9A1 Technical Questions
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Three Wheelin'
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From: Tampa
9A1 Technical Questions
"Mac Miller" posed several unanswered questions re the 9A1 block in the current excellence (May 2009, pg 10). "... enough about the PDK. What about the finer details of the 9A1? It sounds like the cams run directly in the heads without bearing inserts. If so, are the oiling system and oil service intervals up to the task of providing the immediate clean oil such a cam design requires?" ... "Does the crank run in a "bearingless" crankcase as well? How are the cams driven and what are the resulting design compromises? Does the clutch end of the crankshaft have a new design to address the RMS flaw?"
Anyone care to answer Mac's questions or care to provide additional info re the new block ??
Any real world news re the new 9A1 in the 9+ months its been on the road (and track) ??
Thanks
Jack
Anyone care to answer Mac's questions or care to provide additional info re the new block ??
Any real world news re the new 9A1 in the 9+ months its been on the road (and track) ??
Thanks
Jack
RL Technical Advisor
Joined: May 2001
Posts: 11,870
Likes: 75
From: Portland Oregon
"Mac Miller" posed several unanswered questions re the 9A1 block in the current excellence (May 2009, pg 10). "... enough about the PDK. What about the finer details of the 9A1? It sounds like the cams run directly in the heads without bearing inserts. If so, are the oiling system and oil service intervals up to the task of providing the immediate clean oil such a cam design requires?" ... "Does the crank run in a "bearingless" crankcase as well? How are the cams driven and what are the resulting design compromises? Does the clutch end of the crankshaft have a new design to address the RMS flaw?"
Anyone care to answer Mac's questions or care to provide additional info re the new block ??
Any real world news re the new 9A1 in the 9+ months its been on the road (and track) ??
Thanks
Jack
Anyone care to answer Mac's questions or care to provide additional info re the new block ??
Any real world news re the new 9A1 in the 9+ months its been on the road (and track) ??
Thanks
Jack
Having examined the '09 Technical Introduction on this engine, maybe I can help a bit.
1) Cams run in the aluminum w/o bearings, just like every air-cooled engine since '65. With sufficient oil pressure, its very durable. I don't see any unusual issues with these engine aside from one chain running 2 cams and 16 valves (on each side) which may affect long-term wear. IMHO,.....Porsche's oil change interval recommendations are absurd but they are in business to sell cars & parts, NOT to ensure that your investment lasts over 100K. Its a different company than in their earlier years.
2) The crankshaft runs in bearing inserts, just like every other engine from PAG.
3) The cams are directly driven by chains off the crankshaft; one per side. No more intermediate shafts for that purpose. The oil pump is chain driven off the crank, as well.
4) The engine case loosely resembles the air-cooled one in that its a 2-piece design without a crank support girdle. Cylinders are integral with the case so when the bores might require replacement, one would either need a new case or maybe bore and replate the existing one IF there are oversized pistons/rings available.
On paper, it looks a LOT better than its predecessor but only time will tell how durable it is.
Last edited by Steve Weiner-Rennsport Systems; Mar 24, 2009 at 01:44 PM. Reason: Geoffrey's editing is very strict so I added text for clarity,... :)
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I cornered Paul Galiardi from PMNA at Holberts when they had their PDK demo, and asked him specifcally about the new motor. He "allowed" that the previous design was not as strong as they had hoped, and that a return to the split case style added back the crank bearing stiffness (and more) that they had lost. I would think that the added stiffness comes from the integral cylinders. He also said that the new oiling system scavenges much better than the oil system in the air-cooled motors, and that for racing and other-wise, there was no reason to return to the separate oil tank.
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Larry Herman
2016 Ford Transit Connect Titanium LWB
2018 Tesla Model 3 - Electricity can be fun!
Retired Club Racer & National PCA Instructor
Past Flames:
1994 RS America Club Racer
2004 GT3 Track Car
1984 911 Carrera Club Racer
1974 914/4 2.0 Track Car
CLICK HERE to see some of my ancient racing videos.
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Thread Starter
Three Wheelin'
Joined: Dec 2002
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From: Tampa
Seems like there is very little news re the new block; this might be god in no news is good news kind of way. On the other hand, I would think that cars with this block are now being tracked and perhaps race with increasing frequency. Any NEW thoughts ??
Jack
Jack
Thread Starter
Three Wheelin'
Joined: Dec 2002
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From: Tampa
Steve: (or anyone else) Any additional thoughts re the new block ?? Some of these cars might have been tracked for nearly a year. Anyone care to share their experience ??
Is Porsche (or vw) still claiming that this is their intended racing block of the future ??
Thanks
Jack
Is Porsche (or vw) still claiming that this is their intended racing block of the future ??
Thanks
Jack
Race Director
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From: Tampa
Jack I have been tracking my 09 Carrera S and have 6 days on it. The engine is very powerful...seems to have more power than Porsche lit claims. It does burn more oil than the 06 and 07 Carrera S I had. Hope to see you at the track soon.
Mike
Mike
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From: Tampa
Jack, I am saving up for Daytona with PBOC, plus new pads and tires. I also want to try and get invited to the PCA Suncoast Instructor school. I've been instructing with Chin now for 2 years, I know I have to be ready for Suncoast. ot sure I can make the PCA September event. I have a long week of travel for work and do not get home till midndnight Friday.