**car is dead**

**Pics Added**

My '01 Z is being fixed right now and the cam has some damage on lobes and needs replaced. The car was drinking oil and i had 3 lifters go out and this led to finding the cam issue. the heads are being inspected for seals. I don't have any info on the cam other than my mechanic pulled the old one and it is hand engraved with the following info:

I2717-06
2128R
2131R
ART16+2

Trying to get a new one but, what do I need?
Engine info that I have:

Shirl Dickey Race Engineering LS2 Short Block 418cid.
LS2 Aluminum Block.
Eagle LS1 Crank.
RPM Forged Rods.
Diamon Forged Pistons, Pins and Rings.
Clevite Rod and Main Bearings.
LS2 Timing Cover, Valley Cover, Timing Assembly & Cam Sensor.
ARP 12-point Head Stud Kit.
Racetronics LS2 Cam Sensor Adapter Harness.
LS2 Fuel Rail.
Racetronic C5 Fuel System running at 63 psi.
SVO 30lb injectors.
Halltech Cold Air Intake.
LS2 90mm Intake Manifold.
LS2 90mm Throttle Body.
ASP Pulley.
Harland Sharp Adjustable Roller Rocker Arms.
Custom Length Hardened Chromoly ball tip pushrods.
CompR Hydraulic Lifters.
Absolute Speed Stage 2.5 LS6 Heads.
LG Motorsport Pro Long Tube Headers.
LG Motorsport X-pipe.
Titanium Cat-Back Exhaust.


with the adjustable rockers could I get away with not an exact match grind cam? The cam is being measured for more info but I don't know how much it would cost to get a new custom cam vs a standard cam.
Thanks in advance.

 

That's a lot of motor you have there. Did you buy the motor, do you still have contact with the motor builder? Your in trouble if a mechanic is inspecting the heads for seals!

 

If you are trying to replicate your cam, it looks like a Com Cam 281/293 with LSK lobes with 643/653 lift. Not sure about LSA / Cam Advance but it looks a 116 ICL with 2* advance.

Duration @ .050 is 231/243!

 

I bought the car pretty much built already. First vete. went all out. checking the seals cause oil is going down fast. lots in the exhaust.


Thanks for the info. I will fwd this to my mechanic and see what he came up with on his end. He is having it measured.

 

ttt

 

High oil consumption, collapsed lifters and a damaged cam, sounds like a not-so-well sorted out build. You cannot make up for differences in cam lobe profiles as a result of uneven wear patterns with adjustable rockers. You will need to replace your cam, probably with something less aggressive, since it's probably the root cause of your valve train problems. If you cam is not too damaged, you can have it re-ground to something that is more suitable and reliable, I used these guys with good results: http://www.oregoncamshaft.com/order.html

 

My mechanic is questioning the original build as well. Said it looked hastily put together. Cam pinned two times and a really worn looking harmonic balancer. I don't know on the scale how aggressive this cam is but the car had a nice lope to it that I rather enjoyed, albeit reliability is preferred.

 

Good luck with your repairs, sounds like you have a real piece of junk on your hands. You can significalty improve your valve train reliability without having to spend too much money to sort it out by keeping the lift at the valve @ .550" or less and selecting lobe profiles that are not aggressive.

 

I wouldn't go so far as to say a piece of junk. The previous two years the car ran amazing. Autocrossing and a few drag passes, then just over a year of to and from work every now and then. I think I was just unfortunate in that I had one thing that went wrong and it compounded quickly before it was diagnosed correctly. It is being gone through very thoroughly now and other than the aforementioned.... It looks to be a very solid build that has kept a smile on my face and my body pinned back to the seat, although it's been a few weeks since I've driven it now and it's very sunny out.

 

I don't think you are looking at a custom cam. Your old cam had ramps readily available from CompCam.

As far as adjustable rockers, the real key will be to determine proper pushrod lengths on assembly and gentler lobes than the LSK lobes. You could go to a milder lobe, keep the same cam specs as far as duration and LSA and have the same lope/cam sound you had before. An added benefit of gentler lobes would be more valvetrain reliablity. LSK lobes are very hard on valvetrain and springs.

 

This looks to be the route to go. As soon as I get the measurements from the cam back, I will be looking for one so I can be up and running. Gentler lobes sounds a better option as I want to up the injector size a bit and tweak the tune. but a more solid platform first...

 

You do not need much more than stock power for autocross, my Z is stock with the exception of a radiator, oil cooler and a CAI and I have to manage the power very carefully around the course.
I let my instructor drive the car at novice driving event sponsored by the local SCCA clubs last year and he came within 1 second of the FTD. The milder the cam the better in my opinion.

 

Until you isolate the cause of the oil consumption, what's the point?

I'd be looking at coil bind on the springs and whether the V/G seals have been damaged by the springs. If there are no problems there, you have much larger issues.

