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2006 CTS-V
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Discussion Starter #1
Hello All,

I recently replaced all my lifters w/GM stock replacement lifters and will I had the Heads off had them cleaned up ported and Polished by a very well known porter milled the heads .010' 3 angle valve job all new val seals.

Now before I tore the car down to replace the lifters the only issue I had was the valve train was loud and I was told by several personal friends/Techs that lifters sound noisy hence why I replaced them BUT the car ran fine. I torqued all my rockers down to 22ft/lbs using E.O.I.C method which I have done in the past without issues.. OH and Valve train noise is now gone I will report! BUT car runs like crap I mean crap it doesnt die but it definitly isnt hitting on all 8 cylinders.

Now after putting it all back together with Factory GM head Gaskets and seals the car seems almost like its miss firing and the only thing I did differently was when I put the plug wires on I used a die electrical bulb grease in the end of all the spark plug boots before I slipped them on. Do you guys think thats my problem? I usually dont use Die electric grease at all butwas trying to do things right... #DUMB

Just looking for thoughts and suggestions... thanks guys! :confused:
 

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'05 CTS-V
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E.O.I.C method?

There's nothing dumb about using dielectric grease on the spark plug wire boots; that's a perfectly normal thing to do.
 

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2005 CTS-V
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EOIC = Exhaust open Intake closed

In regards to the valves.
At the risk of nitpicking the EOIC = Exhaust opening, Intake closing. The difference is important because there can be a position at which both valves are under load from the camshaft (overlap). The exhaust lash is set when the intake has just past fully open and is beginning to close. The intake lash is set when the exhaust is just beginning to open. http://www.hotrod.com/how-to/engine/ctrp-1012-setting-valve-lash/ Since you have done this before, this all may be academic.

Is it throwing any codes?

It common on an engine/exhaust reassembly for one of the spark plugs to come up with broken ceramics.
 

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Discussion Starter #5 (Edited)
I installed headers first then the plugs purely to try to avoid that exact thing Darkman. Lol funny you mention that.. One thing i failed to mention was I did reuse plugs however only because the plugs i took out had less 500 miles on them after i did my cam swap. Again the car ran perfectly fine after the cam swap only became an issue after heads where removed an reinstalled. Since all this i have put in again All new plugs now ordered new wires just in case. Only other thing i can think of is possibly an injector didnt get plugged in well.. Im going to disconnect an reconnect all 8 of those. #STUMPED

BTW - as for a code i attempted to drive the car around my block an the check engine light started FLASHING never seen that before scanning the car after being parked reviled no codes. BUT the light was definitly blinking on off while driving but i pulled no codes with my scan tool...
 

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A flashing CEL, as opposed to a steady CEL, indicates some condition that threatens the emission system, for example a lean (or rich) condition that could damage a catalytic converter. The flashing CEL often shows up at a certain rpm or throttle range, but not at others indicating that the "threat" is not present under all operating conditions. You are likely chasing some minor issue - recheck things like wires, vacuum tubes, etc.
 

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On second thought, you may want to check your lifter preload. It is possible that your stock pushrods are too long and some of your valves are not completely closing. This is typically not a problem because GM oem lifters have a pretty wide operating range and therefore the workable preload range is pretty broad. However, in this case: milling the heads increases the preload; the valve job removes material from the valves and valve seats and increases the preload; GM oem gaskets come in various thicknesses and can increase or decrease the preload; and the replacement lifters (presumably LS7s) can increase preload. The cumulative effect of these changes may moved the valve train out of the range for the stock pushrods.

It is easy enough to check. You can count the number of turns it takes to tighten the rocker from zero lash (where the all lash is just eliminated) to 22 foot pounds tight. With the LS7 lifter the ideal is at 1 3/8 turns (about 0.082" of preload), but will work at 1 3/4 turns (about 0.111" of preload). Anything over 2 turns (about 0.131" of preload) is problematic, and the lifter will bottom out at about 2 7/16 turns (about 0.165" of preload).
 

