Valve tapping
SilentNinja
09-14-2006, 11:43 AM
1973 nova 350 2bbl has a constent valve tapping noise is the left side of engine...only 57000 original miles....what do i need to do?and i use high octane
bobss396
09-14-2006, 12:14 PM
Is it a tapping sound at idle? Or can you hear it under power. Was the car sitting for a long period of time and when was the last oil change?
silicon212
09-14-2006, 12:15 PM
1973 nova 350 2bbl has a constent valve tapping noise is the left side of engine...only 57000 original miles....what do i need to do?and i use high octane
1st - you're probably throwing your money away by using high octane. Your engine was designed to run on 87 octane.
Now, to answer your question, you probably have a sticking lifter. There's also a chance that you have a bent pushrod, but for now let's stick with the lifter (no pun intended). When was the last time the oil was changed? Perform an oil change, using 10w30 oil - 4 qts, an AC PF25 filter, and one quart of automatic transmission fluid (anything but type F). Once you get the new oil in there with the ATF, fill your gas tank up and drive the car around 'till it's empty (not quite empty, you get the point). Now, do the oil change again, this time using nothing but oil (10w30) and use another new AC PF25 filter.
Yes, it's a bit expensive, but the ATF - being rich in detergents - will clean out the engine including the lifters. This should free them up and eliminate the noise.
1st - you're probably throwing your money away by using high octane. Your engine was designed to run on 87 octane.
Now, to answer your question, you probably have a sticking lifter. There's also a chance that you have a bent pushrod, but for now let's stick with the lifter (no pun intended). When was the last time the oil was changed? Perform an oil change, using 10w30 oil - 4 qts, an AC PF25 filter, and one quart of automatic transmission fluid (anything but type F). Once you get the new oil in there with the ATF, fill your gas tank up and drive the car around 'till it's empty (not quite empty, you get the point). Now, do the oil change again, this time using nothing but oil (10w30) and use another new AC PF25 filter.
Yes, it's a bit expensive, but the ATF - being rich in detergents - will clean out the engine including the lifters. This should free them up and eliminate the noise.
bobss396
09-14-2006, 02:35 PM
Have you ever tried Marvel Mystery oil? The old timers (I'm gettin' there too) always swore by it when I was a youngster. I had a noisy lifter in a '64 Ford and added a pint to my oil, drove it around for a few days and it quieted right down. I did change the oil right afterwards. I still have a can of it around for loosening frozen bolts.
Bob
Bob
SilentNinja
09-14-2006, 05:35 PM
it was sitting up for about 5 months and ran it about every 2 weeks during that time..and it didn't do the tapping...it mostly started until recently and i've been driving it for about a year now...i've had a fresh oil change and new filter...i had marvel mystery in my oil before the change...nothing really happened....and my nova guide said 91OCT and it will not run right at all on 91 or below...and it taps at idle and when i drive but you car hear it mostly at idle......i also have a valve cover on the right side leaks... so i'm going to change that tomorrow...
SilentNinja
09-15-2006, 09:32 AM
how do i just got about adjusting the valves, if needed?
Blue Bowtie
09-15-2006, 10:49 AM
Lash adjustment on a '73 SBC should be hydraulic. You can pre-lash them cold, or set them while running. Since you have a potentially sticking lifter, I'd suggest setting them hot and running. This will allow you to back off the rockers to allow the lifter plunger to fully extend to the retainer clips, then position them halfway into the plunger travel range for final lash. Many times, this will clear out the ridge of varnish which may be preventing the lifter from extending and quiet down the noisy valve. If you don't want to contend with an oil mess, you may decide to set them with the engine off.
Since you are replacing rocker cover gaskets, you have an excellent opportunity to check the valve train. Since stock heads have pull-out rocker studs, teh first thing to do after removing the covers is to check the relative heights of all the rocker studs with a straightedge. If all the studs are pressed in to the same depth, you can proceed with the valve adjustment. If a stud is pulling out, you may want to replace it, or at least drive it back in flush and pin it.
