I'm questioning the 20/50 I used this time...

[HammerDown]

Here's why...this is for a 468ci BBC Jet Boat.
For years I've always run straight VR1-50 Racing oil. Last year I didn't use the boat at all...winterized the whole season since 06.
However, when I pulled the valve covers off this season to set the valves the roller rockers etc STILL had a pretty good film of 50/wt oil on them > I liked seeing that! That told me there was still a oil film on the cam lobes, lifters, piston skirts and bearings.
So this time I tried VR1-20/50 Racing oil...ran the engine and after almost 2 weeks of ot sitting I pull a valve cover off and to my surprise...the rockers etc seem dry...NO OIL CLING to the parts like the straight wt from way back in 06!
ALSO, from this engine sitting some 10 days it still took a solid +90 seconds before oil started pumping out of the push rod tubes!
I thought for sure it would pump to the rockers faster than the straight 50 wt...nope.
(cold psi 75)

EDIT > some people laugh at oil additives like Lucas but I sometimes wonder if it helps the oil to "cling" to moving parts during extended shut down. I've always run it in my Corvette, Harley, and lawn equipment.
I may consider dumping in a qt with this 20/50.

 

[Audi Junkie]

Ever do a UOA? Without it, who knows if "cling" means anything at all, other than in the mind of the observer. I could run strait grease that would "cling", but how is that better if wear rates cannot be determined?

 

[JohnBrowning]

I say buy the oil viscosity you want. It is not a smart move to buy an oil witht he intent of droping a quart of some unknown viscosity additive that is basicly bright stock to thicken it. So if you want a 50,60,70 straight oil then buy it that way instead of trying to add Lucas to it.

In that boat I would seriously consider either a Diesel mixed fleet 5W40 or 15W40. Delo,Rotella or Delvac would be the direction I would go. Your Dieself mixed fleet 15W40 and 5W40 oils tend to have good base stocks and excellent additive package.If I where going to go synthetic I would consider M1 15W50,Amsoil 20W50 and Redline 15W40.

 

[LargeCarManX2]

I understand the clingability issue and your attention to this matter is correct in theory. I wonder what the difference in spec sheets is between the oils? Something is different and your eyes are not deceiving you!

 

[HammerDown]

Originally Posted By: LargeCarManX2
I understand the clingability issue and your attention to this matter is correct in theory. I wonder what the difference in spec sheets is between the oils? Something is different and your eyes are not deceiving you!

Thanks for all the above replies...again my way of thinking is for a engine that is not run daily, weekly or maybe for several months at a time does the "cling" of a thicker oil help at all for the dry start?
My simply mind thinks yes.

 

[HammerDown]

Originally Posted By: JohnBrowning
...In that boat I would seriously consider either a Diesel mixed fleet 5W40 or 15W40. Delo,Rotella or Delvac would be the direction I would go. Your Dieself mixed fleet 15W40 and 5W40 oils tend to have good base stocks and excellent additive package...

Correct me if I'm wrong but I believe did read somewhere that the prior levels of Zinc etc are now much lower if at all in the current diesel oil offerings.
I do have a diesel Ford for 20 years now and have for the most part always used Delvac Mobil in it...and I think it now sports a different rating.

 

[wapacz]

isn't vr1 a racing oil and such have less detergents, and less rust prevention additives. I guess what I am getting at is that none racing oil may be a better option in your situation as you are not changing it often or running it often.

 

[HammerDown]

Originally Posted By: wapacz
isn't vr1 a racing oil and such have less detergents, and less rust prevention additives. I guess what I am getting at is that none racing oil may be a better option in your situation as you are not changing it often or running it often.

Not sure about the detergents/rust prevention etc but because it's for "off road use" the VR1 does carry a higher level of anti wear additives. As for the time I actually use it for one season...maybe once a week for 3 months, then I drain it for winter.

 

[wapacz]

i'm just going by people always say not to use racing oil in street cars here, so I could be totally off base.

You could always set up a pre oiler system on it and turn it on at the same time you turn on the blowers before you start the boat.


so I just scrolled down the forums and saw another post about a jet boat with a 454 so here is a link to it.

https://bobistheoilguy.com/forums/threads/oil-recommendation-please-jetboat-w-454.84165/

Then right above it was a thread by the same guy that bruce responded to and that guy knows his stuff.
https://bobistheoilguy.com/forums/threads/marine-oil-vs-hdeo-oil-vs-race-oil.86406/

 

[PT1]

Lots of guys use straight weight oil in marine engines. Pennzoil 40w is a favorite here in Ohio for that same reason. Plus it is very shear stable compared to multi grades. I use Merc 25w40 because it is 2 straight weights blended and not a 25w with VII's. It has worked well for me for over 20 years. But several of my dock partners swear by 40w.