Quote:
Quote:
Quote:
Quote:
However you make my point very well.
I don't see it, but I'll take your word for it.
Quote:
I took exception to the term "defective" in your previous post. With full knowledge of how an engine is manufactured. One can assume "tolerance" parameters exist. And many a engine meets factory specs and goes out the door "looser" or "tighter" than the next one.
Yes one can assume tolerances exist, but that's not my definition of defective. I define defective as when quality control isn't effectively applied at the factory and parts are definitely "out of tolerance" upon production or become that way through use.
Hey...you guys got a surface profiler to check your aftermarket crank finishes?
I realize we are straying from the post subject. However I feel it is related to the post originators question, our discussion that is. When you mentioned the only LSX engines that took a "thicker" oil were either defective or aftermarket, I took exception to that. You make the point yourself inasmuch as you realize, obviously, the factory "specs" are rather lackadaisical at best and many engines perform well while others do not. Some have slap and some do not. My point is this gentlemen has posted he is not happy with a certain weight of oil. Due noise mainly if I read his post correctly. We see this quite often in the LSX motors and their owners and frankly many LSX motors should be on a XX-40 weight from day one. Not all but many. UOA's seem to be the benchmark for determining these weights of oils here but I submit that performance and engine "noise" do play a role in the owners happiness in his/her oil of choice. Furthermore I will submit a thicker oil does not harm your engine. Results may provide lower MPG or RWHP, but do no harm. Flip side is often time wear metals/noise will be lower with a thicker oil than the manufacturer recommended due CAFE/EPA blah blah blah. So I am recommending this gentlemen try a quality 40 weight and lets both see if he is happy or not versus the weight of oil he is utilizing today. And no we do not have a surface profiler as most of our cranks are custom ground at Hendricks Motorsports and they have one
Some well made points, however, there's a perception by many that somehow a thicker oil will provide more protection in every case, which has been proven not to be the case. Look in the UOA section for tons of evidence. If an engine application does well with 5w20, increasing the viscosity beyond that does not provide any additional protection. And that's where the problem lies.
Someone with a stock in-spec LS-x with a less than in depth knowledge will read that Sarge So-and-So runs 40 weight in his LS-X so he concludes thats what he needs to run in his engine for maximum protection. Problem is, he doesn't realize all the aftermarket work you have done on your engines and they're probably no longer in line with factory clearances and surface profiles, etc.
Further, increasing the viscosity beyond what's optimum does have it's drawbacks. The smarter racer/mechanics will have realized this by observing their oil temp/pressure gauges. Too thick of an oil will just raise the oil temps where it's no longer thicker, and above a certain point, may actually start working against you. Run through the bearing design equations to prove it to yourself. What is needed here is an oil cooler - not thicker oil.
As far as deciding if you need thicker oil from something as subjective as engine noise is just ripe with folly. Look through some of the threads where someone changes to 11.3 cSt M1 from their usual 10.3 cSt stuff and then complains of engine noise. Their first conclusion is M1 is too thin! Wrong!
Now let me correct something I never said:
Quote:
the factory "specs" are rather lackadaisical at best
I didn't say anything like that. I will contend that some LS-x engines did have quality control problems, like excessive piston slap. Early LS-x engines had piston ring flutter issues. And some may have bearing clearance problems from the factory, but I'm willing to bet they are far and few between. Problems that develop after extreme use are a different story.
We're in full agreement on using UOAs to help the original poster decide on what is best for his application. I recommend
Terry Dyson's services if you want to achieve the best results.
Quote:
And no we do not have a surface profiler as most of our cranks are custom ground at Hendricks Motorsports and they have one
Gee...I didn't know that Hendricks Motorsports could take time off from supporting their race teams to custom grind crankshafts for us little guys? I'll have to give them a call and see what their prices are.
