Can we get an autopsy report from the AI LS1 guys. We've all heard differing stories on the LS1...either it's rock solid, mega-motor...or finicky grenade motors.
Since both RayBob and Patterson both had issues with their AI motors at the last event, can we get the straight scoop on what happened and how to prevent it in the future?
Oiling issue or Operator issue? :lol:
Patterson's motor was the end result of running 5+ years on OEM pistons w/ a questionable tune.
2 pistons w/ broken ring lands.
I ran a 450 hp LS1 in my 98 for many years w/ no issues. Stock rods and crank. 7K limiter.
I really want to put an LS1 in my current CMC car.
Must do's:
You must upgrade the oil pump.
You must overfill the oil by 1 qrt.
After running one that was balanced, I would never run one that wasnt.
Run very good double valve springs.
I ran 15/50 M1.
My motor was a bone stock pullout from a Z28 with 10,000 street miles on it. Better oil pump, rod bolts, timing chain and valve springs were added before I dropped it in the car. The motor had about 2,000 race miles on it since 2005. The only "tune" that my T2 computer has is to remove codes such as rear O2 sensors.
It's currently strewn across a table here in the shop.
Background which may have started this motor on the down slide: Motor dyno'd normal as always in January. At Houston I broke a fitting on the header in R2 that may have freaked out/killed the knock sensors. During testing at TMS, I noticed an abnormal amount of oil consumption and oil blowing out my throttle body from the high banks of the oval. Same bad oil consumption at TWS and then Hallett.
After a bunch of research, I've learned that the LS1 PCV system has this issue, and the correction is to replace my LS1 valley cover with an LS6 valley cover - which has a crank case ventalation port. So, based on the quantity of oil that #5 and #7 were burning, it likely killed the octane and caused detonation which the blown knock sensors didn't tell the computer to pull timing.
The end result was a loss of hp from two broken ring lands.
So, I grabbed two pistons/rods out of my storage unit and am stuffing them into the motor with the same rings/bearings - which all look fine. Cylinder walls look fine. I don't have cash for anything "nice" to go back in this motor or the cash to have it balanced. It's bad enough buying gaskets, knock sensors, and a valley cover; and having a sour tranny rebuilt at the same time.
No complaints on the tranny - bone stock for 11 years with 11,700 road race miles.
This will be motor #8.
My LS1 has 125k miles on it.
I have upgraded the oil pump, run 15/50 M1, and run 1 qt over. The motor dyno'd 305 hp stock, unrestricted in Jan, and 260 hp with 46mm plate.
the motor seems responsive enough, but in th last race at Hallet, burned about 1/2 qt of oil. Sometimes I get a puff of smok on initial start up after it has been sitting.
Any reason for concern??
Antthing else I should be aware of with the LS1 or just run her until she breaks, then fix and balance her.
Its cheaper to fix it before it fails. Pick an off season and take it in for a re-fresh.
ARP rod bolts, balance, and a good dampner. Should be good to go.
thanks for the feedback. Let's talk at TWS.
VERY good advice..Originally Posted by GlennCMC70
Over filling an LS1 is a must. High rpm, long left-hand sweepers will cause the oil in the pan to move up the side of the motor, uncovering the oil pickup.
Saves the motor.
The down side ... it will burn off that extra oil. So "using" it is normal when over filling it.
The puff on initial start up is most likley valve guides.
Is there a good, baffled road race pan in the market?
#39 CMC Camaro
Orange is Fast!
CMC-NT01 FTW!
I got a GREAT one... 8 quart, baffles and windage tray...Is there a good, baffled road race pan in the market?
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