Any advice on Engine Oil - Thinking Synthetic

[Lumpy]

I have Crusaders 454/350 1986 with over 800hrs. Thinking about going synthetic oil. Any suggests on brand & weight, Pro's & Con's.

Thx

[BobCT]

as much as people will tell you that switching from conventional to synth causing leaks is an old wive's tale, it's happened to me first hand.

About two years ago I did the entire timing belt job on a V8 Audi engine and the crank seal was bone dry. I decided to switch to synthetic after never running it before (150k miles) and within 100 miles it was leaking like crazy, I mean 3" puddles on the ground. I had to rip it all apart and essentially do the job again.

There's really no way to damage the seal when you reinstall the crank pully so I can only attibute it to the switch.

[P-Dogg]

Synthetics are slippier, if I can speak technically. I agree that extra weeping can be a problem where it wouldn't be with dinosaur oil. The bigger issue is, how often do you use your boat? The old-fashioned oils cling to surfaces better, where they can provide protection from corrosion between uses. Synthetics will run-off more quickly, leaving you with less protection. I use synthetic in my vehicles, and dino oil in my mower and such. Try googling snthetic vs conventional oil and you will be overloaded with information.

[prowlersfish]

Synthetics have their place , but I don't see any advantage in this application . pros / none unless it makes you feel better . Cons ? it costs more . Marine age will do your engines in long before you wear them out on any oil .

[Big D]

Unless it's an OEM requirement on a newer engine, IMO regular oil changes of good quality "dinasour" oil is far less costly and just fine for our application. I know folks that spend a ton on Volvo synthetic because it is OEM recommended then don't want to change the oil regularly because they think it lasts longer and shouldn't have to spend the money as often. I'm still trying to figure out the benefit of that one I'm all for new technology for most things but some of the older stuff that has been around for a long time is still good enough. Whether you use the old oils or synths, combustion by-products will still do a number on your harware if you don't change your oil regularly. The question is how much money you want to throw away when you do

[Paul]

Synthetic oils have much better thermal stability and viscosity shear values than conventional oils which means that they "stick" to surfaces better when load. They also have additives that are great at preventing corrosion. I learned about synthetics after experiencing oil related failures with conventional oil in a racing application. Switched to synthetics and under the same circumstances, no failures. I've been using these high quality synthetics for years in everything that I own and have never experienced any weeping seals due to using such an oil.

The thing to decide is if there is any value added for you to spend the money on synthetic oil. Personally, I know that I will submit my boat engine occasional punishing conditions and the peace of mind using synthetics brings is value enough for me. In all fairness, you'll probably never have an oil related failure using conventional oil as long as you stick to a regular maintenance schedule.

Your boat = your choice.

[prowlersfish]

I do agree with Paul that where switching types its highly unlikely to cause a oil leak . We have agreed to disagree on what oil is better , and agree that what ever you decide it is unlikely you will have a failure due to the oil .

Did I get it right Paul ?

[Paul]

I do agree with Paul that where switching types its highly unlikely to cause a oil leak . We have agreed to disagree on what oil is better , and agree that what ever you decide it is unlikely you will have a failure due to the oil .

Did I get it right Paul ?

Right on the money.

[Lumpy]

Thanks for all the input. I'm going to stay with the "Dino" oil for now.

[EM63]

+1
--
Greetings - Heiner

[1967 seavoyager]

If you want to throw a wrench in the works try Baums Castorine, Rome NY.
They make an animal fat based motor oil that's real nice. I used the Diesel version in a Mack 350hp when I drove for Rome Express. Changed the oil every 20,000 miles. Approved for use by Mack, Cummins, & I can't remember who else. Even hauled the base from Neetsfoot Oil in Philly back up to Baums. They make great greases & soaps too.

[Lumpy]

Thanks for all the input. I put in 15w-40 and now my oil pressure went from sub 40psi to well over 40psi and the gauge is now steady, not jumping around.
Thanks again.