69_340_GTS
Well-Known Member
All it takes is some very fine dirt or metal inside to lock up a hydraulic lifter. Or maybe they were just sitting around too long and the oil got gummy. I'd be tempted to just replace them all.
273 rocker arm adjustment
- Thread starter 70dart65coronet
- Start date
-
Ive heard quite a bit recently of hydraulic lifters brand new not working properly. I think Hughes is a distributor that is frustrated with quality of lifters he sells.
Do a search.
Do a search.
I'm such a dumb ***. And I'm working on both right now. My Impala and my barracuda w/adj. arms and learning a lot in this thread.
nm9stheham
Well-Known Member
Uuuuuh..... the notch orientation is part of the design. Proper orientation place the hole in the bottom nearly vertically downward and the 2nd hole at each rocker pointing to the adjuster side. Putting the shaft in backwards put the bottom oil hole higher and the 2nd hole in totally the wrong direction. The notch should be down and to the left on each head.
OP, your shafts for these rockers should have TWO holes at each rocker, not just one. The shafts for the standard stamped rockers have only one hole, so you may have those instead of the correct shafts. The 2nd hole at each rocker should be uphill from the bottom hole, and about 80 degree around the circumference. It is a bit larger and is important because it pushes oil through the hole in the rocker running back to the adjuster. This is the oil supply to the top cup of the pushrod and the pushrods and balls will eventually fail without this oil supply. The one cup that fell out may have overheated and then expanded the pushrod end, causing it to release. And this may be the source of your metal flakes.
The other things is that if you have a high lift cam, the pushrods may be rubbing the side of the pushrod holes in the heads. Look at the pushrods and check for any signs of rubbing on the sides.
Here is what the shafts and 2 holes at each rocker should look like; the shaft is upside down in this pix. The faint groove visible at the top is ground across the bottom hole and is for the oiling of the rocker itself. The slightly larger hole on the side nearer to the camera is the hole up on the uphill side that feed the hole in the rocker that leads to the adjuster and oils the pushrod cup. You can see the matching hole in the rocker on the rocker to the right
OP, your shafts for these rockers should have TWO holes at each rocker, not just one. The shafts for the standard stamped rockers have only one hole, so you may have those instead of the correct shafts. The 2nd hole at each rocker should be uphill from the bottom hole, and about 80 degree around the circumference. It is a bit larger and is important because it pushes oil through the hole in the rocker running back to the adjuster. This is the oil supply to the top cup of the pushrod and the pushrods and balls will eventually fail without this oil supply. The one cup that fell out may have overheated and then expanded the pushrod end, causing it to release. And this may be the source of your metal flakes.
The other things is that if you have a high lift cam, the pushrods may be rubbing the side of the pushrod holes in the heads. Look at the pushrods and check for any signs of rubbing on the sides.
Here is what the shafts and 2 holes at each rocker should look like; the shaft is upside down in this pix. The faint groove visible at the top is ground across the bottom hole and is for the oiling of the rocker itself. The slightly larger hole on the side nearer to the camera is the hole up on the uphill side that feed the hole in the rocker that leads to the adjuster and oils the pushrod cup. You can see the matching hole in the rocker on the rocker to the right
You can adjust Mopar rockers while running. Use a universal socket on an extension with your ratchet. Been doing all my life.
Just clearance the rockers with a cutting tool or stone. Factory 340 hydraulic rocker arms were clearanced from the factory because of the 1.50 OD valve springs.
yellow rose
Overnight Sensation
Why would you want to? With the adjuster moving around it doesn't make any sense. You can go off the firing order for hydraulics and be done in 15 minutes without all the mess.
Better adjustment. Keep turning your cam and recheck your adjustment. It will almost always need more adjustment using that method. I rarely run a hydraulic cam.
nm9stheham
Well-Known Member
BTW, I have been looking at your pix of your shafts.... I can see a semi-circular 'notch' that is only a partial depth into the casting, and is not in the normal position as the stock notches. The original notches are fully through the shaft and directly inline with the bottom holes. So these are not original shafts. I can't see if you have the 2 holes or just 1 per rocker, and where the holes are.
