Built motors and detonation
12-18-2009, 09:51 PM
#81
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You can get a cheap fiber optic one for $200. The nice one that I got to use once works with a glass tube and is hella expensive, like a few thou for a set and a light according to the engine tech that was scoping my engine. But the view is way, way better than the fiber optic one.
Cheap
http://www.harborfreight.com/cpi/cta...emnumber=95833
Really cheap
http://www.harborfreight.com/cpi/cta...emnumber=66550
Expensive
http://www.fiberscope.net/servlet/th...pes/Categories
Cheap
http://www.harborfreight.com/cpi/cta...emnumber=95833
Really cheap
http://www.harborfreight.com/cpi/cta...emnumber=66550
Expensive
http://www.fiberscope.net/servlet/th...pes/Categories
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12-18-2009, 10:52 PM
#82
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You could probably rig up a boreoscope or whatever with a bunch of stuff---
led gooseneck light with the neck sleeve removed (just the wire connected to the light)
dentist mirror with handle ground down mounted to some small vise e.g. panavise
telescope or microscope or camera with ok zoom lens and good sensor on tripod pointed at the mirror to look at directly or take pictures
It would kind of be a little fiddly but perhaps the elcheapest way to look inside.
led gooseneck light with the neck sleeve removed (just the wire connected to the light)
dentist mirror with handle ground down mounted to some small vise e.g. panavise
telescope or microscope or camera with ok zoom lens and good sensor on tripod pointed at the mirror to look at directly or take pictures
It would kind of be a little fiddly but perhaps the elcheapest way to look inside.
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12-19-2009, 09:02 AM
#85
hmm this has me wondering what my weiscos will look like when i pull my **** apart for the rods hmm. Have we ruled out a material defect in all the pistons or is this just a tunning or design flaw?
I would think the **** in a weisco, and a supertech are diff, but its been a while since i read up on them. I dont believe weiscos have the valve pockets as distended as the supertechs at least. If nothing else then maybe joe perez is right on the money with his per cylinder WI, becouse i could see a distribution problem doing this but there would be no real way to tell outside of per cylinder egts or running the IM on a flow bench at the desired pressure and measuring the per runner flow differential(probly the cheapest way).
I would think the **** in a weisco, and a supertech are diff, but its been a while since i read up on them. I dont believe weiscos have the valve pockets as distended as the supertechs at least. If nothing else then maybe joe perez is right on the money with his per cylinder WI, becouse i could see a distribution problem doing this but there would be no real way to tell outside of per cylinder egts or running the IM on a flow bench at the desired pressure and measuring the per runner flow differential(probly the cheapest way).
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12-21-2009, 01:41 PM
#90
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I'd love to get a peek into my motor as well. Granted it's only been street driven but I have been running 20+ psi with WI for several weeks now. Would be nice to see if there's anything going on in there.
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12-21-2009, 02:29 PM
#92
I think that the average "joe" melting his/her engine can probably be prevented. Sure, we all want to make the max power possible with our setups. Unless you are racing, I think it is best to take hustlers approach. Find a good tune and then back the timing off a few degrees for increased safety. If you want more power, then turn up the boost a little more. Sure, it won't be the most efficient, but you can probably reach your desired power goal. I think then you will have to be more selective when picking a turbo so that the turbo is still in its efficiency zone.
I'm waiting for one of this digital det cans from a member here. I will compare it to physical det cans and see if it works. Then I am going to tune my ms knocksensor. The LINK did do a good job of pulling timing, but I never could tell if it was real or not.
Now that we have determine that a built motor isn't a cure for a blown motor. I think we need a thread dedicated to safety margins and how to implement them. Start with the simplest: spark and fuel, then maybe coolant reroute, duel feed rail, water injection, etc..
All of this info in one place might convince people that spending a couple hundred bucks on a coolant reroute is very little when compared to the 1.5k-3k they spent on their "built" motor. I know I would really appreciate a thread like that.
