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Hi all. So after a long spell of saving and so on I finally had a full set of 273 rockers,shafts,spacers and ball and cup pushrods to go onto my 318.
now in previous posts I mentioned that since the comp cam was installed it was rattly. According to comps website one will get valve train noise with their cams if you don’t have adjustable rockers.
And that’s what was going on.
Now the 273 rockers were installed last Saturday by a friend and myself. It all bolted down perfectly and we did one valve at a time. Wound down adjusting nut in rocker til you feel drag on the pushrod then go 3/4 turn and do up the lock nut! All done.
upon starting it the first time it had a lifter tap. Never had that before?! And even now after two days of running it, if I go for a drive then stop for a while. Start it again and that one lifter taps away for maybe 30 seconds before it shuts up. Anyone got any ideas as to why all of a sudden this would happen?
bit of muck in it maybe?
also after a drive the right hand side becomes a bit tappy. I can hear it even at idle. Not there when cold. I did notice that with the rocker covers off the pushrods seem very close to the tunnel they go down. I wonder if it’s tapping on the side of that but it only does it when warm? And it only seems to be one.
any thoughts appreciated
edit.
I forgot to ask, I cannot find anywhere in my owners manual what viscosity oil to run?
at the moment I’m using a 15w40 mineral by nulon. To thick? To thin?
Good Morning... I went back threw all your post so far. Kind of getting a little hard to follow. But here is my thoughts and a question?
1. What is the oil pressure during all of this. I know you said it had a stock bottom end.
2. 15W40 is ok for a high mileage or a wide clearance engine.. But you have to be careful of the temp range your using the product.
My thoughts on your problem at this point is.... You ether have a bad set of lifters (Its kind of common now days to get a bad set) Or your could have some trash like varnish that came loose during the swap. Or the oil pressure is just too weak from the oil pump.
One thing to look at... after you run the engine.... Dose it look like the upper valve train is getting lubricated well? If not I would say it has something blocking the passage.
about a week ago before installing these rockers I pulled them apart to inspect as they are quite old and I did find two rockers with blocked oil holes. The holes that go through to the pushrod. So all clean now. And with valve covers off I can see that there does seem to be good oil flow. Quite wet at idle and if I rev it up it splashes everywhere!
however after doing lots of reading last night on this subject and seeing some pictures I do believe the pushrods are a bit to short! Wrong geometry.like I mentioned previously some of the pushrods are incredibly close to the tunnel in the head,quite possibly touching hence the tapping.
looks like more saving and take it to a chap down towards the city to determine the correct pushrod length and set it up correctly.
and as for that one lifter, gosh knows why that had suddenly started being noisy. But it doesn’t last long before it’s quiet.
Ah the joys of old cars.
I sometimes wonder why I even bothered in the first place.
but damn it sounds good. Runs nice since being tuned too!
Okay.
then it’s settled, I’ll take them back about a quarter of a turn and try that.
I cannot get to it til Saturday hopefully?
I will update sometime over the weekend.
Okay.
Re-adjusted the rockers. Started from scratch. Went to 0 lash then half a turn from there.
car is driving fine,as before. But still occasionally on a warm start up that one lifter taps away for about 20-30 seconds. Also when cold no tappy tap at idle but is when revs are up. after driving and it’s fully warmed up then the tapping can be heard also at idle? I’m puzzled and sick of taking the rocker covers off and on.
Is it possible to have one bent pushrod? Silly me did not check them when I got them and yes they were used! Also Drag pak,these pushrods do have the oil holes in them whereas my original ones did not but I was told it should be okay to run these?!
the tapping is only on right side of engine and it really does sound like only one? I’ve had it running with the rocker covers off and it’s certainly getting oil everywhere and it’s hard to determine which one exactly is tapping?
the lifter tap is in the left side and I also believe that to be just one also.
or could a rocker be hitting the baffle inside the cover? And if so why only once warmed up?
To find the noisy one, valve covers off, engine running, put your thumb on the rocker end over the valve stem and push down. When the noise goes away that's the one, you couldalso use a mechanics stethoscope.
Haha, we always used a 'rod of sound' – anything long and hollow will work. We had this green thing, looked like part of a fence post, and you put it to the engine and you'd be surprised what you can pinpoint.
UPDATE
Hi all. Well I found the annoying constant tapping. I was reading over the weekend on different Mopar problems and stumbled across a post where this person had the exact same problem!
his 318 had larger valve springs installed along with the new camshaft and he also installed 273 rockers and shafts. See the new valve springs being bigger in diameter we’re hitting the underside of two of the rockers,once I saw it with a bright torch it was very obvious. I took the shaft off and sure enough those two had witness marks on them. The only way to fix this without changing the springs again (expensive) was to use a tiny grinding bit and make shallow concaves where the marks were. Easy fix and no tapping at all so far. Was driving yesterday and today for an hour as well. The thing I don’t understand is that the valves at the front of the engine had a wider gap between that and the rocker than the valves at the back of engine,firewall end. It seems to taper in a bit. Everything is in place as it should be. The shaft is in a cradle so that can’t move? Ah well. It’s quiet now. BUT that one noisy lifter on the left side of engine keeps bleeding down. Regardless of whether engine is warm or not. Once it fills with oil it’s quiet as. I put in an additive and it says on the bottle to give it 500 kilometres so we’ll see how that goes.