BTW, it is NORMAL for a hydrualic lifters to not compress much or at all once they have operated for a little while. If you stops the engine and let it set overnight, none of the lifters ought to compress when they are on the heel of the lobe; the built-in check valve should prevent any oil escape from the inner chamber and should hold the lifter piston. But, nowadays, you will probably find a few that will. The quality appears to have gone way downhill.
BTW, it is NORMAL for a hydrualic lifters to not compress much or at all once they have operated for a little while. If you stops the engine and let it set overnight, none of the lifters ought to compress when they are on the heel of the lobe; the built-in check valve should prevent any oil escape from the inner chamber and should hold the lifter piston. But, nowadays, you will probably find a few that will. The quality appears to have gone way downhill.
69_340_GTS
Well-Known Member
I've not seen aftermarket shafts that have 2 holes at each rocker. Are the ones with 2 holes original 273 Mopar shafts? I know the shafts that Comp Cams, Harland Sharp, and Proform supply with their adjustable rockers do not have 2 holes at each rocker. And if you check the shafts made by Melling and Sealed Power they only have one hole at each rocker as well.
Last edited:
yellow rose
Overnight Sensation
The only shafts I've seen with two feed holes are the T/A shafts and W/2 shafts.
The only problem is the second hole to feed the ball and adjuster isn't in the correct position. Also, I've found GenII hemi shafts that didn't have the adjuster feed hole in the correct position.
nm9stheham
Well-Known Member
My OEM 273 shafts (pictured) have 2 holes. I do indeed question if ALL of the 273 mechanical rocker shafts came from the factory that way...maybe 2 BBL models did not? But after 50+ years, who knows what old parts have been mixed and matched.....
If a high lift cam is being used with heavy springs, it is a recipe for failure to not directly oil the pushrod cups. That much has been found out over the years. But, it just takes a dribble for most cases ..... this was designed back in the day when splash oiling was still not that far in the past LOL. Circle track racing (continuous high RPM's) is the worst case I can imagine.
If a high lift cam is being used with heavy springs, it is a recipe for failure to not directly oil the pushrod cups. That much has been found out over the years. But, it just takes a dribble for most cases ..... this was designed back in the day when splash oiling was still not that far in the past LOL. Circle track racing (continuous high RPM's) is the worst case I can imagine.
yellow rose
Overnight Sensation
When I went from 240/650 to 330/880 I ate adjusters and cups so fast you couldn't even start the car. While warming up I could hear it dropping holes and I knew it was eating itself.
I don't remember why, but I had the intake off and the adjusters out. I grabbed a pick and realized the hole in the rocker didn't line up with the hole in the shaft. Not only were the holes off radially, they were off left to right.
So I blued the shafts, marked the holes and moved them. Shifting at 8800 I never lost another one.
nm9stheham
Well-Known Member
Yeah, that is getting waaay on up there. I'll venture to guess that the OP is not at 330 closed pressures LOL. Good solution..
Sure. Grind a little if you need to. Beehive springs would be better but......
70dart65coronet
mopar or nocar
So the PO must have used the stock 340 shafts? My shafts have one hole per rocker. There is also talk about banana grooves. What would be the best bet, try to find the correct shafts (wrecking yards used, or new after market?) or drill the additional hole and add banana grooves? I think that is something i could do as long as the shafts aren't too hard and i had some measurements. I have heard of people using a die grinder to make the banana grooves.
The notches on the shafts, the PO had them in backwards, some say it doesnt matter, anyway, i orientated them as per the book. The notches were made with an end mill, and they aren't the same depth compared to each other. Since i changed the orientation i will polish the shafts and the inside of the rocker arms, i have a pretty good method for that.
