Programmable knock control systems
02-12-2006 | 03:17 PM
#51
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From: Missouri
Re: Programmable knock control systems
Originally Posted by CcanDo
The promised report is:Two separate systems were compared.The J&S Safeguard / MSD 6M combination .......The other was the Crane HI 6/Anson combination.The J&S appears to have a faster response time,has more visual reporting through the LED lights,more fine tuning capability and the plus feature of individual cylinder recognition.....No horsepower gains or losses were noted by either system......The included system check used with both systems, was tapping on the sensor with a wrench.....Therefore,in my opinion,while detonation is the topic and obvious use of these systems,the unspoken benefit of component " failing " recognition may be even more valuable.....Be it, a part of valve train,timing chain,piston slap and etc.,when metal to metal occurs , the alarm goes off and timing comes out......The system design parameters may be capable of engine shut down, if so desired.....Regardless,I feel this type of system is " must have protection ". Further,the system may provide some of the same benefits on fuel injected motors.
How would the J&S Safeguard capabilities/features relative to knock control with the GM ECU compare with the Merc PCM555 which alledgedy also addresses knock events on a cylinder by cylinder basis for fuel injected engines?
02-12-2006 | 04:42 PM
#52
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From: Missouri
Re: Programmable knock control systems
Originally Posted by John_at_J&S
HP350SC:
Some people have their minds made up about knock sensors. They've heard "knock sensors don't work" so many times, they believe it. As Rush Limbaugh says, "Thinking is hard work."
It is true, however, that knock sensors work best on quiet engines. The biggest interfering noise comes from piston slap, due to loose fitting forged pistons.
GM makes many knock sensors, but, according to a list sent me several years ago by a GM engineer, they are tuned for just three frequency bands.
The different thread styles and internal load resistor values account for the many part numbers. Note that the value of the load resistor is important only when connected to a GM processor.
Engines with a bore greater than about four inches should use the sensor with the lowest frequency band, which is centered around 5.2kHz.
GM sensors are not tuned for some magic or "perfect" knock frequency. They are tuned for a bandwith, about 1kHz wide.
The medium frequency sensor is 6.0kHz, and the highest frequency is 7.0kHz, which is used on the Saturn and the Fiero. I have since read that they aso make an 8kHz sensor, but that would suit the smallest bore engines.
I talked to LB the other day, and told him that the MSD Knock Alert ships with the medium frequency sensor. I had him read off the part number of the sensor included with the Anson gauge, and it is also the medium frequency. Note the the frequency bands overlap, so these sensors would still work on a large bore engine, but may not be the best choice.
Some people have their minds made up about knock sensors. They've heard "knock sensors don't work" so many times, they believe it. As Rush Limbaugh says, "Thinking is hard work."
It is true, however, that knock sensors work best on quiet engines. The biggest interfering noise comes from piston slap, due to loose fitting forged pistons.
GM makes many knock sensors, but, according to a list sent me several years ago by a GM engineer, they are tuned for just three frequency bands.
The different thread styles and internal load resistor values account for the many part numbers. Note that the value of the load resistor is important only when connected to a GM processor.
Engines with a bore greater than about four inches should use the sensor with the lowest frequency band, which is centered around 5.2kHz.
GM sensors are not tuned for some magic or "perfect" knock frequency. They are tuned for a bandwith, about 1kHz wide.
The medium frequency sensor is 6.0kHz, and the highest frequency is 7.0kHz, which is used on the Saturn and the Fiero. I have since read that they aso make an 8kHz sensor, but that would suit the smallest bore engines.
I talked to LB the other day, and told him that the MSD Knock Alert ships with the medium frequency sensor. I had him read off the part number of the sensor included with the Anson gauge, and it is also the medium frequency. Note the the frequency bands overlap, so these sensors would still work on a large bore engine, but may not be the best choice.
Do you have a web site? If so what is the URL.
What is the price of you marine unit and where is it available from?
Can you identify which frequency range is used for the Mercruiser 496HO part number 878187 knock sensor?
02-12-2006 | 04:59 PM
#53
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From: Concord, North Carolina
Re: Programmable knock control systems
I used Crane/Anson system on 36 Skater with 1150 Sterlings. No problems what so ever. You need to run the tach test. I found tach signal off above 6000. Both of mine read 7400 for the 7000rpm test. Rev-limiter has to be set accordingly. e.g. (7000rpm rev-limit on Crane box give me a 6600rpm rev-limit)
02-12-2006 | 11:11 PM
#54
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Re: Programmable knock control systems
Rage: We are not a supporting vendor. I don't know how the product fits in with LB's lineup, but they may carry them after further testing.
GM sensors have the part number engraved on the body, such as "10456082". This number crosses to AC Delco "213-95", but the sensor is still marked with the GM number.
Mercruiser may have the sensor marked with a custom part number.
GM sensors have the part number engraved on the body, such as "10456082". This number crosses to AC Delco "213-95", but the sensor is still marked with the GM number.
Mercruiser may have the sensor marked with a custom part number.
