David L. Lutz

My tapping noise was loudest (when listening through a stethoscope right on the center of the cam cover around Cyl. #5 & 6.

At this point my lifters don't look bad, all the oil passage ways look very, very clean, the oil check valve was spotless so I am still searching for the source. My injectors were loud, but I am certian that was not the main source of the loud tapping.

Tomorrow I am digging into the bottom of the engine and checking rod bearings, etc. However my oil pressure was always good 2.5 - 3 bar at idle and 5+ above idle.

Kevin Johnson

Great to hear you were able to remove the 1/4 piston assemblies and that they were properly oriented.

Now is the time to perform a standard bleed down test on the 1/4 piston assembly. Just like on Fords and Buicks, etc. I guess my PM to you this past Tuesday was lost.

http://www.autozone.com/az/cds/en_us...rInfoPages.htm

Edit: They have changed or deleted the link -- I will find an alternate.

Here is a good general information link on lifters which explains the importance of bleed down rate:

http://www.prime-mover.org/Engines/Marvel/tbo3.html

Read the part on leak down testing. Auto-Zone may lend the tool if they have it or with the info in this link you could probably rig/make your own. As for a rate -- just compare all the lifters if the Porsche FSM does not give one. The bad ones (if any) will probably be obvious.

Good luck,

Kevin

David L. Lutz

Thanks Kevin, I will look for the link.

Kevin Johnson

Here is one from a 1981 Chilton's Manual. Aside: I like a lot of the various older manuals better as they seem to assume that the rebuilder may have to fabricate test tools locally rather than waiting for the Snap-On truck to arrive for its regular visit.

Aside: While looking for this I found a manual that suggested installing lifters empty of oil -- I still don't suggest that.

My suggestions to the above procedure would be to find a weight (barbell perhaps) and hook it to the drill press arm to allow a known downward force. Then just do a cross comparison of the lifters with respect to rate of bleed down.

Good luck,

Kevin

David L. Lutz

Great,

Thanks, I was trying to find the tool as Auto Zone had no Idea what i was even talking about.

I will rig up a test and go from there.

Thanks so much for the info. By the way I got your PM's thanks

Kevin Johnson

When/if they enlist in the Air Force they are prime candidates for being sent on a search for a bucket of prop wash. Although that bit of wit tells you how old my Air Force trained instructors in school were.

Kevin Johnson

Also, be careful not to magnetize your lifters. Check them with some tiny bits of steel. You don't want them to act as collection zones for detritus.

If they are I believe you can degauss them.

GregBBRD

We blow air through the oil hole on the side of the lifter and they "blow" apart easily. (No scratches from the tools and no chance of bending anything.) We have been ultrasonically cleaning the lifters, lately. If you look at the design, the "shelf" inside the lifter collects all the sludge and garbage, without anyway to get it out. We recently had a set that were absolutely full of varnish and sludge. We don't mix the parts from lifter to lifter, but keep the parts separate.

Figuring out if they are good is easy. Once all the pieces are clean, reassemble the springs, check ball, retaining seat, and piston into the center piston. You don't need the large lifter body, yet. Pump the assembly full of oil, through the hole where the ball sits, and see if it can be collapsed. We put a weight on them and leave them for about 20 minutes to see if they leak down. If they all work, we then push down the ball with a small tool, compress the piston, and assemble the center piece into the lifter body.

David L. Lutz

Thanks greg. Great info...

Kevin Johnson

While I was looking for info I noticed that there were services that would provide answers to these questions if you were willing to pay.

Greg probably gave you at least a $1000 answer there.

GregBBRD

You can easily see the "shelf" where all the varnish and crap gets stuck inside the lifters from Bill Ball's cross section picture.

Imagine what collects on that shelf when there is a thrust bearing failure......

That's why I bought an ultrasonic cleaner and have been doing the lifters in there.

Bill Ball

Greg: Thanks for the tips on lifter disassembly and cleaning should we need to do that!

Jim bailey - 928 International

Some 50 plus posts and 700 plus views before Greg Brown happens to tune in and answer the question....I got a fortune cookie they other day it reads...." I hear and I forget. I see and I remember. I do and I understand." ... Greg has 30 years of doing....

ROG100

A little late here but I do stock the light weight lifters that Mike mentioned and they are $12.99 each.
Mike can add the details if he needs to.

RyanPerrella

Great tech info here, again i wish i had a spare lifter laying around to play with.

Someone book mark this or can we rate it? With a star maybe? i would hate the info to get lost in the abyss