Thinking of switching my searay twin 7.4L Horizon engines to a HDEO from Merc 25w40. What do you all think? Which one is best?
Thinking of switching from Merc 25w40 to 15w40 HDE
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Can't say which is best but Hdeos whether dino or syn are the best protecting oils on the market. when I had a boat that is what I used and would use if I ever got another boat. Hdeos is what the commercial marine companies use in their automotive gas and diesels engines in their boats if that means anything .The company I worked for had many marine companies as accounts .
Do it with confidence. I do, and have no problems. So do quite a few other boaters.
My only concern would be with a 5w-40 variant. Stick with 15w40 or the straight weights if you can.
I run Rotella, but all the HDEO majors are pretty fine oils. Buy what's most available and cheapest.
My only concern would be with a 5w-40 variant. Stick with 15w40 or the straight weights if you can.
I run Rotella, but all the HDEO majors are pretty fine oils. Buy what's most available and cheapest.
I've used Mobil Delvac 1300S 15w40 in my last 3 marine SBCs. The 360ci had 375hrs and upon teardown looked great. Lots of life left. I have it as a spare shortblock. Last summers 355 I tore apart to make a 383 looked great after 136 hrs.
I use 25-30 hr change intervals. This years 385ci makes 475hp and runs mid 70s GPS. I run these engines hard too....
http://www.youtube.com/watch?v=t3z0apjY1XQ
http://www.youtube.com/watch?v=vuL_dEX0SoM
I use 25-30 hr change intervals. This years 385ci makes 475hp and runs mid 70s GPS. I run these engines hard too....
http://www.youtube.com/watch?v=t3z0apjY1XQ
http://www.youtube.com/watch?v=vuL_dEX0SoM
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Why a Multi vis? Gonna run in temps under freezing?
bob
bob
Originally Posted By: alreadygone
Why a Multi vis? Gonna run in temps under freezing?
bob
Down your way, it might work. But up here, a 15 or 20w is very helpful in the early and later portions of the season. If the boat sits for a significant period of time (aka weekend boaters), it also helps to not have to wait for a 30+ straight weight to reach the upper end on cold starts.
Of course, we're talkin gassers. Some diesels pretty much demand a straight weight no matter what.
Why a Multi vis? Gonna run in temps under freezing?
bob
Down your way, it might work. But up here, a 15 or 20w is very helpful in the early and later portions of the season. If the boat sits for a significant period of time (aka weekend boaters), it also helps to not have to wait for a 30+ straight weight to reach the upper end on cold starts.
Of course, we're talkin gassers. Some diesels pretty much demand a straight weight no matter what.
Originally Posted By: alreadygone
Why a Multi vis? Gonna run in temps under freezing?
bob
MERC recommends a multi grade for my engines because they have forged pistons, cams & crankshafts and pumpability is the issue. The Quicksilver 25w40 has no VII's and is a blend of 25 & 40 weight oil which they say is important for shear strength. The next recommendation is 40w.
Why a Multi vis? Gonna run in temps under freezing?
bob
MERC recommends a multi grade for my engines because they have forged pistons, cams & crankshafts and pumpability is the issue. The Quicksilver 25w40 has no VII's and is a blend of 25 & 40 weight oil which they say is important for shear strength. The next recommendation is 40w.
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The next recommendation is 40w.
ZACTLY !
Bob
ZACTLY !
Bob
Originally Posted By: lars11
Ryan, why only 30hr oci? And shouldnt a v8 last much longer than 375hrs in any case?
The average well maintained marine gas v8 should go 1500-2000 hours before a top end rebuild.
Ryan, why only 30hr oci? And shouldnt a v8 last much longer than 375hrs in any case?
The average well maintained marine gas v8 should go 1500-2000 hours before a top end rebuild.
Originally Posted By: Volvohead
Originally Posted By: alreadygone
Why a Multi vis? Gonna run in temps under freezing?
bob
Down your way, it might work. But up here, a 15 or 20w is very helpful in the early and later portions of the season. If the boat sits for a significant period of time (aka weekend boaters)
That would be me. But the 25w40 pumps really well and has exceptional fluid film cling as well.
Originally Posted By: alreadygone
Why a Multi vis? Gonna run in temps under freezing?
bob
Down your way, it might work. But up here, a 15 or 20w is very helpful in the early and later portions of the season. If the boat sits for a significant period of time (aka weekend boaters)
That would be me. But the 25w40 pumps really well and has exceptional fluid film cling as well.
Originally Posted By: PT1
The average well maintained marine gas v8 should go 1500-2000 hours before a top end rebuild.