I went ahead and took out all 16 lifters, disassembled and cleaned them. I noticed most of them had very dark oil in side of them. they are all freely moving now. The book says not to pump them up when re assembling, i soaked them in oil and got the air out of them because it doesn't make sense to put them with out oil inside of them.
The cam card specs zero lash and its a hydraulic high lift cam. So i should set the adjuster screws to where i just start to feel drag on the push rods when i spin them in my fingers, i dont want to compress the piston inside the lifter any more than a C hair.
The wear pattern on the end of the rocker tip looks good, nice and centered both directions. so i dont think the geometery is off.
The only push rods that have wear on the sides of them from the heads are the ones that were bent. I have one push rod that is nice a straight. Question is why are the push rods bending? did the PO not have them adjusted right? Or could it be an over rev issue? cam card specs the rpm range is 2700 to 5700. What should i be shifting this thing at? I have a msd box that i could put a rev limiter in. the indicator on the rpm tach was set at 7000.
So then i thought, well most race engines use bigger push rods, 3/8", i have 5/16", but i think if i go with bigger push rods then they will rub on the heads. Also this push rod from sealed power RP-3159 is the only one of its kind, and i dont see alot of other options besides getting custom push rods made.
https://www.summitracing.com/parts/slp-rp-3159
Comp Cam 7821-16 pushrods (340 w/ 273 rockers)
We know where the metal was coming from, which was the oversize valve springs rubbing on the inside of the rocker arms. i can easily clearance these with the die grinder, i will probably use a template so they are all the same. some of the rockers castings vary and some of the rockers are untouched also.
Someone had mentioned going with the studs and lock nut set for the adjusters, i think this is a great idea, so i would have to face the top of the rocker where this lock nut would set. Think i could do that with a basic belt sander?
https://www.summitracing.com/parts/crn-99802-16
You are spot on about the oiling problem causing heat to the cup on the push rod, found one that is turning brown compared to the others.
What do you think these intake valves are made of? whats the purpose?
I seems like i am constantly finding problems from the PO...i wonder when i will get all the wrinkles ironed out...
The notches on the shafts, the PO had them in backwards, some say it doesnt matter, anyway, i orientated them as per the book. The notches were made with an end mill, and they aren't the same depth compared to each other. Since i changed the orientation i will polish the shafts and the inside of the rocker arms, i have a pretty good method for that.
I went ahead and took out all 16 lifters, disassembled and cleaned them. I noticed most of them had very dark oil in side of them. they are all freely moving now. The book says not to pump them up when re assembling, i soaked them in oil and got the air out of them because it doesn't make sense to put them with out oil inside of them.
The cam card specs zero lash and its a hydraulic high lift cam. So i should set the adjuster screws to where i just start to feel drag on the push rods when i spin them in my fingers, i dont want to compress the piston inside the lifter any more than a C hair.
The wear pattern on the end of the rocker tip looks good, nice and centered both directions. so i dont think the geometery is off.
The only push rods that have wear on the sides of them from the heads are the ones that were bent. I have one push rod that is nice a straight. Question is why are the push rods bending? did the PO not have them adjusted right? Or could it be an over rev issue? cam card specs the rpm range is 2700 to 5700. What should i be shifting this thing at? I have a msd box that i could put a rev limiter in. the indicator on the rpm tach was set at 7000.
So then i thought, well most race engines use bigger push rods, 3/8", i have 5/16", but i think if i go with bigger push rods then they will rub on the heads. Also this push rod from sealed power RP-3159 is the only one of its kind, and i dont see alot of other options besides getting custom push rods made.
https://www.summitracing.com/parts/slp-rp-3159
Comp Cam 7821-16 pushrods (340 w/ 273 rockers)
We know where the metal was coming from, which was the oversize valve springs rubbing on the inside of the rocker arms. i can easily clearance these with the die grinder, i will probably use a template so they are all the same. some of the rockers castings vary and some of the rockers are untouched also.