SBC STATIC VALVE LASH ADJUSTMENT - ENGINE ASSEMBLED OR INSTALLED
The most important step in proper setting of valve lash is providing reliable position markings on the crankshaft. Most engines with a stock timing tab and balancer should have a TDC groove in the outer ring of the balancer. It is important to verify that the groove is at TDC and hasn’t slipped significantly. The TDC marker should be nearly in line with the crankshaft keyway (actually, about 7º retarded on the older style balancers/timing tabs). Thus, one of the easiest ways to check this alignment is to remove the crankshaft balancer bolt and observe the keyway in relation to the TDC marking on the balancer outer ring. If the mark is relatively aligned, you can proceed. If not, you’ll have to make a visible mark at the TDC position. Once you have the TDC mark verified, mark the balancer ring at a point 180º from the TDC marking. Make additional markings at 90º intervals, so that when finished you have divided the balancer into quadrants. You will use these marks to determine the positions of all cylinders through the firing order and to adjust the valves in that sequence. If you have removed the balancer center bolt, you should now replace it and torque it to 65 ft/lb - 10.5 Kg/M - 85 N/M.
Align the TDC marking with the timing tab. It is important that you use something OTHER than the crankshaft center bolt to turn the crankshaft. If you are building the engine in a stand, or have the balancer off for any reason, a crankshaft socket is indispensable. If the engine is fully assembled, a strap wrench can be very useful in turning the engine. You can also use a flywheel turning lever, or whatever suitable means other than the balancer center bolt.
Make any additional markings necessary around the timing tab to make the position more obvious, such as chalking a line on the timing tab. Remove the rocker covers if you haven’t already done so. With the timing marks at TDC. The valves on the #1 cylinder will either both be closed, or the one or both will be slightly open. If either of the valves are slightly open, rotate the crankshaft one full revolution, so that both valves are fully closed. This will place the #1 cylinder at TDC in compression/firing stroke. At this position, you can adjust the valve lash on both valves on the #1 cylinder.
Start by backing off the adjusting nuts on both rockers until the push rods can be moved freely either up/down or by gently spinning the push rod under the rocker. If you are setting valves on a freshly built engine, one with lifters that may be leaking, or one with high-bleed lifters, spinning the push rod may not provide an accurate indication of the lash point, since only the lifter plunger spring may imparting force on the push rod. In such cases, checking for vertical movement is preferred. With new or unprimed (dry), leaking, or high-bleed (Rhodes) lifters, you must be very careful to determine the point at which the lifter plunger is fully extended.
When all pressure is removed, the push rods should spin or move very easily with two fingers. From this point, turn the adjusting nut clockwise slowly until the resistance on the push rod increases, or free vertical movement is eliminated. This is the zero lash point. From here, the lifter preload is applied. The factory setting specification for a stock engine is typically 5/8 to 1 turn of the adjusting nut, depending on the year, model, and your specification information source. For a higher RPM engine, it may be desirable to preload by only 1/4-1/2 turn to minimize the chance of a lifter pumping up at higher RPM and creating valve float. The lower preload adjustment on a new valve train may require an additional adjustment as the valve train “wears in” and surfaces are polished together. This is less likely on a roller camshaft engine, but can still occur. The amount of preload should be no more than 1 full turn, but the actual adjustment should be decided before you begin. If you are using jamb nuts or top-lock nuts, set the locks as necessary once the preload is set.
Once you are comfortable with the lifter preload adjustment of both valves on the #1 cylinder, turn the engine in a forward rotation (turn clockwise as viewed from the front end of the crankshaft) 90º to align the next chalk mark on the balancer with the timing tab marker. Some purists will prefer to turn the engine backward to eliminate any timing chain slack, but the typical valve timing of SBC camshafts doesn’t require that amount of precision positioning.
Remember that the SBC firing order is 1-8-4-3-6-5-7-2, and that you will follow this order to adjust the valves at every 90º turn of the crankshaft. After having made two full revolutions of the crankshaft, the adjustment of all valves should be complete.
HOT-RUNNING VALVE LASH ADJUSTMENT
The engine should be at normal operating temperature for this adjustment. You may want to remove the rocker covers when the engine is cold, then install them loosely to start and warm the engine. When the engine is at temperature, remove one cover and check the rocker studs with a straightedge to verify that none are pulling out. With that done, start the engine, allow it to idle, and loosen one rocker adjusting nut until the rocker just begins to make noise. Tighten the adjusting nut slowly until the noise is gone. This is the zero lash point. From this point, turn the adjusting nut an additional number of turns as indicated in your service manual. Many specifications are listed as anywhere between ½ and 1 full turn of the adjusting nut. For higher RPM engines, like to set them at 1/4 turn to help prevent lifter pump-up at high RPM. For a street-driven engine that rarely sees 5,500 RPM, the factory setting is adequate. Adjust the nut about 1/4 turn at a time, allowing a few seconds between adjustments to allow the lifter to bleed down and equalize. Continue adding 1/4 turn at a time until the desired number is achieved.
