As for the primary and secondary ZDDP additives, I suppose that makes a small difference in the high RPM engines.  As marine engines typically don't rev much past 4,000 to 5,000 RPM, I doubt that the ZDDP type matters as much as the ZDDP parts per million (PPM).

I even put full synthetic ATF in my PCM 40A transmission...gasp!

JQ

No respect, I tell ya'. 

I think ZDDP is necessary for sure with the flat tappet engines.  ( non Roller Cams ).   Get it from what ever source makes you happy and floats your boat.  Keep Clean oil in your engines and do not worry.   

I am not saying the Specialty blend oils might not be better in some respects, for $5 more per quart they should be.  I am not yet convinced to upgrade and change what has worked for the past 20 years.

Or another might wonder why the break in instructions for that rebuilt flat tappet 351w marine engine he bought (ATK from Summit for example), say to break it in with high zinc oil or a break in supplement and then use whatever 10w30 oil you want after the break in period is over.

He might also wonder how much zinc is in some of those "high mileage" oils these days or how much zinc is in most motor oil these days

Then again, somebody else might say if a little extra zinc in your oil makes you sleep good at night, that's just fine 

Like JQ said.................it's an oil thread  

Is that a year round thing?

I can't wait to go pull a tube from my lift ring while running on ethanol fuel after an oil change with straight 40 weight low zinc oil.  I might even see if I have a 30 year old quart of Slick50 lying around that I could add.

Like Tom, for some reason I enjoy reading oil threads.  Earlier this morning I was reading about oil for oil-consuming Subaru's.  Everyone has their preferences and fun to see the different views.  I have very mechanically inclined friends that adhere to the "my engine doesn't care what I put in it as long as I change the oil", others that are more of the oil-snob crowd like me.

I run VR1 20-50 in my boats.  I ran Rotella T6 in my Duramax until it was hard to get and switched to Delvac synthetic 15-40.  I run Royal Purple in my RX8 rotary.  I tend to buy more expensive oil filters.  And ... don't attack me on this ... a lot of the time I run 93 octane in my boat and RX8.

On Uncle Buck's original post ... interesting info, not something I'd heard before.  I so far haven't run "diesel oil" in anything but my diesel's but you never know.

Gary S wrote: I was under the impression that oil threads are a winter doldrums discussion only.

Right Gary, but it's always winter somewhere ...

Oops I forget about our Minnesota and northern Wisconsin members  

KENO wrote: When is it fashionable/courteous for people to blame every gas related issue they have on ethanol Gary?

Yes Ken any time it misses,coughs or does not start.

Here ya go 

http://www.speedwaymotors.com/the-toolbox/zddp-content-chart-high-zinc-oil-list-brand-breakdown/32479" rel="nofollow - http://www.speedwaymotors.com/the-toolbox/zddp-content-chart-high-zinc-oil-list-brand-breakdown/32479

It would seem that you've run your engine for the past 33 years with what some people would say was an inadequate oil for protecting your flat tappet cam. Maybe more like 27 years since you gave it a 6 year hibernation period.

If you have a good running engine, it seems that your oil choice through the years didn't kill it and if it dies now it won't be because of the supposed lack of adequate zinc all through the years in your "not exactly a race engine" 351.

That would have killed your engine a long time ago (and a whole bunch of other people's too who are using the "wrong" oil according to someone.

So, use whatever lets you sleep at night, whether it's your old oil, your zinc supplement, some high zinc oil, diesel oil or whatever. 

PS I found a zinc supplement in my wife's vitamin stash, I wonder if that'll be good for my oil

That zinc supplement may help out when your cam lobe has gone, well, flat…

And also mentioning how you were now adding a Zinc supplement to your oil even though it survived the break in and all those years afterwards.  There must be a reason like you got scared or something  

I think your cam inspection will be done with your ears, or was it really already done with your ticking noise thread.

You fixed the tick with a bottle of Rislone and some run time and everything was good, so your cam must have been OK, since nothing in a bottle fixes worn lobes.

I looked at some oil on sale at Costco and wondered if it would work well in my boat.

Did a little research and decided not to use it for the reasons stated in the article at the link I posted.

Shared the information in this forum.

That's it.

I was not criticizing you or anyone else for using diesel oil in a gas engine. And I didn't get scared or have any ulterior motives. 
Use whatever oil you want to use in your boat. It doesn't matter to me.