Someone had mentioned going with the studs and lock nut set for the adjusters, i think this is a great idea, so i would have to face the top of the rocker where this lock nut would set. Think i could do that with a basic belt sander?
https://www.summitracing.com/parts/crn-99802-16
You are spot on about the oiling problem causing heat to the cup on the push rod, found one that is turning brown compared to the others.
What do you think these intake valves are made of? whats the purpose?
I seems like i am constantly finding problems from the PO...i wonder when i will get all the wrinkles ironed out...
Sounds like you are on the right track but I would question the valve lash. I have never known a hydraulic cam to be set at zero. For the hydraulic lifter to work as designed it needs to have preload. The piston needs to be towards the center of it's stroke so to speak. Thats why you always adjust them to zero and a half a to a full turn on the adjuster. The intake valves look to be larger than stock and stainless steel. +++ there.
70dart65coronet
mopar or nocar
Ok so zero lash plus a full turn on the adjuster. I did find some of my adjuster came out really easy, so they might have been moving around which would cause the push rods to bend?
I have contacted Jon Dunken, he is an awesome local mopar guy that i ran into, he is going to find out if he has or knows anyone that has some 273 rocker shafts, arms and push rods. Which might save me from having to modify my shafts with additional holes, banana grooves, and polishing out all the galling marks. My rockers have alot of galling in them, here is a before and after picture of the rocker arm, i ran a berry hone through them to see if they would clean up, think i could run them since they are just low spots which would add more oil surface? What do you think?
Any other comments guys? I am pretty green when it comes to this stuff and i really appreciate all of your experience.
What push rods do you think i should go with? I am thinking i should just buy the same push rods that i have, this way i can see if i have any additional problems...? i need to decided about the rev limit... i have the msd box that i can put the rev limiter in, which would help since i have the heavy foot.
Here is some pictures of the before and after of the clearanceing of the underside of the rocker arm with sand paper roll.
Not sure if i cant quote from other threads? worth a shot
pictures:
I have contacted Jon Dunken, he is an awesome local mopar guy that i ran into, he is going to find out if he has or knows anyone that has some 273 rocker shafts, arms and push rods. Which might save me from having to modify my shafts with additional holes, banana grooves, and polishing out all the galling marks. My rockers have alot of galling in them, here is a before and after picture of the rocker arm, i ran a berry hone through them to see if they would clean up, think i could run them since they are just low spots which would add more oil surface? What do you think?
Any other comments guys? I am pretty green when it comes to this stuff and i really appreciate all of your experience.
What push rods do you think i should go with? I am thinking i should just buy the same push rods that i have, this way i can see if i have any additional problems...? i need to decided about the rev limit... i have the msd box that i can put the rev limiter in, which would help since i have the heavy foot.
Here is some pictures of the before and after of the clearanceing of the underside of the rocker arm with sand paper roll.
Not sure if i cant quote from other threads? worth a shot
pictures:
69_340_GTS
Well-Known Member
You don't need any extra holes or banana grooves. If it were a race car, maybe.
nm9stheham
Well-Known Member
I am suspect it depends on a combination of lift, spring pressure and RPM's. Get any one of them over a certain level, and it'll need it. Without the 2nd holes, the only oil to the pushrod cups is from vapor and maybe a bit that dribbles out of the top hole. Not good enough for performance use IMHO.
The OP has already explained that one of the cups is turning brown from heat... the 'why' is certainly lack of adequate oiling. Plus the galling on shafts and inside rockers says a lot.
And it sure does not hurt; I simply cannot see why not do it.
2nd holes on my shafts are 75-80 degrees around the circumference, straight above the bottom hole on the pushrod side. Diameter is .125" (1/8').
RichB
CherryCuda65
If you don't use oil with zinc in it in this engine, the cam can go flat in a heartbeat.
RichB
CherryCuda65
Are you using the correct pushrods for hydraulic lifters? Solid lifter engines use 7.5 " pushrods and hydraulic lifter engines use 7.33" pushrods.
