chpmnsws6

iTrader: (70)

would it help or harm a fairly built ls1 to run 20-50w? with 10-30, it sat around 40psi at idle and 60-65 psi when playing.

what are the benefits/downfalls?

Patman

There is no need to run such a thick oil, you're just robbing yourself of horsepower and possibly will end up with higher oil temps since the engine has to work harder to push through that thicker oil. I would not go any thicker than 10w40.

chpmnsws6

iTrader: (70)

why do all the higher hp cars run it? keep in mind, the ring gap will be .028 or greater for spray.

i can get the lighter stuff, just didn't know why people seem to push this weight

ss1

iTrader: (32)

I run Amsoil 20w-50 in my racecar engine and have always had good luck with it. So in my LS1 I first tried Amsoil 10w-40, but had quite a bit of valvetrain noise. I did quite a bit of research on why I shouldn't use 20w-50, but figured i'd try it anyway. My next oil change I went with the Amsoil series 2000 20w-50 and it quieted it down a little after the engine warmed up as compared to the Amsoil 10w-40. The reason I don't have a problem with the 20w-50 Amsoil is, it's thinner than conventional 10w-40 (which is what some run in their engines) when the engine is cold. Supposedly, after the engine is warmed up the Amsoil won't lose a lot of its viscosity. Just my opinion, you know how that goes. I'm not an oil expert, but have used many different oils and have had varied results.

Okie5.3

iTrader: (1)

I wouldn't run it in a DD, especially now that it's winter. Lost a main bearing once running 20w-50 when a cold snap snuck up on me.

chpmnsws6

iTrader: (70)

talked to the boys at the shop. they said it was for loose tolerance race motors. the 20-50 holds to parts while going around corners so the parts don't get oil starved nearly as quick