SpeedTalk Store - Opinion Columns

Hydraulic lifter trouble

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Hydraulic lifter trouble

Postby zoomzoom » Mon Jul 12, 2010 8:49 am

Putting together a 351C with a hyd. flat tappet cam. Heads milled for adj. valve train, arp studs, and comp roller rockers. shorter push rods got my rockers sweeping across the mid section of the valve stem. When adjusting the valves, the lifters are incredibly inconsistent. They were manually pumped in a coffee can full of oil prior to installation. Once installed, I have adjusted lash 1/4 turn past initial tension/contact with the lifter plunger (NOT bottomed out).
Several of the lifters would bleed down within 10 seconds, with only the weight of the pushrod on them (used a drill to build oil pressure, but plungers would drop almost as soon as the oil pressure went to zero).
Several others are completely rigid, and the plunger will not compress. :x These push the valve off of the seat as soon as any adjustment beyond initial contact.
These are a new set of comp lifters. I am a competent machinist, and an accomplished engine "assembler", but this has me stumped. Would somebody like to give me a tutorial on what I have done wrong, or do you believe that I just have a crappy set of lifters?
Run what cha brung. Heads up racing RULES
zoomzoom
New Member
New Member
 
Posts: 12
Joined: Tue Aug 07, 2007 11:29 pm

Re: Hydraulic lifter trouble

Postby Headcase » Mon Jul 12, 2010 10:52 am

Ran into Comp stuff before that came out of the box stuck....need to disassemble the stuck lifters and clean and reassemble....wouldn't sweat the rapid bleed down....Headcase
Headcase
New Member
New Member
 
Posts: 15
Joined: Fri Dec 11, 2009 12:48 pm
Location: stoughton ma

Re: Hydraulic lifter trouble

Postby Powertrip » Mon Jul 12, 2010 11:46 am

I also have run into problems with comp lifters bleeding down too fast. Had to disassemble and clean- found a lot of krapp inside. As far as the lifters NOT bleeding down, DON'T fill them with oil before you install them.

Nowadays, the first thing I do is pull lifters apart, clean them, assemble with a LITTLE light oil, install and adjust, pre-lube the motor while turning it over. If you still have lifters collapsing immediately, they are either still dirty or just plain bad.

Does anyone have a source for GOOD hydraulic lifters?
Hobby engine builder.
Professional family man.
Powertrip
Member
Member
 
Posts: 133
Joined: Sat Feb 10, 2007 11:09 am
Location: North West Indiana

Re: Hydraulic lifter trouble

Postby cjperformance » Tue Jul 13, 2010 5:19 am

the adjustment you described will work fine.
As for the lifter's that bleed off, pull one apart and keep a close eye for any grit etc in it, but it may simply still have some air in it.
For the one's that dont bleed off, fine, they will bleed off with time.
BUT, you can pull them all apart, clean and inspect for comfort sake.

As for good hydro lifter's, i have used Sealed Power since 1984 and only had ONE come back after about 300miles in which the hydro unit had collapsed.
ALSO, the lifter,s that CROW CAM'S here in Australia sell in their own box are excellent too, never had a problem with them.

BUT - 'ONCE' i got sucked into, 'against my better judgement', fitting a set of Pro Comp lifter's into a mate's tight budget rebuild 351w. After 100miles they All passed out! No pro comp anything for me ever again!
Craig.
cjperformance
Guru
Guru
 
Posts: 1466
Joined: Tue Aug 19, 2008 6:20 am
Location: South Australia

Re: Hydraulic lifter trouble

Postby Procision-Auto » Tue Jul 13, 2010 6:37 am

Several of the lifters would bleed down within 10 seconds, with only the weight of the pushrod on them


That alone raises some question. The spring in the lifter chamber should hold up the pushrod without any trouble.

If the spring can't hold up the weight of the pushrod, it will not allow proper function of the check ball and plunger
assembly.

