I just traded for this car,it has a 73 340 with a hydraulic cam. When the car arrived and i started it it sounded like it was not pumping oil to the lifters. I went right away and put an oil pressure gauge on it. It has around 20lbs at idle and goes up to 40 with some throttle. I thought the lifters may be bad so i just installed a new set. And it is going the same thing. With the valve covers off it is shooting what seems to be plenty of oil in the rockers. The rockers do seem awful loose on the shaft, could they maybe be worn out and not letting the lifters pump up ? Thanks for any help here.

Did you oil soak and prime the new lifters prior to installing?

i soaked them in oil and stp mixture overnight

i soaked them in oil and stp mixture overnight

Did you prime them too? Typically I'll take a pushrod and prime them until they fill with oil and become solid. You'll see the air bubbles escaping if you do it while they are soaking. Even after I prime them I still let them oil soak for a couple days to make sure all the air has escaped.

if the rockers (both banks) are being fed then the horizontle main galleries & therefore the lifters (which are upstream) are being fed also. I'm assuming you did a cam breakin procedure when you dropped the new lifters (unrelated to the noise tho). Only thing coming to mind is, see what your preload is: get a lifter on base circle. Set a small thin 6" steel scale ruler across on the valve cover rails close to the pushrod. make a sharpie mark on the ruler edge & slide it over fast to make a witness mark on the pushrod. unbolt the rocker shaft evenly so it rises evenly (horizontally) till the pushrod JUST stops moving upward )if it goes sideways it'll skew your test). repeat a witness mark then remove the rocker shaft/rockers all the way off & lift out the pushrod & measure the distance between the two marks. you're sure nothing else is rubbing/touching correct & that it is lifter clatter? I wouldn't think the preload would be borderline not enough then something finally reduced it that last bit/locked it solid (in effect no preload). Holler how it turns out

I can take the rockers and on a few push in the lifters. Not all of them push in. but a few do like they don't pump up, and they are the same ones as the old ones in the same lifer bores. I can also wiggle the rocker arms on the shaft which i think is a way too much play.

I would bet that those rocker arms are a bit wallowed out, or there is possibly a mismatch of parts. (pushrods, lifters wrong etc.)

It`s possible you could have some bad new lifters. You do know that the exhaust and intake rockers are different. They can get them mixed up easily. Rockers are normally somewhat loose on the shaft. If you think they are worn bad, get one new one and compare to see. BTW, i never pump up the lifters prior to installation. I just quickly dip them in oil and put the break in lube on the base. Never had a issue. Also what did the bottoms of the old lifters look like? Worn?

Filling or priming hydraulic lifters is a great way to bend pushrods when installing the rocker assmblies, not so good a way to properly fill them though. If they aren't filling up from engine oil pressure then lack of priming or filling them isn't the problem.

I would take the soft lifters out, disassemble, clean and inspect them.

A lot of lifter suppliers are recommending not soaking new lifters and to install them out of the box. If the top of the engine is getting oil feed then here is what I have learned to do to help get lifters to pump up. It is messy but the vast majority of the time works. Run the engine with the valve cover off and put downward pressure on the pushrod end of the rocker. This helps the lifter bleed the air out and take a prime. Also some times all it takes is to run the engine and then shut it down and let sit for a few minutes, restart and the lifters have bled out and pump up on restart.

Thanks moparforlife i will try that.

Chrysler used some blocks with .008 O.S. lifter bores. They should be stamped with a diamond shaped mark on the lifter boss. If there is a standard diameter lifter in an oversize hole it'll fit like a brick in an ashcan. Check side play on the noisy ones.

