Royal Purple XPR 20W50, 4500 mi, turbo LS6...

[BigRich]

Hi, guys... here's my first UOA on this build; I wish I'd found this site years ago. This is a 1998 Trans Am with a forged/dished piston lower compression LS6 motor from A&A Corvette. This motor has about 10k miles on it now, roughly 8k of that is with a T67 front mount turbo. This turbo setup utilizes the engine oil for lubrication. I run at about 11 psi on the street and use boost-actuated progressive methanol sprayed about 10" in front of the throttle body. There's also a large front-mount intercooler on the car. Tuning is custom 2bar speed-density. Coolant is DI water with water-wetter. Dino oil was used to break-in the setup prior to going with the RP. So here's the Blackstone comments/report:

"Universal averages show typical wear levels from this type of engine (stock) after about 4500 miles on the oil. High metals are coming from a combination of wear-in and the methanol-injected turbo. Copper is very high; it may indicate a problem at the turbo (or another bronze part). Heat damage can be seen in
zinc and phosphorus levels. Silicon is likely from sealers and lubes applied at assembly. 1.0% fuel was found, but this is not a problem level. We aren't sure if this engine is simply going to make a lot of metal due to the methanol, or if there's a problem."

Aluminum 19
Chromium 6
Iron 85
Copper 228
Lead 16
Tin 0
Molybdenum 123
Nickel 3
Manganese 2
Silver 0
Titanium 6
Potassium 3
Boron 5
Silicon 74
Sodium 12
Calcium 3110
Magnesium 109
Phosphorus 1072
Zinc 1976
Barium 2

SUS Viscosity @ 210F 79.5
cST Viscosity @ 100C 15.41
Flashpoint in F 365
Fuel% 1.0
Antifreeze% 0
Water% 0
Insolubles% 0.3

I look forward to your opinions on this UOA. Thanks!

 

[addyguy]

Lots of WOW's in that report....Wow, look at how much Zinc is in that oil....WOW, look at how much it sheared in only 4500 miles...WOW, look at all that copper.....

I'd suspect by the relatively low lead number that this oil did okay, and the rest is damage from the methanol, and copper leaching from the turbo bearings/cooler lines...but i don't know enough to really say....

 

[FZ1]

Dump the oil. Drain and fill the radiator with some "real" coolant. Run the next fill 3k. Check it to see if it improves.

 

[BigRich]

Oil has been swapped to Redline 10W40. Curious to see how it'll look after 3k. As for coolant, DI H20 with water wetter (and just a bit of antifreeze) is a more efficient heat exchanger than standard antifreeze mixes. I'm in CA and this car never sees temps below 50 F; no need for antifreeze (beyond corrosion resistance). The exhaust manis for a 346 ci front mount turbo get REALLY hot, though, and any oil in the motor is going to have to withstand more severe conditions than standard NA applications. Thanks for the input, please keep it coming...

 

[Last_Z]

I say this is a dirt problem. Check your air filtration system. All metals are sky high; a strong indicative of filtration problems.
Was this engine drag raced or otherwise heavily abused? What's your air filtering system comprised of? I would stop driving this car ASAP until I figure out what is wrong.

Rick

 

[Last_Z]

Originally Posted By: FZ1
Dump the oil. Drain and fill the radiator with some "real" coolant. Run the next fill 3k. Check it to see if it improves.


+1

Dump the oil and refill with fresh lube. Dump the water and refill with dex-cool...you are going to do some heavy damage in a years time. If you need increased cooling, then update your radiator and fan settings.

 

[steve20]

I've got a NA LS6 in the 02Z, and boy, does that thing kick. Can't imagine driving the set up you have-must be like a roller coaster ride!
Anyway, no one seems to realize the engine only has 10K on it since the build. That's = 10 thousand miles, and any GM V8 will spit metals at that young age. This one is spitting more than usual. I'd doublecheck the air filter and then run another UOA in 4K miles. I do not see this UOA as a huge problem-yet
Steve

 

[BuickGN]

Check the other UOA on a built GTO with RP and you will see how well it doesn't hold up in a performance application.

I'm not sure what they mean about methanol injection causing more wear. This is a gas motor with meth injection post turbo, right? I've always run cheap Superflo dino 20-50 in my boosted 6 cylinder with a T-66 and methanol injection for the past 5 years sometimes running 29psi and never a problem. I bet it looks much better with the Redline oil this time around.

 

[Last_Z]

Well, he has 10k miles on it with the last 4500 miles on this run of RP. That means he already had 5500 miles prior to ever using RP after the rebuild. He said he used dino to break in the engine. I doubt he ran the dino oil for all those 5500 miles. This run with RP is likely his 3rd OCI on the new engine.

My point is that, yes metals should be high for a new engine, but not this high. He's likely done 2 previous oil changes which likely flushed out the most of the initial concentration of metals. The metal count should be about half what it is in this OCI.

