15 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHX51 motor and the 996 gt3 motor
Reported or suspected cause
oil buildup in the heads during high-g cornering
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that report identifying a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Reported cause
given the x51 was marketed as 'poor man's gt3' they started with the additional scavenge pumps (actually dual scavenge pumps with plumbing to the other end of the head) thinking the issue was oil buildup in the heads during high-g cornering.
Leading evidence: 'oil buildup in the heads during high-g cornering' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'oil buildup in the heads during high-g cornering' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Replace exchanged or modified' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
The following parts in the engine are replaced, exchanged or modified to achieve this increased performance:
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
And other than a couple of items on the outside of the engine, I can't think of any components that are used mutually on the GT3 and the X-51.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
"A parts set -"Carrera Powerkit"- is available to retrofit the standard engine with an increased performance of 254 kW (345 HP).
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
oil buildup in the heads during high-g cornering
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
Discussions that report identifying a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Reported cause
given the x51 was marketed as 'poor man's gt3' they started with the additional scavenge pumps (actually dual scavenge pumps with plumbing to the other end of the head) thinking the issue was oil buildup in the heads during high-g cornering.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
not certain this solved it either, however, as jake will probably tell you he sees dead x51 engines (and engines with x51 sump baffles) as regularly as normal m96's.
Is the x51 motor as durable as the gt3 motor? It seems like it would have the same issues as any m96 motor. Certainly has some goodies but I just notice a lot of guys on BAT saying the motor is almost as good?
Nope. Not even close.
The baffled sump and 3rd radiator might be the two things to give An advantage over the standard m96 motors.
It is though, the most powerful factory na 996 motor behind the gt3.😎 it sounds better/different with the larger headers, too.
X51 Power Kit
(from the tech bulletin describing installation)
"A parts set -"Carrera Powerkit"- is available to retrofit the standard engine with an increased performance of 254 kW (345 HP). The following parts in the engine are replaced, exchanged or modified to achieve this increased performance:
- new intake manifold with modified cross-section (material: sand cast aluminum );
- new intake pipe supports adapted to the form of the intake manifold;
- new exhaust manifolds with larger cross-section and optimized flow behavior;
- new cylinder heads with optimized, CNC-milled inlet ducts;
- new camshafts with larger valve stroke on the inlet side and modified inlet and outlet timing;
- inlet valve springs adapted to the enlarged valve stroke;
- modified partition box in the oil pan;
- modified maps for the DME control module.
The following steps are also taken on the vehicle:
- new underside panel in the transmission area;
- additional radiator in connection with modified front spoiler, except on the 911 Carrera 4S (996).
The higher-performance engine is also available as an option when ordering a new vehicles - 911 Carrera / 911 Carrera 4 /911 Carrera 4S /911 Targa - under Exclusive Option X51."
Can be applied to Engine codes M96.03-04.
The 996 GT3 has a 3.6L normally aspirated Mezger M96. Engine code M96.76.
Not at all the same.
I've heard that in the past that the X51 engine was originally developed as a backup engine in case the GT3 engine did not qualify for certain classifications in motorsports racing. Something along the lines of they were sure the X51 would pass/qualify but unsure about the GT3 configuration. Not sure details or if it had to do with production numbers etc.
Also, I've been told the X51 HP numbers are under rated due to Porsche marketing and that the actual HP numbers for the X51 are much closer to GT3 numbers than the listed 345. The thought at the time was that if the true HP numbers were listed it would be too close to the GT3 and potential buyers wouldn't see the benefit of spending extra money on the GT3 for relatively similar power and less creature comforts.
But as far as the engines go yes there aren't as many similarities between the two.
Gotcha, I was misinformed. The cylinders are individually removable though, no? This was told to me by a tech who said he was rebuilding a GT3. I know the heads cannot be timed in the same way as the M96 in the 996.
Well I went back to look at my info and I see the engine code is M96.76, whereas the Turbo is M96.70. So is there a chance I was correct about the Mezger part but wrong about the "not an M96" part?
No, you weren�t really wrong...only caught by a technicality.
There aren�t many interchangeable parts between the M96/0x engine that our cars have and the M96/7x-8/x Mezger engines.
Certainly nothing internal.
Maybe some sensors are interchangable, but that�s about it.
The rest of the car has lots of interchangeable parts.
Speaking from lots of direct experience, I can tell you that this one isn't true.
And other than a couple of items on the outside of the engine, I can't think of any components that are used mutually on the GT3 and the X-51.
that's the internet - people talk 'x51' or 'powerkit' but don't differentiate between the (rare) 3.4 kit and the 3.6 kit which then leads to confusion. i think porsche knew about oiling problems on their cars in track situations early in the game and were chasing a solution. given the x51 was marketed as 'poor man's gt3' they started with the additional scavenge pumps (actually dual scavenge pumps with plumbing to the other end of the head) thinking the issue was oil buildup in the heads during high-g cornering. this was copied by a german tuning company (can't recall the name) but there is also the mod to buy the porsche pump (over $3k at ecs tuning right now) and retrofit it.
for some reason (simplicity? efficacy?) porsche passed on this solution for the 3.6 and focused on the sump; i presume they determined that oil pooling in the heads was not an issue as long as there was sufficient oil available in the sump to feed the rest of the engine. not certain this solved it either, however, as jake will probably tell you he sees dead x51 engines (and engines with x51 sump baffles) as regularly as normal m96's. personally, i think oil pooling in the heads creates sufficient back pressure to put the oil pump into bypass and starve the entire engine and that some playing with the bypass piston spring might solve some of this. but that would require me leaving the comfort of my armchair and actually prove my opinion which would make this not the internet ... !