If you were having problems with burnt tips or gaulded tips on the pushrods. Then check out the thread called Reworking the 273 adjustable rockers
70dart65coronet
mopar or nocar
Wow there was alot in that thread...i have the 340 single hole shafts, and my rockers have alot of galling in them.
Is everyone having good results from that thread?
So i am getting a set of 273 rocker arms and 273 shafts from a guy for a $100.
What do you think is the best route to go? should i check and see how the holes line up? add holes/banana grooves? and what about the rockers, should i drill and plug them?
As far as i know the only push rods that are available are these:
https://www.summitracing.com/parts/slp-rp-3159
I was planning on filing the top of the rockers so the lock nut sits nice and square/flat on them and using this locking adjusters:
https://www.summitracing.com/parts/crn-99802-16
So i guess my plan would be:
get the rockers and shafts from a 273 engine.
Check to make sure the 2 holes per each rocker line up with the two holes in the rocker arms?
Bottom hole should have banana grooves?
Some guys where drilling an additonal hole on the rocker arm and plugging a hole with a set screw?
I like the idea of using the lock nut adjusters and filing the top of the rocker arm smooth.
I already clearanced my rockers for the valve springs. and i think my geometery is ok because the wear pattern that is left on the rocker tip is nice and centered up.
Thanks
Is everyone having good results from that thread?
So i am getting a set of 273 rocker arms and 273 shafts from a guy for a $100.
What do you think is the best route to go? should i check and see how the holes line up? add holes/banana grooves? and what about the rockers, should i drill and plug them?
As far as i know the only push rods that are available are these:
https://www.summitracing.com/parts/slp-rp-3159
I was planning on filing the top of the rockers so the lock nut sits nice and square/flat on them and using this locking adjusters:
https://www.summitracing.com/parts/crn-99802-16
So i guess my plan would be:
get the rockers and shafts from a 273 engine.
Check to make sure the 2 holes per each rocker line up with the two holes in the rocker arms?
Bottom hole should have banana grooves?
Some guys where drilling an additonal hole on the rocker arm and plugging a hole with a set screw?
I like the idea of using the lock nut adjusters and filing the top of the rocker arm smooth.
I already clearanced my rockers for the valve springs. and i think my geometery is ok because the wear pattern that is left on the rocker tip is nice and centered up.
Thanks
Rapid Robert
Well-Known Member
I just saw a new set of the ball/cup pushrods with slight surface rust on Moparts for $25
nm9stheham
Well-Known Member
BTW, the 2 holes in the rockers don't line up with the 2 holes in the shaft.
- There is a bottom hole in the shaft with the banana groove; there is no matching hole in the rocker there.
- There is a small top hole in the rocker but no matching hole under it in the shaft; this top hole just dribbles a little oil out that eventually finds it's way onto the valve stem tips.
- The only place where there are holes in the shaft and rockers that come close to lining up is on the uphill (pushrod) side of the shaft where the matching hole to the adjuster resides. This is where the matching of the holes may be useful. (I am of the opinion that if these 2 holes pass each other at sometime during the valve lift cycle, that will be adequate for most typical uses; spring pressures at or under 300-400 lbs and maybe RPM at or below 7k.)
- There is a bottom hole in the shaft with the banana groove; there is no matching hole in the rocker there.
- There is a small top hole in the rocker but no matching hole under it in the shaft; this top hole just dribbles a little oil out that eventually finds it's way onto the valve stem tips.
- The only place where there are holes in the shaft and rockers that come close to lining up is on the uphill (pushrod) side of the shaft where the matching hole to the adjuster resides. This is where the matching of the holes may be useful. (I am of the opinion that if these 2 holes pass each other at sometime during the valve lift cycle, that will be adequate for most typical uses; spring pressures at or under 300-400 lbs and maybe RPM at or below 7k.)
-
