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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..Quote:
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.Quote:
Originally Posted by rleng1
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?Quote:
Originally Posted by mitchntx
I got a GREAT one... 8 quart, baffles and windage tray...Quote:
Originally Posted by Fbody383
There are a couple windage trays out there, but I haven't been convinced they are significantly better than the factory unit. At least I wouldn't wager my motor on it. Will still have to overfill.Quote:
Originally Posted by Fbody383
Remember, and LS1 oil pan is only a couple inches deep.
An LS6 replaced the LS1. It has a windowed web main boss design and the LS1 is non-windowed. So the oil compartmentalizes.
Towards the end of production in 02, some F-cars were fitted with LS6 blocks and intakes. So an LS6 should be CMC legal.
The '02's and some '01' F-body's came w/ an LS6 block. Not sure about the heads. LS6 intake as well. Better off using the non-LS6 intake, since the more power you make, the more you will have to restrict for CMC2.Quote:
Originally Posted by mitchntx
The LS1/LS6 have webs between the cylinders but the LS6 has windows cut into them to help air move around when the downward movement of the pistons move air back and forth.
I think the Improved Touring LS1 F-body oil pan baffle is worth the money and time to install it.
Overfilling w/ oil doesnt really cause the increased oil burn Mitch mentioned. It will do this w/ an OEM oil level. The oil is being burned due to a piss poor PCV system. This should be addessed not matter what you do, and once done properly, should stop the oil burn issue - as long as the motor is healthy. Oil in the intake (where the PCV puts it) mixes w/ the air/fuel and lowers the "octain" of the a/f charge. This will induce knock/detonation and fracture pistons and scuff bearings.
I think they are great motors but have a few things to check so they don't starve for oil. First is overfilling by a quart and checking it regulary as it will burn some oil on the track. Next is an accusump which some say is a bandaid. The previous owner of my car popped 4 motors in 6 races of T2 until the accusump.
There is also a new windage tray made by Improved Racing that could help. I'll put one in if I ever have to pull my motor.
Didn't know about Mike's issues. My motor had broken ringlands too. I think caused by detonation from the aggressive T2 tune. I even have one cylinder that has been resleeved and haven't had a problem out of it after probably 12 events.
Mike-do you think your issue caused your knock sensors not to work? One time I ran without my knock sensors plugged in and the car had no timing so I think you would have noticed a drop in power.
On the PCV issue I also run a vent that I got from SLP that catches oil instead of it all going back in the intake.
Randy-1/2 quart over a weekend I don't think is anything to worry about. I would suggest switching to 15/50 Motul and just change the oil in the offseason. I would guess the puff of smoke is from the oil that comes into the intake via the PVC system.
Here is a nice race LS1 with 9,000 miles of racing and 4,000 since the last rebuild. Put it in unrestriced and run AIX.
http://cgi.ebay.com/ebaymotors/ws/eB...EL%3AUS%3A1123
Why do the ASA and GTA cars apparently not have these issues?
thx,
jb
I thought ASA ran the "fast burn" ZZ4 motor as the spec motor, carbed...Quote:
Originally Posted by jeffburch
That and the LS1. Both are limited to about 550 hp.Quote:
Originally Posted by David Love AI27
Naa. The zz4 is the spec motor for ASC.
Jb
I'm not an expert on the ASA series. But from what I have seen they were spec motors built by Lingenfelter and maybe others. They had spec cams, injectors, etc.
The biggest factor I think would be they are a dry sump setup which takes care of the oiling issue. Those motors run 6500 rpm all day long in a circle and I think went a full season before freshening. I wanted to buy one off Ebay awhile back.
I still think the #1 issue is oiling and oil starvation, then aggressive tuning, bad engine building. Saw a high horsepower LS motor on Ebay recently from Katech. Can't remember what series the corvette it was in but it had to run a restrictor and still made 550+ and think they said around 700 unrestricted. It had 9,000 race miles on it with a refresh at 5,000.
Brady Morehead blew up a brand new crate LSX motor at TWS. Went from crate to Corvette....lasted less than a session.
Only smoking gun they have is that the negative terminal fell off the battery during the session.
-=- Todd
If he can't put the battery in right, are you sure you are safe in applying fault to the LS1 motor?
If I shoot myself w/ a Barret 50 cal sniper rifle while looking down the barrel, do I also get a confirmed kill?
Give it a try and we'll let you know...Quote:
Originally Posted by GlennCMC70
Only making it one session definitely points to an assembly or install error regardless of what kind of motor was installed. I'm sure removal and inspection would point to a direction.Quote:
Originally Posted by Todd Covini
Are those LSX crates dyno tested?
Doesn't sound very Christian like David. :(Quote:
Originally Posted by David Love AI27
sorry... forgot the :wink:Quote:
Originally Posted by GlennCMC70