0W40 vs 10W40 for SBF stroker

[SpaceGoast]

I bought a car that has a 302 based 347 stroker with 10.5:1 compression. The previous owner said his engine builder told him to use 10w40 for it. I went to the local auto parts houses and walmart and the only full synthetic 10w40 is the mobil 1 high mileage stuff, I don't want all the garbage making my seals all swell up. I could also order 10w-40 online but its 3x the price of the 5qt jugs locally.

They do have 0w40 mobil 1, I've read that this is typically "better base" oil than a 10W. I live in florida, and will rarely ever see freezing let alone negative temperatures.

Does 0W oil provide enough protection when cold for for an old pushrod stroker motor? I'm mainly just worried about it providing enough lubrication for the crank and cam bearings. I am not an expert on oils and want some informed opinions.

 

[tundraotto]

I would think you would look for a high ZDDP type oil...youre in Florida so I would look at a 15w40 diesel oil with a robust zinc content.

 

[kschachn]

Originally Posted by SpaceGoast
Does 0W oil provide enough protection when cold for for an old pushrod stroker motor? I'm mainly just worried about it providing enough lubrication for the crank and cam bearings. I am not an expert on oils and want some informed opinions.

In Florida a 0W or a 5W or a 10W or a 20W rated oil will all have substantially the same viscosity at ambient temperatures. It's not a "0 weight" oil. All oil is very thick when cold and thins as it warms up.

Mobil 1 0W-40 FS has 1100 ppm of zinc which is more than sufficient for this application.

 

[Stickygreen]

Just my opinion...

M1 15w50 or Redline 10w40 depending on how much you want to spend

 

[neil57]

I would think you would look for a high ZDDP type oil...youre in Florida so I would look at a 15w40 diesel oil with a robust zinc content.[/quote
If it has a non roller cam, should use ZDDP type oil as tundraotto says. 10/40 Dino may have been the engine builders recommended oil if it is an older build. Flat tappet cams don't play nice with non ZDDP oil.
I used T6 Rotella 5/40 in a 383 stroker with no issues.

 

[SubieRubyRoo]

Originally Posted by SpaceGoast
the only full synthetic 10w40 is the mobil 1 high mileage stuff, I don't want all the garbage making my seals all swell up.


First step of becoming a member on BITOG: don't ever again listen to whoever told you that high mileage oils have "garbage" that "make your seals all swell up". Complete and utter hogwash. Even though I'm not a Mobil 1 user, you've got some really unfounded fantasies about one of the most developed, best proven high mileage oils out there. It's 100% interchangeable with any other 10W40 and will cause exactly zero harm to your engine.

 

[BillyE]

I used 10W-30 in mine.

 

[CT8]

What garbage will make your seals swell up . Look at the viscosity of the oil a 40c or about 100* f to give you an idea at the oils viscosity at start up . 0w rating. is the oils ability to pump at around -40*f. I would say the 0W-40 is the better of the two oils.

 

[Jimmy_Russells]

Originally Posted by SpaceGoast


Does 0W oil provide enough protection when cold for for an old pushrod stroker motor? I'm mainly just worried about it providing enough lubrication for the crank and cam bearings. I am not an expert on oils and want some informed opinions.


If you're starting the car at a normal Florida type of temperature it makes pretty much no difference, in your case the number before the W almost doesn't matter. You could use 0w40 Mobil/Castrol, 5 or 10w40 Redline/Amsoil/Royal Purple, or even 15w40 T6 or something like that someone mentioned earlier. I bet you'd notice almost zero difference. I would only worry about zinc content if the engine has a flat tappet cam and/or non-roller rockers, which isn't very common anymore on most builds.

FWIW in my younger days I had a nine second naturally aspirated Mustang with a 393. I used 10w30 in it but that was based on the clearance in that engine. If your builder said to use 40 weight I would stick with that.

 

[A_Harman]

Just put in the 10w40 M1 High Mileage.

 

[A_Harman]

Originally Posted by SubieRubyRoo
Originally Posted by SpaceGoast
the only full synthetic 10w40 is the mobil 1 high mileage stuff, I don't want all the garbage making my seals all swell up.


First step of becoming a member on BITOG: don't ever again listen to whoever told you that high mileage oils have "garbage" that "make your seals all swell up". Complete and utter hogwash. Even though I'm not a Mobil 1 user, you've got some really unfounded fantasies about one of the most developed, best proven high mileage oils out there. It's 100% interchangeable with any other 10W40 and will cause exactly zero harm to your engine.


Dittos!

 

[OVERKILL]

Originally Posted by tundraotto
I would think you would look for a high ZDDP type oil...youre in Florida so I would look at a 15w40 diesel oil with a robust zinc content.


It's a roller motor, it does not need copious volumes of ZDDP.

 

[OVERKILL]

I've used M1 0w-40 in a number of built SBF 302's with excellent cleanliness and no observable wear upon tear-down. I'd run it without reservation in this application.

 

[metroplex]

This is going to sound odd, but I had a 1981 Ford Thunderbird with the 302 V8 (same engine as the 1979 Cobra, an anemic 120 hp or so 5.0L V8). The manual said to use 10W-40, and that is what my dad did since day 1 when he bought it new in 1981. When I got the car, I experimented with 10W-30 and 5W-30, but it would cause a hard-to-start or refusal to start condition and the spark plugs would be completely soaked in oil if I recall correctly. I'd drain the oil, and go back to a dino 10W-40, and the engine would fire right up. As the engine got older, we switched to a 15W-40 HDEO. I had replaced the valve stem seals, and the engine never burned blue smoke or anything like that.

 

[SpaceGoast]

Originally Posted by SubieRubyRoo
Originally Posted by SpaceGoast
the only full synthetic 10w40 is the mobil 1 high mileage stuff, I don't want all the garbage making my seals all swell up.


First step of becoming a member on BITOG: don't ever again listen to whoever told you that high mileage oils have "garbage" that "make your seals all swell up". Complete and utter hogwash. Even though I'm not a Mobil 1 user, you've got some really unfounded fantasies about one of the most developed, best proven high mileage oils out there. It's 100% interchangeable with any other 10W40 and will cause exactly zero harm to your engine.


Don't listen to Mobil 1?

Straight from their product page:
A boosted level of seal conditioner to protect engine seals because, over time, rubber seals can harden or shrink, resulting in oil leaks"

Higher amounts of seal conditioner cause seals to swell, then it's just a ticking time bomb before they all disintegrate. There's a reason normal oil doesn't have so much. Mobil 1 is more concerned with mechanical damage than leaks. I love Mobil 1 and have used it for years, but I don't believe in chemical fixes for leaks. Who knows, maybe they have the exact right amount to perfectly condition every type of seal of every shape and material for every engine. I've seen plenty of destroyed gummy seals from people who used extra seal treatment in their oil as a bandaid instead of paying to get a gasket or seal replaced.

I'll give the 0W40 a shot, as others said this is a roller engine.