m96 track reliability? (noob question)

[Topless]

Originally Posted by PaulE

I'm no expert on this, isn't it also due to the location of the oil scavenge pumps in the cylinder heads. The M96 uses the same cylinder casting on both sides. They're not interchangeable though because there is some different machining on each side for something. So the timing chain for one side of the engine is on the front - where the serpentine belt, etc. is located and the timing chain for the other side is on the back - where the flywheel is. Inside each cylinder head is a scavenge pump, and on one side it's in the front and on the other side it's in the rear. Those left sweepers can cause the oil to move by centrifugal force away from the scavenge pump in one of the cylinder heads - or maybe the asymmetrical nature affects both scavenge pumps on left handers, there doesn't appear to be an issue with right sweepers.

Yes.

The scavenge pump in the right bank is at the rear of the engine in a Boxster. On a long hi G Left sweeper oil accumulates in the right bank head and when you go to the brakes, the oil moves forward, away from the scavenge pump leaving the pan with very little oil left. Now zing the throttle to redline with an overzealous heel/toe downshift and the oil pickup cavitates causing temporary zero oil pressure and connecting rods sticking out of uncomfortable places on the casing. A bad day.

The 996 has the same motor configuration but reversed 180* so the long R sweeper is the one to adapt your driving style to.

When Porsche developed the 9A1 they went back to the Metzger design with 4 scavenge pumps in each of the 4 corners for much better oiling under high G forces. Now the engine runs safely under hi G just like the GT3, 993, 964 etc.

If you keep your oil topped off, run street tires, and stay well away from redline in the sweeper you have little to worry about. An SPBOX driver racing in a pack on fresh comp tires, not paying attention to his oil situation is likely to get bit at Fontana. At least a dozen Boxster Spec motors have been sacrificed entering turn 3 Fontana with a big redline (money) heel/toe downshift while reaching for 2nd gear.

[DWBOX2000]

Sorry, how (what) does a baffle work?

[DWBOX2000]

And how difficult to add to a 986?

[Topless]

Originally Posted by DWBOX2000

Sorry, how (what) does a baffle work?

It doesn't solve the scavenge pump problem but it does help to keep the remaining oil centered in the pan so it to does not migrate all the way to the edge. The X-51 windage pan is the one we added once we started running R-Comp tires. A simple bolt-on pan.

https://www.ebay.com/i/283348441283?chn=ps

[Racer Boy]

The baffle helps to keep the oil around the pickup, it's a essentially a box around the pickup with hinges on the walls, so oil can move towards the pick up when cornering, but it can't move away from it (if that makes sense).

It's a relatively easy project to do. Lots of threads on it, if you use the search function you should get all the information you need.

[Quadcammer]

Mezgers dont use 4 pickups, they have a completely different case design and true dry sump

[tzincp]

Originally Posted by Topless

Yes.

The scavenge pump in the right bank is at the rear of the engine in a Boxster. On a long hi G Left sweeper oil accumulates in the right bank head and when you go to the brakes, the oil moves forward, away from the scavenge pump leaving the pan with very little oil left. Now zing the throttle to redline with an overzealous heel/toe downshift and the oil pickup cavitates causing temporary zero oil pressure and connecting rods sticking out of uncomfortable places on the casing. A bad day.


If you keep your oil topped off, run street tires, and stay well away from redline in the sweeper you have little to worry about. An SPBOX driver racing in a pack on fresh comp tires, not paying attention to his oil situation is likely to get bit at Fontana. At least a dozen Boxster Spec motors have been sacrificed entering turn 3 Fontana with a big redline (money) heel/toe downshift while reaching for 2nd gear.

I see what you mean with T3: such a long left sweeping braking zone to starve it of oil
https://www.autoclubspeedway.com/~/media/076F3CE929A84DACBD9EF4D9E1E298DF.ashx

Would this imply that in a right sweeper under acceleration the opposite scavenge pump would be starved for oil?