You've been very helpful to me through the years and I very much appreciate your assistance.
But your reading of my mind is off the mark...

But it's just another oil thread and it is a forum after all.

I could post a link to an article that talks about why the reduced zinc levels didn't kill your engine (and a bunch of others) and also recommends not using a zinc supplement and is well worded, written by someone who was a gas and oil engineer for 30 plus years with one of the major oil companies.............but I won't.

I could also post PCM's latest oil recommendation from 2019 that specifies an oil rating and weight even for the old Fords.

We all do what lets us sleep at  night

www.BobIsTheOilGuy.com

Apparently there is some guy named, well, “Bob” at the heart of the oil issues.   

JQ

I definitely think some info gets overblown.  But I also think there's some reason to follow new info as it comes along.  Of course 351's aren't failing left and right from using Supertech oil with a Fram oil filter.  That doesn't mean it wouldn't make sense to read, reason through what we've read, and maybe take some steps to avoid problems.  Bruce said it well, "the info is out there to use zinc and it seems reasonable".  That's exactly where I am with all of this.

There is no question that I don't have to change my oil every year with the hours I put on my boat.  But I do.  Makes me feel better.

I know that slapping a prop on without first lapping it in with prussian blue isn't the best method.  But I do it and for some reason that one doesn't bother me.

I think it's possible that every single wood stringer inboard boat doesn't have bad stringers.  But sometimes you'd think they all do.

I once drove into our yard and saw my siblings towing a boat with my '63 Skier, rope attached to the stern lift ring.  Somehow the boat survived.

Lots of great info on all sides of every subject, just have to make decisions we all feel comfortable with.

I love that site, was on it a few days ago.  No idea who Bob is, but the web address and site name are a classic.

Whilst we're on the subject of oils, can anyone explain the rationale for using trans fluid on a teak swim platform?

Well, if it's Indonesian Teak, you must use conventional as the fibers will definately wear out prematurely. Studies show that the Teak's natural oils give up an electron to certain emulsifiers found in the synthetics and will degrade substanially unless you're on-plane most of the time.

However if it's African Teak, then synthetic is OK. (provided it's Dextron).

Check out from 01:45 in on Ron Tanis's video (The hyperlink function created a link, but it wouldn't work, so you'll have to cut/paste.)

https://youtu.be/cCcwFxcyBWo

NeilMcG wrote:   Check out from 01:45 in on Ron Tanis's video (The hyperlink function created a link, but it wouldn't work, so you'll have to cut/paste.) https://youtu.be/cCcwFxcyBWo

Umm........why did it work for me?

http://www.google.com/search?q=correctcraftfan+teak&oq=correctcraftfan+teak&aqs=chrome..69i57j0i546i649j0i546l2j69i64j69i60.12763j0j4&sourceid=chrome&ie=UTF-8" rel="nofollow - link

You know it's gonna be a rough day when you're outwitted by a caveman 

In case anyone is looking for teak I found a place-  https://buy.advantagelumber.com/products/1-x-6-teak-wood-decking?variant=39470155563050" rel="nofollow - https://buy.advantagelumber.com/products/1-x-6-teak-wood-decking?variant=39470155563050

I needed some to replace some broken and missing pieces on another branded boat and quickly found out that it is very hard to find, even boat salvage yards don't have a lot especially wider sizes

So a mix of transmission fluid and linseed oil on a platform.  Not sure how they came up with that one, but I suppose if it works, it works.  I'll stay with my Watco teak oil.

The way that platform was sanded I'd expect it to be like standing on wet ice.  Unless maybe that oil combination creates some grip.

If transmission fluid works on the swim platform, can I use teak oil in my transmission?

Neil

I don't see many answers coming your way, so here's what I think are some things that would possess somebody to do something like that

A  They're not very smart

B  They're cheap and had some laying around

C  Somebody told them that it wouldn't work so they had to try it and see what happens

D  They were just curious ( or maybe I read about it here on CCF years ago)

Since I fit into each of those categories, I guess I can say that I've used it before...........and it works pretty well with the right prep 

I can't remember if it was synthetic or conventional, new or used, might have been mixed with boiled linseed oil and something else I read about here on CCF

Check the link in my last post and you'll find a TRBenj concoction in one of those threads

Now as far as what's the best............remember .it's just another oil thread