small block mopar issues

[spun360]

hello everyone.
i'm new here, though a novice on the wrenches, i've been working on my own vehicles for 20yrs. so forgive me if i seem nieve or crude.
i've had a 96 ram truck 360 magnum motor rebuilt twice in the past 5 months. the first build was a nightmare! i still seem to be chasing problems, that i suspect are a lifter issue. my block builder assures me the lifter bores are within spec. what ever that means. so my build has an adjustable valve train. i have tried three different types of oe replacement lifters. the valve spring pressures are 120lb seated and 300lb open @ .495 lift / 1.65 roller rocker arm ratio. when i adjust to .0375 "3/4 turn" pre-load on the lifters i notice some roller lifters are softer than others. johnson lifters have since met the garbage= so soft & i could watch them bleed off quickly. mopar lifters i just wasnt happy with and would take forever to pump up- they would bleed off over night. now i have crowers in it. they seem the best so far. responsive to pump up ,though they still bleed off after 12 hours or so.
i had such a journey in the aftermarket scene. WHAT A GAMBIT! returning parts that dont fit. lifters that dont operate properly. comp double roller chain that stretched in 1000 miles. now i've hit the wall. i cant seem to finalize this engine.
just at cold start, the lifters make noise. it runs down the road fine. lots of hp and torque. the roller valve train maybe alittle noiser than stock, but i can put up with that. its just these bleeding lifters that bug the hell out of me. every lifter change has made a difference. once with the mopar lifters, i had the truck on the dyno. my horse power dropped suddenly after 4000rpm. like a rock! i suspected the lifters were giving up. but the crowers have let me down also. i have yet to dyno the crowers in. they just give the most resistance when i load the rocker arms. sometimes its the cyl 6 intake soft. other times the cyl 6 is tight and the soft one is cyl 2 intake. other times its cyl 5 exh and cyl 2 intake is fine. i dont get it. they pump up. if my lifter bores were too big, then they wouldnt pump up at all right? why am i still chasing a soft lifter around in my engine?
i was told crowers are all tested and can be relied on. not so sure of that now. can anyone suggest a GOOD lifter for a performance truck engine? am i looking for something other than a stock replacement? crane "check ball" lifter or a roads "anti pump up" lifter.
thank you in advance for sharing your experiances!

[Powertrip]

What type of lifter problems are you having exactly? You claim that they bleed down too quickly, but they are supposed to as you adjust them. Are they noisy on startup and then quiet down, or do they stay noisy? Noise can be caused by the design of the rockers, an agressive cam, misadjustment. I've had good luck with Johnson lifters, but admittedly don't mess with hydraulic rollers. Morel's have a good reputation if they are available.

I would start with taking your existing lifters and taking them apart and cleaning them thoroughly. I've found most hydraulics have dirt inside from the factory. I would then adjust them 1 full turn in, don't be afraid to experiment a little with this setting. Good luck and let us know how it goes.

[spun360]

i ususally have one or two lifters that are soft to adjust against. everytime i've been under the valve covers a lifter usually a different bore than last time is fully depressed. why am i chasing colapsed lifters all over the engine? johnsons all colapsed in seconds! mopars seemed soft to adjust against. the crowers are the stiffest so far. at least the crowers i had to go 3/4 turn in 1/4 turn increments. pretty tight. yet i still find a lifter or two down from time to time.
the crowers do pump up at cold start quickly. they run warm quietly. but the cold starts sound like a paint can!
i suspect the valve thats left in the open position is colapsing the lifter if its let go cold. is thats whats going on here?

[Powertrip]

Could be, I would guese the collapsed lifters are the ones up on the lobe. Surprised the Johnsons were so weak. At least it's quiet when warm.

[hodge]

You need to check the lifter collapse that mopar requires the norm is 2 to 3 turns down not 3/4 of a turn. What you need to do is turn down till lifter is collapsed all the way then back it off 30 % of the turns you went in from .000" clearance. and the adjuster should have no more than one thread exposed below rocker.


8.64 et 160 mph 500 ci, pump gas, all motor, mopar door car

[spun360]

i've talked to alot of people about this.
someone who answers the phone over at mopar performance was able to shine some light my way. he talked to me in depth about the lifters them selves. said the normal pre-load was .030-.050.. said if i was going to adjust further to be careful. more than 1/4 inch will damage the lifter. if i'm correct, .25 of pre-load on course thread is 5 turns at .05 each turn. the rocker arms i bought from hughes engines. he stated that occasionaly he sets up the engines at 2 full turns. the speed shops in my area all had a general consensus, no more than 3/4 turn. the stock motor had .030 load on the lifter. i seem to have a spectrum of advice to fallow here and am only chicken chit to go further. the guy working on the motor last professionaly had the no #1 cylinder cranked to 1 full turn and told me he started to loose compression that far down. as if the lifter was hanging open? huh? is it OK to load the lifter down two full turns or more? should i check for this compression loss at 1 turn and call his bluff? chevy guys i talk too, and most go to 1/2 turn on a performance 350 roller. i'm just really banging my head here. and the speed shops are too. the engine blue printer is blue in the face. he doesnt recommend further than 3/4. i still keep making the same mistake over and over. i need to do something else.