[tzincp]

Originally Posted by Topless

Yes.

The scavenge pump in the right bank is at the rear of the engine in a Boxster. On a long hi G Left sweeper oil accumulates in the right bank head and when you go to the brakes, the oil moves forward, away from the scavenge pump leaving the pan with very little oil left. Now zing the throttle to redline with an overzealous heel/toe downshift and the oil pickup cavitates causing temporary zero oil pressure and connecting rods sticking out of uncomfortable places on the casing. A bad day.



If you keep your oil topped off, run street tires, and stay well away from redline in the sweeper you have little to worry about. An SPBOX driver racing in a pack on fresh comp tires, not paying attention to his oil situation is likely to get bit at Fontana. At least a dozen Boxster Spec motors have been sacrificed entering turn 3 Fontana with a big redline (money) heel/toe downshift while reaching for 2nd gear.

I see what you mean with T3: such a long left sweeping braking zone to cause issues...
https://www.autoclubspeedway.com/~/media/076F3CE929A84DACBD9EF4D9E1E298DF.ashx

Does this imply that in an accelerating right sweeper the opposite scavenge pump would be starved for oil?

[Topless]

2009 9A1 engine dry sump test rig:
https://www.youtube.com/watch?v=fv53RbvgfGc

https://nnjr-pca.com/9a1-engine/

[thstone]

With more than 175 track days (including 80 races) on stock M96 engines, I think that your mechanic needs to reconsider his position.

I routinely get 60-80 hours of track time plus 10,000 miles of street driving out of a used (90K mile) engine before it finally fails.

I would recommend installing the X-51 baffle since its cheap and easy to install and will give you peace of mind. If you run sticky tires (R-compounds), then I'd recommend a deep sump with the horizontal baffle to go with the X-51 (see photo below).

Yes, I consider 2.5L M96 engines to be disposable, but only because the cost of parts and labor to professionally fully rebuild an engine ($7,500 to $10,000) far exceeds the cost of a decent used (salvage) engine (under $3,000). And no, there isn't a significant increase in engine life of a fully rebuilt engine vs a used engine under racing conditions.

Since I started racing, I don't baby my engine. I shift at redline and downshift at redline (and occasionally over-rev). Maintaining position is the name of the game.

[maytag]

Originally Posted by thstone

With more than 175 track days (including 80 races) on stock M96 engines, I think that your mechanic needs to reconsider his position.

I routinely get 60-80 hours of track time plus 10,000 miles of street driving out of a used (90K mile) engine before it finally fails.

I would recommend installing the X-51 baffle since its cheap and easy to install and will give you peace of mind. If you run sticky tires (R-compounds), then I'd recommend a deep sump with the horizontal baffle to go with the X-51 (see photo below).

Yes, I consider 2.5L M96 engines to be disposable, but only because the cost of parts and labor to professionally fully rebuild an engine ($7,500 to $10,000) far exceeds the cost of a decent used (salvage) engine (under $3,000). And no, there isn't a significant increase in engine life of a fully rebuilt engine vs a used engine under racing conditions.

Since I started racing, I don't baby my engine. I shift at redline and downshift at redline (and occasionally over-rev). Maintaining position is the name of the game.

What brand of manufacture is that baffle, plate and sump? Looks nice!

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[pharaohjb]

30+ track days on my '99 Boxster with zero engine, smoke, or oil-related issues. Running 0W40 oil, 180 or 200 treadwear rated tires for all of them.

[jsceash]

Strong believer in the sump and baffle shown in THStone's post. I ran for 2 years before doing anything with my oil system other than changing oil after each event. It was 28 days on track. The third year I started running Dot 100-A-A tires and added a similar kit. The 4th year I went to a LN block with all the bells and whistles. I have 44,000 on that motor and easily 50 % of that is on track with Dot 40 slicks.

[maytag]

Originally Posted by jsceash

Strong believer in the sump and baffle shown in THStone's post.

What brand is it? It looks great!

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