993 Engine undertray
07-07-2006, 09:20 AM
#46
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Originally Posted by max911
It was funny to read in the above joke, but actually pretty cool to see. Nice job.
07-07-2006, 10:34 AM
#47
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Originally Posted by Jean
I was puzzled by the 11% leak in cylinder number 6, that my mechanic apparently didn't spot (with the number of cylinders being 6, one sometimes can miss 1 or 2 of them) I looked closely at the tray yesterday and it turns out that it is not well fitted. The only bolt remaining is at the cylinder 6 level.
Could it be be that all the other cylinders were properly "aired" since the tray was loose while number 6 was the only one well covered by the tray and therefore I have premature valve guide wear at 111.7k miles on cylinder 6?
Worth digging further, I will share the results with this great board.
Maybe this explains the instability on one side of the car at 150mph, and why I have one rear tire more worn out than that other? I bolted the tray properly now and will use my datalogger to compare.
Mike, I hear ya.
Could it be be that all the other cylinders were properly "aired" since the tray was loose while number 6 was the only one well covered by the tray and therefore I have premature valve guide wear at 111.7k miles on cylinder 6?
Worth digging further, I will share the results with this great board.
Maybe this explains the instability on one side of the car at 150mph, and why I have one rear tire more worn out than that other? I bolted the tray properly now and will use my datalogger to compare.
Mike, I hear ya.
A thought: Perhaps if you ran it in reverse for 111.7k miles, it would even out the wear.
07-07-2006, 10:57 AM
#48
Originally Posted by Jean
Could it be be that all the other cylinders were properly "aired" since the tray was loose while number 6 was the only one well covered by the tray and therefore I have premature valve guide wear at 111.7k miles on cylinder 6?
I need some help understanding here.
I've searched every thread regarding premature valve guide wear but I still can't seem to find out at what mileage the valve guides are susposed to wear out
07-07-2006, 05:22 PM
#50
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Well the 964 was the last hand made 911 and therefore is much more solid than a 993
07-09-2006, 09:18 AM
#52
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Originally Posted by Mike in Chi
Brilliant analysis Jean.
A thought: Perhaps if you ran it in reverse for 111.7k miles, it would even out the wear.
A thought: Perhaps if you ran it in reverse for 111.7k miles, it would even out the wear.
Your suggestion was outstanding, I have been giving it a lot of consideration in the last 2 days, and finally thought that it makes perfect sense!
I tested going in reverse 3-4 times during the last 2 days on the main highway (with the headlights on all the time of course), and I am not able to get the odometer to count backwards.
, Also when in reverse, the airflow coming into the tray, is bringing hot air from the exhaust into the cylinder heads, so it might be worse?Porsche engineers must have done something to prevent this sort of thing,otherwise everyone would do a few thousand miles in reverse just before selling their cars. Also, the max speed seems to be about 30mph only, so it is a bit boring.
So what I did is that I removed all the guages from the dashboard, and opened up the odometer, and broke the driving teeth behind, so that it does not work anymore. Now I can drive my car for thousands of miles more without any risk of premature valve guide wear
WHILE keeping the tray on!I will post a DIY. Thanks Mike for your help, this is such a great place
07-09-2006, 02:13 PM
#53
Took the tray off my car after I purchased it with the first oil change at 84K miles. Since its been off, the car was lowered with new suspension. Due to it being so low without the tray, the lower engine is exposed to the ground. Ive had one of the air vents rip and seperate and Ive had to repair that and more recently a dip in the road caused the tray holder which is affixed to the rear of the engine to scrape the ground and twist up a bit.
Lots of quick little dips in the side streets here in CA...so the trays going back on this week....
to protect the lower engine so its no longer exposed.
great idea about drilling it
Lots of quick little dips in the side streets here in CA...so the trays going back on this week....
to protect the lower engine so its no longer exposed.
great idea about drilling it
07-09-2006, 07:07 PM
#54
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Originally Posted by Sonic dB
... Due to it being so low without the tray, the lower engine is exposed to the ground. Ive had one of the air vents rip and seperate and Ive had to repair that and more recently a dip in the road caused the tray holder which is affixed to the rear of the engine to scrape the ground and twist up a bit.
07-09-2006, 07:17 PM
#55
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Originally Posted by deltawedge
This may be an indication that the car is a bit too low. The one thing that no one has mentioned as a use for the tray is as a skid plate
07-09-2006, 07:35 PM
#56
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My car is about as low as you can go and still be able to turn the wheels. I've never scraped anything near the engine compartment, except for my Supercup tailpipes if my loading ramps to my trailer are on uneven ground. I also drive very carefully on speedbumps and the like.
Last edited by Mark in Baltimore; 07-09-2006 at 08:01 PM.
07-09-2006, 07:38 PM
#57
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Originally Posted by Mark in Baltimore
My car is about as low as you can go and still turn the wheels. I've never scraped anything near the engine compartment, except for my Supercup tailpipes if my loading ramps to my trailer are on uneven ground. I also drive very carefully on speedbumps and the like.
07-09-2006, 08:28 PM
#58
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Originally Posted by Jean
Thanks Mike.
Your suggestion was outstanding, I have been giving it a lot of consideration in the last 2 days, and finally thought that it makes perfect sense!
I tested going in reverse 3-4 times during the last 2 days on the main highway (with the headlights on all the time of course), and I am not able to get the odometer to count backwards. , Also when in reverse, the airflow coming into the tray, is bringing hot air from the exhaust into the cylinder heads, so it might be worse?
Porsche engineers must have done something to prevent this sort of thing,otherwise everyone would do a few thousand miles in reverse just before selling their cars. Also, the max speed seems to be about 30mph only, so it is a bit boring.
So what I did is that I removed all the guages from the dashboard, and opened up the odometer, and broke the driving teeth behind, so that it does not work anymore. Now I can drive my car for thousands of miles more without any risk of premature valve guide wear WHILE keeping the tray on!
I will post a DIY. Thanks Mike for your help, this is such a great place
Your suggestion was outstanding, I have been giving it a lot of consideration in the last 2 days, and finally thought that it makes perfect sense!
I tested going in reverse 3-4 times during the last 2 days on the main highway (with the headlights on all the time of course), and I am not able to get the odometer to count backwards.
, Also when in reverse, the airflow coming into the tray, is bringing hot air from the exhaust into the cylinder heads, so it might be worse?Porsche engineers must have done something to prevent this sort of thing,otherwise everyone would do a few thousand miles in reverse just before selling their cars. Also, the max speed seems to be about 30mph only, so it is a bit boring.
So what I did is that I removed all the guages from the dashboard, and opened up the odometer, and broke the driving teeth behind, so that it does not work anymore. Now I can drive my car for thousands of miles more without any risk of premature valve guide wear
WHILE keeping the tray on!I will post a DIY. Thanks Mike for your help, this is such a great place
simply brilliant
why you aren't working in Weissach instead of Saudi is beyond me
07-10-2006, 02:34 PM
#60
Originally Posted by Ty Smith
Funny thread... But on a serious note.
Can I remove the tray without jacking the car up. It looks like it might just have enough room. anyone ever tried that...?
Can I remove the tray without jacking the car up. It looks like it might just have enough room. anyone ever tried that...?
The car has to be raised some. If you can't jack it up, you might be able to drive the rear wheels up on some wood planks. You need about 6 in of clearance.