Move to the next rocker arm nut, and repeat the procedure. If you encounter a valve train that will not adjust to a quiet point, Allow the engine to run with the adjusting nut backed off and raise the RPM to increase oil pressure. This can sometimes force the lifter plunger past any accumulated varnish or sludge in the lifter body and restore normal lifter operation. After running the higher idle for a few moments, try adjusting the rocker nut to a zero lash point again. If the noise is not eliminated in this manner, shut off the engine, count the number of turns of the adjusting nut as you remove the nut fully, and remove the rocker and pivot ball. Inspect the rocker and pivot ball for wear, galling, and cracking. Inspect the spring and retainer for breakage or damage. Remove the push rod and check it for tip damage and straightness. Reassemble the valve train, replacing anything necessary, and resume the adjustment procedure.
Once all rockers on one side of the engine are adjusted to your satisfaction, shut off the engine, install that rocker cover and gasket, check the oil level, and remove the opposite rocker cover to repeat the procedure on that side.
Since you are replacing rocker cover gaskets, you have an excellent opportunity to check the valve train. Since stock heads have pull-out rocker studs, teh first thing to do after removing the covers is to check the relative heights of all the rocker studs with a straightedge. If all the studs are pressed in to the same depth, you can proceed with the valve adjustment. If a stud is pulling out, you may want to replace it, or at least drive it back in flush and pin it.
SBC STATIC VALVE LASH ADJUSTMENT - ENGINE ASSEMBLED OR INSTALLED
The most important step in proper setting of valve lash is providing reliable position markings on the crankshaft. Most engines with a stock timing tab and balancer should have a TDC groove in the outer ring of the balancer. It is important to verify that the groove is at TDC and hasn’t slipped significantly. The TDC marker should be nearly in line with the crankshaft keyway (actually, about 7º retarded on the older style balancers/timing tabs). Thus, one of the easiest ways to check this alignment is to remove the crankshaft balancer bolt and observe the keyway in relation to the TDC marking on the balancer outer ring. If the mark is relatively aligned, you can proceed. If not, you’ll have to make a visible mark at the TDC position. Once you have the TDC mark verified, mark the balancer ring at a point 180º from the TDC marking. Make additional markings at 90º intervals, so that when finished you have divided the balancer into quadrants. You will use these marks to determine the positions of all cylinders through the firing order and to adjust the valves in that sequence. If you have removed the balancer center bolt, you should now replace it and torque it to 65 ft/lb - 10.5 Kg/M - 85 N/M.
Align the TDC marking with the timing tab. It is important that you use something OTHER than the crankshaft center bolt to turn the crankshaft. If you are building the engine in a stand, or have the balancer off for any reason, a crankshaft socket is indispensable. If the engine is fully assembled, a strap wrench can be very useful in turning the engine. You can also use a flywheel turning lever, or whatever suitable means other than the balancer center bolt.
Make any additional markings necessary around the timing tab to make the position more obvious, such as chalking a line on the timing tab. Remove the rocker covers if you haven’t already done so. With the timing marks at TDC. The valves on the #1 cylinder will either both be closed, or the one or both will be slightly open. If either of the valves are slightly open, rotate the crankshaft one full revolution, so that both valves are fully closed. This will place the #1 cylinder at TDC in compression/firing stroke. At this position, you can adjust the valve lash on both valves on the #1 cylinder.
Start by backing off the adjusting nuts on both rockers until the push rods can be moved freely either up/down or by gently spinning the push rod under the rocker. If you are setting valves on a freshly built engine, one with lifters that may be leaking, or one with high-bleed lifters, spinning the push rod may not provide an accurate indication of the lash point, since only the lifter plunger spring may imparting force on the push rod. In such cases, checking for vertical movement is preferred. With new or unprimed (dry), leaking, or high-bleed (Rhodes) lifters, you must be very careful to determine the point at which the lifter plunger is fully extended.
