well when you live in a stop and go enviroment 95 + degree weather plus 95% + humidity and no wind the conditions in miami arent that great especially with the AC on all the time almost all my high mile and turboed cars run straight 50W oil over 200 clients have had there oil changed with 50W with me in my opnion i have had no ENGINE failures so recomendation it is.
NO BAND AID HERE 60 PSI OF OIL PRESSURE AT IDLE AND HOT IN TRAFFIC AND TWIN TURBO.
but then again the best oil is the one you change RELIGOUSLY i change my oil every 2000 miles so 50W is fine for me and all of the bearing clearences in miami.

THEREFORE SERIOUS I AM. i know people who run straight 70 and or 100W in there race cars.

 

How do you evaluate the increased engine wear resulting from no oil circulation on cold start? That when a majority of the engine wear occurs.

Why wouldn't you at least use a 20W-50 to have some cold start circulation?

Still serious?

 

I run 20-50 in my 385.

 

I run 25W-50 in my 381, when I run a 300-shot..... But for cooler weather, with cold starts and no nitrous, its 10W-30. Exactly what the engine builder reocmmended.

Interesting that racers are now looking for the thinnest oil they can find, that will still provide adequate lubrication. There are now 0W-2, 0W-5 and 0W-10 racing oils.

 

I wouldn't change anything until the oil cooler is bypassed and pressure is confirmed with a mechanical guage. The stock guage and sending unit are not accurate.

 

serious as long as you use a filter with a built in anti drain back valve then cold start circulation isnt an issue if theres sufficient oil on start up Injuneer but your still not putting into acount the added weather variables that play apart in detiorating a stock high mileage lt1 in the conditions on my region of the US.So i wouldnt see why a thicker weight oil would be so frowned upon as long as its changed IMO.

 

The only thing "SERIOUS" is your obvious need of an education!

 

Anybody got any seals left at the front and rear of the crank with this molasses thier puttin in thier engine?Just a simple question,no flames ment,but come on now.I mean, don't you normally put 20-50 in a car with high mileage(a regular car),to compensate for extreem engine ware?I blew seals out with 10-30.My o2.

 

10w-30 is no thicker than 5w-30 and often 0w-30s are thicker than the common choices in those other two weights so you certainly are confused.

I have run everything from 0w-30 to 15w-40, believe it or not overseas 15w-40 is what was recommended for the LT1. 5w-30 is a CAFE recommendation and if you bothered to open your owners manual you will find 10w-30 is approved down to 0F.


rkrause wrote up a good thread on oiling in the advanced section some time ago, think it is worth a read for most of you. You would understand that the oiling system does not need pressure, it needs VOLUME and that we just use pressure gauges because it is easier to measure. It is NOT oil pressure that keeps parts separated it is basically hydroplaning. Once you hit bypass pressure for the oil pump relief spring oil starts to just recirculate from the pressure side of the pump to the intake side meaning no additional volume of oil is making it through the bearings.

IMO based on my understanding having the oil so thick it maxes out the bypass spring by just a few thousand rpms is a bad thing because you endup recirculating and heating a lot of oil within the pump and no additional volume is moved across the bearings to cool them.


Far as anecdotal evidence I have known people who put 1 quart of gear lube in engines at every oil change and the engines survived, does not mean the gear lube helped anything and does not even mean it was harmless.

 

You still don't seem to understand how the oil system and the (pseudo) positive displacement oil pump works. If the oil is too thick on cold start (even if ambient is 95*F, its still a "cold" start), as Dwayne pointed out, the relief spring will open, and NOTHING will circulate. What does reach the heads will not drain back, because its too syrupy. More than 1/2 of engine wear occurs on cold start, even with the correct oil. Changing the oil does nothing.... its still too thick.

 

I'm using 20w50 on my motor as recommended.

 

FYI (written by me)

http://www.kennedysdynotune.com/Oil%...ure%20Tech.htm

A big reason to use 50wt on a blown alcohol car is that a lot of raw fuel gets past the rings into the crankcase and dilutes the oil, which may not get hot enough to burn the methanol off. But straight 50wt on anything else doesn't make sense to me.
Rich

 

I know some Sprintcup teams that use 0000W oil.

 

I alway run oil(s) to what the bearing clearences are set up for as well as the type of driving done..... But what the hell do I know, I don't have any customers

 

well I went ahead and put the 20w 50 in since i already had it, I let it warm up and get completly hot, 30psi at idle 50psi at 6 grand. Is the oil pressure just telling me that the thicker oil is harder to push into all the bearings or is it oiling better? I guess if i spin a rod then running 20w 50 was'nt a good idea. But with 20psi I figured it's bound to happen anyway. The oil clearances worried me though, for the rods on a stock lt1 they are .0008 to .0022. would'nt everybody run 20w 50 if with 5w 30 they had 20 psi at 5 grand and with the heavy stuff you could get 50psi.