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87MCProstar
05-22-2008, 10:57 AM
the person who rebuilt my engine told me with my new cam i have to add a zinc additive because the oil compaines are taking more and more of these things out of the oil. the question is isn't that why we are supposed to use diesel motor oil? but if even heavy duty oil does have that benefit anymore because he also said that rotella has or is in the process of taking that stuff out too. if thats the case is any 15/40w oil going to work??

TRBenj
05-22-2008, 11:32 AM
No. Within the last year or so, many diesel oils have had the amount of zinc reduced in order to comply with the new particulate filters being installed. Rotella-T 15w40 (formerly my favorite) can be included in that group as well.

Stick with straight weight Rotella (30w or 40w) or go with Valvoline Racing VR1. I prefer the VR1 because its available in multiweight (10w30 and 20w50). Advance on East Main usually stocks it.

TMCNo1
05-22-2008, 01:32 PM
the person who rebuilt my engine told me with my new cam i have to add a zinc additive because the oil compaines are taking more and more of these things out of the oil. the question is isn't that why we are supposed to use diesel motor oil? but if even heavy duty oil does have that benefit anymore because he also said that rotella has or is in the process of taking that stuff out too. if thats the case is any 15/40w oil going to work??

That's why I use Valvoline VR-1 40 wt Racing Oil,
35371

87MCProstar
05-22-2008, 05:00 PM
thanks tim and harold.

brucemac
05-22-2008, 05:02 PM
hey not to hi-jack, but my mechanic put amsoil synthetic in my mcx

he didn't ask, but they told me when i picked her up.

thoughts?

Gamble
05-22-2008, 07:47 PM
.....on the same note.......just changed my oil and due to high engine time, I put the valvoline high mileage 20w50.....I was told this should help increase oil pressure and is good for the higher heat/useage in boat engines.....anyone here concur?

vogelm1
05-22-2008, 11:03 PM
So I take it this only applies for older engines? Do late model engines require this too...say an MCX?

bigmac
05-23-2008, 02:08 AM
hey not to hi-jack, but my mechanic put amsoil synthetic in my mcx

he didn't ask, but they told me when i picked her up.

thoughts?
Synthetic vs conventional oil...doesn't matter as long as it meets the API specs required by the engine manufacturer.

bigmac
05-23-2008, 02:09 AM
So I take it this only applies for older engines? Do late model engines require this too...say an MCX?ZDDP (zinc additive) is a pressure wear additive and is important for engines with solid lifters. Not so for later models with roller cams like the MCX.

TRBenj
05-25-2008, 02:34 PM
ZDDP (zinc additive) is a pressure wear additive and is important for engines with solid lifters. Not so for later models with roller cams like the MCX.
Its important for flat tappet lifters, which can be solid or more commonly, hydraulic.

bigmac
05-25-2008, 04:37 PM
Its important for flat tappet lifters, which can be solid or more commonly, hydraulic.

Yes. Flat tappet, not solid. 'scuse me..

TMCNo1
05-25-2008, 04:57 PM
They are making EggMcMuffins smaller and smaller at McDonalds for the same price, I guess removing additives in oil also helps offset the cost of the increase in crude oil pricing!:uglyhamme

TX.X-30 fan
05-25-2008, 05:24 PM
They are making EggMcMuffins smaller and smaller at McDonalds for the same price, I guess removing additives in oil also helps offset the cost of the increase in crude oil pricing!:uglyhamme




Blatant threadjack. :D

TMCNo1
05-25-2008, 06:00 PM
I'm thinking of using bacon grease as a additive to my oil instead of Z-Max, STP, Slick50, cause if it's bad for humans, it's got to be good for engines, right!

Chaser_rct
05-30-2008, 09:16 AM
Hope this isn't a dumb question but i have a 351W in my 81 haven't had it on the water since i bought her two years ago.....what oil should i use?

TRBenj
05-30-2008, 12:20 PM
Hope this isn't a dumb question but i have a 351W in my 81 haven't had it on the water since i bought her two years ago.....what oil should i use?

87MCProstar has the same 351w in his boat- so this discussion applies to you as well. Stick with straight weight Rotella (30w or 40w) or Valvoline Racing VR1.

Chaser_rct
05-30-2008, 01:22 PM
cool i use Valvoline in all my vehicles so my boat so i believe i will go with the Racing VR1

Gamble
06-01-2008, 10:35 PM
which oil will create better oil psi.....straight 40 weight or 20w50?

Jesus_Freak
06-03-2008, 12:57 PM
which oil will create better oil psi.....straight 40 weight or 20w50?

At startup, especially if the engine is below maybe 50F, the straight 40 is going to be more viscous (higher pump differential pressure). At normal operating temp, the 20/50 is going to be more viscous.

Gamble
06-03-2008, 08:22 PM
great, so with me runnin the 20w50, I should have better pressure after the engine gets up to running temp, correct?

Jesus_Freak
06-04-2008, 01:30 PM
great, so with me runnin the 20w50, I should have better pressure after the engine gets up to running temp, correct?

Yes, as long as the oil is in good shape and the polymer additives have not begun thermal decomposition.

bigmac
06-04-2008, 06:21 PM
Yes, as long as the oil is in good shape and the polymer additives have not begun thermal decomposition.Or breakdown from shear. The latter is probably more likely - these engines tend to run cooler than automobiles. The reason that Indmar recommends CI-4 diesel oils is that they are universally made with Group II base stocks. Those catalytically refined oil tend to have minimal viscosity index improvers, therefore much less affected by shear (or thermal breakdown).

I'm not sure how to check for polymer breakdown though...;)