adjustable rockers with hyd. cam

[charger318]

So I have a question I was hoping someone could answer. I have been looking into using 273 adjustable rockers with a hydraulic cam. from what I have read you adjust them much like a solid lifter cam with the lifter on the heel of the lobe until you get to zero lash, and then you preload it to .020-.060.........and all of this is done with the lifters being empty of oil, so not primed. but if u go to zero lash and then preload it to .030 lets say what happens when u start the engine and they want to pump up? you already adjusted the push rod down with them collapsed all the way? just trying to get more info before I finish putting the old 318 back together this spring. thanx

 

[62 Dart Convertible]

Preloading a lifter 0.030" is not a lifter that is anywhere near "collapsed all the way".. if you kept adjusting further until the valve started to open, then the lifter plunger has bottomed out...

Found rocker gear but can't find pushrods? Find 2 sets of slant six pushrods and cut them down (on a lathe preferably) - you'll have a few spare to practice on..

 

[charger318]

I guess I just figured if the lifter bleeds out all the way it would be bottomed out, and then u would be preloading it. So I guess it isn't bottomed out even if it bleeds out. I saw a pic online that made me think I have some kind of spring on bottom internally or something?

 

[62 Dart Convertible]

Lifter does have a spring loaded plunger that contacts the pushrod. With lifter on base circle of lobe, adjust rocker until pushrod just begins to move plunger down (compressing the spring) and give it 1 more turn and that's where you lock it. I have the chart in a MP book with the cyl/valve order in which you do them when you turn the crank in 90 deg increments. I'll post it tmrw...

 

[bigmanjbmopar]

I just switched over to hydraulic rollers and 1 full turn is what it to get them set. we experimented with 1/2, 3/4 but in the end it was 1 full turn in that did it. If you are hearing train noise they maybe too loose.

 

[charger318]

Ya I used a caliper to see how much 1/2 turn would be which was .021 so 1 turn would be about .042 preload. Sounds good

 

[62 Dart Convertible]

Here's the chart -

 

[charger318]

Thanks alot

 

[PurpleBeeper]

Lifter does have a spring loaded plunger that contacts the pushrod. With lifter on base circle of lobe, adjust rocker until pushrod just begins to move plunger down (compressing the spring) and give it 1 more turn and that's where you lock it. I have the chart in a MP book with the cyl/valve order in which you do them when you turn the crank in 90 deg increments. I'll post it tmrw...

OK, please explain why I'm doing this wrong....I have adjustable rockers and a hydraulic cam in my 440. I follow the Mopar valve adjusting chart and with the lifters full of oil & the rockers backed off I twist the pushroad with one hand while tighten the rocker slowly and when I feel the very slightest drag on the pushrod (zero lash) I tighten the rockers only 1/4 turn more and lock them down. It sounds like you are pre-loading the lifters more than I am. Please tell my why a full turn is better???

 

[bigmanjbmopar]

Go 1 full turn not 1/4. Rod snug then 1 turn

 

[IQ52]

Lifter preload is more than just a generic 1 turn or 1/2 turn crap. For instance, Comp cams High energy lifters should have .045" preload or one turn. The Comp Cams Pro Magnum lifters are to have .000"-.006" preload or zero to 1/8 turn. You must know what the lifer manufacture requires for their lifters. I have however run stock generic lifters successfully from zero to one turn preload, depending upon the engines requirements. You must be smarter than your lifter.

 

[khryslerkid]

Lifter preload is more than just a generic 1 turn or 1/2 turn crap. For instance, Comp cams High energy lifters should have .045" preload or one turn. The Comp Cams Pro Magnum lifters are to have .000"-.006" preload or zero to 1/8 turn. You must know what the lifer manufacture requires for their lifters. I have however run stock generic lifters successfully from zero to one turn preload, depending upon the engines requirements. You must be smarter than your lifter.

I was shopping for lifters awhile back, haven't committed to any yet but what's the difference between High energy and Pro magnums? They both sound like high pump, the Pro's being stronger. What's the formula for selecting a hydraulic lifter now days and what's the best make/ company?

 

[Meep-Meep]

I typically run one full turn from zero lash and seem to have good results. The idea on an OEM style lifter is to put the lifter plunger in the middle of it's travel. Per FSM you measure the total travel (about .200") then select the pushrod length (non adjustable rockers) that puts the plunger in the middle.

 

[bigmanjbmopar]

1 turn, 1 turn only please.
"Red October, Red October"

 

[charger318]

ya I just have the original lifters in there I was going to re use them because they didn't have a problem before and look really good still the previous owner might have changed them because someone has changed timing chain and intake gaskets and stuff. So probably still 1 turn or in my case about .042 preload on the original type lifters?

 

[pistol_grip_polara]

:book1:

just subscribing to this thread as I have a hydraulic cam, and a set of 273 style adjustable rockers.. scored a set of thicker ball and cup pushrods..

once I degree the cam in I will be adjusting them all and there is a lot of useful information here..


Thanks

 

[IQ52]

I was shopping for lifters awhile back, haven't committed to any yet but what's the difference between High energy and Pro magnums? They both sound like high pump, the Pro's being stronger. What's the formula for selecting a hydraulic lifter now days and what's the best make/ company?

http://www.compcams.com/catalog/255.html

http://www.compcams.com/v002/Products/CC-%27Hydraulic%20Lifters%27-0.aspx

 

[69 GTX]

Might be just me but I try to stay away from powdered metal in any part. The high energy lifters have the pushrod seat made out of this. They are probably fine for lower lift & spring pressures but I would opt for the pro's if it were me. Just my 2 cents worth.