This is worthy of a signature quote. There is nothing more true. On cars as highly engineered and constructed as Porsches, I rarely consider anything other than OE Porsche parts, especially for critical areas such as drive train or suspension. Exceptions are parts developed by reputable vendors and used with good results over long periods of time, or Audi/VW parts that are often the same but labled with different part numbers. Unless a part is NLA, there are few reasons to deviate from spec. Remember, you don't have to purchase from dealers. You can get the real stuff from good vendors, like Pelican, and others at great prices (in the 928 world, we have exceptional vendors, including 928RUs, Roger Tyson, who has also supplied me with Boxster parts).

I'm not convinced about that, linderpat.

I bought a some VW parts that fit exactly for my Boxster. They were about 1/4 of the price Porsche wanted to charge from me. And they are 100% identical.

Concerning the hydraulic lifters. I'm pretty shure the INAs are OEM. http://986forum.com/forums/438869-post40.html

There are not so much companies that produce OEM hydraulic lifters in the world. ;)

And yes, there are parts you can't get after market, because of contracts with suppliers. Learned that when looking for OEM brake rotors. In this case the OEM supplier was SHW AG - Home

But i found a small manufacturer that does them in OEM quality and sold me some directly. They look 110% the same and the quality is really like OEM. Could also take a look at production. So no "china relabeling". ,) And gues what - some guys at ebay sell these too. ;) So i don't believe that the poeple you've listet can get OEM parts from suppliers if there are contracts form Porsche with the the supplier. And you can believe me that Porsche is very meticulous and restrict concerning contracts.

Regards from germany
Markus

Markus - did you read my whole post?;)

Part numbers and catalogs aside, break out precision measuring devices and if you are proficient with them, you'll find the differences.

Hopefully BEFORE they find you.

The parts company that we do a ton of 3rd part development for is German owned, they are Tier 1 with INA. My information is direct because of this.

Jake, i'm absolutey with you.

If you don't find a supplier part number on the part, besides that it's also recommended not only to measure parts but to check weight.

So best way is to order one hydraulic lifter and compare it exactly.

I think that people who rebuilt a Porsche Boxster engine should be able to rate risks and also should know the difference between OEM parts, parts from OEM suppliers, after market parts and chinese bling bling plagiarism.

@ linderpat: yes i did. Maybe i didn't get it 100% because english is not my first language. Sometimes it's hard for me to understand exactly how things were meant. Sorry for that, but i allways try hard to get better.

Regards
Markus

Smallblock,
Thanks for all your research on this subject. You have contributed more factual info than was available to we diy owners before this thread was started.
Realistically , how are we going to test the Rockwell hardness of a tappet crown? We have to just hope.
How are we going to measure/compare/understand the radius and concentricity of the crown of a tappet? I have all the old engineers measuring equipment ,but that is a daunting task to perform accurately.
I agree with your short cut of relying on OEM part numbers . And BYprodrivers helpful comments are always reliable. One of us just has to try a specific part number and share the results. The cryptic "I know the secret but I am not sharing it" comments are not helpful. I am glad Markus took the time to share his research and help those who follow.Thank you.

@ Gelbster: i've sent you a pm. ;)

Hopefully my just-rebuilt M96 is not sacrificed on the altar of Hydraulic Lifter Wisdom.:ah:
If it does, the world gets access to $9 lifters instead of $40++. From the original source. It saves $400+ on a lifter replacement job.:cheers:

I'm hoping some one could respond to the op's question and give some clarity. It does seem that lifters removed from a fresh tear down vary in their movement. some have a fair amount of spring travel, and some are completely ridged with oil pressure. Which is correct? And if reassembling the engine, should the lifters be installed without being pre-pumped with oil-allowing full spring travel, or, should they be pre-pumped with oil making them ridged upon reinstalling?

The only problem I encountered were stuck tappets.They were impossible to release with reasonable methods. So, if they are solid - they need to be replaced IMHO.
I am on a tight budget with this car but replaced all 24 parts. Why? Because of the stupidity/ignorance/cheapskate tax that Jake mentions.
These cars are complex ,with lots of quirks that will puni$h you if you don't take the time to study the many issues an ask questions here that indicate you've done some research and are ready to follow advice.
The information is scattered over innumerable Posts,websites and Blogs. So it requires some diligence to understand these issues in any depth. The lifters seem expensive until you contemplate having to replace the re-purposed/used ones after you've run your rebuilt engine for a few thousand miles. There are many other mechanical issues with the M96 that are like this. I suspect that is why some owners just give up ,sell them cheap and buy a Mustang/Miata/Z4. Those cars are less trouble and seem more forgiving so owners get less dollar-fatigue repairing and maintaining them. My Jag is way cheaper to keep running then the Boxster S but eventually I shall get to the end of the Boxster's to-do list and have a great car !

