Destroyed push rod-Why?
09-23-2018, 01:30 PM
#21
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Ok,
I took the right side apart. checked lifter lash first on #2, was about .170", but then although rocker felt loose on the valve, I did not verify TDC, so I checked again on #4, this time about .060".
I do not have a caliper to measure pushrods, but compared to new ones I just received, melling MPR-614, which are strd spec at 7.397. I also had standing oil on all the rockers, so indication of good oiling.
Do we agree, my failure is not due to over or under stroke of the lifters?
Now the bad.
I have 5 more bad rockers, including 2 that have the pushrod ball stuck in the rocker cup, for a total of 8 bad rockers.
could any of this be related to running 10w-30 rather than spec 5w-30? Possible startup damage when I was indicating no oil pressure?(even though I thought to have isolate that issue to a bad sensor)
I am guessing I would be better to start with another new, know quality, set of lifters, one piece push rods, and a new full set of rockers.
could all this just be related to using old 200k miles ball pushrods on new lifters?
This is just a stock build, is it worth the cost for heavy duty rockers and springs as recommended above, this project has already cost more than I planned, and looks like about another $500.
Also looking for recommendations on brand of lifters, pushrods, rockers
I took the right side apart. checked lifter lash first on #2, was about .170", but then although rocker felt loose on the valve, I did not verify TDC, so I checked again on #4, this time about .060".
I do not have a caliper to measure pushrods, but compared to new ones I just received, melling MPR-614, which are strd spec at 7.397. I also had standing oil on all the rockers, so indication of good oiling.
Do we agree, my failure is not due to over or under stroke of the lifters?
Now the bad.
I have 5 more bad rockers, including 2 that have the pushrod ball stuck in the rocker cup, for a total of 8 bad rockers.
could any of this be related to running 10w-30 rather than spec 5w-30? Possible startup damage when I was indicating no oil pressure?(even though I thought to have isolate that issue to a bad sensor)
I am guessing I would be better to start with another new, know quality, set of lifters, one piece push rods, and a new full set of rockers.
could all this just be related to using old 200k miles ball pushrods on new lifters?
This is just a stock build, is it worth the cost for heavy duty rockers and springs as recommended above, this project has already cost more than I planned, and looks like about another $500.
Also looking for recommendations on brand of lifters, pushrods, rockers
09-23-2018, 03:16 PM
#23
Ok,
I took the right side apart. checked lifter lash first on #2, was about .170", but then although rocker felt loose on the valve, I did not verify TDC, so I checked again on #4, this time about .060".
I do not have a caliper to measure pushrods, but compared to new ones I just received, melling MPR-614, which are strd spec at 7.397. I also had standing oil on all the rockers, so indication of good oiling.
Do we agree, my failure is not due to over or under stroke of the lifters?
Now the bad.
I have 5 more bad rockers, including 2 that have the pushrod ball stuck in the rocker cup, for a total of 8 bad rockers.
could any of this be related to running 10w-30 rather than spec 5w-30? Possible startup damage when I was indicating no oil pressure?(even though I thought to have isolate that issue to a bad sensor)
I am guessing I would be better to start with another new, know quality, set of lifters, one piece push rods, and a new full set of rockers.
could all this just be related to using old 200k miles ball pushrods on new lifters?
This is just a stock build, is it worth the cost for heavy duty rockers and springs as recommended above, this project has already cost more than I planned, and looks like about another $500.
Also looking for recommendations on brand of lifters, pushrods, rockers
I took the right side apart. checked lifter lash first on #2, was about .170", but then although rocker felt loose on the valve, I did not verify TDC, so I checked again on #4, this time about .060".
I do not have a caliper to measure pushrods, but compared to new ones I just received, melling MPR-614, which are strd spec at 7.397. I also had standing oil on all the rockers, so indication of good oiling.
Do we agree, my failure is not due to over or under stroke of the lifters?
Now the bad.
I have 5 more bad rockers, including 2 that have the pushrod ball stuck in the rocker cup, for a total of 8 bad rockers.
could any of this be related to running 10w-30 rather than spec 5w-30? Possible startup damage when I was indicating no oil pressure?(even though I thought to have isolate that issue to a bad sensor)
I am guessing I would be better to start with another new, know quality, set of lifters, one piece push rods, and a new full set of rockers.
could all this just be related to using old 200k miles ball pushrods on new lifters?
