SHINER

iTrader: (18)

I understand there are threads about this coming outta the Wahzoooo, but Im not grasping the concept very well. Picking out oil is sometimes a hard descion for me (like going shopping, i dont just pick out ANY shirt, etc.)

I got a cammed LS1 with 136K on it and I change the oil very frequently(Doesnt even have time to turn dark brown).

Im wanting to run a lil thicker oil to make just a tad more pressure.

Would run 20w-50 FULL SYNTHETIC be the same as running 10W-40 Dino oil??

The oil i have been running is castrol syntec either 10W-30 or recently 10W-40.


Any input is apprecited!

Thanks

greysteel_M6

iTrader: (5)

I would stick to the tried and true. No a synthetic merely resists thermal breakdown and adheres better to parts than dino oil, it has nothing to do with it's actual viscosity which the "x"w-"x" rating refers to.

greysteel_M6

iTrader: (5)

I think sythetics also resists change in viscosity when heated. Someone correct me if I'm wrong.

SHINER

iTrader: (18)

viscosity also contributes to parasitic lost, and the more viscosity the more pressure being built

spy2520

iTrader: (3)

they dont break down as much when heated, but changing viscosity with heat is part of the idea with a multi-viscosity oil, i think the first number is at 40*C and the second number is at 100*C.

SHINER

iTrader: (18)

so the ls1s dont like thick oil though, correct?

SHINER

iTrader: (18)

ttttt

dailydriver

It depends on where you are, and how you're using the car. What you want/need for an Austin based race car LSx in the summer, is very different from what you would want/need for a northern Minnesota or Maine based daily driver in the winter!

But generally, LSx's do "like" slightly thicker (higher Csts @ 100*) when fully warmed up. This means the slightly thicker synthetic oils within the given viscosity ranges (5W-30, 10W-30, 5W-40, maybe 10W-40) our cars/engines require. You have to get the spec sheets on what you want to use and LOOK at them! (For where you live, the Cst @ 100* is the most important; over 15.0 is TOO THICK, under 11.5 is probably too thin.) The ONLY time I would use something as viscous as a 15W-40/50 or 20W-50, would be if I were road racing/open tracking/endurance racing for an extended period of time, in the heat, OR if my engine builder told me to use something that thick because of the way he set up the clearances in the bearings, etc. Either way, you will lose some power as you go up in actual viscosity. The trick is to balance that loss with engine protection for it's given use.

SHINER

iTrader: (18)

where do i get syntheic 10W-50?

dailydriver

I would stay away from oils with a W-I-D-E viscosity spread like this, as it means they had to use much more viscosity index improvers than an oil with a narrower spread (even when they use the best ester base stocks!). Usually, the more V.I. improvers added to the oil, the less shear stable (lower HTHS) it is, and the quicker it will "break down" (and possibly thicken up till it's way out of spec).
Generally, the closer (5W-30, 10W-30) the spread, the better (with a few exceptions).

SHINER

iTrader: (18)

well what oil would you suggest I use?

getting ready to break 137K it has a cam(232/234) with 243 heads, and does not burn any oil

my oil pressure sits around 35-40psi. and fluctuates(maybe lope of the cam)

If I go WOT a couple of times in one day my oil pressure will be a lil lower than usual.

When I open the hood and manual open the TB to 50%-80% throttle white smoke comes out (Blow by).

what do you suggest? IM running currently a 10W-40 CAstrol Syntec(hard to find)

TransAminal

This is true...but with synthetics, it is possible to achieve a much greater viscosity range without sacrificing the performance of the oil. With conventional oil, achieving a range of something like 5W-40 would be near impossible.

SHINER

iTrader: (18)

thats why i said 20W 50 Synthetic.

Ive been using 10W-30 and recently 10W-40.


I cant make up my mind. Something tells me i want to run 20 W 50 syntec for my older motor for extra protection, but i thought id ask here first!

dailydriver

Now I see why you are asking about such thick oils. Without knowing more, I would probably try the Redline 10W-40 (yes, I know it's $$$$$!). If you still have those symptoms, maybe their 15W-40 or even 15W-50. Are you sure you don't need new rings/valve seals?? (I know that's what you are maybe trying to avoid, but thicker oil is only going to help so much.)

SHINER

iTrader: (18)

the heads are practically new I got them off an 06 GTO that went ported.(I know 06 goats are 6.0L w/ 4.000 bores but you are still able to use these heads without probs)

So valves seals going bad are outta the question. Rings...well I dont really consume oil...ever. Its always at the same mark as a filled it at .

I think I get blowby (white smoke outta the breather oil cap) becuase of my motor being more "radical" and having the 65cc chambers my 243 heads have is giving more compression. more compression=more pressure inside

dailydriver

Yes, of course this is true. But what I'm saying is that despite using the BEST synthetic base stocks, some V.I. improvers are needed to get the big spreads of some wide viscosity range synthetics. Case in point; Redline 5W-40 is the ONLY oil in their full range that has ANY added V.I. improvers (this is from their tech).

Jefro6996

iTrader: (21)

Why dont you just buy an ls6 poted oil pump. I got mine from TSP and the oil pressure stays between 65-70 psi.

SHINER

iTrader: (18)

oil pump is fine, i bought one an sold it(didnt have the time or resources to install it)

sounds stupid i know, im just lookin for the best oil for me right now

dailydriver

Man, I don't know. What do you figure your S.C.R. is? Maybe go right to the 15W-50 RL? The only straight weight racing oil that is somewhat streetable (that I know of, at least) is the Royal Purple racing 41, but this stuff makes the Redline seem like a bargain (price wise). In any case, if your CR is that high, thick oil is only going to slow the blowby so much, until you get into the 60 weight + straight weight racing oils. NOT a good idea on a street driven engine.

SHINER

iTrader: (18)

guess ill just stick with Syntec 10W-40

Anyone heard of "Supertech" is that oil any good? I think its Walmarts brand.

They sell a full synthetic for 3/qt.