10w40 with these bearing clearences=more protection???
08-12-2009, 10:05 PM
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10w40 with these bearing clearences=more protection??? I called my engine builder that did my engine about 4 years ago and was hoping he remembered the bearing clearences. I think he said with my setup he would have did it 2.5 to 3. I guess this means .0025 to .0030. Right? I heard a thicker oil will possibly add more protection as long as the bearing clearences were acceptable at the cost of losing a few ponies. Will 10w40 be more protective compared to 5w30 with these bearing clearences? I will be spinning my motor to 6800rpms. Thanks for any help.
08-12-2009, 10:15 PM
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Are those main or rod clearances? I'm hoping main b/c that would be a very loose setup for rods...
I'm running almost the exact same clearances as that on mains and use 10W-40, haven't had a problem yet. You might HAVE to run the thicker oil to maintain proper pressure with the more loose clearances.
When talking about losing hp if you would have the same psi with the looser clearances and 10W-40 as the stock on clearances on a 5 or 10W-30 you would have the same hp. That is assuming the psi is exactly the same. PSI is resistance to flow and that is what makes the pump harder to turn thus robbing hp.
I'm running almost the exact same clearances as that on mains and use 10W-40, haven't had a problem yet. You might HAVE to run the thicker oil to maintain proper pressure with the more loose clearances.
When talking about losing hp if you would have the same psi with the looser clearances and 10W-40 as the stock on clearances on a 5 or 10W-30 you would have the same hp. That is assuming the psi is exactly the same. PSI is resistance to flow and that is what makes the pump harder to turn thus robbing hp.
08-12-2009, 10:29 PM
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5w 30 is to thin for those clearances. I would recommend something like a 15w 40 or 50 at minimum, especially if its a standard volume pump. (.003) clearance is perfect rods and mains for a high performance engine. Just run a thicker oil.
08-13-2009, 05:25 PM
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.0025 for the rods and mains, except for the rear main which I like at .003.
I'd go 10w40 as a starting point to see how the hot pressure looks.
.
Ever wonder why so many LT1s spin rod bearings? Check out the factory clearances.
Jake
West Point ROCKS!
I'd go 10w40 as a starting point to see how the hot pressure looks.
.
Ever wonder why so many LT1s spin rod bearings? Check out the factory clearances.
Jake
West Point ROCKS!