This is just a stock build, is it worth the cost for heavy duty rockers and springs as recommended above, this project has already cost more than I planned, and looks like about another $500.
Also looking for recommendations on brand of lifters, pushrods, rockers
My recommendation (and others have already mentioned some of these) moving forward would be 16 new GM rockers with a quality bushing trunnion kit, 16 new AC Delco or Delphi LS7 lifters and head bolts and gaskets to get the job done. Then once these are assembled, use a checker tool to measure for pushrod length. It SHOULD be 7.4, but I would go through all this trouble to assume the length. If it winds up being 7.4, then you would have the choice to use your new Melling pushrods or buy something a little better. I’ve used Melling replacement in stock builds with no problems, but the choice is yours.
BTW Sounds like WS6Store has good parts at good prices!
Oh,and make sure to use some quality assembly lube on both sides of the pushrods. A little dab on each cup works. You did when you assembled the first time around, right?
09-23-2018, 06:53 PM
#24
Why buy more ball end pushrods?
Peace of mind is hard to put a price on, but we have so many starting at $70 and going up.
We can get you in a brand new set of lifters, rockers with hd trunion, zddp break in lube, head gaskets, head bolts for $375 shipped (if you have notched heads add $18)
Thats it.
Peace of mind is hard to put a price on, but we have so many starting at $70 and going up.
We can get you in a brand new set of lifters, rockers with hd trunion, zddp break in lube, head gaskets, head bolts for $375 shipped (if you have notched heads add $18)
Thats it.
09-26-2018, 11:24 AM
#25
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I think you either have the wrong length pushrods. I would measure to confirm. Or an oiling problem which i think is your problem since the pushrods were stuck in the rockers. The lifter that had the bad pushrods can you push the plunger down and does it return?
09-26-2018, 11:37 AM
#26
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not sure about current lifter plunger, will check this pm.
new parts on order, lifter set, rocker set, head gaskets and bolts, and a length checker. Plan to order 1 piece pushrods based on length.
As head was milled, new lifter plungers sat higher, i am guessing the reused pushrods we too long, just about bottom out lifter pistons, causing limited oiling.
09-26-2018, 07:31 PM
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Confirmed that the lifters were pumped up, and I could not depress the lifter plunger at all. I did compare and original lifter to the new ones I installed, and found that the plunger retaining wire was .086 below the top on the original lifters and .068 from the top on the new lifters, .018 higher on the new lifter. Also looking at my machine work paperwork, the heads were milled down .007. In effect my pushrods were .025 inches higher/ longer than they were originally. Not sure if this was enough to bottom out a lifter and cause the lack of oiling on some of the rockers......
09-30-2018, 01:21 PM
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New parts on hand(new lifters,new rockers with trunnion upgrade, head gasket)- please help me confirm push rod length to orderI put in 4 of the new lifters over 1&3, and got #1 to TDC, then bolted on the head with the new headgasket to just 30inlb just the bolts around cyl #1 and a couple of bolts around #5. Setting the new rocker arm over #1 In, I could feel where I could move the lifter a bit, vs just a gap in the rocker/valve.Using the Comp Cam length adjust tool 7702-1, I found 0(zero) lash at 8-3/4 turns out. Verified 8-1/2 had a gap, 8-3/4 did not. Repeated on #1 Ex with same measurement, then repeated again on #1 In.So if my math is correct7702-1 starting length 6.8”+(8-3/4 turns x .050).4375= 7.2375 zero lash, + .03 preload = 7.2675, rounded to 7.27” pushrods required
7.27 seems like a weird number. Does this seem like a reasonable number, or am I doing something wrong? Does this help explain the original damage using 7.4 pushrods?
Brian
7.27 seems like a weird number. Does this seem like a reasonable number, or am I doing something wrong? Does this help explain the original damage using 7.4 pushrods?
