Engine knocking...I am positive it is........
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From: Cheyenne, Wy
Engine knocking...I am positive it is........ either a rocker too loose, or a bent pushrod....I know its not a lifter and my mechanic friends all agree with that. I am looking at tearing the valve covers off today and testing it to see which one it is, and then pulling that off to test the pushrod for any bends....My only concern is...
I have never pulled rocker arms off before and then re-installed them...I know how to remove them and install them, BUT I dont know the specifics such as how tight they should be tightened, etc. Anyone know any ways to get this right without any special tools? I am a backyard mechanic with a socket set and wrenches lol.
I have never pulled rocker arms off before and then re-installed them...I know how to remove them and install them, BUT I dont know the specifics such as how tight they should be tightened, etc. Anyone know any ways to get this right without any special tools? I am a backyard mechanic with a socket set and wrenches lol.
Do you have a TORQUE WRENCH? or what is the plan as far as tightening things back up? if you do all you need is the FSM or something like a Chilton's manual to look up the correct specs on all the engine fastners.... Make sure you clearly mark the parts when they come off as to which cylinder/valve the go on, a couple bucks worth of ziplock sammy bags and a sharpie goes a long way here....
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From: Cheyenne, Wy
I am only going to be taking one of them off anyways for now. I know it is driver side so I am just going to pull the cover off, poke and prod while the engine is running for a minute, and ill figure out which rocker it is...then I will only loosen THAT rocker and check the rod, then if rod is straight ill just re-tighten to specs...if not then ill replace it and re-tighten...my only concern is that this car is not stock, to include the heads and rockers...so will the specs in a chiltons which are based off of stock specs be accurate for my modified LT1?
just a basic set of tools will get the job done if all you doing is adjusting rockers.
actually this is all you will need:
3/8 wrench for the valve covers
5/8 socket wrench and an open end wrench for the rockers
5/8 socket to spin the engine by hand
i personally like doing method 2. read this:
http://shbox.com/1/4th_gen_tech2.html#adjust_valves
actually this is all you will need:
3/8 wrench for the valve covers
5/8 socket wrench and an open end wrench for the rockers
5/8 socket to spin the engine by hand
i personally like doing method 2. read this:
http://shbox.com/1/4th_gen_tech2.html#adjust_valves
I like doing the engine-off method personally, I don't trust my ears enough
pretty much make sure the valve you are working on is closed, tighten the nut until the pushrod no longer spins without resistance and add a 1/2-3/4 turn of preload
pretty much make sure the valve you are working on is closed, tighten the nut until the pushrod no longer spins without resistance and add a 1/2-3/4 turn of preload
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So I pulled off the valve cover and got a nice suprise...discovered I have Crane Cams Gold Roller Rockers! Gave me a slight chubby...Anyways...upon investigation I found out one of the rockers way HELLA loose...so loose I could remove the nut and rocker with my fingers....the knowcking was because it was sliding off of rht speing and had slack, then it would slam back down when the pushrod came back up...
It wore on the rocker a slight bit, but not enough to hinder performance or anything. I checked the rod and it was straight and clean which was great. I also found out that the nut to hold the rocker on has an adjustment inside it to allow removal of the rockers without having to worry about setting the lash upon re-install....and that adjustment was WAY off on that rocker so it would not bolt down far enough to keep the rocker from being loose. I adjusted to what I thought was close to the right adjustment, bolted it back down and started the engine...it took a few tries but I finally got it where I needed it and put it all back together and now it runs GREAT! Im happy something went well for a change lol
It wore on the rocker a slight bit, but not enough to hinder performance or anything. I checked the rod and it was straight and clean which was great. I also found out that the nut to hold the rocker on has an adjustment inside it to allow removal of the rockers without having to worry about setting the lash upon re-install....and that adjustment was WAY off on that rocker so it would not bolt down far enough to keep the rocker from being loose. I adjusted to what I thought was close to the right adjustment, bolted it back down and started the engine...it took a few tries but I finally got it where I needed it and put it all back together and now it runs GREAT! Im happy something went well for a change lol
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Hi Corey 
Another thing you need to check is your pushrod length...
If whoever put that cam in before put in longer pushrods (and theres a good chance they did as most aftermarket cams have a smaller base circle) they could be too long for the stock cam that they put back in to pass emissions.
Just something I was thinking about, might be related to the valvetrain issues your having now, as well as not properly seating the valves bec of too much preload which would make your car run like ***!
It runs good from the ride we took the other night, but should honestly run a whole lot better. This may be one of your big issues...
Later
Another thing you need to check is your pushrod length...
If whoever put that cam in before put in longer pushrods (and theres a good chance they did as most aftermarket cams have a smaller base circle) they could be too long for the stock cam that they put back in to pass emissions.
Just something I was thinking about, might be related to the valvetrain issues your having now, as well as not properly seating the valves bec of too much preload which would make your car run like ***!
It runs good from the ride we took the other night, but should honestly run a whole lot better. This may be one of your big issues...
Later
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From: Cheyenne, Wy
I did not think of that, that is a REALLY good point...Either way though, when I put that cam back in with the LS7 Lifters I am replacing whatever pushrods are in now with Trick Flow Chrome-moly ones. I already have a length checking tool and will use that to double check what length I need when I get the cam and lifters in and I'll have the new rods overnighted to me so I can piece her back together.
