I installed new lifters without priming them so I could physically see when the plunger was centered. After I set all of them at the center of their travel (ended up being 1 1/2 turns) I primed them with the oil pump. After that, some I could not compress to bottom them out, others I could. I had to prime the pump with a ratchet and I assume some might have gotten primed more than others. Am I wrong? All the pushrods seeped oil.

Another concern I have is the new Melling High volume Oil Pump makes a clicking sound when I spun it.

So you've proved that the lifter and engine manufacture did guess the plunger travel correctly. I always shudder when people use the 3/4 turn for adjustment for reason that you asked your question (some bottoming out and some not). Once the plungers are pumped up and wear in, they will all be tight. The plungers are not traveling all of the way out and the volume of oil that is compressed is less than folks who use the 3/4 turn. Anyway, I'm glad to see that someone didn't accept the old wives tale of the 3/4 turn and experimented to see for themselves.

You pump is making that noise because the gears haven't yet worn in. It is normal and more noticable on a new pump than a pump that has been broken-in.

Did you add any mods or is this a stock rebuild?

[This message has been edited by 87GTZ34 (edited 08-31-2003).]

I am actually replacing a failed cam and lifters. The first time I went 3/4 turn and 2 lifters imploded and wiped out their lobes. $300 later, I'm worried everything I'm doing is wrong. On the last cam I thought I did everything right, but I guess I didn't.

So here I am asking for reassurance.

If the lifters are installed dry, then primed will they not have the downward travel they did before they were primed?

As far as the motor goes: Turbocharged 2.8 GM shortblock with polished heads, SI valves, SI bronze guides, Aluminum flywheel, ported/polished intakes, CC 1.6 roller rockers, Crower custom grind turbo profile cam and a few other goodies.

So here I am asking for reassurance.

If the lifters are installed dry, then primed will they not have the downward travel they did before they were primed?

Well most likely you will get inconsistent results from lifter to lifter. For a more accurate downward travel experiement, you would need to keep consistent oil pressure (and flow) on them as well as cycle them thru a few strokes. While running they will compress and then bleed. The compression is slight from the rest position of the cam and the bleed is also slight due to the real time of the return distance. If the plunger bores have oil in them the "free" travel will be reduced but may bleed out if you leave them compressed w/ no oil pressure pumping them back up.

While I believe in centering the plunger in the lifter bore, I don't think only going 1/4 of the way down was the 1st domino of your cam problem. If you have changed the rocker ratio, then the thread count (# of turns) needed to center the plunger will also change. Also, were the cam surfaces hardened after they cut the cam? One other item (you may have already checked it) but did you verify that your springs are not binding anywhere?

I was just doing lash today, I have read your post about the 1 1/2 turn thing. I have installed a crane powermax 2030 (.423" valve lift) in my otherwise stock (with exeption to porting) 2.8. I first tried to set the lash by wiggling the rockers and pushrods and tightening to the point where the movement started to see the smallest resistance, then I gave it a 1 1/2 turn, this opened the valve. Then proceded to move onto the next rocker. As I was spinning the motor, it locked up as the valve retainer hit the metal sleeve within the valve spring. Tried this again with the 3/4 method, seems ok now. Perhaps its because I have never had to do valve lash before. Amature, yes. (iron dukes are just tighten till tight) But maybe I should have waited longer for the lifters to bleed down, I don't know.

Can you give me an Idea of how lifters are supposed to work? and, Why you want the lifter's internals in the center of there travel? I would have thaught that they would have to be tightened till the piston part of the lifter is just off of unloaded, because you are always more worried about the lifter plunger bottoming out and holding a valve open as the motor heats up, like what might happen on a car with solid lifters.

"The plungers are not traveling all of the way out and the volume of oil that is compressed is less than folks who use the 3/4 turn."

Why would the plunger travel all the way
out? It can't, right?

Thanks.

