Built motors and detonation - Page 5 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 12-18-2009, 10:51 PM   #81
Elite Member
iTrader: (15)
 
Join Date: Dec 2007
Location: San Antonio, Texas
Posts: 4,889
Total Cats: 28
Default

Quote:
Originally Posted by hustler View Post
Where the he'll can I rent a borescope.
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
ZX-Tex is offline   Reply With Quote
Old 12-18-2009, 11:52 PM   #82
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

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.
Faeflora is offline   Reply With Quote
Old 12-19-2009, 12:23 AM   #83
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

So...what do I do if I see drama tomorrow?
hustler is offline   Reply With Quote
Old 12-19-2009, 12:36 AM   #84
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Any low compression drama aside from Savington?
hustler is offline   Reply With Quote
Old 12-19-2009, 10:02 AM   #85
:(
iTrader: (7)
 
Join Date: Jul 2006
Location: nowhere
Posts: 8,281
Total Cats: 2
Default

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).
magnamx-5 is offline   Reply With Quote
Old 12-21-2009, 09:50 AM   #86
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

I haz a borescope now. After I do a few home-colonoscopies I'll use on my cylinderinatrons.
hustler is offline   Reply With Quote
Old 12-21-2009, 01:14 PM   #87
Elite Member
iTrader: (13)
 
Join Date: Nov 2006
Location: Tigard, Oregon
Posts: 3,908
Total Cats: 0
Default

Quote:
Originally Posted by hustler View Post
I haz a borescope now. After I do a few home-colonoscopies I'll use on my cylinderinatrons.
Just clean the peanuts and corn off first.

Interested in what you find. I'm guessing they are perfect as you haven't been pushing the outer limits the way Sav was. Your 12psi is a whole lot safer than his 20.
cueball1 is offline   Reply With Quote
Old 12-21-2009, 01:51 PM   #88
Senior Member
iTrader: (2)
 
Join Date: Oct 2007
Location: Northeastern CT
Posts: 547
Total Cats: 2
Default

Quote:
Originally Posted by flipt86 View Post
Is WI a must for a street car at around 300whp?
Just bought some m-tuned rods and am going to slowly start my engine build. 300 will be my goal, but my car is not tracked.
How long has Paul been pushing the "machine" and does he have WI?
i'm not running WI

or an egt gauge, or a wideband gauge, or any number of other "must have's"

*shrug*
therieldeal is offline   Reply With Quote
Old 12-21-2009, 01:55 PM   #89
Elite Member
iTrader: (13)
 
Join Date: Nov 2006
Location: Tigard, Oregon
Posts: 3,908
Total Cats: 0
Default

It's the lack of wideband gauge that scares me the most out of that list.
cueball1 is offline   Reply With Quote
Old 12-21-2009, 02:41 PM   #90
Elite Member
Thread Starter
iTrader: (30)
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,282
Total Cats: 0
Default

Quote:
Originally Posted by hustler View Post
I haz a borescope now. After I do a few home-colonoscopies I'll use on my cylinderinatrons.


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.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
levnubhin is offline   Reply With Quote
Old 12-21-2009, 03:25 PM   #91
Elite AbsurdFlow Member
 
Laur3ns's Avatar
 
Join Date: Mar 2008
Location: Enschede, NL
Posts: 2,058
Total Cats: 11
Default

Borescope is stupid unless you suspect something. You won't _SEE_ 5% leak in #3 anyway with a scope. Do a leakdown each year and get over yourselves.
Laur3ns is offline   Reply With Quote
Old 12-21-2009, 03:29 PM   #92
Elite Member
iTrader: (11)
 
Join Date: Feb 2009
Posts: 2,982
Total Cats: 10
Default

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.

miatauser884 is offline   Reply With Quote
Old 12-21-2009, 03:56 PM   #93
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by Spookyfish View Post
Borescope is stupid unless you suspect something. You won't _SEE_ 5% leak in #3 anyway with a scope. Do a leakdown each year and get over yourselves.
Hey, Eurotrash...I'll be able to see perfectly smooth piston tops, unlike the dimpled cottage cheese *** you have to live with from going through life as a beta-male scavenger. A leak down won't show phantom detonation, but it will show that you're a latent homosexual, living the hetero lie.

Why the hell would I use a bore scope to do a leak-down or compression test?
hustler is offline   Reply With Quote
Old 12-21-2009, 03:59 PM   #94
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Quote:
Originally Posted by Spookyfish View Post
Borescope is stupid unless you suspect something. You won't _SEE_ 5% leak in #3 anyway with a scope. Do a leakdown each year and get over yourselves.
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.
Faeflora is offline   Reply With Quote
Old 12-21-2009, 04:03 PM   #95
Senior Member
iTrader: (2)
 
Join Date: Oct 2007
Location: Northeastern CT
Posts: 547
Total Cats: 2
Default

Quote:
Originally Posted by cueball1 View Post
It's the lack of wideband gauge that scares me the most out of that list.
i have an LC1, but no dash gauge. its just run straight into the MS and thats all.
therieldeal is offline   Reply With Quote
Old 12-21-2009, 04:05 PM   #96
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by therieldeal View Post
i have an LC1, but no dash gauge. its just run straight into the MS and thats all.
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.
hustler is offline   Reply With Quote
Old 12-21-2009, 04:18 PM   #97
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Quote:
Originally Posted by djp0623 View Post
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.


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?
Faeflora is offline   Reply With Quote
Old 12-21-2009, 04:28 PM   #98
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

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.
hustler is offline   Reply With Quote
Old 12-21-2009, 04:31 PM   #99
Elite Member
iTrader: (11)
 
Join Date: Feb 2009
Posts: 2,982
Total Cats: 10
Default

Quote:
Originally Posted by faeflora View Post
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?
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
miatauser884 is offline   Reply With Quote
Old 12-21-2009, 04:50 PM   #100
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Quote:
Originally Posted by djp0623 View Post
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
Right. But that only works if the engine is a steady state device where the combustion conditions are unchanging. Airflow at 15psi is probably quite different than at 9psi and your plugs, injectors, heatsoak etc all is different as well and that's not including stuff like fuel temperature, AITs, humidity, elevation blah blah blah. Again, OEMs probably have better closed loop sensors and spend more time, more money, have better practices, are more experienced, have engine dynos, better measurement sensors etc etc. I think.

Failsafe thread! Yes please!
Faeflora is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
New M62 Miata owner Pist0n Meet and Greet 4 10-01-2015 09:18 PM
Bizarre connection issue? nick470 MEGAsquirt 1 09-30-2015 11:32 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:42 AM.