Oil Viscosity Question for LSX Engine with Mods.

[440Magnum]

Originally Posted By: The_Eric
I wouldn't think that 1.8:1 roller rockers would constitute a need for a heavier oil.


I don't think its the rockers that really need the heavier oil... its the dealer recommending it so that drivers who get this modification don't complain about the "sewing machine" sound.

I still say if you WANT to go to a heavier oil a "thick 30" ("German" Castrol) or "thin 40" (M1 0w40) would be just the ticket.

If you don't care about a little more harmless noise, use the stock grade in your favorite brand and don't worry about it.

 

[Hammer]

Originally Posted By: fnbrowning



There are over 500 needle bearings in the rocker set



I thought I would just throw it out there that the OEM LSX rockers use a needle bearing fulcrum while maintaining the sliding friction valve tip end.

If anything, these new rockers will stress your oil less. The needle bearing section of your new rockers are caged and less likely to fail compared to the OEM LSX rockers, which have been known to fail due to their uncaged needle bearing design. And of course the roller tip of the new rockers will have less friction then the OEM sliding tip.

So basically, the OEM recommended viscosity ratios will perform just fine.

 

[OVERKILL]

If the only mod is rockers.... I'd just stick to whatever it calls for.

Did you upgrade the valve springs? What is the stock rocker ratio?

 

[fnbrowning]

Originally Posted By: 440Magnum
Originally Posted By: The_Eric
I wouldn't think that 1.8:1 roller rockers would constitute a need for a heavier oil.


I don't think its the rockers that really need the heavier oil... its the dealer recommending it so that drivers who get this modification don't complain about the "sewing machine" sound.

I still say if you WANT to go to a heavier oil a "thick 30" ("German" Castrol) or "thin 40" (M1 0w40) would be just the ticket.

If you don't care about a little more harmless noise, use the stock grade in your favorite brand and don't worry about it.


Originally Posted By: Hammer
Originally Posted By: fnbrowning



There are over 500 needle bearings in the rocker set



I thought I would just throw it out there that the OEM LSX rockers use a needle bearing fulcrum while maintaining the sliding friction valve tip end.

If anything, these new rockers will stress your oil less. The needle bearing section of your new rockers are caged and less likely to fail compared to the OEM LSX rockers, which have been known to fail due to their uncaged needle bearing design. And of course the roller tip of the new rockers will have less friction then the OEM sliding tip.

So basically, the OEM recommended viscosity ratios will perform just fine.


I appreciate these insights. I was pretty much leaning toward the >>"dealer recommending it so that drivers who get this modification don't complain about the "sewing machine" sound."

On page two, Patman wrote >>"If it were my car I would initially try Ultra 5w30, . . . and if I wasn't happy with the numbers from Ultra 5w30, I'd try out Redline 5w30 and if I still wasn't happy then I'd go thicker and try GC 0w30."
Since I was already runnning PP, Ultra is no problem, as the extra $5.00 or so is nothing for a once-a-year oil change.
I consider the question resolved, and thanks to all who participated!