Coaxing a sedately driven car back to a spirited life
#1
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Coaxing a sedately driven car back to a spirited life
My best guess is that my car has never been driven hard, say, above 3000 rpm. The PO (3rd owner) told me he rarely got above 2000 rpm. That ain't no way to drive a Porsche, it seems to me. I would enjoy an occasional excursion to 5000 or so.
Somewhere, very long ago, I read something that gives me a vague sense that there is danger to abruptly going to high rpm in an engine that was not accustomed to it. I have been slowly increasing my operating rpm limit - I hit 3800 yesterday. Is this what you would do?
Both facts and opinions are welcome, as long as they are properly labeled.
Somewhere, very long ago, I read something that gives me a vague sense that there is danger to abruptly going to high rpm in an engine that was not accustomed to it. I have been slowly increasing my operating rpm limit - I hit 3800 yesterday. Is this what you would do?
Both facts and opinions are welcome, as long as they are properly labeled.
#2
All opinion.
Can't see how it would hurt to gently coax it back to life and build some confidence in the car. Think an Italian tune up will be in order eventually. I guess just make sure all the critical maintenance is up to date
Can't see how it would hurt to gently coax it back to life and build some confidence in the car. Think an Italian tune up will be in order eventually. I guess just make sure all the critical maintenance is up to date
#3
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Drive it like you stole it!!!
#4
Burning Brakes
If all the parts are low mileage and in good condition, I'd push the little pedal all the way down and hold it there. It's not like it's a living being that needs to be slowly work itself back into shape.
#7
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Fluids good?
Quality fuel in the tank?
Warm the engine to operating temp.
Put the hammer down and hold it to redline.
Repeat as necessary to insure happy life.
Opinion, but we shall say - pretty well qualified.
Quality fuel in the tank?
Warm the engine to operating temp.
Put the hammer down and hold it to redline.
Repeat as necessary to insure happy life.
Opinion, but we shall say - pretty well qualified.
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#8
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I am O K with this as long as the car is NOT in neutral....
#9
Devil's advocate, hearsay opinion, and certainly not cold fact for 928 V8s:
The old school engine builder I chatted with about this very subject spoke of piston-ring-to-cylinder-wall bedding and rod stretch. He illustrated that at low RPMs the rods never approach full stretch, therefore the height at which the rings stop bedding is low and the higher wall is virgin. Then when you buy granny's car at the estate sale and take it up to redline the rings get lots of sudden trips a wee bit further up the wall as the rods stretch farther, smacking past the microscopic ledge where the virgin wall begins. And then the rings fail.
However that phenomenon may very well be a relic of the olden days before silicon-impregnated cylinders, and not an issue for 928s.
The old school engine builder I chatted with about this very subject spoke of piston-ring-to-cylinder-wall bedding and rod stretch. He illustrated that at low RPMs the rods never approach full stretch, therefore the height at which the rings stop bedding is low and the higher wall is virgin. Then when you buy granny's car at the estate sale and take it up to redline the rings get lots of sudden trips a wee bit further up the wall as the rods stretch farther, smacking past the microscopic ledge where the virgin wall begins. And then the rings fail.
However that phenomenon may very well be a relic of the olden days before silicon-impregnated cylinders, and not an issue for 928s.
#10
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Omg
Drive it....hard
I may be wrong (it happened ...once)....
I know that with the race bikes I used to build after the first minute or two you should run them hard.
This causes the rings to be forced out of the ring grooves against the cylinder wall slightly and allows them to properly bed in.
Not sure if this would be the same with a used engine.
The real question is why anyone would buy a porsche to drive it like that.... Get a Cadillac instead
Drive it....hard
I may be wrong (it happened ...once)....
I know that with the race bikes I used to build after the first minute or two you should run them hard.
This causes the rings to be forced out of the ring grooves against the cylinder wall slightly and allows them to properly bed in.
Not sure if this would be the same with a used engine.
The real question is why anyone would buy a porsche to drive it like that.... Get a Cadillac instead
#11
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In steel-blocked cars, rings "bed in" by wearing the cylinder walls. In your 928, that cylinder wear doesn't happen the same way. I wouldn't worry about cylinder or ring issues, bottom line.
My car lives an easy life, most driving is gentle. It seldom sees 2500 RPM in normal driving. Once in a while, I do air it out a bit getting onto the freeway. It sails right up to redline painlessly, no ill effects. As others note, the cars do run better after they've been stretched out some. I attribute a lot of that to getting enough flow to the injectors to clean them some. Maybe some of the deposits on the backs of the exhuast valves ext with the highre heat and flow. Regardless, it does drive noticeable better after a bit of spirited throttle.
My car lives an easy life, most driving is gentle. It seldom sees 2500 RPM in normal driving. Once in a while, I do air it out a bit getting onto the freeway. It sails right up to redline painlessly, no ill effects. As others note, the cars do run better after they've been stretched out some. I attribute a lot of that to getting enough flow to the injectors to clean them some. Maybe some of the deposits on the backs of the exhuast valves ext with the highre heat and flow. Regardless, it does drive noticeable better after a bit of spirited throttle.
#13
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I would make sure the provenance of the timing belt/water pump is known, stick some SWEPCO 502 in the oil and a bottle of Techron or Redline total fuel system cleaner in a with a full tank of fuel and find a quiet stretch of road not frequented by the boys in blue. I generally keep the revs below 3k until it warms up and above 3k rpm after it has warmed up otherwise what is the point [ha ha]? you might do well to have the injectors ultrasonically cleaned if they have been idling around like that.
Seriously, these motors need to be worked, you do not have to thrash the *** of them every time it is on the street but at least make the motor work some if you can. A track day or a good hard run always makes them feel better- just the way it is.
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It's the piston ring ridge / rod stretch thing described by JEC-31 that I remember reading about a long time ago. Conceptually, it is a disturbing image, having your piston rings slamming up against grooves formed by 27 years of sedate driving. Is it myth or reality? One element of this is easy to assess: do 100K engines have these grooves? Is it standard practice to hone the cylinders when new rings are installed?
I'm hoping to be persuaded that I can let 'er rip.
My engine seems to run quite well. As the PO was driving me around in it - sedately - he was about to demonstrate its power, but knowing the TB was 20 years old, I told him "No! Don't drive it differently than you normally do." After taking title, I did the TB/WP before I drove it at all. Of course, one source of my caution is that I did the job myself, as a rookie. I'm pretty sure I put all the bolts back in....
Winter is still taking a break here, so I'll take her out. Not yet persuaded to go to redline, but perhaps 4500 rpm will be a good target.
I'm hoping to be persuaded that I can let 'er rip.
My engine seems to run quite well. As the PO was driving me around in it - sedately - he was about to demonstrate its power, but knowing the TB was 20 years old, I told him "No! Don't drive it differently than you normally do." After taking title, I did the TB/WP before I drove it at all. Of course, one source of my caution is that I did the job myself, as a rookie. I'm pretty sure I put all the bolts back in....
Winter is still taking a break here, so I'll take her out. Not yet persuaded to go to redline, but perhaps 4500 rpm will be a good target.