I'm waiting for one of this digital det cans from a member here. I will compare it to physical det cans and see if it works. Then I am going to tune my ms knocksensor. The LINK did do a good job of pulling timing, but I never could tell if it was real or not.
Now that we have determine that a built motor isn't a cure for a blown motor. I think we need a thread dedicated to safety margins and how to implement them. Start with the simplest: spark and fuel, then maybe coolant reroute, duel feed rail, water injection, etc..
All of this info in one place might convince people that spending a couple hundred bucks on a coolant reroute is very little when compared to the 1.5k-3k they spent on their "built" motor. I know I would really appreciate a thread like that.
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12-21-2009, 02:56 PM
#93
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Why the hell would I use a bore scope to do a leak-down or compression test?
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12-21-2009, 02:59 PM
#94
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I disconcour. Couldn't a piston be melting/hotspotting in various places without leakdown symptoms? Isn't leakdown rings? If your piston is melting and getting brittle I'm guessing detonation will break it more easily. If you saw signs of fuxage at least you could try to do something about it before your piston dies and scores up your cylinders etc.
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12-21-2009, 03:05 PM
#96
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I get all warm and fuzzy when I've been into the loud pedal for 20-seconds, in 5th gear at 130mph, and look down to see 11.2 on my AFR gauge. It takes away the pain. I've looked down before and seen 12.0...I don't think my motor would last 10-hours at 12.0:1, do you? For whatever reason, I have to change the VE table when I go to the track.
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12-21-2009, 03:18 PM
#97
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I think that the average "joe" melting his/her engine can probably be prevented. Sure, we all want to make the max power possible with our setups. Unless you are racing, I think it is best to take hustlers approach. Find a good tune and then back the timing off a few degrees for increased safety. If you want more power, then turn up the boost a little more. Sure, it won't be the most efficient, but you can probably reach your desired power goal. I think then you will have to be more selective when picking a turbo so that the turbo is still in its efficiency zone.
I'm waiting for one of this digital det cans from a member here. I will compare it to physical det cans and see if it works. Then I am going to tune my ms knocksensor. The LINK did do a good job of pulling timing, but I never could tell if it was real or not.
Now that we have determine that a built motor isn't a cure for a blown motor. I think we need a thread dedicated to safety margins and how to implement them. Start with the simplest: spark and fuel, then maybe coolant reroute, duel feed rail, water injection, etc..
All of this info in one place might convince people that spending a couple hundred bucks on a coolant reroute is very little when compared to the 1.5k-3k they spent on their "built" motor. I know I would really appreciate a thread like that.
I'm waiting for one of this digital det cans from a member here. I will compare it to physical det cans and see if it works. Then I am going to tune my ms knocksensor. The LINK did do a good job of pulling timing, but I never could tell if it was real or not.
Now that we have determine that a built motor isn't a cure for a blown motor. I think we need a thread dedicated to safety margins and how to implement them. Start with the simplest: spark and fuel, then maybe coolant reroute, duel feed rail, water injection, etc..
All of this info in one place might convince people that spending a couple hundred bucks on a coolant reroute is very little when compared to the 1.5k-3k they spent on their "built" motor. I know I would really appreciate a thread like that.
OK. Maybe.
If your motor is spinning at 7000rpm, that's 116 revolutions per second, and each cylinder's plug is firing 58 times per second. Right?
Say you're doing pulls on a dyno, or brake-assisted pulls on the road. How much actual time in seconds do you actually spend in each cell of your fuel/timing map? Half a second? Whole seconds? If you do steady state tuning holding the rpm at a particular cell in your map(s), do you take the time go through all your trim settings? When you do hear detonation, how long does it actually last for? How many instances of detonation do you actually miss? I'm not experienced with tuning or dyno pulls but when I dynod my car it was each cell for less than a second, and on the street it's even less time. If your engine detonates will you actually hear a detonation event that lasts a tenth of a second? Will your ecu pick it up in time to react to it? Even if you tune your motor well and run conservatively, you could still have some **** up spot in your map that you pass through over and over again, detonating over and over again until things break right?