Seems like you have some faulty lifters, or very dirty as the others mention. Initially I thought you had an incorrect
preload setting, but your method is fine (lifter's on the base of the cam lobe, correct?).
Procision-Auto
Guru
Guru
 
Posts: 1603
Joined: Tue May 02, 2006 7:11 pm
Location: Kitchener, ONT., Canada

Re: Hydraulic lifter trouble

Postby zoomzoom » Tue Jul 13, 2010 8:42 am

I will pull them all out, and disassemble/clean & inspect. Dissappointing to hear that Q/C at Comp is so poor.
The rapidly collapsing plungers are also leave the valvetrain LOOSE prior to oil pressure build up. No pushrods out of the cups in the rockers, but close, and disconcerting. Is this type of plunger collapse common with high bleed down rate lifters?
As far as my technique, I have always used a firing order/TDC method, in which I set #1 at TDC-compression stroke, and adjust both valves for that cylinder, rotate the crank 90 deg's, and adjust both valves for the next cylinder in the firing order. This always seemed like a no brainer to me, as TDC-compression stroke should be a guaranteed point of zero lift...
Anything specific to watch for inside these lifters, aside from dirt/contaminates/obviously mangled components?
Is there a specific plunger preload that I should shoot for aside form 1/4 turn of the poly lock? I have read of Vizards thoughts on adjusting to .010" from the bottom of the plungers travel, but I would rather have minimum maintenance suggestions, rather than max effort ideas.
This engine does have a fairly stiff dual valve spring, and I would like to hear if anybody thinks that high spring pressures are harmful to hydraulics. (No spring pressure spec's in front of me, but I recall it's at the top end of what comp recommended for this cam.) Please no lectures about going to a solid lifter cam, as I am assembling this for somebody who is as thick as a brick wall, and thinks this is the low maintenance way to horsepower happiness. #-o
Run what cha brung. Heads up racing RULES
zoomzoom
New Member
New Member
 
Posts: 12
Joined: Tue Aug 07, 2007 11:29 pm

Re: Hydraulic lifter trouble

Postby cjperformance » Tue Jul 13, 2010 6:38 pm

zoomzoom wrote:, I have always used a firing order/TDC method, in which I set #1 at TDC-compression stroke, and adjust both valves for that cylinder, rotate the crank 90 deg's, and adjust both valves for the next cylinder in the firing order. This always seemed like a no brainer to me, as TDC-compression stroke should be a guaranteed point of zero lift... --- OK for most mild/hot flat tappet, BUT at tdc you are not on the center of the base circle, with a big cam you will find that this method will put the lifter on the opening/closing ramp and fudge your adjustment.



This engine does have a fairly stiff dual valve spring, and I would like to hear if anybody thinks that high spring pressures are harmful to hydraulics. (No spring pressure spec's in front of me, but I recall it's at the top end of what comp recommended for this cam.) --- So long as the springs you have are 'basically' close to what the maker suggests the lifters will be perfectly fine.

Please no lectures about going to a solid lifter cam, as I am assembling this for somebody who is as thick as a brick wall, and thinks this is the low maintenance way to horsepower happiness. #-o--- In this case then hydro is great!! keep the plunger adjustment the way you have described for many many fuss free miles :)
Craig.
cjperformance
Guru
Guru
 
Posts: 1466
Joined: Tue Aug 19, 2008 6:20 am
Location: South Australia

Re: Hydraulic lifter trouble

Postby A HotRod » Tue Jul 13, 2010 9:31 pm

[quote="zoomzoom"] Dissappointing to hear that Q/C at Comp is so poor.

All they do is buy them from the lifter companies and box 'em up...
Glenn
User avatar
A HotRod
Pro
Pro
 
Posts: 209
Joined: Tue Jan 13, 2009 8:21 pm
Location: Gulf Coast of Florida


Return to Engine Tech

Who is online

Users browsing this forum: bohnstrj, Cid, David_viny, gofaster, hoffman900, Rizzle, WPH and 43 guests