Tin Indian

Well, I used Penn 05-30 dyno oil in my 98 TA for it's first 10,000 miles. The rings broke in great. Then switched to Mobil 1. But, now with 40,000 miles on the car, I think I am going back to regular Penn oil and change it evey 3,000 miles.

Although I only use about 1/4 qt in between the 4,000 mile oil change intervals, I am going to now start using regular dyno oil again as recommended by GM for LS1 engines as per there TSB for piston slap (even though I don't have piston slap myself).

I can't see any benifit from the high priced Mobil 1. If this car had a turbocharger on it like my old 89 TTA, I would not hesitate to use synthetic oil. But, in this car .... I don't think so.

I may try 10-40 weight Penn this time. This may even quiet down the "sewing machine" noise made by the fast ramp cam in the car. Maybe, maybe not.

Ron,

Patman

From what I understand it's not GM who said LS1s should be run on dino oil, it's Chevy High Performance magazine.

Considering the Vette's need synthetic in order to satisfy their warranty, I doubt GM would say that LS1's require dino oil.

Tin Indian

Chevy High Perf mag. said it was GM that now recommends dyno oil.

critter

iTrader: (9)

My LS1 slaps the same with dino oil or Mobile 1. I don't hear a difference.

Patman

Well GM needs to get their head out of their *** then, because there is no way that conventional oil is going to lessen the piston slap (or oil burning), unless it's a thicker viscosity.

Perhaps GM needs to stop telling people to use Mobil 1 5w30 and 10w30, and use their 0w40 instead. Mobil 1 5w30 and 10w30 are too thin and can definitely consume more oil than other thicker synthetics.

But if someone switches to a 5w30 dino oil, it will thin out very easily under hard use, and you'll burn more of it and would have louder piston slap. And most common 10w30 dinos are just as thin as Mobil 1.

So instead of telling everyone synthetics are bad, which they are not, they need to rethink what viscosity they are recommending.

Or better yet, GM needs to admit they screwed up! They would simply rather get owners to change oil types than to bring the cars in for new piston rings.

Patman

One more point too, since the LS1 runs such high oil temps when driven hard for long periods of time, running a conventional oil under these conditions could be a big mistake.

EVIL

i just put some 15-50 mobil 1 in my motor and i get great oil pressure now and no valvetrain noise like before.

Hardtop

iTrader: (3)

I run 10/30 Mobil 1. No piston slapping, no excessive valvetrain noise, very little oil consumption, and plenty of oil pressure. I see no reason to run thicker oil. Car is run hard at the track too. When we had the motor out changing the rod bolts everything looked great. Rod bolts were changed for piece of mind not mechanical failure. Considering the above, why should I run thicker oil?

Bruce

Chicago Crew UnderBoss

iTrader: (1)

EVIL:

As my oil pressure is lower than i would like it be on my 427 C5R block Engine, can you kindly let me know how much improvement you got in oil pressure from going to the thicker oil?

If you can give before and after regarding idle, normal cruising and WOT blasts, that would be GREAT!

THANKS

bill99hawk

Patman, do you use 0w40? I was wondering, because I think you have the most knowledge around here and would like to take your advice. Also, I currently have an extra 6 quarts of 5w30 Amsoil sythetic sitting on the shelf, could I mix a thicker oil with the 5w30 to get better and safer results?, If so, what weight and how much would you recommend.

Patman

I'm not using 0w40 right now, but the oil I do use is actually very close to being a 0w40. It's German made Castrol Syntec 0w30, and it's viscosity at 100C is 12.2cst, which puts it at the extreme upper end of the 30wt scale so it's only 0.3cst away from being a 0w40 anyways. I'm going to try out this oil for a while and if I don't see the wear numbers I'm hoping for (through oil analysis) then my next step will be to go with a 0w40 or 5w40 oil.

Amsoil 5w30 is also a very thick 30wt which is at the top end of the scale, so you don't need to mix anything with that either, it should do very well on it's own. Amsoil's viscosity is 11.9 cst at 100C. By comparison, Mobil 1 5w30 and 10w30 are both only 10.0cst at 100C. The very bottom end of the 30wt scale is 9.3. Because the LS1 runs such high oil temps under extreme use, and because it's clearances are looser than a lot of other engine designs, running a thinner 5w30 like Mobil 1 means you don't have as much protection against wear as you do with the slightly thicker oils which are at the top end of the 30wt range or into the lower end of the 40wt range.

JMBLOWNWS6

iTrader: (17)

So with that being said is it better to change your oil from mobil 1 10w30 to royal purple 10w30 in Texas.Also using an k&n oil filter.

EVIL

my motor i guess is built very loose and never got good pressure, but everyone i talked to said that 20 at idle and 40-45 wide open was enough. now that i have the thicker oil, i get 35-40 idle and 55-60 wide open. before cruising down the highway at 65 it would run around 25 and now its at 40. seems more like what the stock oil pressure should be.

Visceral

iTrader: (1)

Patman;

So if those of us who dont run our car at low temperatures want an oil that will best protect our engines, why dont we run say a Syntec 20w-50? The implication on the website is that if your engine runs very high temps, this is the oil for you.

Im just starting this 387 on its new life, and I need to get this engine oil thing *perfect*.

chris

Patman

The problem with a 20w50 is that even if you're only running it in hot climates, that oil is still going to be very thick when you first start it up, and the thickness at operating temperature is too high for optimal flow too, and you're just needlessly robbing yourself of horsepower and gas mileage with these excessively thick oils too.

You'd be much better off with a 10w40 synthetic than 20w50.

Visceral

iTrader: (1)

and you think that the 10w40 from Castrol has the nice numbers? I certainly appreciate start-up protection as well as high temp operability.

This really is just a very very fast "sunday driver" that will see a few track days (road racing or "high speed driving schools").

chris

Visceral

iTrader: (1)

and its very very rare to see below freezing temps here when I would be starting or driving the car (its a temperate rain forest :-/) Nothing like Ontario, the MidWest, or a daily driven car.

chris

Visceral

iTrader: (1)

Im VERY interested in how the oil can reduce valvetrain noise (other than making hte lifters work better). I have the noisiest valvetrain Ive ever heard.

chris

robertbartsch

Patman#1:
I've owned an LT1 and an LS1 engine and I always assumed the LT1 oil temperature ran much higher.

...My assumption is based on the fact that new oil added after an interval turned black in the LT1 much faster than in my LS1. The oils added after each interval were true synthetics...neither engine had a chance to get gummed-up since my intervals never exceed 3K miles....

In addition, have you any experience with engine oil coolers; these are external units that bolt into the filter connection in the block; the cooler is mounted in front of the radiator and the external oil filter is usually mounted on the firewall.... they are connected by high temp hoses...

Patman

I think the LS1 and LT1 run similar oil temps Robert. I don't have any personal experience with oil coolers, but think they are a great idea.

By the way, I got my oil analysis results back on German Castrol 0w30, and the results look great! Here is the link:

http://theoildrop.server101.com/ubb/...c;f=3;t=000907