I had a customers car 71 roadrunner with a 440 that had the same problem. Car came in with a blown head gasket and clacking away. Replaced the head gasket and reset lifter preload as the owner said he tried adjusting them. Rolling the engine by hand I would have loose lifters by the time I got the bank done. You could push the lifters down like slinkies!!! Finally got the to adjust fired the engine and it was noisy for about one minute and settled down. The customer took the car and ran it about three weeks and came back with same clacking and wanted to change the lifters. Changed the lifters and it ran good for about 5 miles and the ducks were back. Just couldn't get the lifters to hold a prime. The engine had about 500 miles on a complete rebuild that another shop did. Only thing I could come up with was the lifter bores had excessive play but the new lifters felt good in the bores. The owner parked the car and is planning to bring it back when he has the funds to open it back up. This one always puzzled me and I looking forward to getting it back to find the answer.

oh boy lifter bore sizes don,t sound good. thanks for that info

Phil, interesting topic! post what it ends up being

Have not messed with it ,am going out now to start work on it, I will let you know what i find out.

Sorry it has taken so long to get back, Latest thing i did was install new pushrods and adjustable rockers. Same clatter as before, so when I feel like it I am pulling the motor and install all new bearings and oil pump. And new cam and lifters, Hope for the best then.

You really need to determine what the EXACT problem, problems, are before throwing some more parts at it

Parts replacing may not fix it. you already did the lifters once. What is the most oil pressure it will make running?

Hoping will not fix it!

I just went through soomething similar on a 340 a guy brought in and found the caps out of the hole behind the cam thrust plate, it was driving us nuts because it was only one lifter and just at 800 or so idle then it would go away with reving it a bit. It had 12-15 PSI at idle and it has always been enough in other engines I have seen but this one just would not quit the ticking. The pressure would jump right on up to 70 with a few RPMs. After putting in the plugs it now holds 50PSI hot idle and zero ticking.

No mention whether the engine has a recent rebuild or if had been vatted. Before pulling engine remove the oil sending unit and take a straight piece of coat hanger or welding wire and stick in the hole that the sending unit came out of.About 4 inches down in the hole 340s have a small plug about 5/16s in diameter that looks like a small freeze plug which diverts oil to the top of the engine. Sometimes when vatted this plug comes out and the result is poor oil pressure. If the wire goes 6 to 8 inches down the hole then that plug is missing. Easy to check before pulling engine and can be installed from the top.Hope this helps!

this thing at idle has 9 lbs. And holding it at about 2000 rpm it has 35 lbs and will drop slightly while it is revved up to 30 lbs. I recently pulled the distributor out and used my drill with the priming rod and it held 50 lbs. I don't get it?

you have to take into account you drill may be running faster than the distributor drive is. And no I do not know what the ratio between the crankshaft RPM and distributor drive is. only other explanation would be cold vs hot oil

I just did the wire hing and there is no plug. I took ,y light also and looked down the hole there is nothing there.

If I may respectfully disagree, if that internal plug is missing the oil psi will be the same or even a bit higher (cuz the oil has a straight shot vertical up from the #5 cap to where it turns into the horizontle gallery & it ain't held back by the filter restriction) however the oil will be unfiltered (very bad deal) & if that ain't caught early on the eng will have an earlier(er) demise years on down the line while all the time the owner is thinking he is doing the right thing/being proactive with frequent oil/filter changes. We gotta find out what passage etc (something) that is being partly uncovered etc when it is running that ain't opened when bench testing with the primer. I'm thinking it is lifter related.

well once the lifters are pumped up solid they should stay solid,am i correct? If I have some lifters that are not holding pressure then i would assume they are bad lifters.

I'm thinking the height of the side oil hole/gallery height interface especially if lifter to wall clearance is healthy. I'm just thinking out loud but we are losing alot of PSI & not thinking that the crank/bearing clearances would be altered significantly from running/not running esp if you are running full groove mains (but I ain't sure on this/just speculating) but with FG mains I'd think the passages (saddles to crank innards) would be open all the time.

Fix the broken part first and see if that is the problem or not You have treid a lot of things to fix this problem You have now found a problem that needs fixing so fix that and see what the results are

The lifter on the one we were working on did bleed down when the pressure got low, replaced it a couple times and no difference.

Cab is right, fix what you know is wrong and go from there.

FYI full groove bearings do tend to cost a few PSI.