Brian
09-30-2018, 05:34 PM
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Also the new lifters that WS6store sent me are supposed to be stock OE rollers, and everything I can find seems that lifter preload should be .020-.060 with .030 desired. Please tell me if I am wrong.
now that I have a proper measuring tool, I have also thought about trying to get a measurement with the old headgasket, lifters, rockers and see just how far it was off.
I might mess with this, as I am still waiting on new pushrods to length and head bolt set.
09-30-2018, 06:06 PM
#31
Your new head gasket will compress and change thickness slightly once it’s torqued down. That’s why most people will use an old head gasket when checking pushrod length, with the caveat that they need to be the same head gasket or at least have the same advertised compressed thickness. Another option is to measure your new uncompressed gasket thickness and then subtract the difference between advertised compressed and uncompressed thickness when calculating pushrod length. Or the third option is to skip these steps since most gasket compressed/uncompressed thicknesses are too small to matter.
Your measurements do seem short, but you have to consider if the block and/or heads were decked. Removing metal from either will bring the lifter and rocker closer to each other, requiring a shorter push rod. One common error that could cause a short measurement would be if the checker pushrod was not fully seated in the lifter or rocker cups. If it was caught on one of the lips, it would cause a false short measurement. Seeing as how you got the exact same measurement on intake and exhaust, I would think this wasn’t the case and your measurements are good.
FWIW, if it were me I would be curious on measuring your old setup too. If you still have the old gasket, lifters and rockers it would be quick just to see what you had before. If your old pushrods were too long, it would put additional stress on your valvetrain. This would usually result in a collapsed lifter, but since your lifters were new and the old pushrods had 200k+ its not too surprising the pushrods failed first. I think WS6STORE called it early on.
Your measurements do seem short, but you have to consider if the block and/or heads were decked. Removing metal from either will bring the lifter and rocker closer to each other, requiring a shorter push rod. One common error that could cause a short measurement would be if the checker pushrod was not fully seated in the lifter or rocker cups. If it was caught on one of the lips, it would cause a false short measurement. Seeing as how you got the exact same measurement on intake and exhaust, I would think this wasn’t the case and your measurements are good.
FWIW, if it were me I would be curious on measuring your old setup too. If you still have the old gasket, lifters and rockers it would be quick just to see what you had before. If your old pushrods were too long, it would put additional stress on your valvetrain. This would usually result in a collapsed lifter, but since your lifters were new and the old pushrods had 200k+ its not too surprising the pushrods failed first. I think WS6STORE called it early on.
09-30-2018, 09:55 PM
#32
Never add preload. always measure it.
This is what i normally do. turn the checker out to 7.400. Then turn rocker bolt down to 0 lash as in 0 net movement. Then count turns after. You are looking for 3/4 of a turn til bottomed out.
Its that simple. more than 3/4 you are too long. less you are too short.
Do not put .030 preload on those lifters. .050 to .060 is the window.
Also MAKE SURE YOU HAVE YOUR ROCKER RAIL ON THE HEAD. That seems like a trivial sentence but ive literally had 20 guys call mad because their pushrods were wrong or measurements were wrong because they didnt do that.
This is what i normally do. turn the checker out to 7.400. Then turn rocker bolt down to 0 lash as in 0 net movement. Then count turns after. You are looking for 3/4 of a turn til bottomed out.
Its that simple. more than 3/4 you are too long. less you are too short.
Do not put .030 preload on those lifters. .050 to .060 is the window.
Also MAKE SURE YOU HAVE YOUR ROCKER RAIL ON THE HEAD. That seems like a trivial sentence but ive literally had 20 guys call mad because their pushrods were wrong or measurements were wrong because they didnt do that.
10-01-2018, 05:56 PM
#33
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Never add preload. always measure it.
This is what i normally do. turn the checker out to 7.400. Then turn rocker bolt down to 0 lash as in 0 net movement. Then count turns after. You are looking for 3/4 of a turn til bottomed out.
Its that simple. more than 3/4 you are too long. less you are too short.
Do not put .030 preload on those lifters. .050 to .060 is the window.
Also MAKE SURE YOU HAVE YOUR ROCKER RAIL ON THE HEAD. That seems like a trivial sentence but ive literally had 20 guys call mad because their pushrods were wrong or measurements were wrong because they didnt do that.
