imos-ss 01

I just threw some 20w50 valvoline synthetic in my ls1. First, will this oil be too thick for an ls1? Second, will the internals still be able to move and the oil not break down as much as if i were using 10w30?? I know what the recomended weight is but already blew a gasket running 10w30...

Tranzor

20w50 is WAAAYYY too thick for the LS1... 10w40 tops is what I'd go with.

Taspeed

iTrader: (1)

i agree. unless you have rebuilt the motor and opened up the bearing tolerances about .002 more I wouldn't really use it. However, I did use it when I would run it at the track, and I ran my **** HARD! I did change it very often and would run 10-40 in it when I was just driving around town.

Judd

iTrader: (1)

I think I would run M1's 0W40 or their 5W40 Delvac1 if you like M1, 10W40 with Redline or Amsoil. 0W30 German if you like Castrol. But hey, I ran 0W30 M1 untill two changes ago {0W40 M1 and now 0W30 Castrol}. If you want to stay with a less expensive oil and chage it more often,,, I think 10W40 Castrol GTX or maybe some of the diesel oils {Mobil 1300 maybe?} would fit the bill well.

I was pleased enough with the cleanliness {very impressed actually}of my engine when I did a cam swap. It also didn't use an abnormal amount of oil either, most of the time it was under around or under 1 qrt. in 7K miles. The only reason I changed was because of the overwhelming good results posted up by folks who had had an oil analysis done. Haven't seen a bad report yet on the German Castrol.

Anywho,,,, just don't have a ****-fit and go out and drain it out right now. With the summer temps, it shouldn't be that terrible to go ahead and use it for 3K miles or so.

crainholio

iTrader: (2)

I just posted my latest Blackstone Labs oil analysis on bobistheoilguy.com running Mobil-1 15W-50. The engine had been road-tripped from NJ to Indy, 2 days of hard road course driving in 20+ minute sessions continuously, then driven home plus some street driving. Wear metals were amazingly low.

http://theoildrop.server101.com/ubb/...c;f=3;t=001630

So...where's the data supporting the conclusion that xW-50 oils are too thick for an LS1??

Patman

Like I mentioned on BITOG though, when you're road racing you're going to be seeing 300 degree oil temps in the LS1, so that 50 weight oil ends up being like a 30 weight oil. If you were to run 15w50 in normal daily driving with 220F oil temps, you would most likely see much higher engine wear than you would running one of the better 5w30s or 0w30s.

crainholio

iTrader: (2)

Unless you have some actual data to support that assertion, it's nothing more than theory.

I wish I could stay off the road courses long enough to run up a good 3K mile OCI of all street useage, but I lack the willpower. July 1st I'll be back at Pocono, this time on the North course.

jaberwaki

ummmmm... you do know the heavier weight (thicker) oil you use , the higher your oil pressure...right?

if you were blowing gaskets b4... how did you think RAISING the pressure would help?

crainholio

iTrader: (2)

The pump bypass spring doesn't know what viscosity oil you're running.

Higher oil pressure at idle, yes. But as soon as you build enough pressure to open the bypass valve, net system pressure levels off at whatever the spring pressure is set for.

Offhand, there are only three gaskets I can think of on an LS1 that are exposed to pressurized oil...the oil filter gasket, the oil pressure sender, and that little plate right above the filter where Vette engines have the oil temp sensor. The rest are just splashed to my knowledge. Valve covers, front and rear main seals, etc. only get gaseous pressure and even then only when the PCV isn't under vacuum (eg. WOT).

Patman

My data comes from speaking with Terry Dyson, who has been interpreting oil analysis reports for about 25 years. He has many customers with LS1s, and based on the many reports he's interpreted for them, he informs me that the 50wts are not the way to go (unless you're doing road racing and have no oil cooler) In my own observations, the LS1 shows it's best engine wear if you run an oil that is between 12 to 14 cst at 100c. So it likes a thick 30 wt to middle 40wt the best for street driving.

But I'd still like to see more reports from people using the thicker oils on the street.

JS

iTrader: (4)

Valvoline 10/30 for me...
Nuff said....

crainholio

iTrader: (2)

I'm definitely not equipped to dispute anything Terry says, referencing him pretty much puts the issue to bed far as I'm concerned.

I'll stick w/ 15W-50 during the season (Jun-Sep) and use Mobil's 5W-40 the rest of the year. Given the car has no A/C or rear seat, it doesn't get much street mileage during the Summer. When track season ends, the rear seat goes back in and I use it for more daily driving, so the thinner 5W-40 is more suitable.

Patman

With all this being said, the difference in wear between a 15w50 and a 10w30 in the very hot summer months would probably not be all that bad (I'm assuming) But in the colder months it would definitely be risky to run 15w50. I don't really recommend using this thick of an oil to begin with for street driving, but if you are going to run it, make sure you take it out once the temps get below 50 or 60 degrees.

I do believe more people on here should try out doing an oil analysis on whatever oil they do run though. That is the best way to determine if you've chosen the correct oil for you because everyone's needs can be slightly different.

JS

iTrader: (4)

Summer time---->Valvoline 10/30
Winter time----->Valvoline 5/30
Nuff said.....