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Valve adjustment advice

This is a discussion on Valve adjustment advice within the Technical / Maintenance forums, part of the General Discussion category; I had a few questions on adjusting valves on a 5.7L vortec motor. If anyone has experiance doing this could ...

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    formerly 981500Chevy 04dezert1500's Avatar
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    Valve adjustment advice


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    I had a few questions on adjusting valves on a 5.7L vortec motor. If anyone has experiance doing this could you post, then Ill ask my questions.. Thanks

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    Re: Valve adjustment advice

    Start the truck up and get it to normal operating temp. Turn it back off. Take the valve covers off. Start the engine back up. Listen for the rockers that are tapping. Tighten until they are not tapping anymore. Do not tighten anymore than necessary, just until it stops tapping. Once all the tapping has stopped turn the engine off and reinstall the valve covers. That's it. Make sure you have fire extinguisher or a water hose close by.
    1991 C1500 Ext. Scrapped. I still have the engine, tranny and Detroit tru-trac.
    2005 GTO LS2 with full Pedders track II suspension. StreetsweeperHT cam with Kooks exhaust. Tuned.

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    Re: Valve adjustment advice

    TITANIUM is right. I follow his program the same, with the engine running and at operating temp I tighten any rockers that are noisy. Then 1 by 1 loosen each nut until its noisy, then tighten until it quiets, then another 1/2 a turn. Do this for each rocker nut, you ahve to do this 1 rocker at a time and yes it can be messy, esp. if you have a fast idle.
    If you follow this you should have around a 1/2 a turn of preload on each lifter, prettu easy.


    pauly
    97 GMC 2wd RCSB 5.7, s10 2700 footstall, Hooker 24621hkr LT's , 2.5" cats dual 4"pipes exit B4 pass. side tire, custom driveshaft 3.42 G80 FIPK MAF descreen GM/Mercruiser Marine intake manifold 29lb LS2(EV6) injectors Ed Wright PCM(best mod), LT4 KM 14.8@94mph 2.007 4000lbs 122mph

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    formerly 981500Chevy 04dezert1500's Avatar
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    Re: Valve adjustment advice

    Cant start the truck its basically torn down to the block...

    As you know its a roller cam and has hydraulic roller lifters...

    I Adjusted them allready but I think somethings not right...Im running Comp Cams 1.6 ratio rockers btw..I turned the engine over to TDC and adjusted the intake and exhaust valves on the cylinders im supposed to. I then turned it over to the exhaust stroke and adjusted the remaining intake and exhaust valves.

    Problem is...After I tightened the valves at TDC then rotated the crank to the exhuast stroke the pushrods were loose on the ones I just adjusted at TDC. Same thing when I did the exhaust stroke adjustment then rotated back to TDC. They pushrods have quite a bit of play in them...Is this normal it doesnt seem right.

    I followed the procedure of removing all the valve lash then rotating the bolt 360 degrees.

    Am I missing something?

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    Re: Valve adjustment advice

    Oh, Then turn the crank, check for looseness of the pushrods by twisting them. Tighten each rocker until you can twist the push rod slightly. Keep turning the crank until you can barely twist all the push rods. What you are doing is adjusting the rockers so there is no gap between the lifter at the bottom of each lobe on the cam shaft.
    Last edited by TITANIUM; 08-15-2005 at 02:36 PM.
    1991 C1500 Ext. Scrapped. I still have the engine, tranny and Detroit tru-trac.
    2005 GTO LS2 with full Pedders track II suspension. StreetsweeperHT cam with Kooks exhaust. Tuned.

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    Re: Valve adjustment advice

    Quote Originally Posted by TITANIUM
    Start the truck up and get it to normal operating temp. Turn it back off. Take the valve covers off. Start the engine back up. Listen for the rockers that are tapping. Tighten until they are not tapping anymore. Do not tighten anymore than necessary, just until it stops tapping. Once all the tapping has stopped turn the engine off and reinstall the valve covers. That's it. Make sure you have fire extinguisher or a water hose close by.
    Wow, didn't know it was that easy. I need to do this to the '67 I just got. Just out of curiosity, why the hose/fire extinguisher? If something catches fire and the valve covers are off, soaking it in water could be just as bad as it burning up....
    '67 C-10: Getting parted out.

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    Supporting Member Badluck95's Avatar
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    Re: Valve adjustment advice

    In my case i had the distrubutor out and it is very easy to do IMO. Bring number one to top dead center on the compression stroke. I used an oil primer to pump up the lifters with the nuts backed off ,tightend it down till you can not spin the push rod with your fingers anymore then give half a turn. You do that for the intake and exhaust on number one .From their turn your crank 90 degree and follow your firing order then you set those lifters.Turn crank another 90 degree again following the firing order and repeat everything , keep doing this until you reach number again. I found this method to very accurate , i have a timing tape on the balancer . I don't know if this method works on the newer motor's , maybe someone else can help out . I have a 95 Vortec with a roller cam and it worked great. Not much of a writer so hope this helps out .

