www.mobil.us/USA-English-LCW/heavydutyengineoils.aspx?WT.srch=1