previous owner thinks "motor might have been replaced at some point" because it looks pretty clean and sounds and runs like new, but it could just be good maintenance. currently i'm running delo 10w-30. oil pressure is great, 60psi cold, lowest at hot idle it ever gets after a ~75mph highway run is 20psi. would i be an idiot to step down to a 5w-30 for sake of buying the same oil for both my vehicles?
5w-30 in 277k mile chevy 350 tbi
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In this "step down" scenario, what exactly is going down?
I've got 20w50 in my 89....
These tbi v8s aren't picky about oil, they'll run on anything from 5w20 to 20w50 and everything in between, including monogrades. Your delo 10w30 is a good choice, but 5w30 would more than suffice.
These tbi v8s aren't picky about oil, they'll run on anything from 5w20 to 20w50 and everything in between, including monogrades. Your delo 10w30 is a good choice, but 5w30 would more than suffice.
Oh I see. Since both are 30-grade oils and you apparently are able to accurately measure oil pressure, why not try them?
You're in a mild climate so there's no need to worry about cold start viscosity, 10w30 or 5w30 will be fine. So I say go ahead and change to 5w30 for simplicity among your vehicles. You really won't notice any difference in how that engine performs.
It's a robust engine. Buy for convenience and what is on sale the engine will be fine as long it is something close to modern spec.
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
How does one build an engine for a specific winter rating?
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
How does one build an engine for a specific winter rating?
Beats me that that is what the manufactures spec. Maybe you can help us out here?
10W-30 would be a great choice for both vehicles, too. Its especially good in your older vehicle, FWIW.
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
Originally Posted by maxdustington
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
????
It's a TBI SBC. It's not from 1956. Loads of TBI SBC's from the 1980s and 1990s ran 10w30 and 5w30 since new.
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
????
It's a TBI SBC. It's not from 1956. Loads of TBI SBC's from the 1980s and 1990s ran 10w30 and 5w30 since new.
Dave I really don't think most bitogers know just how good of an engine the tbi small block was and is. Robust is an understatement. I'm fond of the [censored] things.
Originally Posted by kschachn
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
How does one build an engine for a specific winter rating?
I would think bearing clearances would be a determining factor, along with the ability to start and get the oil flowing in subzero temps (not likely in CA). My 215K mile TBI 350 had too low hot idle oil pressure, it took 20W50 to get it high enough, guessing worn cam bearings due to no unusual noises other than lifter ticking.
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
How does one build an engine for a specific winter rating?
I would think bearing clearances would be a determining factor, along with the ability to start and get the oil flowing in subzero temps (not likely in CA). My 215K mile TBI 350 had too low hot idle oil pressure, it took 20W50 to get it high enough, guessing worn cam bearings due to no unusual noises other than lifter ticking.
Originally Posted by maxdustington
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
SBCs used to run straight 20 and straight 30 in the old days, and could even run 10 in super cold arctic conditions. We usually ran 10W40 & 20W50 because we didn't know any better in the '70s & '80s. Straight 40 would work in Australia.
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
SBCs used to run straight 20 and straight 30 in the old days, and could even run 10 in super cold arctic conditions. We usually ran 10W40 & 20W50 because we didn't know any better in the '70s & '80s. Straight 40 would work in Australia.
Originally Posted by jayg
Originally Posted by maxdustington
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
????
It's a TBI SBC. It's not from 1956. Loads of TBI SBC's from the 1980s and 1990s ran 10w30 and 5w30 since new.
It's the same mill but with cetnerbolt valve covers and a one piece rear main seal. I can't remember what year they switched to roller cams.
First car I ever drove was an 1988 Sierra. TBI is a lot closer to a carb than MPFI.
Originally Posted by maxdustington
Originally Posted by ka9mnx
Your engine was originally built for 5w-30. The 10w-30 is fine for where you live. So if you want to buy one oil the 5w-30 will work.
SBC? Probably designed to run on 20W50, SAE40 or something insane like that.
????
It's a TBI SBC. It's not from 1956. Loads of TBI SBC's from the 1980s and 1990s ran 10w30 and 5w30 since new.
It's the same mill but with cetnerbolt valve covers and a one piece rear main seal. I can't remember what year they switched to roller cams.
First car I ever drove was an 1988 Sierra. TBI is a lot closer to a carb than MPFI.
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