Motor oil for '95 Nautique

[LOTW]

The boat is getting older and oil is harder to find also. What would be a recommended oil for this thing these days? Pro Boss GT40 efi.

Thanks!

[MDB1056]

Just now, LOTW said:

The boat is getting older and oil is harder to find also.

Oil is harder to find? What am I missing? Stores are full of it. My boat is a 92 5.7 that I run full synthetic 5w30 in . Mobile 1, Valvoline, or Quaker State. All excellent . Don't think you could go wrong in your GT40 at all. Are you using something special?   

[BraceMaker]

Anything flat tapet which I think a GT40 still would be I tend to use the Valvoline VR1 products easy to find and high zinc.

I've also used products from other brands like Brad Penn and belray but you can get vr1 at auto zone so it's a clear winner.

[Killer]

Any 15w40 oil.  Non synthetic. I've been using the Mobil delvac diesel oil.  The shell Rotella is also popular.  

I just picked up a box of zinc additive as most oils now don't have the zinc the 351 likes.

[foxriverat]

When I had my 96 supra ts6m with the gt40 the manual said VR1 racing oil, straight  40w that's all I ever used. https://www.napaonline.com/en/p/VAL822390 They have it at Amazon also but more expensive.

[ETskier]

I think the Shell Rotella 10w30 was the OE oil. All of the above are winners. Personal preference. 

 

[jhughes]

VR1 20W50 is the go-to for most Ford ski boat guys these days. Easy to find, high zinc content.

[RichardDoane]

Engine building friend of mine told me long ago, “try to use the lightest weight oil possible, as long as oil pressure at hot idle is adequate. “. So a quality 5w30 with zinc goes well in the GT40. Too heavy of a viscosity is not an engine’s friend. 

[skiermanbrad]

I have a '98 with the ProBoss GT-40. I called PCM because there were so many opinions about oil on the forums. The engineer I talked to said they recommend Shell Rotella 15w-40. I've been using it for years and my engine runs great.

[S1Pitts]

Just make sure the oil used has the SM/SN designation. This ensures the zinc additive.

Last I looked the newest version of Rotella dropped the SM/SN, Make sure to check your Rotella being used. We cannot afford to loose these engines.

[Dano]

I've run full synthetic 5w30 in my 351w for the past 20years. Still runs like it's brand new. 

[MDB1056]

Shop that rebuilt my GM 5.7 in my 92 Hydrodyne Comp when I had a gasket failure and hydrolock had me run VR1 straight 40wt for break in to seat the rings , then said fine to run full synthetic of my choice . It’s a roller cam engine. 

[Dano]

.

[LOTW]

Small town Canada, we don't have the big retailers and stores that are available in the U.S.

Thanks for the replies and help!

[DW]

Hopefully CT has an option for you:

https://www.canadiantire.ca/en/search-results.html?q=engine oil

Amazon can be your friend for oil or additives.

[Ski_Dad]

well any 15w40 should be fine - but I would consider Mobil 1 15w50 - it has the more zinc you need and easily available at Walmart.

[Dano]

There are a lot of opinions out there on the levels of zinc (ZDP) required for flat tappet engines. Her is a link to what GM's tech guy had to say about the topic.   

https://www.nonlintec.com/sprite/oil_myths.pdf

[Ajskier]

I use Valvoline VR1 40w in my GT 40.  

[Jody_Seal]

Ah yes the bi yearly oil discussion...

wabbit season! 

Duck season! 

wabbit season! 

Duck Season!

[ALPJr]

Always ran straight 30w Napa in our 92 with a 351. That what the manual recommended 

[Mateo_Vargas]

After we get the oil selection figured out do we prefill the filter or not?

[MDB1056]

Not needed

[DW]

I lean towards filling the filter as that reduces time to achieve oil pressure after change and I use the truck version oil filter which tends to be larger.  

[MDB1056]

Many boats the maneuvering needed getting it into position to install would prevent it anyway 

[BraceMaker]

Most every filter you can buy it with or with out an antidrain back valve the Ford FL-1A from motorcraft doesn't have one but there are aftermarkets like Mobil 1 and Baldwin come with it.  So if you're obsessed you might prime by pushing that valve flap open filling the filter and then installing it which would be the work around.

Personally if you've run the engine to get the thing hot and then drain it you're not going to have any oil in the whole system but everything is wet.  I would just install and run it.

On one of my old BMW's the instructions re: the cam chain tensioner which was oil pressurized was once you finished changing it, start the engine and immediately rev the engine and hold it till the tensioner popped out.  I'll tell you that gives you the feels.

[GaryJanzig]

I have been using SAE 40 since day 1. Pennzoil, STP, NAPA. I have been using FL-1A, Wix, or PCM oil filters. Change every 50 hours and at winterization. 2300hours season 30 coming up.

 

[slow]

40w in the manual for 1999