Where to begin..........these lifters/cam followers have a "dead end" oil passage design, meaning that once oil gets in, it often cannot get out again, leading to degradation in place, not to mention becoming a receptacle for any debris that is in the oil galley. This results in some lifters becoming solid objects that won't pump.

But now to get to your question, and that of the poster you quoted; you should not be mixing lifter/cam follower locations when using used parts from one engine, or taking them out of one engine and putting them in another. These units take a wear pattern to match that of the cam lobe they have been riding on, moving them to another lobe means they need to re-wear to their new location, which is not a good idea. Both Jake and I commented above on the criticality of the "crown" of the lifter, which promotes proper rotation and reduces wear on both the follower and the cam itself; wearing in the lobes and followers a second time can be very bad news to both.

When disassembling one of these systems, you should be keeping the followers in the correct order to put them back where they came from, or tossing the old units and using all new. In either case, I prefer to hand pump them before installation, and always coat the wear surfaces on the followers and the cam lobes with a good quality flat tappet break in grease to limit excessive wear on start up and break in. Every cam company sells this stuff, so it is easy to find.

Scrounging up used pieces from multiple engines to make one good one is never a good idea, that is how Frankenstein got started, and we know how that worked out.

So is it accurate to say that a properly functioning lifter can be pumped by hand, allowing oil to pass in and out?

Is it normal for the lifter to pump to a state of being solid once it has filled with oil?

And, if after being out of an engine for several months would a healthy lifter be solid, or would it be soft, enabling it to be pumped by hand?

I read posts that refer to lifters "draining down". I interpret that to me that in an idle state, the lifter drains of the oil that had filled it while in operation....the engine running. Is it normal for the lifter to drain down, or should it retain the oil, keeping it rigid?

Sorry about all the questions...I know some seem redundant. But, with my engine apart and ready to reassemble, I am concerned about understanding how to to best evaluate the condition of my lifters. I have picked up bits and pieces of information, but, nothing that really summarizes just what to be looking for in the behavior of a healthy lifter....or, an unhealthy lifter.

Thanks

Hello,

if the lifter is filled with oil and is soft it's gone. Especially if you pull him out of a "running" engine.

There is a spring and ball mechnism in the lifter that in general stops the oil getting out of the lifter chamber. If the spring is worn the ball valve can't work and the lifter will be soft. So the lifter won't be able to generate the correct height for a correct valve play.

If the lifter is new or was a long time out of the engine, just press him and put him in an oil bath (completey covered with engine oil) for some time so he can soak oil in. If the lifter is OK in in general it will work than. Also it will be hard. If it will stay soft something is wrong.

Regards, Markus

When you pump them up by hand, as they become full, they feel solid, because the oil is not compressible, but this may bleed off over time if left to sit as the oil drains off. Because of their design, the oil has to go in and out thru the same opening.

A healthy unit should pump up a appear to hold pressure by feeling rigid. I never like to put any engine parts in "dry", so giving them a pump up will help on start up.

How are you planning to pre oil the engine before start up?

Hello JFP,

What is the most prsctical way to pre-oil the boxter engine after reassembly?
Do you crank it without the fuse for the oil pump?

Thank you!

No. We use a small pressure tank (air over oil) filled with break in oil to pressurize the entire engine without having to spin it, sort of like an over sized accusump set up. Once wet, light it off.

Cool, so you connect the hose from the pressurized tank to the oil filter housing?

You can use a modified filter housing, but I prefer to use the oil pressure sender port, and the oil ports on the cylinder heads so that the filtration system is wet as well.

Does it then mean that, if a lifter that has been out of a car for an extended period of time and remains rigid, there is a problem with that lifter since it did not drain down and become compressible again?

rah rah 986: Did you understand how these hydraulic lifters work? Just do some research on the internet. Easy to find. ;)

Regards, Markus