The cam & lifter issues are probably a result of improper setup. The comp R lifters are often installed with the wrong preload. They are suppose to be 2 to 4 thousandths of an inch hot and people repeatedly read it wrong and set lifter preload to 20 to 40 thousandths.

What's the indication that bigger injectors are required?

 

I agree. the car will be 100% before I attempt anything else. I've been trying to do research as to what size injectors for x amt hp. the car was tuned around 485rwhp/484rwtq. from what I have been reading this is capable but at the high end of the 30# injectors, so I am trying to find out if i should go to a slightly larger size to keep the duty cycle within .8... Still learning a lot about this... but the car will be fixed first and foremost.

 

You really Need to stay with in that industry standard/rule of thumb 80 percent IDC on your injectors. Ask mr how I know. . If i were a betting man id say you will be fine with a 42lb injector such as the ford racing "green top" injector. Last time i checked hinson super cars had the best price on then. I think i picked mine up from them for avout 320 bucks shipped about a year and a half ago. As for the cam being wiped out I would have to agree on lifter failure probably related to improper lifter preload or not measuring for the correct push rod length. This is a common mistake that Novice builders make. Unfortunately for the average car enthusiast he or she will pay some guy a lot of money to build an engine and measuring pushrod length. I believe most pro engine builders would consider this part of the blueprinting process. so this time ensure that your mechanic measures twice and installs once.

On that same note (sort of). It could have been an oiling system issue or just a faulty component(s) i.e. Lifter Ect.

A few questions first? Did the car smoke? Is there any piston damage?

Did the supposed engine builder install the piston rings correctly? Were the cylinders honed correctly for the piston rings? (I hate to ask). How was the engine oil pressure?

How many miles were on the engine in total? How many miles before you started seeing oil consumption issues?

Finally who in the world is absolute speed? I know they must be a performance shop of some sort but I've never heard of them. Good luck and keep us posted on your findings.

 

42 lbs was the direction I was looking. I'm hoping to clear 500rwhp. Really, I'd like at least 510-520rwhp so as to clear 600 flywheel. Assuming ~15% drivetrain loss. A numbers game really.... As long as I'm not on the brink of detonation that is.

Answers to your questions...
The car did start to smoke... Initially on cold starts it would let a small plume and then that was it. then after about a two times of this, it stopped and transformed to when it was at normal temp when I came to a stop and the rpm dropped off, i had a small cloud around me so i started limping it home, by the time I made it home it was a steady "train down the tracks, locomotive smoke"

from there, on a trailer to the mechanic.

I bought the car built and the shop, Gen III Motorsports in Portland OR, seems to not exist any more. I can find no website or number, Just the name Robert Judd, not that he had a hand in this build, but his name has been associated to the shop, according to forums on LS1tech. He's had no activity on the forums for quite some time so no dice there.

I was told that all pistons looked perfect, no oil residue, rings looked great. The heads are being inspected now and I should hopefully get a report on that today, Mon, sometime. The oil pressure has been normal, tracking with rpm.

As for miles, I bought the car with 17xxxmiles and around 5k ish on motor. it now has 25xxx miles on car and 13xxx on motor. past few thousand miles the oil consumption was minimal, I can't remember exact amt, but was told it was common of the Vette. after a 3000 mile oil change i was about half a quart low. It's been awhile, don't quote me on that.... even though I'm the one who said it... i digress.

As far as Absolute speed, They apparently went out of business back in '05 sometime. here's a post from '03 about the heads... From absolute speed on LS1tech.... newsflash, this just in- I have decided to step it up and make a change in the production of my heads. Effective immediatly stg2.5 heads with the 2.040 intake valves will now take over the previous 2.02 stg2 designation the new stg2.75's will be called stg 2.5's. the 2.5 heads{previously known as 2.75} feature the same custom intake valves but with more agressive porting and also port reshaping, look for flow numbers and dyno/track results coming to a post near you soon. Ill give you a hint peak flows through a stock ls6 intake will be over 290 cfm with both ls6 and 5.3l heads

And I asked my mechanic about the lifter pre-load issue and he said he was all over that and he would call me with numbers before hand to make sure I was ok with it.

That is the update as I know now. lengthy, but hopefully this will help others be able to help me. Thanks to all so far....

 

that is a bloody big cam for an LS2 block with 243 heads.

 

Agreed. He could probably get away with running less cam and the car would probably be faster then it was previously.

To the opening poster. Are your pistons fly cut (valve reliefs) or dished or something?

 

I agree Smaller cam and the car WILL be faster.

remember 243 heads ported or not, do not flow to well with cam of .600 lift or larger, so why even have a cam with a lift above .600 ?

 

Do not buy aftermarket injectors.

Have your oem injectors cleaned, resized, and flow matched by John @ FIC. When you use the oem injectors that have been resized, the only parameter you need to change in the PCM is injector flow rate. It's simple and less costly. I learned this the hard way.