LS1x2

iTrader: (11)

Why? I dunno. A alittle extra cylinder pressure maybe? Mine did the same thing after a H/C install. I've been through it all and narrowed it down to the rings. It sucks.

ABNRNGR (Aka Dean)

iTrader: (1)

rings being 1.5 mm with the LS1 with added cylinder pressure = blowby. that's my belief

wizkid

iTrader: (3)

Well, I guess that makes sense. I wonder if that HotCam makes more cylinder pressure than a Hammer/Thunder/T1 etc. cam?

The car does have some miles on it so I am guessing that is the problem.

Do you think all that blowby could cause a lot of knock retard? Probably if oil is getting in the combustion chamber wouldn't you think?

How dangerous would it be to bypass the Knock Sensor (knock out box etc) with blow by?

ERic

SlowLS1

I am the person that Eric is referring to.

I can honestly say that the car had no oil consupmtion issues prior to the cam swap. It never even smoked abit... i was proud of that <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Put in the hot cam..... run the car alittle bit....first WOT run....look in rear view mirror....can't see the car behind me!

Pull the plugs at about 500 miles after cam swap, all the plugs look the same....looks like i have been running weed wacker gas thru the engine, the plugs are greenish,brown! Not what i was used to seeing!

Did a compression check, all cylinders within five psi ranging 170-175psi....

i have completely eliminated the PCV system as a possibility. I feel as tho i have ran out of options...except for a vacuum pump...but even then, i don't have a good feeling that it would help! i don't want to re-ring it, just for it to happen again.

what are the chances of this problem going away if i pull the cam back out? Don't want too, but would be better than a rebuild.....

the car burns over a quart of oil in one week of normal driving and a weekend of spirited driving. all together around 300 miles.

All ideas are welcomed....i'm open to anythign at this point.

wizkid

iTrader: (3)

What are the chances that the oil rings collapsed or are not sealing immediately after a cam install?

A friend has a 98 TA that he installed a cam on and it smokes oil like crazy. It is SUPER Cloudy and the worse smoking LS1 I have ever seen. That is saying a lot too since I have a mini smoker myself. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Anyway, it happened immediately after the cam was installed. New valve stem seals have been installed since the install too to eliminate that as the reson for the oil getting into the intake.

Also, the PCV is working properly and not pulling oil through it either.

So this leaves the oil rings (blowby) and I just don't buy that the oil rings went bad immediately after a cam install.

BTW, it is a GM LS1 Hotcam.

Eric <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
www.InstallUniversity.com

SJH

VERY ODD. But it won't be the oil rings that is causing this. Oil rings don't suddenly all go bad.
You would need to outline exactly what you guys did when installing the cam for more help.

Have the heads been ported with the rocker arm boss's removed? If so, forget to seal the threads?
Steve

SlowLS1

The heads are stock with the exception of new valve seals and ls6 springs...the only reason the valve seals were replaced was to make SURE that wasn't the problem. the heads were never removed from the car...and never have been to the best of my knowledge.

the car does not smoke at idle,start-up or under steady part throttle. The PCV system is not the problem...i am certain. the interesting part is that all 8 plugs look the same....so all the cylinders are getting oil from somewhere.

the car smokes heavily at WOT above 3500 rpms. and it tends to "puff" a smoke cloud between high rpm shifts.

anyone have any other ideas..... i don't care how far fecthed they are.... all the normal stuff isn't helping <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

what could cause all the cylinders to burn massive amounts of oil, yet at the same time not be going thru the intake.... and it all happened at once when the cam was installed.

Mike at Boost Performance.co.uk

I have seen turbo engines show these symptons, puffing from the breathers when the revs are rising but on fairly light loads and then smoking under full load/boost. Sometimes there is a slight variation in idle rpm. The owner of the car I have in mind can hear the difference but somebody else may not. The plugs always look clean and are all the same colour. A strip down would reveal the problem to be a cracked piston. The rings would be fine and even with the cracked piston the car would pull like crazy and clock up loads of miles. You could check with a cylinder pressure guage or pull the pan and do a visual inspection. If you pull the pan use a directional pencil beam torch and look for a fine crack visible in the burnt oil stuck to the underside of the piston. If there is a crack you may not see it first time round. Check and check again. Be really thorough. I have seen this on a V6 Cosworth turbo several times owned by a friend who is a bit shakey when it comes to mapping his management system. The amazing thing is that even with the cracked piston this car is blisteringly fast to the point where you aren't sure that a fault exists. Maybe you damaged something soon after the cam change? Did you nail it? Mike.

LS1derfull

I think Mike has a point, tune requirements after cam change could have caused damage to pistons by detonating, its possible at WOT. What makes you so sure PCv system isnt pulling oil in? I would try a top engine clean (decarb) first to try and unstick piston rings, you may have problem there.

wizkid

iTrader: (3)

The first thing thing that makes us sure about the PCV it was disconnected.

The second thing is it is connected now with one of those air compressor filters and you can see the amount of oil it traps. Very little.

Top engine cleaner is one of the next steps.

A compression test was done with all 8 cylinders being between 170 - 175 psi.

Knock Retard is 4 degrees to 1 degree at WOT on most runs.