When all pressure is removed, the push rods should spin or move very easily with two fingers. From this point, turn the adjusting nut clockwise slowly until the resistance on the push rod increases, or free vertical movement is eliminated. This is the zero lash point. From here, the lifter preload is applied. The factory setting specification for a stock engine is typically 5/8 to 1 turn of the adjusting nut, depending on the year, model, and your specification information source. For a higher RPM engine, it may be desirable to preload by only 1/4-1/2 turn to minimize the chance of a lifter pumping up at higher RPM and creating valve float. The lower preload adjustment on a new valve train may require an additional adjustment as the valve train “wears in” and surfaces are polished together. This is less likely on a roller camshaft engine, but can still occur. The amount of preload should be no more than 1 full turn, but the actual adjustment should be decided before you begin. If you are using jamb nuts or top-lock nuts, set the locks as necessary once the preload is set.
Once you are comfortable with the lifter preload adjustment of both valves on the #1 cylinder, turn the engine in a forward rotation (turn clockwise as viewed from the front end of the crankshaft) 90º to align the next chalk mark on the balancer with the timing tab marker. Some purists will prefer to turn the engine backward to eliminate any timing chain slack, but the typical valve timing of SBC camshafts doesn’t require that amount of precision positioning.
Remember that the SBC firing order is 1-8-4-3-6-5-7-2, and that you will follow this order to adjust the valves at every 90º turn of the crankshaft. After having made two full revolutions of the crankshaft, the adjustment of all valves should be complete.
HOT-RUNNING VALVE LASH ADJUSTMENT
The engine should be at normal operating temperature for this adjustment. You may want to remove the rocker covers when the engine is cold, then install them loosely to start and warm the engine. When the engine is at temperature, remove one cover and check the rocker studs with a straightedge to verify that none are pulling out. With that done, start the engine, allow it to idle, and loosen one rocker adjusting nut until the rocker just begins to make noise. Tighten the adjusting nut slowly until the noise is gone. This is the zero lash point. From this point, turn the adjusting nut an additional number of turns as indicated in your service manual. Many specifications are listed as anywhere between ½ and 1 full turn of the adjusting nut. For higher RPM engines, like to set them at 1/4 turn to help prevent lifter pump-up at high RPM. For a street-driven engine that rarely sees 5,500 RPM, the factory setting is adequate. Adjust the nut about 1/4 turn at a time, allowing a few seconds between adjustments to allow the lifter to bleed down and equalize. Continue adding 1/4 turn at a time until the desired number is achieved.
Move to the next rocker arm nut, and repeat the procedure. If you encounter a valve train that will not adjust to a quiet point, Allow the engine to run with the adjusting nut backed off and raise the RPM to increase oil pressure. This can sometimes force the lifter plunger past any accumulated varnish or sludge in the lifter body and restore normal lifter operation. After running the higher idle for a few moments, try adjusting the rocker nut to a zero lash point again. If the noise is not eliminated in this manner, shut off the engine, count the number of turns of the adjusting nut as you remove the nut fully, and remove the rocker and pivot ball. Inspect the rocker and pivot ball for wear, galling, and cracking. Inspect the spring and retainer for breakage or damage. Remove the push rod and check it for tip damage and straightness. Reassemble the valve train, replacing anything necessary, and resume the adjustment procedure.
Once all rockers on one side of the engine are adjusted to your satisfaction, shut off the engine, install that rocker cover and gasket, check the oil level, and remove the opposite rocker cover to repeat the procedure on that side.
bobss396
09-15-2006, 12:54 PM
Great tutorial Blue Bowtie. I have a set of rocker stoppers made by Lisle that clip onto the rocker arms. They plug the oil hole in the rocker arm so you don't get the oil bath. There will still be some mess to clean up.
Got an old timer trick for static valve lash setting. You can do a couple of cylinders at a time, 1-6, 8-5, 4-7, 3-2 cylinders can be done in pairs which cuts down the time.
I personally go with a 1/2 turn past zero lash on used engines with a questionable pedigree. Better to hear them than to start having to look for them. But this should take care of 90% of the valve clacking.
Bob
Got an old timer trick for static valve lash setting. You can do a couple of cylinders at a time, 1-6, 8-5, 4-7, 3-2 cylinders can be done in pairs which cuts down the time.