The ratio between crank and distributor is 2 to 1 so if your drill turns 500 RPM it is like the engine turning 1000 RPM. Also the cam lube may or may ont be getting through depending on where the cam is stopped when drill priming.

Thanks guys for all your input, I almost have the engine out so im putting new bearings and oil pump also new cam and lifters ( I DID"NT LIKE THE ONE IN IT ANYWAY ) And cam bearings. I have the front off the motor and pulled the cam out, FRom my past memory one of the cam retaining bolts used to have a hole in it. This one has all solid bolts. I'll read my manual and check that out.

They only have a hole through them if you put a hole in it. I usually do it on the top passenger side bolt to drain the little puddle onto the chain, gives more chain lube and aids drainback time.

Some OE had a 1/8" hole in the top pass bolt and some had the angled drip tray & a guy said some had both. It is a drip oiling and I drilled a good sized hole in the retainer flat plate and a .015" hole behind that in the front pass mini cup plug in the front of the horizontle gallery for a constant squirt onto the chain and the same .015" hole in the rear 3/8 NPT pipe plug in the drivers rear of the horizontle oil gallery for a constant squirt onto the intergear (when you preoil you can see its function). Get an aluminum pipe plug & drill it REAL slow especially on steel ones like the cup plug & buy several of the .015" bits as you will likely break one especially on the steel front cup plug.

What would they call this plug at the parts store? I sure want to put it back in while im working on this thing.

Ma has it & a parts store would also & likely called a cup plug. its a small one & you need the exact size. You drive it in up thru the #5 main cap block saddle

So if I understand this thread correctly, this "cap" cannot be installed from the top of the engine! It must be installed from the bottom? I am having the same problem, on a 340. No one has been able to figure out why the lifters rattle.

My 340 rattled when they didn't install that plug but also missed the threaded plug in the galley by the distributor!

That normally ends up with a motor having no oil pressure, epsecially when trying to prime it with a drill motor, don't ask me how I know that now There be two galley plugs on Mopar SB motors on the drivers side at the rear of the block, the large one one is for access to the smaller one inside in front of the distributor and that one is essential to seal the oil galley passages up on that side

Ok now we are confused. 68 gts said you can put this plug in from the top. Who is correct?

installing vertical oil gallery plug. bottom saddle hole ID .570". top threaded NPT sender hole .336" (& NPT threads get narrow(er) further down).

Sorry if I confused the issue, that drive in welsh plug, cap, needs to be installed from the bottom with the #5 main cap off the block I believe, I've never had to reinstall one in any SB Mopar I've ever worked on It makes all the oil from the oil pump go through the oil filter instead of going straight up that oil passage directly to right side lifter

Ok thanks guys

Ok all you guys that gave me advice. Sorry it has taken so ling to get back,but just got the engine back together and problem solved. So whoever put the engine together before I got it,left the oil galley plug out near the distributor shaft at the rear of the lifter galley. In the meantime it started eating up all mt rod bearings and the crankshaft. I had the crank reground and all new rod's and main's. Put new cam bearings along with new cam and lifters again. Just started it this past weekend and has 80 lbs at cold start and 60 lbs after it got warmed up. Not one bit of lifter noise. Thanks for all the advice on here.

I had a buddy who had me looking at his 340 for low oil pressure as he had a solid cam in it and he had a machine shop build his eng. He had about 10 psi at idle and at 3000 rpm it would only go to about 35 to 40. The machine shop told him that was fine ! Ah I told him no way as this was a complete rebuilt eng with all new bearings and oil pump. Anyway I pulled the pan and put a jug of oil up to the oil pump screen and ran the pump with a drill. Then I saw all this oil leaking internally near the dist running down past the mains onto the ground as they had forgot to put that oil galley plug in near the rear of the eng in the lifter galley. Sounds like the same one you had missing as this you can see when you take the dist out. Since then I have seen this a few other times. Ron

Yep,that was the same one here. Also about the same oil pressure I had before