Depends on the vessel and how it gets run. I've seen well-kept Mercruiser small blocks go south with under 800 hours. Some go fasts can burn up a big block faster than that with an idiot at the helm.
Of course with Mercruisers, the best maintained engine is only 1/8 inch from disaster if that stinking manifold/riser/elbow joint leaks. Worst design ever.
The average well maintained marine gas v8 should go 1500-2000 hours before a top end rebuild.
Depends on the vessel and how it gets run. I've seen well-kept Mercruiser small blocks go south with under 800 hours. Some go fasts can burn up a big block faster than that with an idiot at the helm.
Of course with Mercruisers, the best maintained engine is only 1/8 inch from disaster if that stinking manifold/riser/elbow joint leaks. Worst design ever.
Originally Posted By: PT1
Thinking of switching my searay twin 7.4L Horizon engines to a HDEO from Merc 25w40. What do you all think? Which one is best?
My first choice and what I currently use is Chevron Delo 15w40, Second is Mobil Delvac 1300 Super. I'm not a Rotella fan although it is probably plenty good enough. Just my preference.
Thinking of switching my searay twin 7.4L Horizon engines to a HDEO from Merc 25w40. What do you all think? Which one is best?
My first choice and what I currently use is Chevron Delo 15w40, Second is Mobil Delvac 1300 Super. I'm not a Rotella fan although it is probably plenty good enough. Just my preference.
Merc now offers a syn blend 25W-40 with a good load of ZDDP.
I am into Cigarette boats that have 600-1500 HP engines that cost up to $100,000 ea.
Many of these guys are using 20W-50 M-1 V-Twin. The ones using conventional oils use Valvoline 20W-50 VR-1 Racing a lot of the time.
1600 ppm Zinc/Phos/ excellent oil pressures and lab results. Nothing seems to hold up as well though as M-1 V-Twin.
Blower motors can dilute fuel with gasoline so it's better with an oil that is "overkill".
I am into Cigarette boats that have 600-1500 HP engines that cost up to $100,000 ea.
Many of these guys are using 20W-50 M-1 V-Twin. The ones using conventional oils use Valvoline 20W-50 VR-1 Racing a lot of the time.
1600 ppm Zinc/Phos/ excellent oil pressures and lab results. Nothing seems to hold up as well though as M-1 V-Twin.
Blower motors can dilute fuel with gasoline so it's better with an oil that is "overkill".
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The Volvo recommendation is straight sae30 full synthetic or 20w50 synth or mineral. This recommendation is for volvos wihtout separate oil cooler. According to volvo tech, if your engine has an oil cooler, you can do well with a Xw40. Some volvos and more mercruisers have oil coolers, and that expands your options for oil, so check what's on your engine.
Obviously the internal oil temps are high in these engines and mercruiser have addressed it by using a very specific 25w40 and volvo by using a 20w50.
Oil cooler is a second way to deal with it and an HDEO 15w40 may be attractive if you have that.
Obviously the internal oil temps are high in these engines and mercruiser have addressed it by using a very specific 25w40 and volvo by using a 20w50.
Oil cooler is a second way to deal with it and an HDEO 15w40 may be attractive if you have that.
According to volvo dev tech you shoud aim at 50hrs long intervals (6mo) or up to 75 hrs for shorter intervals. For me, 50 hrs is one season so I'm happy with that rec. It won't kill you to go shorter (obviously) but 25 hrs is like a grass mower w/o oil filter, I think it is a slight waste of oil and work. I think that different kinds of corrosion will do more harm than oil deficiensies on marine engines as long as you use HD oil.
One thing, if you have rich carbs, you probably dump fuel in the engine and then maybe 35 hrs is reasonable to get the thinning agents out. Maybe.
I have TBI and they are more exact.
One thing, if you have rich carbs, you probably dump fuel in the engine and then maybe 35 hrs is reasonable to get the thinning agents out. Maybe.
I have TBI and they are more exact.
The engine OCI for my Hroizons is 100 hours/ 1 year. I do 50 hours/1 year. Both my engines and transmissions have oil coolers. My ZF 63a transmsiions use DEXIII with a 300 hour OCI but I change at 100.
Trying to figure out a proper oil change interval?
Think of converting hours to miles thusly:
If you run a boat hard, is that comparable to running a car at 100mph? Then 1 hour would be equivalent to 100 miles.
50 hours would be equivalent to a 5,000 mile oil change.
Adjust according to taste.
Think of converting hours to miles thusly:
If you run a boat hard, is that comparable to running a car at 100mph? Then 1 hour would be equivalent to 100 miles.
50 hours would be equivalent to a 5,000 mile oil change.
Adjust according to taste.
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