I believe I can take out stuffed lifter through the hole in the head? Using a long telescopic magnet?
anyone done this?
UPDATE
Hi all. Well I found the annoying constant tapping. I was reading over the weekend on different Mopar problems and stumbled across a post where this person had the exact same problem!
his 318 had larger valve springs installed along with the new camshaft and he also installed 273 rockers and shafts. See the new valve springs being bigger in diameter we’re hitting the underside of two of the rockers,once I saw it with a bright torch it was very obvious. I took the shaft off and sure enough those two had witness marks on them. The only way to fix this without changing the springs again (expensive) was to use a tiny grinding bit and make shallow concaves where the marks were. Easy fix and no tapping at all so far. Was driving yesterday and today for an hour as well. The thing I don’t understand is that the valves at the front of the engine had a wider gap between that and the rocker than the valves at the back of engine,firewall end. It seems to taper in a bit. Everything is in place as it should be. The shaft is in a cradle so that can’t move? Ah well. It’s quiet now. BUT that one noisy lifter on the left side of engine keeps bleeding down. Regardless of whether engine is warm or not. Once it fills with oil it’s quiet as. I put in an additive and it says on the bottle to give it 500 kilometres so we’ll see how that goes. I believe I can take out stuffed lifter through the hole in the head? Using a long telescopic magnet?
anyone done this?
Hello again fellow mopariuns!
After a long spell, I changed out all the lifters yesterday and I’m pleased to say the tappy tap tap is gone!
and yes I pulled them out through the heads. Drivers side a bit fiddly as the brake booster and master cylinder were in the way(right hand drive) but done now.
One more question folks if I may, I’m concerned about the pushrod length as this whole set I bought was used. The current pushrods are ball and cup and from tip to tip they measure 185mm. Now the reason I ask is because my engine is reluctant to rev over 4,000rpm and I’ve read if the geometry is out then things like this can happen! Also read that once the rockers are adjusted there should be about one to two threads showing on the adjuster screw! Mine are showing no threads.
I did find an interesting article on another forum in which I’ll add(not sure if I’m allowed to or not) but I need advice and I’m not sure on who to take my car to over here.
thank you in advance
vance
Hello drag pak.
well that certainly is an option,cheaper for me too BUT I still need to find out how much (mm or thou) to shim it by. Hmmmm. One does ponder 🤔
Hello drag pak.
well that certainly is an option,cheaper for me too BUT I still need to find out how much (mm or thou) to shim it by. Hmmmm. One does ponder 🤔
If you go this route, I would start with 0.010 shim stock and stack them as needed. And make sure the shaft seats on the shims and the shaft oiling holes are considered.
Hi all. I contacted a Mopar guru last weekend whom said that pushrods DO NOT change rocker geometry in a shaft mounted set up whatsoever and he went on to say that spacers will change the geometry and usually for the worst!
the cars running great but I can’t help but wonder IF the pushrods were a wee bit to long what the consequences of this would be?
as I said before, I have no threads showing in the adjustable screws whereas I’ve read that there should be one to two threads showing. Dunno 🤷
mind you there’s not a lot of adjustment left before thread starts to appear?
And these crane units are slightly longer than the stock adjustable screws. I think I may be reading into it to much.
I’ll just enjoy it and drive it for now me thinks.
I think I’ll save for a diff with a 3:23 ratio. Currently a 2:92. A bit sluggish.
Let me understand, you dont have threads on the top or bottom of the rocker?
there is threads on the rocker adjustable screw yes but from what I’ve been told there should be one to two threads showing on the underside of the rocker. In other words, just above the ball that goes into the pushrods cup.
here we go folks. My Chrysler so far.
in this video you will hear the tapping is not so bad at all now. May just re-adjust tappets later on otherwise it runs well.
And to add to this I still believe that the pushrods are to long!
it just doesn’t want to rev past 4,000rpm.
The heads have never been off this engine so can I just compare the base circles from the stock cam to the new cam and determine pushrod length from
there?
I read that the comp 268H had a base circle of .7040.
anyone know a standard LA 318 cam base circle?
tanku
Have you looked at the ignition and carburetor yet? Is the choke opening as it should??
hi lowan.
I know it’s the pushrods, it has to be. This is the only change that was made, rockers,shafts and pushrods.
the original pressed steel rockers that were on there along with the original ball and ball 7.50 inch pushrods and the engine would pull 5,500 rpm easily so it’s only since it all got changed.
It was all professionally tuned and runs well. So yes I’m confident that it’s the wrong length pushrods!
it’s either this or I go back to the original set up and use lash caps to eliminate the chatter it had. In which I’m seriously thinking of doing!
and I don’t have a choke anyway. It doesn’t need it.
Hi again all.
UPDATE
So I got sick of all the tappy trouble I was having with this valve train so I actually did buy lash caps in an 80 thou size, reverted back to the standard rockers and shafts and voila,quiet as now! Fantastic.
And I found the issue with it not wanting to rev past 4,000rpm. It was not the wrong length pushrods as I had previous stated,although I don’t believe that this helped, but it turned out that it was the ignition module on my HEI distributor. I changed it for a new Bosch unit and it just feels better all round now.
I deleted the old video I had of my car as I didn’t like the engine noise but I recorded a new video of it now.
Tanku all
02-15-2021, 01:09 AM
