Redbull87

iTrader: (3)

Gent im looking for advice/recommendations. I have a 03 lq4 that I thought I had fairly stout setup. 2 yrs ago I grenaded my other lq4 with stock pistons/rods on pump 94 with some meth cranking over 20lbs.It scattered ringlands and damaged the block and crank.I took my spare lq4 and decided to put good parts in it to handle the boost im running or more safely. I put in Dssracing forged pistons with -15cc reliefs/4340I beam rods with clevite tm-77 bearings.Crank and the mains looked great and within factory specs. I put in a ljms stg 2 turbo cam,7.4 tsp pushrods,cam bearings were good, original oil pump,317 heads with btr tit 660 springs,stock rockers with staub bushings, new ls7 lifters/trays.All was great,car made 770whp/810tq

Fast forward to last yr spring I had a ls7 lifter fail and got stuck in a bore.I pulled the heads off in the car,cleaned and flushed everything I could,replaced all the lifters with johnson drop-ins and put it back together.car ran great again and was quiet. A few nights ago I had some fun making pulls on the hwy with some cars. Looking back at the footage now i missed the signs of the failing oil pressure.I drive to work with the car daily as its a 15 min drive. On cold start i was seeing 40-50psi yesterday morning. At the end of my shift as i started the car to let it warm up and go home,pressure went 40 to 20 warm.Thought it was a tad low but picked up some with up on a small rev. 10 mins into the drive home..i was seeing 9psi and no increase blipping the throttle to 2000.I knew my window of major damage was within mins.Limped it into the driveway and as I blipped it to just get over the bump..the screeching sounds like dying mice came and I could hear lifter tick inside the car. Plus the way it was idling,sounded like 1 cyl was dead as if a cam lobe is wiped with less choppyness.FML

Checking the oil and its super clean with no glitter/copper i could see. I havent ran the motor since. I will be needing to pull the motor and im sure the oil pump is probably trash,my nice lifters or some new to be replaced,cam,bearings throughout the block period for starters.

My question is what else should i look for as a weak point to prevent this from happening again.the car ran clean,rings were gapped 30 top and 2nd,safe timing and afr on pump/meth and mainly ran 15psi of boost on the street was enough for most. Should i get a ported stock oil pump,have my block completely cleaned.hopefuly reuse my pistons,seems ljms no longer make the stg 2 cam so need something comparable to it. Im at a loss of what else to upgrade for a moderate setup.

KCS

iTrader: (20)

When a lifter fails, the cam will usually take some damage too. Just replacing the lifters without inspecting the cam might have contributed to the situation you're in now.

Without knowing what exactly failed and why, it’s hard to suggest any upgrades to prevent the mystery problem from reoccurring. It could just be clearances were tight, tune was bad, or a problem with the oil supply to the bearings. None of those can be really fixed with stronger or more expensive hard parts.

SoCalDave

Change your oil pump, cam, lifters and check your bearings. If could be that the O ring on the oil pump pickup tube is bad.

Redbull87

iTrader: (3)

When the lifters were replaced last yr the cam had very minor damage and 1 lobe was polished from a small scor. I hope in the next few weeks to maybe have it out and torn down to know exactly what I need. I hope I don't need pistons/rods and crank.Thats my main concern

Redbull87

iTrader: (3)

Loaded question as Ive heard different opinions but what would be recommended for an oil pump on a boosted motor? I run rotella 15w30 here in the summer. Some have told me just do a new oem pump,some have said high pressure or ported/shimmed. others say hp/hv. I have fbody pan and pickup tube. I would think a good stock replacement is all I need..or at best high pressure.

1FastBrick

iTrader: (16)

With the drop in oil pressure and the Squeaking sound I wonder if it spun a cam bearing.

Be interested to see what you find.

SoCalDave

There is a mod you can perform on a stock Melling M295 oil pump. You put 2 or 3 washers in the pressure relief spring to increase pressure. I used 2 washers and it's given me an exta ~5 psi of oil pressure on my '01 LS1 Camaro. I helped swap a cam in an '05 C6 about 2 years ago. The C6 had 1 cam lobe that was wiped due to a bad lifter. We swapped the cam, installed new lifters and it has been fine since. Take the steps you feel will get er done.

Redbull87

iTrader: (3)

Im making a list at TSp right now. Im thinking of going with a hp oil pump, replace my johnson lifters to be safe,and use their stg 2 turbo cam which is almost identical to the stg2 ljms cam i had.Id have the machine shop replace all the bearings with something better than stock that are hardend. I really hope nothing along the pistons/rods are hurt and same with the heads. Luckily it happened when I wasnt on it hard to sling things flying too bad.