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Discussion Starter · #1 ·
Hi all - im either going nuts here or i already am nuts. Just finished our 393 for the mustang - could NOT get it to run. comp test showed about 5 cylinders with ZERO compression..

Popped heads off - checked everything, deck perfect, heads brand new, reassembled. SAME!!! system is primed.. head botls were chased and I made sure they werent bottoming out (could run them right onto alu without the washer so def enough threads in the block).. Now when I run NO lash, cranking psi hits 180 in 3 rotations..

when I add just a touch on the lash, it drops to 130, at 1/2 turn (my usual on hydr lifters) NOTHING!! Then I tried a leak down test - 7% loss! zero leaks at valves, only some slight crank case loss - NORMAL!!

I thought yes - thats it! these must be solid rollers - jumped online and nope - Hydraulic lifters!!

Which is it? am i nuts or going nuts here.

:/

Do I run zero lash and see how she runs? That does yield 180 cranking across the board pretty much.. or should I keep lashing till it just drops to 170, nudge back up to 180 and lock it there?

 

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Discussion Starter · #2 ·
ive rechecked the lash 20 times and done this a billion times - wondering if these lifters are just super picky? they were rock solid when i removed em which tells me they are pumped - i primed till oil flowed out of the tops plus we half ran it alot on the stand.

Just confirmed, if I so much as touch the lash (even just 16th of a turn)- compression vanishes..

fyi these are new primed lifters :/
 

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steel heads will lose lash when the engine is hot, aluminum heads will gain lash.
you can try and run it at zero to 0.002 lash but that defeats the purpose of running hydraulic lifters.
if you tighten one valve down a couple turns after zero lash and leave if for 20 minutes, does the lifter bleed down?
 

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Post a picture, it might help.

Lifter cup up against the snap ring, like it should be when unloaded, or is it bottomed out in the lifter body even when loose?

i wonder who makes those lifters....because Edelbrock don't make cams or lifters themselves, they just buy from a supplier and add their name on tha part and box.

Any chance the lifter plungers are just stuck from sitting dry with rust preventative on them while boxed up?? The common rust preventers dry up and get stiff and sticky.

Maybe pull a pair and soak overnight in lacquer thinner....
 

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Discussion Starter · #7 ·
Good point - let me check.. far as i remember the lash seemed right when i started opening it up yesterday (stood for a week at the shop)..

steel heads will lose lash when the engine is hot, aluminum heads will gain lash.
you can try and run it at zero to 0.002 lash but that defeats the purpose of running hydraulic lifters.
if you tighten one valve down a couple turns after zero lash and leave if for 20 minutes, does the lifter bleed down?
 

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I can't see the lifter cup retainer in those pics. Can you compress the plunger?
I can't either, unless that is a full circle flat lock ring in picture #2....and if it is, plunger looks completely collapsed and stuck at bottom of it's travel.
Last Pic looks the same way unless that is an optical illusion cause by the camera....plungers look bottomed out and stuck down.

Fstarocka, is the lifter's pushrod cup rim up against the snap ring in the plunger bore??
 

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Discussion Starter · #11 ·
its official - i wanna buy a hotrodders.com tee- you guys are awesome! In my haste never even thought to catch it.

So i popped em out with air- now im wondering shouldnt oil pressure be enough to pump them up? I primed the system for a long time till rockers were showing oil..

Ill test the collapsed one - fill with oil, lash and leave for 20 minutes (do i leave it with valve open or closed?)

616663
 

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You can pump them up, but many will say that is a no no. I have no idea why, but.....that's the word. I can say that I've done many times and never caused an issue.

I'll guess that whomever adjusted the valves didn't use the jiggle method. And in the process set the preload on a collapsed lifter. Not being a Ford guy, it might be difficult to feel with the rockers installed.

You can resolve all of this by adjusting the valves with the intake off so you can put your finger on the pushrod. It is extremely easy to see how much preload is on each lifter. And you can then spin the engine over by hand to check if any of them stick in the compressed position.

FWIW, someone should have noticed the differences in the valve adjustment/poly locks/nut or whatever was being used. Also, I use the jiggle method and the twist method on dry lifters. If both methods don't result in the same adjustment, then I know I have something whacky/wrong.

Edit - forgot to mention, it's a good thing this did misfire and run like garbage, otherwise more damage would've ensued.
 

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Discussion Starter · #13 ·
indeed, that lasher was me.. i did notice the rockers differing and primed and primed as much as i could to try get the motor to pump them up. I also checked for the most minute amount of pressure knowing i was on a spring initially and not oil before priming.. I figured it might run bad but enough to pop them out but clearly not. I hardly buzzed it with air and both of them popped up.

Plus it just so happens that the one cylinder i chose to "check" yesterday had both cups depressed so didnt notice any difference in rockers.. the rest were all out..
 

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Oil pressure won't overcome valve spring pressure....so if they are adjusted too tight and bottomed out oil pressure won't push them back up.
Oil pressure 60-80 lbs, spring pressure 130+ lbs seat and 300+ lbs open.

What would happen is you'd buzz the rpm up and the oil presure would start to lift the plunger on the closing side of the lobe as you get near valve float rpm(doing it's hydraulic lifter job of taking up all clearance lash in the running valvetrain)....and then hold the valve open off the seat either just killing power if there is plenty of valve-to-piston clearance....or bending valves or pushrods if there isn't.
 

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Discussion Starter · #15 ·
Gotcha.. I was under the impression the lifter springs alone would keep them in the pumped position.. so when i lashed them i checked for a very very light contact- and assumed the priming would fill/stiffen them for running - never seen them half collapsed like this.. they have always been open by the cup spring - lightly but open.. First time having some with the cups all the way in -

Lesson learned!!

Oil pressure won't overcome valve spring pressure....so if they are adjusted too tight and bottomed out oil pressure won't push them back up.
Oil pressure 60-80 lbs, spring pressure 130+ lbs seat and 300+ lbs open.
 

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Discussion Starter · #18 ·
not sure if that makes a difference but these are new lifters - out of the box. Im going to re-prime with them popped up and see how it holds.. they have never ran - I hardly buzzed the dropped ones with air and they popped right up.. really didnt take much at all.. as eric said perhaps my initial and rushed lash job kept them down-

and yes im VERY glad there was no interference!!!
 

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"...for Big-Block Ford." 289 302 351

For 800 and change they can't get the description right.
 
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