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84 Indy fiero Quad 4 HO (almost done!!)
85 2m? Getting parted out soon
Silver 88 GT, Newest addiction.

quote Originally posted by Fierobsessed: Can you give me an Idea of how lifters are supposed to work? and, Why you want the lifter's internals in the center of there travel? I would have thaught that they would have to be tightened till the piston part of the lifter is just off of unloaded, because you are always more worried about the lifter plunger bottoming out and holding a valve open as the motor heats up, like what might happen on a car with solid lifters.

A hydraulic lifter is a self-adjusting device designed to keep the lash, or slop, in the valvetrain at a predetermined amount. The amount of distance that a lifter can adjust within is called the travel, basically that's the distance that the poppet can be depressed in a dry lifter. There are all sorts of factors that affect the lash on a valvetrain. Thermal expansion and wear are the main ones. When you set a lifter poppet at the middle of its travel, you are giving it the most self-adjusting capacity in either direction of travel. If you only barely move the poppet off of its upstop, then wear will cause you to have to adjust the lifters again. A properly adjusted lifter will maintain proper valve lash for the life of the engine.

JazzMan

I thought that you wanted to set the hyd. lifter at it's upper most travel. Thinking is that as the rpm goes up, you have less time between cycles to "re-fill" the plunger each time. Thus giving you less lift while maintaining higher rpms, and losing power (less valve opening each time) as you go up the rpm's.

With the valve in the closed position,tighten the valve lash until you feel resistance, then tighten another 3/4 - 1/2 turn. Racers set theirs at an 1/8 turn to get the most lift possible without hitting the lifter lip with the plunger.

Just my .02 from what I have read from engine books.

John

I have a different take on this, mostly based around the 60*V6, is not a turn of the rocker nut technique, but a pre load, which is what you may be calling "bore travel" (?).

I like to set then as close to .040" preload, using the hydralic flat tappet lifters, the accepted range is .020" to .060", at least according to specs and what I have to be experiance of myself and others. I know this is not half way through the travel of the pushrod seat in the lifter, I don't remember what actual travel was on my lifters, but I do remeber it being well over .100" travel. I have found that too much preload can collapse the lifter and/or when the lifter is pumped up can hold the valves open slightly.

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The Raven :Under Construction
"James" 1985 GMC Jimmy, 3.2L turbocharged intercooled hybrid

"Speed Costs, How fast do you want to go?"

I used 'zero lash' when I raced and it worked very well.
Race engine.
Street engine.
The two above items are NOT the same. The lifters in my Fiero are centered as I do not tear down this engine every week. In fact, just about every clearance and spec in the engine is different than what I would race with. I expect a street engine to last much more than ten hours between rebuilds, heck, I expect it to go months and months without major work because it is a DAILY driver, NOT a race car. I would like to have a race car in my garage for occasional use, but without a sponsor I cannot afford the maintenance.

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I primed the motor again and now all the lifters are solid. It must be OK. But I went to do a pressure test on the cooling system and found a slit in a turbo cooling pipe. It's almost impossible to get to. Fun stuff.

Anyone ever run their engine without valve covers? Just wondering how messy it's gonna get.

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SAVE THE SHAUN!!

Blown '88 Fastback Coupe!

Ill give you a hint, I was cranking the motor by hand without the valve covers. I didnt notice the oil pouring down the side of my block till there was a puddle on the ground. The edge of the rocker sticks out over the side of the block. So it will just make a huge mess. OOH and when its running, they push the rockers up so fast it will throw oil that is on the rocker up and away. REALLY messy. And, its really a fire hazard, especially on a Fiero.

[This message has been edited by Fierobsessed (edited 09-01-2003).]

A custom fit piece of cardboard will catch most of the outboard oil squirt, but not all, and the inboard side doesn't get all that much to start with.
But just guessing, it looks to me to be about a half a cup per minute oil coming out of the rocker top. That makes a big mess pretty darn quick.