Hello new to the forum, today I pulled the valve cover from the passenger side abecause of a no compression problem and found the lifter and pushrod missing from the #4 intake side of the hole and 2 more bent pushrods in 6 and 8 but the lifters are still there. Not quite sure what happend but we had it running so good and it just went away in a matter of seconds. First question is where the heck did the lifter go and what would cause the rods to bend.never seen anything like this,the vehicle is a 74 p/u with a 392,it did have some gas that was most likely made by the cavemen but 15 gallons of fresh gas and some 2 stroke should of helped,is this thing worth the time to rebuild if it needs it? I got the truck for free but it sat since 2001 its all original and looks good,any thoughts would be appreciated thanks
missing lifter and pushrod!
- Thread starter outlaw69
- Start date
Robert Kenney
Super Moderator
That is very common on the sv. Bet all are intakes....right?
So what could be going on it that the bad gas ( caveman made) will work it's way in to the intake guides and stick them up in a hurry.
The rods bend and fall into the lifter valley under the manifold. The lifter is laying down there too. You'll need to fish the pieces out with a magnet. Reinstall the lifter and replace the rods.
Remove the intake valve springs and work all of the valves free and lube well. Drain the fuel and replace with fresh fuel and 2stroke oil. Next time you run it take it for a long drive before shutting it down.
So what could be going on it that the bad gas ( caveman made) will work it's way in to the intake guides and stick them up in a hurry.
The rods bend and fall into the lifter valley under the manifold. The lifter is laying down there too. You'll need to fish the pieces out with a magnet. Reinstall the lifter and replace the rods.
Remove the intake valve springs and work all of the valves free and lube well. Drain the fuel and replace with fresh fuel and 2stroke oil. Next time you run it take it for a long drive before shutting it down.
Robert Kenney
Super Moderator
When you get the one out that popped out of it's home, inspect the face. If you see a lot of cupping(concave appearance) nothing will help, in fact new lifters will wear faster on the rounded lobe..... I see no reason to remove the other ones that are still in place other then to inspect them for wear.. Just do them one by one so there is no chance to mix them up.
Either way use the old lifters in their original positions.....
The push rods if still straight are fine as they are... Roll them on a flat table or something to check them....
A bit more on the sticking issue from bad gas... This repeats it's self in all makes and models of engines across all applications. The more the epa screws with the fuel (adding alcohol) the worse it gets... Even general aviation planes that have been stc's to run auto gas (strict alcohol % restrictions) stick valves when run on old stinky fuel...
On another note the sv's have their own set of lubrication problems that I'm sure you have read... Even a properly oiling engine will succumb to bad gas.
Either way use the old lifters in their original positions.....
The push rods if still straight are fine as they are... Roll them on a flat table or something to check them....
A bit more on the sticking issue from bad gas... This repeats it's self in all makes and models of engines across all applications. The more the epa screws with the fuel (adding alcohol) the worse it gets... Even general aviation planes that have been stc's to run auto gas (strict alcohol % restrictions) stick valves when run on old stinky fuel...
On another note the sv's have their own set of lubrication problems that I'm sure you have read... Even a properly oiling engine will succumb to bad gas.
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So you are saying dont replace the lifters other than the one that is so badly cupped,I am posting a couple of pics of the rods and the worst lifters if you could in your opinion tell me how many you would change and possibly tell me what would be the best thing to use to free up the valves,some say a/t fluid some say 2 oz of 2 stroke to 15 gallons of fresh gas,im open to try anything other than pulling the heads!
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Robert Kenney
Super Moderator
Re: missing lifter and push rod!
No I said that replacing a badly cupped lifter with a new one will create a ticking time bomb that will start grinding the cam lobe up immediately. You are not going to gain anything with a new lifter..... If the cam is wiped out like it appears to be from the lifter cupping I think I see in the blury pix, all you can do is. Either get the valves loosened up and run it like it is of tear it down and replace the cam and lifters........ Doubt you want to do that...