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    Re: Valve adjustment advice

    Quote Originally Posted by 981500Chevy
    Cant start the truck its basically torn down to the block...

    As you know its a roller cam and has hydraulic roller lifters...

    I Adjusted them allready but I think somethings not right...Im running Comp Cams 1.6 ratio rockers btw..I turned the engine over to TDC and adjusted the intake and exhaust valves on the cylinders im supposed to. I then turned it over to the exhaust stroke and adjusted the remaining intake and exhaust valves.

    Problem is...After I tightened the valves at TDC then rotated the crank to the exhuast stroke the pushrods were loose on the ones I just adjusted at TDC. Same thing when I did the exhaust stroke adjustment then rotated back to TDC. They pushrods have quite a bit of play in them...Is this normal it doesnt seem right.

    I followed the procedure of removing all the valve lash then rotating the bolt 360 degrees.

    Am I missing something?
    I think your problem is that the hydraulic lifters are not pumped up with oil, pull the dist. and spin the oil pump drive with a drill or air ratchet, you'll know when you have oil pressure bcause the tool you are using to turn the oil pump drive will bog down a bit. When they are pumped up, thighten the nuts till they JUST strart not to spin then give em another 1/2 turn of preload. This should be performed on each cylinder with that cylinder when the cam is letting BOTH of the valves remain closed.

    peace
    pauly
    97 GMC 2wd RCSB 5.7, s10 2700 footstall, Hooker 24621hkr LT's , 2.5" cats dual 4"pipes exit B4 pass. side tire, custom driveshaft 3.42 G80 FIPK MAF descreen GM/Mercruiser Marine intake manifold 29lb LS2(EV6) injectors Ed Wright PCM(best mod), LT4 KM 14.8@94mph 2.007 4000lbs 122mph

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    Re: Valve adjustment advice

    Quote Originally Posted by 03BlueBowtie
    Wow, didn't know it was that easy. I need to do this to the '67 I just got. Just out of curiosity, why the hose/fire extinguisher? If something catches fire and the valve covers are off, soaking it in water could be just as bad as it burning up....
    Sometimes the oil will get on the exhaust manifold or the headers and catch fire. Normally it will not catch fire, but have a hose or a extinguisher just in case. Better to be safe than sorry IMHO.
    Last edited by TITANIUM; 08-15-2005 at 04:32 PM.
    1991 C1500 Ext. Scrapped. I still have the engine, tranny and Detroit tru-trac.
    2005 GTO LS2 with full Pedders track II suspension. StreetsweeperHT cam with Kooks exhaust. Tuned.

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    formerly 981500Chevy 04dezert1500's Avatar
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    Re: Valve adjustment advice

    K I think i figured it out...Im retarted...I think I was adjusting some of them when the lifters where on the cam lobes. Ill check tonight.

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    Re: Valve adjustment advice

    Well, checked mine, pulled the valve covers off and it's definitely not the valves or lifters. To be honest, I don't know where it's coming from, but I loosened a couple of the rockers and heard the tapping they make when loose. NOT THAT. Since I have the covers off I'm going down to the auto parts store and gonna git me some nice chromies. I'm hearing more of a "ticking", not near as loud as the rocker tapping, and also a little higher pitched. Maybe an exhaust leak?? Dunno. I'm stumped. Any ideas??
    '67 C-10: Getting parted out.

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    Re: Valve adjustment advice

    If it is in the same area then yes most likely a exhaust leak.
    1991 C1500 Ext. Scrapped. I still have the engine, tranny and Detroit tru-trac.
    2005 GTO LS2 with full Pedders track II suspension. StreetsweeperHT cam with Kooks exhaust. Tuned.

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    formerly 981500Chevy 04dezert1500's Avatar
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    Re: Valve adjustment advice

    I just finished adjusting them (I was 360 off on the crank)

    One more question though... I wiggled the pushrods up and down while finger tight the stud nut to get the valve lash out. Then I tightened the bolt 360 degrees.

    On some when I did the 360 degree the springs in the lifters compressed which should be right. Problem is (I think), on some of them the valve spring actually compressed causing the valve to go down slightly.

    Wont this cause burnt valves since some are probably adjusted to tight? Is the reason the springs in the lifters arent compressing is because there not primed with oil? Should I leave it and when Im done putting it all back together run it for a little and re-adjust?

    Whats my problem?