[LoneRanger]

Has it back fired at any time?

[spun360]

no has not ever back fired.
does pre-loading a lifter help it keep oil pressure on the p-rods cold? and when oil pressure and rpm is high what keeps the lifter from pumping up to its full stance past its pre-load and keeping things hanging open? does the lifter know when to stop loading with oil and pressure? i just dont know enough about this lifter thing. niether does any one else around here, including the speed shops. seems to be real inportant!

[hodge]

If you go back you said hughes told you 2 turns mopar it is hard to find in print but that is what they spec, you are complaining about bleeding down it is what they are suposed to do the thing is they need more time to pump up if you only have them preloaded 3/4 down. If you checking them after being shut off overnight you need to go back to 0 the same turns back from where you started before.

[Rick71]

Also since you're using adjustable rockers with hyd lifters....are you using any particular method to adjust them?

Either the Mopar 90* pattern or the Exhaust Open Intake Closed Method.

I believe they should only need about .050 preload from zero lash.

[LoneRanger]

I use a piece of metal plate bolted to the head ( rocker cover bolt holes ) & magnetic stand with dial gauge & measure preload while adjusting

[autodoctor911]

what he means is, how are you determinin that the particular rocker that you are adjusting is at the base circle portion of the cam rotation?

if the rocker you are adjusting is on a lifter that is starting to come up, or not all the way down yet, you will end up with either too little preload or even some lash.

I usually only set the preload by turning the engine over by hand on a motor that is being put together. If the engine runs, I just run it with the valve covers off, and adjust them running.

How to adjust hydraulic lifter preload for a stock type lifter(not an anti-pump up):

run the engine with the v/c's off, try to use rags where the oil is squirting to, or put a piece of cardboard up across the outside of the valve cover flange.
most likeley, it will still be messy.

on a chevy, I use 1/2 a turn of preload, so I back off the adjuster nut till I can hear it making noise, then tighten till the noise stops, then turn it another 1/2 turn, repeat 15 times.


I looked to find out how many turns it will take to achieve the proper preload but chrysler does not list one since they aren't adjustable stock, they do list the dry lash though, which is the type of spec used when adjusting an anti-pump up lifter. the spec is .060-.210. this is measured from the point where the lifter bottoms out to your final position.

if you are going to do this turning the engine by hand:

you turn the engine till the valve you are working on is at bdc(tdc of the piston compression strokeis close enough)

slowly crank down the lifter while giving it time to collapse bleeding off the oil. it is best to do this if the intake is off, but you can peek down the pushrod opening sometimes. each time you turn it a few turns and stop the valve will open slightly if the lifters don't bleed very easily, then you wait till the valve closes and turn it some more. you can start off with more at a time, then as you get close to the bottom slow down. It,s allright to go a little too far, but be gentle.

When the lifter cup is all the way down you will turn on the adjuster, avalve will open slightly, and not slowly go back closed.

at this point, back off very slowly till the valve just closes again, then back off the number of turns that equals the specification.


to do this kind while engine is running, just tighten adjuster till you can hear a misfire, then wait for it to subside as the oil goes out of the lifter, until the misfire remains constant, then back off the specified amount.

[hodge]

is this a mopar or chevy you are working on

[mmmitch588]

spun360, if lifter noise will not bother you & you are after max. performance, when your ex. valve just starts to open set your intake to .000" - .002" clearance. When your int. valve has just returned to the seated position, set your ex. to the same. This will give max. performance & it "should" rid you of the problems. Try it, nothing to lose & perhaps much to gain.

[spun360]

thank you fellas.
i set the lifter loads at TDC for each cylinder. i turn the mopar crank buy hand.
well! taking advise could get confuseing.
i bought a remote starter button, so tomarrow i have a few more tricks to try. i'll check compression at 3/4. from there i'll just keep trying cyl #1 till i start to fail out of compression. mopar reps stated more than 1/4 inch of preload will damage the internals. i could believe that. so on course thread adjusters, one full turn will be .050. one quarter inch would be a full 5 turns. hughes engines reinforced that his engines are adjusted to 2 full turns. 20TPI 2 full turns is only .100 preload. when the stock preload was .030 to .050! i'm just worried that i'm damaging things or hanging open the valves and burning out the heads!
i think tomarrow i'll crank down and see if .100 hangs open the valves. coil unpluged, injectors unpluged, hit the remote starter and take some readings as i adjust.
does this sound like a good idea?