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View Full Version : Intresting Q and A about Syn. Oil-For My East Coast Brothers



HammerDown
07-18-2002, 07:13 PM
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WHAT ABOUT SYNTHETIC OIL?
Question: I would like to know if it is okay to run synthetic oil in a boat engine? I have read many different answers to this question, but would appreciate your professional opinion. I am running a stock 502 Magnum MPI and have always used Mercury's oil in it. I use Valvoline SynPower synthetic in my tow vehicle, but don't want to put synthetic oil in my boat without knowing if it is okay. If it is okay, what brand do you recommend?
Answer: This is a widely debated topic. Of course, the synthetic oil manufacturers would want you to believe that their products are going to increase your engine life. I have used a few synthetic oils with pretty good success, including Red Line, Mobil 1, and Amsoil to name a few.
In racing applications, I have done testing by using two different types of oil in each engine in the same boat. After the race, when the engine was disassembled, there was evidence that the synthetic oil was slightly superior in the competition environment. The same results have not been observed in the recreational marine engines, though.
More recently, I have noticed that engines with roller lifters used in the pleasure-boat environment have exhibited undesirable wear patterns when synthetic oil is used. Specifically, because the oil is more "slippery," it appears that the rollers are sliding on the cam instead of rolling. This results in flat spots on the rollers and increased wear on the cam lobe. This problem only seems to present itself with lower valve-spring tension applications typically used with hydraulic roller cams. In race applications, with solid roller setups where 250 or more pounds of spring pressure exists when the valve is on the seat, there seems to be enough pressure to keep the roller on the lifter rolling on the cam instead of sliding.
Depending on your climate and the water temperature you typically operate your boat in, the viscosity of your oil should be selected accordingly. I believe that a straight grade SAE 40 oil is the most suitable for the majority of the performance marine engines. SAE 30 would be better for cooler climates. For extreme performance and supercharged engines, SAE 50 is suggested. Most synthetics are a multi-viscosity oil. Fuel dilution of the oil and contamination as a result of increased moisture in the crankcase seems to affect the multi-viscosity oils faster.
The most important thing is that you change your engine oil regularly and use a good quality oil. I think an oil change every 25 to 50 hours is a good idea. The higher performance your engine is, the more often the oil and filter should be changed. I use Kendall SAE 40 in all the pleasure boats in our Southern California climate, and SAE 50 in the hot rods.
I have found the synthetic oils are always superior in gear boxes, blower gear cases, and stern drives. Red Line's 80-140, and Amsoil's 80-90W, to name a couple, seem to provide extra protection in Bravo drives. If you are a reader that has a Casale V-drive in your boat, put synthetic oil in it. You will be surprised how much cooler it operates.
*The question was asked from a reader of Power Boat Mag.(not me) The answer was given by Mr. Gary Teague. (Teague on Tech)
*I always did like Kendall products...HammerDown
[ July 18, 2002, 08:15 PM: Message edited by: HammerDown ]

fat rat
07-19-2002, 03:07 AM
I read the same article and it came at a good time....getting ready for mid season oil change. I've ask a couple machinist friends (engine biulders) they both tell me synthic oil will typically run a lower oil pressure, I'll let you know after my next outing. Excellant Topic! :D :D :D

nitro557
07-19-2002, 05:33 AM
ive run synthetics in lencos and blowers with great success as far as engine oil i stick with non but i change my oil alot,when raceing i changed it after every pass rec boating every three outings

burbanite
07-19-2002, 12:19 PM
I use Halvoline synthetic in mine. I have used Mobil 1 as well, it jusy depended on what was available.
We use Mobil 1 in our IRL cars and Halvoline in the CART cars, Halvoline because they are an associate sponsor and Mobil because the engine builders have always had good results from it. These two engines are built by different companies and both would have no problem with either oil, they have tested them extensively and they pass with flying colors. The CART engines in particular see a LOT of abuse, they run around 17k RPM and can (sometimes) sit there the whole race in the case of an oval or see changing loads in the case of a road course.
I know that my environment is different but I have no qualms about using synthetic based on what I have seen and have been very happy with it in my boat.
By the way this is off the shelf, store bought, same container regular oil - nothing special.....also, free is good.
[ July 19, 2002, 01:20 PM: Message edited by: burbanite ]

burbanite
07-22-2002, 01:51 PM
OK,
now that I have just finished saying all that what turns up today? - 6 drums of 15W-50 Chevron Synthetic.....new flavor of the month, all the (Toyota) kids are doing it.

fat rat
07-22-2002, 06:19 PM
burbanite:
OK,
now that I have just finished saying all that what turns up today? - 6 drums of 15W-50 Chevron Synthetic.....new flavor of the month, all the (Toyota) kids are doing it.Damn BBnite, I just had this discusion with a good friend of mine, but we asked what are the Nascar Guy's running......not even thinking what IRL is running.....17K RPM, so are you you runnning box stock oil?

HammerDown
07-22-2002, 07:39 PM
NASCAR and NHRA...run a special blend of oil. Not what ya would get of the local store shelf. I recall one time I was at the track...John Froce's crew was dumping some Castrol in the Hot Rod for the next round. So I ask...is that the store stuff...I don't think so the man responds...this motor would'nt last 3 seconds let alone 6! They all use a special blend. At least at that time.

CV-23
07-22-2002, 07:44 PM
I've been told that Stock Motors with roller cams don't like Synthetic Oils. Valve spring pressures are not high enough to keep the roller lifters from sliding/slipping instead of rolling on the camshaft. Its just to slippery without higher spring pressures. Just what I've read and been told by others, Mike.

HammerDown
07-22-2002, 07:55 PM
cv-23, did ya read the top post? Intresting...there are lots of thoughts out there about syn. I've here everything from its to slippery, (which oil should be)...to it dosent evaporate moisture as well as dino oil...to it dose'nt (cool) such parts as valve springs as well. Some people sware by it, some say no way.
Who knows!

burbanite
07-23-2002, 01:46 PM
fat rat
Damn BBnite, I just had this discusion with a good friend of mine, but we asked what are the Nascar Guy's running......not even thinking what IRL is running.....17K RPM, so are you you runnning box stock oil?[/QB]fat rat,
the IRL engines (3.5 litre normally aspirated) are limited to 10700 rpm, we have a soft limiter that starts at 10400. The CART engines (2.65 litre turbocharged)run up to 17000. Yes, we use off the shelf oil. At various times in the past (and probably again in the future) we have used "special" oils, it just depends on what is popular at the time.
Our Winston Cup team uses Union 76, 10W-30 for qualifying and 20W-50 for the race.

CV-23
07-25-2002, 05:14 AM
Thanks HammerDown....I knew I read it somewhere but I thought it was last week.....Da. To many hours of Weekend Play and are they going fast in PA. I just keep using MerCruiser 25-40 and change it out every 50 hrs, Mike.

CV-23
07-25-2002, 12:32 PM
I now have my avitar under control....Mike.