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    Re: Valve adjustment advice

    When the lifters DO pump up itll only make your problem worse. Are you sue that the lifters in question arent starting to open the valves because they are starting up or down the ramp of the cam lobes? When you turn the crank does the valve close completly? If it doesnt you have a serious problem.

    You dont wiggle the pushrod up in down, you you twist it around in a circular motion back and forth, Do this as you tighten the rocker nut. As you are tightening the rocker nut it will become difficult to cintinue to twist the pushrod back and forth. When twisting of the pushrod becomes difficult with just a thumb and 1 finger, you turn the rocker nut by 1/2 to a full turn(I would and have gone 1/2 turn) from that point.

    This is usually the last thing done before intstalling the valve covers. Its best to do this with the lifters pumped up. If you lash them when collapsed, when the get oil pressure on startup, you can bend the pushrods I think(Ive never bent any).

    its better to have the valves adjusted to loose than too tight.
    When adjusting the valves on say cylinder 1, Bring piston 1 to top dead center with both lifters in the FULL down(valves closed position) if 1 lifter is higher than the other rotate the crank another 360 degrees. Both lifters MUST be in the FULL down position, totally on the lowest spot of that cylinders cam lobes. Install pushrods then begin tightening the rocker nut until there is no play in the 2 pushrods of that cylinder, the n tighten 1/2 a turn.
    You must do this complete procedure for EVERY cylinder(16times total 8 adjustments of the crank position so that the cylinder you are adjusting's valves are fully closed). This will set your valves VERY loose but probably enough to start the engine, but not enough to bend push rods. When it does start it will be very noisy, when the engines at operating temp while its running, tighten each rocker nut just enough to quiet that particular rocker. When all of the rockers are quiet, this helps you to hear for the next step . loosen 1 nut until it gets noisy, then slowly tighten until it stops clacking, then give it 1/2 turn more, repeat 15 more times and you are done.

    Its really just a lot easier to stick a flat screwdriver into the oilpump drive down where the distributer gears is, if you can spin it fast enough, you probaby will need to cut it off and use a drill, the lifters will pump up and you can do this out of the vehicle on the engine stand. Look at the bottom of the dist. gear on the distributer, there is a raised slot on the bottom which engages the oil pump slot when its installed, driving the oil pump.

    post back buddy
    pauly
    97 GMC 2wd RCSB 5.7, s10 2700 footstall, Hooker 24621hkr LT's , 2.5" cats dual 4"pipes exit B4 pass. side tire, custom driveshaft 3.42 G80 FIPK MAF descreen GM/Mercruiser Marine intake manifold 29lb LS2(EV6) injectors Ed Wright PCM(best mod), LT4 KM 14.8@94mph 2.007 4000lbs 122mph

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    formerly 981500Chevy 04dezert1500's Avatar
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    Re: Valve adjustment advice

    I think what I was worrying about was no big deal. I am sure I adjusted the valves when the lifters where all the way down (that was the original problem I had). I didnt have the lower intake manifold on when I adjusted them so I could also see they were all the way down.

    The part that got me was when I was adjusting the valves on some the lifters spring would compress and on some the lifters spring wouldn't. I had the lifters out and cleaned them maybe this is why some arent primed. I think on some theres no oil inside and allowed the lifter springs to compress while some had oil in them and they wouldn't compress. I figure when I start the engine up it should be fine once the oil pump starts flowing and everything equalizes.

    This sound right Pauly?

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    formerly 981500Chevy 04dezert1500's Avatar
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    Re: Valve adjustment advice

    Quote Originally Posted by Pauly
    post back buddy
    pauly
    ....

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    Question Re: Valve adjustment advice

    I'm swapping Vortec heads to my 94 350 block, with the engine still in the truck so I need to know how to properly adjust the valves before the engine is running. Or at least direct me to a site that has detailed instructions. I'll be removing the intake and distributor of course, but will not be changing a cam now. (sometime later). It has a flat-tappet cam, so if I put the engine to TDC, and pull off the heads without moving the engine, will I be able to just put the new heads on, tighten the rockers up pretty good (till the pushrods barely move), and then start it and do the running valve adjustment??? I'm 18 going on 19 and I don't want to screw anything up, as I will be working primarily on my own. I know Pauly should be able to help here, but I need all available hands on deck. PLEASE!
    Last edited by Bigdrumma22; 10-23-2005 at 07:30 PM.
    1984 K10 Scottsdale, 350/TH350, Edelbrock AVS O/R 4Bbl, K&N, Flowtech Ceramic LT's, Dual 2 1/4" exhaust, Dynomax Super Turbos, MSD 6AL, Accel Billet Distributor, 31X10.50 Falken Rocky Mountain A/T's, PIONEER DEH-33HD, GM-X362 & TS-A1304C comps, GM-D510M & 2 TS-SW124D's, and more to come

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    Re: Valve adjustment advice

    Quote Originally Posted by 981500Chevy
    I think what I was worrying about was no big deal. I am sure I adjusted the valves when the lifters where all the way down (that was the original problem I had). I didnt have the lower intake manifold on when I adjusted them so I could also see they were all the way down.

