996 Lifter replacement questions
#31
Instructor
Oh wow never heard this information about the piston offset for the bore scoring issue. Sorry to hear OP. Man all of these threads make me want to sell the car while it is still running ok
#32
Rennlist Member
By the way, for anyone that want to look at their cylinders, you can get a really affordable ($37) endoscope here:
https://www.amazon.com/dp/B01MYTHWK4...517669530&sr=1
Then just pull your plugs and take a peek. (Make sure someone is nearby in case you need a hug)
https://www.amazon.com/dp/B01MYTHWK4...517669530&sr=1
Then just pull your plugs and take a peek. (Make sure someone is nearby in case you need a hug)
#34
Racer
Is a billet crank available for the M96 NA engine? Looking at EVOMS & Protomotive, it appears these are for the turbo and GT3. So 3.4 > 3.8 with nickies, billet crank, single mass flywheel is doable? I'll start a new thread if this is going too off-topic.
#35
Rennlist Member
Billet cranks are indeed available and come with a hefty price tag. Something Jake uses in his builds exclusively.
#37
Rennlist Member
I'm not the Charles you were looking for , but can answer your question. The JE pistons included with Nickies are zero offset, therefore are ambidextrous.
#38
Rennlist Member
The DFI and Cayenne V8 pistons we make must have offsets or the engine sound like diesels.
#40
Rennlist Member
Offsetting piston pins in either direction will soften the "snap" when piston changes direction at TDC and BDC, this reduces the stress on the rods.
Offsetting opposite the direction of rotation will decrease the piston slap and reduce side loading of the piston.
Offsetting in the direction of rotation will increase slap and side loading, but will slightly increase power and dwell time at TDC, as mentioned above any offset in either direction will reduce "snap" stress on the rods.
Ultimately the decision on whether or how much to offset in determined by the engine/piston designer and/or their accountants.
#42
#43
Rennlist Member
Ideally like Charles Navarro said, when they do offset them, they offset bank 1 to the exhaust side (major thrust side), and bank 2 to the intake side (major thrust side).
Then you have the best of all worlds, offset to reduce piston slap , to reduce side loading, and to soften the "snap" at TDC.But requires two different pistons be made, and close attention to orientation during assembly.
#44
Rennlist Member
It's just my opinion but I think the engineers of the m96 engine chose to use piston offset for the softening of the "snap"at TDC .And they figured they could get away with using one piston,( even running an unfavorable offset on bank 2) due to the surface of the Lokasil cylinder, the iron piston coating , hypereutectic piston material, and close clearance, would withstand the side loading and piston slap all to a minimum, but as we know , not so much.
#45
So you guys bring up the best info as 996 owners and builders....I've decided to go back to purchasing a 996 after looking for a 997 and it seems the Gen1 ones are getting below the $36k range but with the 996 offering better bang for bucks, but still having issues. Would a PPI catch scorned pistons? Or this something one will have to ask for?