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2006 CTS-V
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Discussion Starter #9
Thanks Darkman will recheck things again. As you suggest in your first reply.

As for the lifter preload reply. Question... Should the new lifters come oil charged out of the box? I did place all 16 lifters in a bucket of oil for about 5 days standing straight up before they where installed all felt very firm pushing on them before i put them..

Also i did exactly as you mentioned as far as preload goes. I am using 7.4" rods but i got about 1&1/4 turn to 22lbs, however with this said i had the SAME thought of a valve or valves hanging open slightly.. Just not sure why with getting 1 an 1/4" turn to 22lbs??? :(

Im going to double check basics first all wiring connections an then go from there check lifter preload again. Thanks for all suggestions sir!
 

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2005 CTS-V
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Thanks Darkman will recheck things again. As you suggest in your first reply.

As for the lifter preload reply. Question... Should the new lifters come oil charged out of the box? I did place all 16 lifters in a bucket of oil for about 5 days standing straight up before they where installed all felt very firm pushing on them before i put them..

Also i did exactly as you mentioned as far as preload goes. I am using 7.4" rods but i got about 1&1/4 turn to 22lbs, however with this said i had the SAME thought of a valve or valves hanging open slightly.. Just not sure why with getting 1 an 1/4" turn to 22lbs??? :(

Im going to double check basics first all wiring connections an then go from there check lifter preload again. Thanks for all suggestions sir!
You should be fine on the oil question. Soaking them in oil provides the initial lubrication. Whether you pre-oil the lifters or not, preload measurements assume an empty lifter supported only by its internal spring. Regardless of how much oil the lifters start out with, they will drain by the time you install the heads.

1 1/4 turns translates into a preload of 0.072" which should be great. You may want to check more than one valve - or at least one set on each bank - the valve job can create some cylinder to cylinder variance. Given that 1 1/4 turns is pretty close to the middle of the range however, it is unlikely individual cylinders would vary outside the limit.
 

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Unless you are using adjustable rockers you are not adjusting preload "properly".
All you are doing is torquing down the mounting to adjust preload, which is not the way to do it.
Generally lifters have a 0.125" of travel.
Most recommend you adjust to get the plunger off the stop, I set my Morels for 0.015" of preload,I let the hydraulics do the rest, and Morels are picky!
Since you shaved some material off the head, I would get a pushrod that is shorter by the same amount (at least).

The attached image is how I set my Comp Cams #1500 adjustable rockers.

From Comp Cams:
Setting Hydraulic Lifter Pre-load (Non-Adjustable Valve Train)

COMP Cams® recommends using an adjustable pushrod to check the pre-load. Typically, only one cylinder needs to be checked in this process. After applying lube, install the adjustable pushrods and assemble the valve train. Using the same procedure mentioned earlier, adjust the intake and exhaust valves to zero lash by changing the length of the adjustable pushrod for precise fitment. Order a pushrod that is .020"-.070" longer than the pushrod length at zero lash to ensure the proper pre-load.

Link: http://www.compcams.com/v002/Pages/405/lifter-tech-faq.aspx#HydraulicLifterPreLoadNonAdjustableValveTrain

More info:
http://www.enginebuildermag.com/2011/06/getting-to-the-bottom-of-hydraulic-lifter-preload/

 

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The existence of at least two common methods for establishing preload on non-adjustable rockers, one requiring an adjustable pushrod and one not, has been discussed ad nauseam on other forums. Attached is the mathematical reconciliation of the two methods as well as the preload specs on current and prior versions of GM lifters.


http://ls1tech.com/forums/generation-iii-internal-engine/1431835-help-getting-pushrod-size-vids-2.html#post15069830

http://ls1tech.com/forums/generation-iii-internal-engine/1418721-how-check-proper-pushrod-length.html#post14866693
 

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IMO it is better to shim under the pivot mounting bolt to lessen preload if you refuse to replace pushrods.