    The part that got me was when I was adjusting the valves on some the lifters spring would compress and on some the lifters spring wouldn't. I had the lifters out and cleaned them maybe this is why some arent primed. I think on some theres no oil inside and allowed the lifter springs to compress while some had oil in them and they wouldn't compress. I figure when I start the engine up it should be fine once the oil pump starts flowing and everything equalizes.

    This sound right Pauly?
    Yeah man that sounds allright, its better to have them too loose than to tight. I had an engine that wouldnt pump all the lifters up, its tough sometimes to get them pumped up.
    The oil pump will be able to no problem.

    This site doesnt alway tell me when a new post comes in, sorry for the delay.
    pauly

    EDIT, it you look on the bottom of your dist shaft, you will see a slot, that is the oil pump drive, find something with that pattern (like an old dist.) and put it on an air ratched or drill. Then you can fully pressurize the oil system. I think you should be able to buy a prelubing tool at any tool store.

    pauly
    Last edited by Pauly; 10-23-2005 at 10:20 PM.
    97 GMC 2wd RCSB 5.7, s10 2700 footstall, Hooker 24621hkr LT's , 2.5" cats dual 4"pipes exit B4 pass. side tire, custom driveshaft 3.42 G80 FIPK MAF descreen GM/Mercruiser Marine intake manifold 29lb LS2(EV6) injectors Ed Wright PCM(best mod), LT4 KM 14.8@94mph 2.007 4000lbs 122mph

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    Re: Valve adjustment advice

    Quote Originally Posted by Bigdrumma22
    I'm swapping Vortec heads to my 94 350 block, with the engine still in the truck so I need to know how to properly adjust the valves before the engine is running. Or at least direct me to a site that has detailed instructions. I'll be removing the intake and distributor of course, but will not be changing a cam now. (sometime later). It has a flat-tappet cam, so if I put the engine to TDC, and pull off the heads without moving the engine, will I be able to just put the new heads on, tighten the rockers up pretty good (till the pushrods barely move), and then start it and do the running valve adjustment??? I'm 18 going on 19 and I don't want to screw anything up, as I will be working primarily on my own. I know Pauly should be able to help here, but I need all available hands on deck. PLEASE!
    i just install them really loose, and when the engine is running I tighten them all up until they are quiet. Then 1 at a time, I loosen them off until its noisy, then I slowly tighten til it goes quiet, then I give a ful 1/2 turn, some say 1 some say 3/4, I go 1/2 turn esp on a high revving engine.
    It sbetter to have them too loose than to tight.
    97 GMC 2wd RCSB 5.7, s10 2700 footstall, Hooker 24621hkr LT's , 2.5" cats dual 4"pipes exit B4 pass. side tire, custom driveshaft 3.42 G80 FIPK MAF descreen GM/Mercruiser Marine intake manifold 29lb LS2(EV6) injectors Ed Wright PCM(best mod), LT4 KM 14.8@94mph 2.007 4000lbs 122mph

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    Raw-Edged Aggression Bigdrumma22's Avatar
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    Question Re: Valve adjustment advice

    Quote Originally Posted by Pauly
    i just install them really loose, and when the engine is running I tighten them all up until they are quiet. Then 1 at a time, I loosen them off until its noisy, then I slowly tighten til it goes quiet, then I give a ful 1/2 turn, some say 1 some say 3/4, I go 1/2 turn esp on a high revving engine.
    It sbetter to have them too loose than to tight.
    So as long as the engine doesn't move, I don't have to really worry about cold adjustment? Should I put it to TDC before I pull them, or does it matter? Oh and since I ended up with just roller rocker for now, I can still reuse the old pushrods, right?
    Last edited by Bigdrumma22; 10-23-2005 at 10:21 PM.
    1984 K10 Scottsdale, 350/TH350, Edelbrock AVS O/R 4Bbl, K&N, Flowtech Ceramic LT's, Dual 2 1/4" exhaust, Dynomax Super Turbos, MSD 6AL, Accel Billet Distributor, 31X10.50 Falken Rocky Mountain A/T's, PIONEER DEH-33HD, GM-X362 & TS-A1304C comps, GM-D510M & 2 TS-SW124D's, and more to come

 

 

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