I personally go with a 1/2 turn past zero lash on used engines with a questionable pedigree. Better to hear them than to start having to look for them. But this should take care of 90% of the valve clacking.
Bob
SilentNinja
09-15-2006, 01:09 PM
ok so i'm going to do it when the engine is hot and running....so can i just adjust them on the right side of the block then on the left....or do i have to go in fireing order WHile the engine is running?
bobss396
09-15-2006, 01:15 PM
It doesn't matter, I just pick one side and go for it. But leave the other valve cover on loose so you minimize the mess. If I have a motor that is way out of adjustment and excessively noisy, I'll go over it quickly a second time to see if it improves any.
Bob
Bob
450HP
09-15-2006, 01:49 PM
Bob and Blue Bowtie speak the truth... it may sound a bit intimidating, but take your
time and you will be fine! :thumbsup:
Scott
time and you will be fine! :thumbsup:
Scott
SilentNinja
09-15-2006, 03:05 PM
ok just got done with it....that was the problem....the number 6 piston was raddleing like biotch...i did all of them to 1/4 and it seems to run fine and smooth...going to go test it...thanks for all the help....
Blue Bowtie
09-18-2006, 11:27 AM
bob - I think I have the same clips. Mine have the little pointed white nylon (well, the USED TO be white) plugs on two-legged spring wire clips. They usually stay on sotck rockers, btu are all but worthless on ProMags and most recycled beer can rockers.
Perhaps now the Ninja is even more silent.
Perhaps now the Ninja is even more silent.
450HP
09-18-2006, 12:10 PM
ok just got done with it....that was the problem....the number 6 piston was raddleing like biotch...i did all of them to 1/4 and it seems to run fine and smooth...going to go test it...thanks for all the help....
Congrats! That's gotta give ya that real good, feel good feeling! :thumbsup:
Scott
Congrats! That's gotta give ya that real good, feel good feeling! :thumbsup:
Scott
bobss396
09-18-2006, 10:18 PM
bob - I think I have the same clips. Mine have the little pointed white nylon (well, the USED TO be white) plugs on two-legged spring wire clips. They usually stay on sotck rockers, btu are all but worthless on ProMags and most recycled beer can rockers.
Perhaps now the Ninja is even more silent.
Yeah, they used to popoff on the stock rockers. Most of my fast toys ran solid cams, so the lash was set with the engine off.
Good deal that the Ninja adjusted his own valves! Even a 1/4 turn will quiet it down significantly. I always liked a 1/2 turn on unknown engines, 3/4 or a full turn could have bottomed out a lifter.
Bob
Perhaps now the Ninja is even more silent.
Yeah, they used to popoff on the stock rockers. Most of my fast toys ran solid cams, so the lash was set with the engine off.
Good deal that the Ninja adjusted his own valves! Even a 1/4 turn will quiet it down significantly. I always liked a 1/2 turn on unknown engines, 3/4 or a full turn could have bottomed out a lifter.
Bob
alblogg
09-18-2006, 10:39 PM
bob - I think I have the same clips. Mine have the little pointed white nylon (well, the USED TO be white) plugs on two-legged spring wire clips. They usually stay on sotck rockers, btu are all but worthless on ProMags and most recycled beer can rockers.
Perhaps now the Ninja is even more silent.
I made me a deal out of a old valve cover, cut the one side out out fabed it a little bent it a little drilled a hole or two and it keeps the oil off the exhaust and the smoke out of your face.
Perhaps now the Ninja is even more silent.
I made me a deal out of a old valve cover, cut the one side out out fabed it a little bent it a little drilled a hole or two and it keeps the oil off the exhaust and the smoke out of your face.
SilentNinja
09-21-2006, 04:15 PM
just curious is rtv required when i put the new gaskets on...i got some rubber ones...
JustSayGo
09-21-2006, 06:19 PM
If you use RTV the gasket may slide out of place when you tighten your valve covers or even hours later. If you have Fel-Pro dark grey colored gaskets they are called Felcoprene because they are a mixture of cork and rubber. Fel-Pro says they are better than rubber or cork. I think most users agree. Useing 3M 8001 weatherstrip to glue the gasket to the cover is also the most common procedure. Just read and follow the directions about removing and resticking the gasket.
Automotive Network, Inc., Copyright ©2026