This is what i normally do. turn the checker out to 7.400. Then turn rocker bolt down to 0 lash as in 0 net movement. Then count turns after. You are looking for 3/4 of a turn til bottomed out.
Its that simple. more than 3/4 you are too long. less you are too short.
Do not put .030 preload on those lifters. .050 to .060 is the window.
Also MAKE SURE YOU HAVE YOUR ROCKER RAIL ON THE HEAD. That seems like a trivial sentence but ive literally had 20 guys call mad because their pushrods were wrong or measurements were wrong because they didnt do that.
10-01-2018, 09:33 PM
#34
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Your measurements do seem short, but you have to consider if the block and/or heads were decked.
FWIW, if it were me I would be curious on measuring your old setup too. If you still have the old gasket, lifters and rockers it would be quick just to see what you had before. If your old pushrods were too long, it would put additional stress on your valvetrain.
FWIW, if it were me I would be curious on measuring your old setup too. If you still have the old gasket, lifters and rockers it would be quick just to see what you had before. If your old pushrods were too long, it would put additional stress on your valvetrain.
I went ahead and put a new lifter in #1 intake, and a old lifter in #2 exhaust. Still at #1 TDC compression. Then put on a old head gasket, and torqued head down to 50ftlb. I tested exhaust side with an old rocker, and the intake side with a new rocker.
Never add preload. always measure it.
This is what i normally do. turn the checker out to 7.400. Then turn rocker bolt down to 0 lash as in 0 net movement. Then count turns after. You are looking for 3/4 of a turn til bottomed out.
Its that simple. more than 3/4 you are too long. less you are too short.
Also MAKE SURE YOU HAVE YOUR ROCKER RAIL ON THE HEAD. That seems like a trivial sentence but ive literally had 20 guys call mad because their pushrods were wrong or measurements were wrong because they didnt do that.
This is what i normally do. turn the checker out to 7.400. Then turn rocker bolt down to 0 lash as in 0 net movement. Then count turns after. You are looking for 3/4 of a turn til bottomed out.
Its that simple. more than 3/4 you are too long. less you are too short.
Also MAKE SURE YOU HAVE YOUR ROCKER RAIL ON THE HEAD. That seems like a trivial sentence but ive literally had 20 guys call mad because their pushrods were wrong or measurements were wrong because they didnt do that.
I tested per WS6store suggestion to count rocker bolt turns from zero lash. The attached chart shows I should have used 7.35 push rods, where I actually reused stock 7.4s. Not sure if being .050 too long accounts for my damage and lack of oiling, but maybe.
Now with the new lifters and rockers, if everyone agrees, I need to order 7.30 one piece pushrods.
Also, per head gaskets, I looked of their specs,
Old gasket felpro 26191pt .048 thick
New Gm ls1/ls6 12498544(57/HO53L) .051 thick
not much different, .003
Last edited by bkuhr; 10-01-2018 at 09:46 PM.
10-01-2018, 10:11 PM
#35
Ok looking at your chart got me wondering... are you torquing the rocker bolts to 22 ft/lbs when checking for pushrod length? If so, there’s no reason to and doing so will actually skew your test. That extra turn of the bolt for final torque will actually cause you to measure too short a pushrod. You only need to ensure the rocker trunnion is fully seated with zero lash on the pushrod/valve tip as well as zero lash side to side on the trunnion to stand seat. Hopefully you can visualize how additional turning of the bolt past this point to achieve 22 ft/lbs would affect your length test.
Also, I prefer 1 full bolt turn past zero lash on the pushrod to achieve zero lash on the trunnion. The rocker bolt pitch is 1.25 which equals about .050” for 1 full turn of the bolt.
Also, I prefer 1 full bolt turn past zero lash on the pushrod to achieve zero lash on the trunnion. The rocker bolt pitch is 1.25 which equals about .050” for 1 full turn of the bolt.