To the OP, my suggestion would be (if you didn't find a plug connection problem) to try a 7.385 pushrod.
No one is suggesting that you can change the existing preload without going to a different push rod.

All the discussion has been about measuring the preload that the "pushrod in hand" is providing in order to determine whether a different length push rod (and therefore different preload) is necessary.

Since OEM LS7 lifters work with preload levels over a broad range (from about 0.050" to more than 0.100") a single change, such as milling the heads by 0.010" may, or may not, cause the preload provided by the existing push rod to be out of the acceptable range.
 

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Do a cold cylinder test. Fill a spray bottle with plain water. Get the engine running as bad as it will run and spray down the header pipes close to where they meet the heads. It will be intuitively obvious to the most casual observer which cylinder or cylinders are the trouble makers. Work on it/them.
 

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No one is suggesting that you can change the existing preload without going to a different push rod.

All the discussion has been about measuring the preload that the "pushrod in hand" is providing in order to determine whether a different length push rod (and therefore different preload) is necessary.

Since OEM LS7 lifters work with preload levels over a broad range (from about 0.050" to more than 0.100") a single change, such as milling the heads by 0.010" may, or may not, cause the preload provided by the existing push rod to be out of the acceptable range.
Then the talk of torque settings is just what?

OK, just so we are on the same page, we agree the torque on the pivot mounting bolt has nothing to do with preload.

Preload is the distance from the lifter plunger to the retainer.
 

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Then the talk of torque settings is just what?

OK, just so we are on the same page, we agree the torque on the pivot mounting bolt has nothing to do with preload.

Preload is the distance from the lifter plunger to the retainer.
Yes, preload is the distance from the lifter plunger to the retainer.

Regarding the torque setting - The idea is that for a given pushrod, one can measure (approximate) the preload by counting the number of turns it takes to move from condition A to condition B.

Condition A is where the bolt has been tightened to the point of zero preload - that is, there is no slack between the pushrod and the retainer and no slack between the pushrod and the rocker.

Condition B is where the bolt is tightened to the factory 22 foot pound setting.

The approximation of preload based on the number of turns assumes a linear relationship between the number of turns and the amount of preload. The linear assumption is workable over short intervals.

The linear assumption however, becomes increasingly inaccurate over longer intervals because of two factors. The first factor is bolt stretch which occurs when torque is applied - about one-third of a turn is actually "spent" stretching the rocker bolt. The second factor is the rocker ratio. So, if you need to extrapolate the method over longer intervals, the linear assumption must be "corrected." The attachment corrects the longer intervals to account for the non-linearity.

In any event, if you perform the "test" with your existing pushrod it is a "pass or fail" test. The existing pushrod either yields an acceptable number of turns, or it doesn't.
 

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Discussion Starter #18
Man you guys are all awesome very knowledgable I might add thank you all for input!

Question just came to my mind could i blow air into the spark plug holes an see if any are escapes from the intake valves? I know the exhaust maybe open but what if i plug the exhaust? Or just check each cylinder when both are closed? Or is that even possible?
 

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Man you guys are all awesome very knowledgable I might add thank you all for input!

Question just came to my mind could i blow air into the spark plug holes an see if any are escapes from the intake valves? I know the exhaust maybe open but what if i plug the exhaust? Or just check each cylinder when both are closed? Or is that even possible?
The short answer is no. When the engine is off and both valves are closed, unless your pushrod is so long that it literally bottoms out the lifter, the oil will bleed off and allow the valve to close. You could run a dynamic compression test on an individual cylinder and compare the results with a static test on the same cylinder.http://support.alldata.com/article/tech-tip/running-compression-tests If it were me, I would rather invest in an adjustable push rod and double check preloads.
 

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Discussion Starter #20
Well said Darkman i have a comp cams adjustable push rod length checker :) i just gotta pull some valve covers yet AGAIN. Lol


Still hoping its an injector not plugged in good pr something BASIC.. I will report back hopefully can check this weekend.

Thank you again
 
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