How thick is too thick?
06-17-2008, 01:20 AM
#1
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How thick is too thick? yes i did a serch and looked threw all 300 and some results and i still coudlent find a simple "yes" or "no" anser so i thought i would just ask
i have an lt1 with some good ol miles on it and running low boost. i was talking to my grandfather whos built tons of diffrent and fast N/A motors and he was saying i should go to some thicker oil. scince ive have the car ive been running the 5w-whatever the book says, but after talking to him and doing some thinking. it makes sents that a tinner oil under stress would have less "cussion" between the moving metal parts and under stress is more likley to get squeezed out, right? so i was wondering how thick is to thick for a stock, with some good ol miles on it, lt1
gramps said i should have lots of room to run 20w- what ever, and not worrie a lot about pre mature kaaa-boom as long as i let it warm up befor i beat on it. becuse it would be like a fatter heavier pillow between the moving parts it would be harder to kick out udner heavy stress. this makes scents..right?? now my question is
is 20w-XX going to cause some silly un seen problem?
this is a summer only car.. 20*c *im in canada eh* and up kinda deal. its a totaly stock internal motor with stuff in sig running 7-8psi.
i have an lt1 with some good ol miles on it and running low boost. i was talking to my grandfather whos built tons of diffrent and fast N/A motors and he was saying i should go to some thicker oil. scince ive have the car ive been running the 5w-whatever the book says, but after talking to him and doing some thinking. it makes sents that a tinner oil under stress would have less "cussion" between the moving metal parts and under stress is more likley to get squeezed out, right? so i was wondering how thick is to thick for a stock, with some good ol miles on it, lt1
gramps said i should have lots of room to run 20w- what ever, and not worrie a lot about pre mature kaaa-boom as long as i let it warm up befor i beat on it. becuse it would be like a fatter heavier pillow between the moving parts it would be harder to kick out udner heavy stress. this makes scents..right?? now my question is
is 20w-XX going to cause some silly un seen problem?
this is a summer only car.. 20*c *im in canada eh* and up kinda deal. its a totaly stock internal motor with stuff in sig running 7-8psi.
06-17-2008, 03:13 AM
#2
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i guess you should be fine , i ran 20-W50 for a while on my old "worn" ls1 motor without any issues ( unless you call more oil pressure an issue 
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06-17-2008, 03:18 PM
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oil pressure doesnt = oil flow,the only time that is the case is if the oil is the same thickness and the restriction is the same and the pressure goes up.The only way to raise oil flow is to change pumps.The reason pressure goes up is because its harder to push the thicker oil through the bearings.oil viscosity is base solely on bearing clearance and usage.
Back to the oringinal question-do you have low oil pressure now-if not no reason to change oil thickness.
Back to the oringinal question-do you have low oil pressure now-if not no reason to change oil thickness.
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06-17-2008, 04:09 PM
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Thicker oil is for larger bearing clearances such as a race motor. This does not apply to a high mileage motor. Too thick of oil will starve and burn up your motor. Gramps never had it as good as 0w-XX.
06-18-2008, 12:37 AM
#9
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what is the bearing clearance on a stock lt1?
im not 100% sure what my oil PSI is becuse i have that junky stock gauge. at a warm*half temp gauge* idling its at or just below the first notch on the oil gauge and thats running 5w- what ever the owners manual says. i would like to go a bit thicker just to have that little extra. would diesel car oil should be fine to use, correct?
looking in the haynes book it says min of 6 oil psi at 1000
18 at 2000
24 at 4000
im not 100% sure what my oil PSI is becuse i have that junky stock gauge. at a warm*half temp gauge* idling its at or just below the first notch on the oil gauge and thats running 5w- what ever the owners manual says. i would like to go a bit thicker just to have that little extra. would diesel car oil should be fine to use, correct?
looking in the haynes book it says min of 6 oil psi at 1000
18 at 2000
24 at 4000
Last edited by 94m6Z28; 06-18-2008 at 12:44 AM.
06-18-2008, 12:01 PM
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i'm just not sure why you would go to thicker oil if your not having any issues,and by the way,the thicker oil wouldnt fix anything.all thicker oil would do in your situation is rob horsepower due to the fact its harder to pump