JL ws-6

iTrader: (50)

I wouldn't go too thin. That's really cutting down on the safety you'd be better off with a good race oil with a decent thickness, then trying to go really thin, too much risk IMO

JBM

iTrader: (15)

Its all relative to temp. Towing to the lane the oil prob wont ever reach 180 degrees. Most of the class guys I'll be racing with set the motors up to run 5wt to 20wt oils.

racer7088

Right but be careful like was said. The lighter oils are usually for running colder engine temps and smaller clearances or lower power. I'd have no problem running the lighter oil as long as engine was colder and pressure looks normal. An all out engine will run very cold and run very thin oil but if they are hot lapped you need a thicker oil.

OneQuickCoupe

iTrader: (1)

Erik,

My application is to drive down the road and a blast at the track once or twice a year. I have been know a time or two to run someone on the street with the Z06 but I'm not sure about this old car. Everything on the under side will be state of the art for road course or drag race with adjustability for both. It should do both to my liking but neither to it's limit, just mine.

So it looks like the correct bearing clearance should be .0025" to .003", (mains) if I'm reading everything correctly.

LSX Nova

racer7088

Too many posters! Yes you should be fine with that overall but if you're close err to the looser side.

JL ws-6

iTrader: (50)

I always warm my junk up pretty good in the pits, then change all the plugs to teh cold nitrous plugs, I do this to help them from fouling out on the starting line/in the lanes when pulling the car up, once it's warm they don't foul as easy.

I run a 20-50 oil, have from day one, and have 60 psi of oil pressure at idle, about 90 going down the track or so.

Been that way for 3 years, I change it every trip, wether I make 1 run or 10, and the clearnaces for my alum ls2 based 402 were on the loose side of all listed clearances.

It's never been apart other then a valve spring change every year, it's coming apart before the car goes back out, I'll take pic's of the bearings and we'll see what 200_ passes says.

Castrol 20-50 too, regular old castrol. No synthetic, nothing else has ever been in the motor.

When it goes back together, I'm going to run rotella 15w40, just because my diesel runs the same oil and I can get it in a 20 or 50 gallon drum.

I have been known to hot lap it here and there, stuff like pinks allout and whatnot.

Newbie racer

OLD thread but very relevant to what I am going to ask. Below is my motor set up. You can see my clearances at .0025 for the mains and .00175 for the rods, what do you guys think about that??... running a 0-50 weight for oil?? This is a road race only application running with an accusump

•LS6 383 CID stroker
•LS6 243 heads with port work
•Eagle 4” stroker crank
•Eagle 6.125 H Beam Connecting Rods w/ARP 2000 Rod Bolts, 2.100 Crank Journal
•Texas Speed Custom ported high volume LS6 oil pump

Louis

iTrader: (7)

Road race bearing setup vs big power clearance vs OEM vs NA are not all the same!

On a road race engine that makes 550-600 fwhp, you need them tight, because the block grows a LOT, thus lowering pressure via increased clearances.

I have no experience with super high HP stuff ( 1500+) but I can tell you that road racing clearances change big time.

Measure your block at ambient. Then put it in the oven, and measure it again.

A drag car never sees the temps that a road race car does, so its not an apples to apples comparison.

This thread started out about road racing clearances, and drag and street got in the mix as well. No one bearing clearance fits all, its up to you, the end user, to make sure you spec/build the setup for what you intend to do with it.

Newbie racer

Louis, so what do you think about my clearances based on my estimated 500hp road race motor that really only sees 25 min HPDE sessions at a time. With my oil weight and accusump, do you think my mains are too loose?

racer7088

Rods are too tight. They don't open up at all from heat only the mains do on an aluminum block. Your mains are fine too although you could tighten them up a lil if you always have a warmer engine before you start beating on it.

The oil in a road race car is thinner at temp often from much higher oil temps so you might start with a higher oil viscosity as well if it's a dedicated road race car.

Joe gibbs has some good references in their literature or listen to someone like Louis thats been there and done that with a setup like yours that has a bunch of LSx road racing experience.

ChucksZ06

iTrader: (9)

Listen to Erik and Louis...they are both experienced smart guys. Your rods need to be .0025 I would never go much over .002 with alum block on the mains. I do hpde with my z06 and the oil pressure can change a lot with engine getting hot continuously. I have built my last 2 engines with a little higher oil pressure from the pump because of this.

Newbie racer

Well, Motor is built and going in the car. Again, this is a ROAD RACE application. We finished at .0014 for the mains and .002 for the rods, using Clevite coated bearings. I got some very solid advice from some KEY LSX race motor builders and thats what we decided on. Thanks for your help guys.

Speed Demon

iTrader: (14)

Bringing this one back up.

Was the low oil pressure resolved?
What was root cause?

I'm having a similar issue but it's on a Stage 1 LS system which uses the factory internal pump for pressure. I need to review my bearing clearance specs. The cam is Comp 242/248 .625 lift, which I understand from reading this post could cause the lifters to uncover lift oil galleys?

Louis

iTrader: (7)

Hyd roller? Typically lift that low doesn't uncover the lifter galley.

Louis

iTrader: (7)

Is your pressure low? Or start out high and fall to a low pressure?

tazmo65

iTrader: (3)

Bringing this one back. My oil pressure starts high 70+ cold then drops down to about 30 at idle at temp. At about 40 or so I start to get valvetrain noise on passenger side Only. Any ideas?

GrannySShifting

iTrader: (10)

I love dragging stuff like this back up. Guy asked about bearing clearances and was told by guys that build stuff for that exact application that rod bearings were too tight. But after speaking to "KEY" engine builders he decided it was already built jam it in...

Then every one asks what happened and ...crickets... lemme tell you WHY you never heard back LOL. If you didn't ask Erik Koenig (or asked but didn't listen) you asked the wrong person.

Che70velle

iTrader: (6)

Lollzzzz