To free up the valves you must remove the springs and clean up the sticky varnish deposits.. Carb cleaner and a rag to clean the exposed stem and follow up with engine oil work up and down ans rotationaly till they fall by their own weight. Button it back up...
The oil you add to the fuel is for added stem lubrication during the first few 30 minutes of driving to make sure things don't stick again... I use 2 stroke oil because it is made to be burned in a engine and leave no harmfull deposits.. Atf not so much for burning....
Fill the engine with good engine only oil and drive it like you stole it for a while. Constant highway speeds are best...
A couple of things need to be ok... Cam bearings have to be sending oil up to the rockers and the rocker assemblies need to be clear.... When you pull them to do the valve springs, slip them apart and clean them up inside and out.....
Not good news but my honest opinion...
No I said that replacing a badly cupped lifter with a new one will create a ticking time bomb that will start grinding the cam lobe up immediately. You are not going to gain anything with a new lifter..... If the cam is wiped out like it appears to be from the lifter cupping I think I see in the blury pix, all you can do is. Either get the valves loosened up and run it like it is of tear it down and replace the cam and lifters........ Doubt you want to do that...
To free up the valves you must remove the springs and clean up the sticky varnish deposits.. Carb cleaner and a rag to clean the exposed stem and follow up with engine oil work up and down ans rotationaly till they fall by their own weight. Button it back up...
The oil you add to the fuel is for added stem lubrication during the first few 30 minutes of driving to make sure things don't stick again... I use 2 stroke oil because it is made to be burned in a engine and leave no harmfull deposits.. Atf not so much for burning....
Fill the engine with good engine only oil and drive it like you stole it for a while. Constant highway speeds are best...
A couple of things need to be ok... Cam bearings have to be sending oil up to the rockers and the rocker assemblies need to be clear.... When you pull them to do the valve springs, slip them apart and clean them up inside and out.....
Not good news but my honest opinion...
Robert Kenney
Super Moderator
No problem, hope you get her running and can enjoy it....
Well finished the rocker assemblies on both sides, drained the old gas and changed the oil got good flow toall the rockers now but the number one intake valve is inop,seems like the lifter isnt going up and down or the valve is in the open position,it is the only one on either side that isnt working also got a small pop through the carb.if I put a little pressure on the pushrod side of the rocker I can feel the lifter working but only when I put pressure on it! The valve feels free and will pop back up when I tap it with a rubber mallet, any thoughts would be great,just trying to get by so as not to have to pull head!
71mtnscout
Member
It is possible that the cam lobe is flat, can you verify that the lobe is there? The other thing is a bad lifter, I had to disasemble and clean all the lifters in one of my 80's, they were really noisey!
Lifters were all cleaned and functional and it was working before the lifter assembly was removed and cleaned. Im thinking its a valve hanging up or not fully seated, did not check lobes before I reinstalled lifters is it possible to do this without taking rocker assembly off
Robert Kenney
Super Moderator
Re: missing lifter and push rod!
Did you pull the valve springs and make sure the valves were ok?
You have some very cupped lifters from what you posted earlier... It is quite possible that a lobe is flat but it ran before...
If a valve was sticking open you would have a loose push rod and loud taping..
Also possible that you miss assembled a lifter and it won't pump up... The lifter plunger could be absorbing the lobe lift... Especially possible with a badly worn lobe..
Did you pull the valve springs and make sure the valves were ok?
You have some very cupped lifters from what you posted earlier... It is quite possible that a lobe is flat but it ran before...
If a valve was sticking open you would have a loose push rod and loud taping..
Also possible that you miss assembled a lifter and it won't pump up... The lifter plunger could be absorbing the lobe lift... Especially possible with a badly worn lobe..
Is it possible to check lobe lift if I purchased a new lifter and tried it to see if it is a bad lifter or a bad lobe, I think in either case I am looking at new cam and lifters,but wouldnt a incomplete seated valve also cause popping through the carb? And how would I check to see if a lifter isnt pumping up fully,never delt with hydro lifters and that is the same lifter and pushrod that ended up missing to begin with.