My point is that you can always be fucked and you may not hear knock, and your ecu might not pick up the knock.
Right jkav?
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12-21-2009, 03:28 PM
#98
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Sav and I both tune with analog det cans. People make fun of them, but they work and possibly work better than electronic monitoring systems. Its more than listening for knock in terms of a sound, its listening to the rhythm of the engine...if its not smooth and steady, something is wrong. I know there are a lot of technological heavy-hitters for recording and listening to sound, but before I was a Bureaucrat I was a musician for my adolescent life and two years of college. I'll be god-damned if someone tells me there is a recording device that can listen with more resolution and ocular logic than the human ear in respect to either visual or aural.
Of course, 30-minutes of glowing exhaust parts is more load than you'll probably put on a dyno, which is why we've relaxed timing and run so fat, against the advice of most people "in the know." More reasons to look in the scope.
Of course, 30-minutes of glowing exhaust parts is more load than you'll probably put on a dyno, which is why we've relaxed timing and run so fat, against the advice of most people "in the know." More reasons to look in the scope.
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12-21-2009, 03:31 PM
#99
OK. Maybe.
If your motor is spinning at 7000rpm, that's 116 revolutions per second, and each cylinder's plug is firing 58 times per second. Right?
Say you're doing pulls on a dyno, or brake-assisted pulls on the road. How much actual time in seconds do you actually spend in each cell of your fuel/timing map? Half a second? Whole seconds? If you do steady state tuning holding the rpm at a particular cell in your map(s), do you take the time go through all your trim settings? When you do hear detonation, how long does it actually last for? How many instances of detonation do you actually miss? I'm not experienced with tuning or dyno pulls but when I dynod my car it was each cell for less than a second, and on the street it's even less time. If your engine detonates will you actually hear a detonation event that lasts a tenth of a second? Will your ecu pick it up in time to react to it? Even if you tune your motor well and run conservatively, you could still have some **** up spot in your map that you pass through over and over again, detonating over and over again until things break right?
My point is that you can always be fucked and you may not hear knock, and your ecu might not pick up the knock.
Right jkav?
If your motor is spinning at 7000rpm, that's 116 revolutions per second, and each cylinder's plug is firing 58 times per second. Right?
Say you're doing pulls on a dyno, or brake-assisted pulls on the road. How much actual time in seconds do you actually spend in each cell of your fuel/timing map? Half a second? Whole seconds? If you do steady state tuning holding the rpm at a particular cell in your map(s), do you take the time go through all your trim settings? When you do hear detonation, how long does it actually last for? How many instances of detonation do you actually miss? I'm not experienced with tuning or dyno pulls but when I dynod my car it was each cell for less than a second, and on the street it's even less time. If your engine detonates will you actually hear a detonation event that lasts a tenth of a second? Will your ecu pick it up in time to react to it? Even if you tune your motor well and run conservatively, you could still have some **** up spot in your map that you pass through over and over again, detonating over and over again until things break right?
My point is that you can always be fucked and you may not hear knock, and your ecu might not pick up the knock.
Right jkav?
I'm still rooting for a safety measures thread
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12-21-2009, 03:50 PM
#100
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You might be right. I was assuming that as long as a map stays well interpolated it would remain safe. Please bare with my simplistic example. If I have no knock at a given rpm and "low" kpa and no knock at same rpm and "high" kpa. Then if interpolating between the two then there should not be knock at that rpm and "medium" kpa. Now obviously you can not expect to interpolate from 20 kpa to 220 kpa and be assured it won't knock. There has to be certain confirmed (no knock) blocks throughout the map under load that don't have knock. Then interpolate between these cells. This also assumes a pretty linear relationship between fuel, load , and timing.
I'm still rooting for a safety measures thread
I'm still rooting for a safety measures thread
Failsafe thread! Yes please!
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