ERic

SJH

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">The amazing thing is that even with the cracked piston this car is blisteringly fast to the point where you aren't sure that a fault exists.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have had to make that decision more than once.
Motor runs so good and strong you hate to tear it down, yet the plugs do not lie and told me "yes Steve there is something wrong here as 1 plug will not turn orange" <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> .
Pulled motor and found cracked piston. Never doubt the sparkplugs.I found it from running MMT based octane booster. That stuff only colors plugs when the cyl is running right.If you have a weak cyl it will not color the plug with the rusty orange residue and will only show up sooty or dark and you know you have a probelm.If you run extremely lean it will stay white and the others will color.
With no plug coloring agent it is difficult to see a big change in plug running conditions with unleaded gas.
Just a poweradder tip <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Have you guys actually looked inside the intake through the T.B. to check for heavy oil residue?
If nothing inside it's time for a leakdown test.
But I just can not think how you could kill all 8cyls at once N.A.
FYI- every motor I have compression checked with a hotcam ran 190-200psi.
But a bad guage will read low.
Steve

Rpm2800

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">
ERic[/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">As far as the valve seals, just because they are new does not mean they were put on correctly. (They may not be down far enough.) Not saying that's the problem though.

Do a leakdown test. It's better than a compression test, and it will also tell you if the leakdown is comming from the valve seals, or the rings.

Rpm2800

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wizkid:
<strong>

How dangerous would it be to bypass the Knock Sensor (knock out box etc) with blow by?

ERic</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Why would you want to?

NicD

iTrader: (7)

Welcome to my world. Shortly after my cam install, I started to get the smoke at WOT also. I changed out my valve seals because I thought that might have been it. Didn't fix it. After that installed breathers on the valve covers and completely disconnected the PCV to eliminate that as the cause of the oil burning. No dice either. It has to be the rings somehow, maybe its the additional cylinder pressure from the cam? Either way, it really bugs me and it just might make me buy a forged built short block.

wizkid

iTrader: (3)

This seems to be a problem on a very low percentage of cam'd (with or without heads) cars. Over the past few days I have run into more and more people with the problem. We need to get this figured out. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Some good suggestions so far.

As far as the knock out box with blowby. It seems that the cars with this problem have lots of KNock Retard. They have ordered and put on the Knock Out box or equivalent. I would like to know if that is a bad idea because it wouldn't be false knock. But would it cause detonation? Just wanting to verify.

How does a person go about doing a leak down test? I have heard this said many times but I have no clue what is involved.

Thanks for the help so far,

Eric

wizkid

iTrader: (3)

Anyone have a round about number for compression (i.e. 150 psi or so?) in a stock cam'd LS1?

I have a pretty good pressure/vaccum gauge and I just might have to do a stock car and then Brian's car to see what is going on.

Eric

SlowLS1

WoW, this thread has really come alive! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I find it hard to believe that it could be a cracked/damaged piston for one reason, all the plugs show signs of oil burning and they all look the same.

I have never tried the top engine cleaner....car has alot of miles, maybe the rings are stuck and the cam just made it bad enough to become a problem?
What is the best way to do it...i heard of using the Seafoam in liquid form and allow it to slowly suck it in at idle thru the pcv hose, should i consider more than one can with 70k miles on the clock.... will that method help "stuck" rings if that is the problem?

one other thing that i failed to mention, the oil has a hint of gas smell to it...maybe it is stuck rings and allowing fuel past the rings also? is there a better way to "clean" the rings and pistons,etc....?

once again, i am certain that the oil is not coming thru the intake....i have even pulled the intake off twice and competely flushed it out and cleaned it very well.... "just to be sure"

as for a leakdown, i have no idea what is involved...please fill me in...i will consider that also.

can the oil burning cause KR? i cannot hear the car detonating, actually the car runs very smooth! but KR is present during WOT runs.

Nic00Z28M6, I feel your pain, i have been battling this for a few mths now with no luck....i just don't want to do a rebuild if i don't have too, i just have a hard time believing that all 8 cylinders took a crap at the same time....there has to be a problem associated with it, i'm afraid that if i don't figure it out...i may end up with it again.

i have talked to over 10 different individuals that have a similar problems that i am having! of all of them, no one has been able to figure out the cause of the problem, much less fix it <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

I really feel like we are starting to pull together and making progress, Thanks to everyone!

ABNRNGR (Aka Dean)

iTrader: (1)

I've got a 98 and it used oil from the beginning. I put stage one heads and cam and the oil usage went from 1/2 qt to over a qt with that combo. I rebuilt the block with aftermarket rings then put stage two heads and the hammer cam and the oil usage went to 1.5 qts. My plugs were showing oil all over the threads. It was detonating and smoking. I took the stage two's off and left the hammer cam in. Now i have no oil on the plugs and my oil usage went down to less than 1/2 qt/3000 miles.These rings are too thin when the car detonates it rattles the piston and rings and oil passes. That isn't good for long periods of time. Also add in that the tapper on these cylinders is only .0007 and out of roundness isn't much better which basically means if it's not perfect from the factory you will have these problems. My next block will have thicker rings which i believe will help alot with the ring issue.

wizkid

iTrader: (3)

I didn't actually install the cam. Brian did. His heads are stock and were not removed during the install (at least that is my understanding).

The valve stem seals were replaced as well so that can be ruled out too.

Brian can shed more light on this.

Eric

DG Gordon

I to have that same problem. I have a 2000 SS and recently installed a Comp. custom grind cam and Mac headers. The car had 15k miles on it when the job was done and used absolutly no oil. After the install which went off without a hitch the car started burning oil like crazy. My wife took it on a 175 mile road trip and it used 2 qts. It now used 1 qt. every 50-75 miles and smokes alot when under hard aceleration. I am imbarassed to even try and race it people might think I am spraying for mosquitos. The car has a lot of valvetrain noise but I guess it is due to the cam which has a 569. lift. My warrenty is voided so I on my own.
I find it hard to believe the rings failed in 1 day.