I have to once again, refer to the silicon number as the culprit. Aluminum is sky high indicating dirt is being ground up between the cylinder walls and the piston skirts.
Either that or this engine was badly put together. One other possibility is that this is one stressed out engine.

Rick

 

[Drew99GT]

I agree Z - Aluminum and chromium are through the roof. I know a lot of guys with aftermarket turbo systems simply put a screen over the turbo inlet - to keep the boulders and squirrels out, but it does nothing for filtration.

Get a big cone filter on there if you don't already have one.

 

[BigRich]

Hey, guys... 1000 miles of dino oil for engine break-in prior to fitting the turbo. 3500 miles of dino prior to the RP synthetic.

As for the airflow, there's a big cone MACK filter on it, plumbed about 3 ft from the turbo inlet. It looks OK to me. Output from the turbo goes through a large Griffin intercooler and up to the throttle body.

Methanol is injected about 10" in front of the throttle body. I don't quite see where methanol (injected progressively from 4-11 psi boost) would be the culprit for the metals. It's straight into the combustion chamber, vaporized and burned as fuel. Now there is a possibility that the reservoir for the methanol may be contributing metals... I'll see if I can get a mass spec analysis of the methanol that's in there right now.

As for hard use, sure, the throttle sees the floormat. But honestly, it's a punch here and there, no extended racing or similar long-term hard use. I trust A&A for their build on the motor, I doubt there's a problem there.

 

[BuickGN]

I especially doubt that a progressive methanol system is contributing to wear. I remember in the old days of the on-off systems if you got into the boost too slowly it would choke for a second but that's not the case now.

 

[BigRich]

A GN guy, EXACTLY the people I need to talk to :!. The kit is an AlkyControl unit, I think quite a few turbo Buick guys use them.

 

[BuickGN]

Originally Posted By: BigRich
A GN guy, EXACTLY the people I need to talk to :!. The kit is an AlkyControl unit, I think quite a few turbo Buick guys use them.


LOL. Me, my dad's two GNs, and a friend all use the same kit. I've used others but always had reliability problems which usually meant blown headgaskets. So far, all 4 of our cars have been 100% trouble free over the past two years with Julio's kit.

And an LS6 under boost must be amazing. It's a single turbo T-67, right? Sounds like a very street friendly turbo for that displacement.

 

[BigRich]

Exactly. I chose the AlkyControl kit in part because of Julio's reputation... and it's been flawless.

The car is great on the street; I stayed small with the single T67 to ensure quicker spool-up. It's over 500 rwtq from 3000 to 6500 rpm; max 627 rwhp and 648 rwtq by Dynojet. The main problem is traction.

I'd love to see more higher-power turbo UOAs just to see what's "normal". Also hoping that swapping to Redline will help.

 

[BuickGN]

Well I hope the Redline works. I have a feeling it will and it's exactly what I'm going to try when my car is out of the bodyshop.

Not to jack your thread but I like your logic with turbo size. So many people get caught up in dyno numbers that the car is no longer fun to drive due to turbo lag and they can't put the power down anyway. I've worked very hard on my combo and finally have something that makes full boost at 3,000rpm. But I would give anything to make it at the low boost levels that you do. That's what's so nice about a little displacement and some killer factory heads.

 

[Drew99GT]

Originally Posted By: BigRich
Hey, guys... 1000 miles of dino oil for engine break-in prior to fitting the turbo. 3500 miles of dino prior to the RP synthetic.

As for the airflow, there's a big cone MACK filter on it, plumbed about 3 ft from the turbo inlet. It looks OK to me. Output from the turbo goes through a large Griffin intercooler and up to the throttle body.

Methanol is injected about 10" in front of the throttle body. I don't quite see where methanol (injected progressively from 4-11 psi boost) would be the culprit for the metals. It's straight into the combustion chamber, vaporized and burned as fuel. Now there is a possibility that the reservoir for the methanol may be contributing metals... I'll see if I can get a mass spec analysis of the methanol that's in there right now.

As for hard use, sure, the throttle sees the floormat. But honestly, it's a punch here and there, no extended racing or similar long-term hard use. I trust A&A for their build on the motor, I doubt there's a problem there.


What is your PCV/crankcase ventilation setup? That could be another source of the silicon. Or, it could just be silicon gasket material I guess.

 

[BigRich]

Yah, I hadn't thought of the recirc. setup. This car has a simple breather on the passenger valvecover and a catchcan for oil that has made its way to the top.

BuickGN, the factory heads certainly can work with the LS motors, but many guys go with aftermarket for FI... I use AFR 225 72cc and have been very happy with them.

 

[hustler]

big rich, lets see that Redline UOA. I run a turbo roadtrack car and I'm on the fence about using Redline with reasonable OCIs.

 

[Adam86]

Hopefully you put up another UOA soon. I'm very curious to see what the next one reads.