Hydraulic cam followers
 

If you go over to the Rennlist.com website and look under the 996 Forum, there is an interesting discussion under <Lifter replacement/upgrade/fix> last July by Schnell Gelb covering his experiences with hydraulic lifters.
I think he stripped the old frozen lifters only to find clean oil and no debris so then submerged the lifters in heated new oil - but maybe my memory is playing tricks again.....

Yes Steven,that was me- 'cooking' lifters.Not effective.I also posted a crankshaft being dry-roasted in my wife's oven.
The lifters have an updated INA part number. Most of the old ones get the tappet 'hammered' or jammed into the bucket. No repair possible. This causes the "they all make that ticking noise" comments about the older M96 engines?
Replacing all 24 @ $40+ each is a bit steep. $8 was much better!
Lots of geekish details scattered around the Forums.I got very little participation at the time.Many months ago I discussed the BMW-lifter interchange issue with Rock Auto & their vendor in England(BGA).They now list it for the M96 under the interchange number.In the past it was only listed under BMW.Be sure you order/get the correct part number!
I have not heard on the Forums of anyone other than me trying the substitution. Hmmm ,there may be a reason?
No info on exactly what the INA upgrade/mods were.I suspect just clearance/tolerance. Until we get field results it is a very risky substitution.Obviously they fit physically and measure up exactly but the proof will be running them for a few thousand miles.

Cook at 250 F degrees & pump the plunger.

http://986forum.com/forums/uploads01...1424712751.jpg

During my 3.6 LN sleeved rebuild I naturally had to do this trick. After looking at Bypros picture I cooked mine in "Jo Gibb´s run in oil" intil my I eyes hurt from the fumes. Did it in the kitchen in my part of a dublet house. I don´t think my neighbors that own the other half of the house will ewer forgive me. But the engine is still running strong....interesting subject.....subscribed

If Bill "BYprodriver is on the thread, please disregard anything I wrote and listen to him.
"Cook at 250 F degrees & pump the plunger."
Some deep fried finger tips if you do that at 250 degrees? :-).

But what do you do if after cooking, the tappet is either soft or jammed up into the bucket?
What do you use as new replacement lifters? OEM/Porsche?

I replace any suspected bad ones with INAs.

There is an interesting hint in the Bentley manual regarding the risk of damaging lifters if only oil-foam instead of liquid oil reaches them.
Porsche revised the de-foamers in the sump for the 987. They are quite different to the originals. I fitted the latest style because I have a paranoia about foam in a flat engine without a dry sump.I also fitted my own peculiar version of an aftermarket deep sump+horizontal baffle arrangement. It adds 2qts and ensures the pickup is submerged at all times.
I also plan to use engine oil with high anti-foam additives/low detergent. The jammed lifter problem is so common on the flat 6 but so rare on the I6 and V6 engines that use the same INA lifter .... well maybe it is the foam issue?
It may all be nonsense ,I know.

Gelbster,

I remember reading that Vision Motorsports recommends using the earlier type 996 'aerators' versus the 987's because they promote a better separation of the oil and air (foam)...

.

Gelbster,
Where did you find lifters for $8/ea? For that amount I wouldn't even bother shattering domestic tranquility with motor oil smoke in the kitchen.

That is an interesting comment -thank you. I thought that since it was the latest version ,it would be and improvement in de-foaming.
Even more strange ,the 987 parts came as part of the deep sump kit I mentioned. so the kit manufacturer went to all the trouble of supplying the later part with the intention that you dump the old defoamers.
here is a link to the kit:
2001 Porsche Boxster S Convertible - Oil Circulation - Page 3
Here is the original part number :
99610708054
The upgrade is the same as an '06 997. Sorry I had typed 987 above.
This ad has a photo of both the old and the new design.
Huge difference in design/size.
06 Carrera s Porsche 997 Coupe 3 8 Engine Motor Oil Pickups Lower Bottom 67 971 | eBay

Gelbster,
May I ask you where did you buy the INA lifters for $8..?
Thank you!

.

from Rock Auto

found this on youtube.... https://www.youtube.com/watch?v=oRNbKG_xLJs

hope this also helps

not any more @ $8... :-(
 

2007 PORSCHE CAYMAN 3.4L H6 : Engine : Valve Lifter Price
BGA Part # HL5368 {#0K95K12101A} Hydraulic Type; Height: 24mm; Outer Diameter: 33mm; For Exhaust Valves
[Flag indicates this part fits vehicles sold in the European Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide.] S; Coupe; From 11/05; To 08/09; RWD
[Flag indicates this part fits vehicles sold in the European Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide.] S; Coupe; 6F Model; From: 11/2005; To: 08/2009; RWD; Exhaust; Engine Code: M97.21

* Stocked in outlying warehouse--shipping delayed up to 1 business day
$41.79

This is more like the M96 lifter.
https://www.youtube.com/watch?v=HT71uhnNYjg
The problem is - do you think that merely cleaning the lifter will prevent it getting jammed again? If so , why?
If you look at the effluent from the dismantled lifter ,it is just dirty oil and a little carbon. The oil is so dirty ,it looks like a neglected oil-change history to me.

are the M96 and 987 lifters different?
 

I would like to know if the M96 and the 987 lifters are indeed different or we are just talking a marketing gimmick perhaps…?

If by any chance these are interchangeable with each other there will be a Big price difference…!

987?
for the M96, just look it up the Rock Auto catalog BGA....
Check with INA
Check the Interchange catalogs.
They fit but I do not know if they work -yet.
Whatever ,they will work much better than the ones I removed!

99610504172 is the 987 2005 and 2006 intake and exhaust tappet and 2007 up exhaust tappet in 2007 the intake Tappets changed because of VarioCam Plus. With that said this is the same as the previous 99610504150. I purchased 6 -99610504172, from the local Porsche dealers part department. I used 4 to rebuilding my 2004 motor. The Porsche parts clerk said the 72 part supersedes the previous 50 number.

I now have a Tappet from a 2003 2.7 inside is imprinted INA 577.9 I have A tappet from a 2004 3.2 Inside it is also marked INA 577.9 I also have a 99610504172 the part listed as the 987 current used part Inside it is marked again INA 577.9.

After looking at the video post previously, I took all 3 apart. The internal parts are all the same. The internal parts can be install in all three bodies and they all compress and return.