Cammed LS4 GXP OIL?

**molecularmann** · 09-19-2010, 07:32 PM

We are changing my buddy's oil but we cannot find full synthetic oil that is 15W-40 or 20W-50 that isn't Royal Purple. Can anybody suggest an oil that will be good for 3000miles? As well as a quality oil filter to go along with it.

Thanks,
molecularmann

**molecularmann** · 09-19-2010, 07:36 PM

I did a bit more searching and found Red Line 20W-50 synthetic motor oil. Anybody use this stuff before?

**98TransAmWs-6** · 09-19-2010, 07:41 PM

Advance Auto Parts sells Pennzoil 20w-50 synthetic as far as RedLine I have heard of them but don't have any information as to the quality of the oil. I would go with the Pennzoil I suggested. I use K&N oil filter but there are others too.

**Wesman** · 09-19-2010, 07:59 PM

Why the hell are you putting 15 or 20 viscocity oil in an LS4?? The engine is not set up to run such a heavy oil, and there is no advantage to using it. If anything, its worse.

5W-30 synthetic is more than sufficient, if you want a higher operating viscocity, go with 5W-40 synthetic. Either would be good for 5000+ miles between changes. Also make sure to use a high quality filter, such as Mobil 1, K&N, or Bosch Distance Plus. AC Delco at a minimum. Thats just as important as the oil.

**molecularmann** · 09-19-2010, 08:02 PM

Originally Posted by Wesman

Why the hell are you putting 15 or 20 viscocity oil in an LS4?? The engine is not set up to run such a heavy oil, and there is no advantage to using it. If anything, its worse.

5W-30 synthetic is more than sufficient, if you want a higher operating viscocity, go with 5W-40 synthetic.

It's a 224/228 lsa 144 Cam and forged pistons/rods and moly oil pump. The shop that installed his cam told him to use 15W-40 or 20W-50 oil. the higher the W number the thicker it is at a lower temps right? Doesn't that mean if he starts the car is would be starving for oil for a lil if there is non left sticking on the moving parts?

**98TransAmWs-6** · 09-19-2010, 08:06 PM

Originally Posted by molecularmann

It's a 224/228 lsa 144 Cam and forged pistons/rods and moly oil pump. The shop that installed his cam told him to use 15W-40 or 20W-50 oil. the higher the W number the thicker it is at a lower temps right? Doesn't that mean if he starts the car is would be starving for oil for a lil if there is non left sticking on the moving parts?

All oil is too thick at a cold start up .

**molecularmann** · 09-19-2010, 08:07 PM

I understand that, just stating if my understanding was correct.

**Wesman** · 09-19-2010, 08:09 PM

Originally Posted by molecularmann

It's a 224/228 lsa 144 Cam and forged pistons/rods and moly oil pump. The shop that installed his cam told him to use 15W-40 or 20W-50 oil. the higher the W number the thicker it is at a lower temps right? Doesn't that mean if he starts the car is would be starving for oil for a lil if there is non left sticking on the moving parts?

Well if the shop built the engine and set the bearing clearances, then thats a different story. Still seems on the high side though.

Correct, the first number on the oil viscocity is its "thickness" at startup in lower temps.

The car probably wouldn't starve any parts for oil (its not like molasses, just more "viscous") but it would have higher oil pressure and possibly take longer to build pressure on startup. This can result in increased wear on startup, which isn't good.

The original idea behind 15W-40 and 20W-50 was to provide a higher viscocity at operating temps, and to do that, the cold viscocity had to rise as well.

With todays modern synthetic oil, you can have a much wider viscocity range. For instance, Castrol Syntec comes in 5W-40, as well as 5W-50. That gives you nice flow on a cold start, and the higher viscocity required at operating temperature.

**molecularmann** · 09-19-2010, 08:09 PM

Originally Posted by 98TransAmWs-6

Then yes it is

ok. BTW is that your car in your profile pic? If so, it looks awesome!

**98TransAmWs-6** · 09-19-2010, 08:24 PM

Originally Posted by molecularmann

ok. BTW is that your car in your profile pic? If so, it looks awesome!

Yes it is, Thanks!

**rkvette** · 09-20-2010, 11:32 AM

i agree with wesmans post.. 5w-30 is more than suffcient, most ford oils now5w-20.. heavy oils are out.!! even nascar stock cars running 950 horsepower at 9,000 plus rpm/all day,are using light oils ! lighter oils / more power/ easy to push threw oil pump ,thats why they do it..