10-02-2018, 04:51 AM
#36
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Ok looking at your chart got me wondering... are you torquing the rocker bolts to 22 ft/lbs when checking for pushrod length? If so, there’s no reason to and doing so will actually skew your test. That extra turn of the bolt for final torque will actually cause you to measure too short a pushrod. You only need to ensure the rocker trunnion is fully seated with zero lash on the pushrod/valve tip as well as zero lash side to side on the trunnion to stand seat. Hopefully you can visualize how additional turning of the bolt past this point to achieve 22 ft/lbs would affect your length test.
Also, I prefer 1 full bolt turn past zero lash on the pushrod to achieve zero lash on the trunnion. The rocker bolt pitch is 1.25 which equals about .050” for 1 full turn of the bolt.
Also, I prefer 1 full bolt turn past zero lash on the pushrod to achieve zero lash on the trunnion. The rocker bolt pitch is 1.25 which equals about .050” for 1 full turn of the bolt.
In the case of the old lifter that is pumped up, I could actually see the valve open during this final 3/4 turn. The new lifters, I am pretty sure that final turn depressed the lifter plunger, and not the valve.
My previous process was to adjust the checker until I could turn the rocker bolt down tight to zero lash, which is the point where the rocker is both fully seated on the trunnion and just zero gap at the valve, ensuring I was not pushing into the lifter. At this setting I am able to lift the rocker tip against the lifter spring. Then I mathamatically added the additional desired preload to the checker length..... I used .030 as a desired preload value, But WS6store said it should be .050-.060, and that this was an inproper procedure. I came in at 7.265, but an additional .030 to get to total preload of .060 would be 7.295, rounded to 7.30"
Both processes got me to the same length- 7.30". I do appreaciate everyone taking the time to help me ensure this is correct, but I can not see where I am doing it wrong.........................
The old thing I see that my be off is I have the lifter under test sitting at pistion TDC compression, rather than measure 'Intake when Exhaust Opening', and measure 'Exhaust when Intake Closing', because I figured TDC compression would allow me to measure both I and E sides at the same time without moving the crank, and at TDC compression puts both lifters on the cam base circle. Is this incorrect?
Last edited by bkuhr; 10-02-2018 at 04:59 AM.
10-02-2018, 06:14 AM
#37
You dont have to torque the bolt down. That merely springs the bolt in the hole. Bolted down flush and tight is all you need. It takes additional movement to torque it down and that may be where you are running into an issue.
Measure your checker to make sure it is right also I have seen them off before.
That pr length is just way too short even inlcuding the clean up on deck surface. You could have an odd short deck but cant say for sure there.
Youre 100% sure you are on the base circle of the cam also?
Something isnt right there. Thats a tenth of an inch which is a considerable amount of difference esp in an engine where .050 is a mile.
Measure your checker to make sure it is right also I have seen them off before.
That pr length is just way too short even inlcuding the clean up on deck surface. You could have an odd short deck but cant say for sure there.
Youre 100% sure you are on the base circle of the cam also?
Something isnt right there. Thats a tenth of an inch which is a considerable amount of difference esp in an engine where .050 is a mile.
10-02-2018, 10:11 AM
#38
You are changing way to many variables at once to get a good and consistent answer. Use the old gasket, tighten down the head. Open the pushrod to 7.250" and insert and tighten the rocker snug. Don't keep going to full torque in the aluminum heads.
With this setup, you should not be at zero lash but be short. Now use a feel gauge and measure between the rocker tip and the valve stem. Let's say you get 0.020" with the feeler gauge. Remove the pushrod and then open the pushrod by 0.020"/1.54 or 0.013" or 1/2 turn and try again. You should be darn near zero lash. Get your zero lash measurements first, then move on from there.
With this setup, you should not be at zero lash but be short. Now use a feel gauge and measure between the rocker tip and the valve stem. Let's say you get 0.020" with the feeler gauge. Remove the pushrod and then open the pushrod by 0.020"/1.54 or 0.013" or 1/2 turn and try again. You should be darn near zero lash. Get your zero lash measurements first, then move on from there.
10-02-2018, 01:02 PM
#40
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Possibly silly engine block history questions but,,,
What are the chances the head has been milled before?
Was the block line bored oversize moving the cam up? (Ie: they didn't center the boring tool correctly.. )
What are the chances the head has been milled before?
Was the block line bored oversize moving the cam up? (Ie: they didn't center the boring tool correctly.. )