Synthetic oil

[Manipulator]

I'm thinking of running synthetic motor oil in my boat. This boat is an older boat (83' OMC Chevy 350). Is this a bad idea? I never have used synthetic in it before. I have heard that on older motors it can mess with the seals and cause leaks. Is that true? What would be the advantages to using synthetic oil over conventional oil in a boat?

 

[Don S]

Re: Synthetic oil

I've never had it cause seals to leak, but I have had it cause the lifters in old engines to start rattling. Give it a try, if it doesn't work and the lifters rattle, change back to regular oil.

 

[Manipulator]

Re: Synthetic oil

Thanks Don. As far as rattling filters,is that like the valve or something in the filters? What weight? 20w-50? I assume they don't make a straight 30 synthetic.

 

[vipzach]

Re: Synthetic oil

I am running mobile 1 10w-30, I couldn't find it in a straight 30. I haven't had any problems.

 

[QC]

Re: Synthetic oil

Originally posted by Manipulator:<br /> Thanks Don. As far as rattling filters,is that like the valve or something in the filters?

Manipulator, Don S is talking about lifters, not filters. Lifters are what ride on the camshaft to push the push rods up to open your intake and exhaust valves. They can become noisy if valves are out of adjustment, something is failing or if they don't "like" the oil you're using. You would hear a tapping sound that follows engine speed exactly.

 

[Manipulator]

Re: Synthetic oil

Sorry I misread that....thought that was a little strange. OK lifters....humm....that interesting....I assume since they are hydraulic.

 

[QC]

Re: Synthetic oil

Yeah, I don't know much about hydraulic lifters as they are not used in my area of expertise. Maybe Don will comment . . .<br /><br />I really hate it when my filters rattle though!

 

[blackz3]

Re: Synthetic oil

mobil one has a new 0-30 and 0-40 maybe there what you need

 

[Silvertip]

Re: Synthetic oil

When considering a switch from conventional to synthetic, if the engine uses conventional oil it will likely use more synthetic. If the engine has any oil leaks it will leak more synthetic. That doesn't always happen, but its generally true. There is no problem switching from conventional to synthetic oil other than the synthetic tends to clean up the engine internals including hydraulic valve lifters that Don mentioned.

 

[codfather II]

Re: Synthetic oil

I was told not to use synthetic in new engines until the break in period is over, is this true? Also if you use synthetic oil, is it true you can go longer between oil changes and still have the same or better performance???

 

[LubeDude]

Re: Synthetic oil

Originally posted by codfather II:<br /> I was told not to use synthetic in new engines until the break in period is over, is this true? Also if you use synthetic oil, is it true you can go longer between oil changes and still have the same or better performance???

yes on both points.<br /><br />We use the Amsoil Marine 15W-40 Synthetic in both of the inboard type boats, One I/O, and One V drive.

 

[codfather II]

Re: Synthetic oil

I currently use sae 30 oil. Are you saying I should use the 15w-40 if I go to synthetic? I have been using this forum to try to get some info on Crusader engines. I bought two this past fall and have had nothing but trouble. Have you heard of any problems with the pickup falling off the oil pumps? The engines are 270 hp. GM.350ci. They come from the factory pressed on and not fastened with a pin. I was told from the Crusader factory that this problem has happened to only me. I find this hard to believe. thanks Codfather in Connecticut.

 

[lowshovel1]

Re: Synthetic oil

funny that you bring that up,In the prosess of a recent GM 350 rebuild,I found the pickup tube tack welded!so I did the same on my pump--why take a chanse on fresh engine?

 

[codfather II]

Re: Synthetic oil

good thing you did. The pickup lines have fallen off of two brand new engines. I'm hoping for two new engines from Crusader and I will DEFINATELY insist that the lines are tack welded this time.

 

[LubeDude]

Re: Synthetic oil

Originally posted by codfather II:<br /> I currently use sae 30 oil. Are you saying I should use the 15w-40 if I go to synthetic?

You will find it difficult if not imposable to find the 15W-40 synthetic in anything but a diesel oil, which is fine. You dont have to use a 15W-40 though. A 10W-30 Mobil1 would be fine also.<br /><br /><br />

I was told from the Crusader factory that this problem has happened to only me. I find this hard to believe. thanks Codfather in Connecticut. [/QB]

Not likely, I have seen it many times if they are not spot welded.