02-13-2006 | 08:42 AM
#55
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Joined: May 2003
Posts: 3,133
Likes: 2
From: E-Dock
Re: Programmable knock control systems
Originally Posted by CcanDo
Hi MTI 42, You already have piston sprayers from my fixtures.....These are new motors we have tweaked the design on.....Completely disassembled,changed several components and reassembled.....Bits and pieces of design from Dubui race team,Keith Eickert,Sterling,Zul,ourselves,Boyd Machine and others.....Boyds have done the additional machine work and reassembly.The application focus is on pleasure/poker run that is user friendly,durability and competitive power,in that order....Sanitary aesthetics is a buy product......We have more thoughts to come while looking at the marine industry as a possible business endeavor.........We will be doing a similar process to the next new set of motors,shortly.
02-20-2006 | 08:58 AM
#57
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Joined: Sep 2005
Posts: 1,987
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From: Missouri
Re: Programmable knock control systems
Originally Posted by John_at_J&S
HP350SC:
Some people have their minds made up about knock sensors. They've heard "knock sensors don't work" so many times, they believe it. As Rush Limbaugh says, "Thinking is hard work."
It is true, however, that knock sensors work best on quiet engines. The biggest interfering noise comes from piston slap, due to loose fitting forged pistons.
GM makes many knock sensors, but, according to a list sent me several years ago by a GM engineer, they are tuned for just three frequency bands.
The different thread styles and internal load resistor values account for the many part numbers. Note that the value of the load resistor is important only when connected to a GM processor.
Engines with a bore greater than about four inches should use the sensor with the lowest frequency band, which is centered around 5.2kHz.
GM sensors are not tuned for some magic or "perfect" knock frequency. They are tuned for a bandwith, about 1kHz wide.
The medium frequency sensor is 6.0kHz, and the highest frequency is 7.0kHz, which is used on the Saturn and the Fiero. I have since read that they aso make an 8kHz sensor, but that would suit the smallest bore engines.
I talked to LB the other day, and told him that the MSD Knock Alert ships with the medium frequency sensor. I had him read off the part number of the sensor included with the Anson gauge, and it is also the medium frequency. Note the the frequency bands overlap, so these sensors would still work on a large bore engine, but may not be the best choice.
Some people have their minds made up about knock sensors. They've heard "knock sensors don't work" so many times, they believe it. As Rush Limbaugh says, "Thinking is hard work."
It is true, however, that knock sensors work best on quiet engines. The biggest interfering noise comes from piston slap, due to loose fitting forged pistons.
GM makes many knock sensors, but, according to a list sent me several years ago by a GM engineer, they are tuned for just three frequency bands.
The different thread styles and internal load resistor values account for the many part numbers. Note that the value of the load resistor is important only when connected to a GM processor.
Engines with a bore greater than about four inches should use the sensor with the lowest frequency band, which is centered around 5.2kHz.
GM sensors are not tuned for some magic or "perfect" knock frequency. They are tuned for a bandwith, about 1kHz wide.
The medium frequency sensor is 6.0kHz, and the highest frequency is 7.0kHz, which is used on the Saturn and the Fiero. I have since read that they aso make an 8kHz sensor, but that would suit the smallest bore engines.
I talked to LB the other day, and told him that the MSD Knock Alert ships with the medium frequency sensor. I had him read off the part number of the sensor included with the Anson gauge, and it is also the medium frequency. Note the the frequency bands overlap, so these sensors would still work on a large bore engine, but may not be the best choice.
What is the GM part number for the 5.2kHz knock sensor that will fit on the 496HO? I want to check and see if that is the unit on my 496HO.
Thanks.
02-20-2006 | 11:42 AM
#58
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Re: Programmable knock control systems
GM makes several sensors tuned at that frequency. Mounting thread and internal load resistance account for the many part numbers.
Key on, engine not running, knock sensor connected, measure the DC volts on the knock sensor wire. If it reads about 2.5v, then the sensor load resistance may be important.
With the sensor disconnected, measure the resistance of the sensor itself, between the pin and the body (ground).
Report thread size and load resistance.
Key on, engine not running, knock sensor connected, measure the DC volts on the knock sensor wire. If it reads about 2.5v, then the sensor load resistance may be important.
With the sensor disconnected, measure the resistance of the sensor itself, between the pin and the body (ground).
Report thread size and load resistance.
02-23-2006 | 01:03 PM
#59
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Joined: Sep 2005
Posts: 1,987
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From: Missouri
Re: Programmable knock control systems
Originally Posted by John_at_J&S
GM makes several sensors tuned at that frequency. Mounting thread and internal load resistance account for the many part numbers.
Key on, engine not running, knock sensor connected, measure the DC volts on the knock sensor wire. If it reads about 2.5v, then the sensor load resistance may be important.
With the sensor disconnected, measure the resistance of the sensor itself, between the pin and the body (ground).
Report thread size and load resistance.
Key on, engine not running, knock sensor connected, measure the DC volts on the knock sensor wire. If it reads about 2.5v, then the sensor load resistance may be important.
With the sensor disconnected, measure the resistance of the sensor itself, between the pin and the body (ground).
Report thread size and load resistance.
The sensor (pn 878187) is a donut shaped unit with an electrical cable and pin connector. There is no thread. The sensor is bolted to the block with a stud (PN 16-862915) with a "0.25-18/M10 special thread". Is this the thread to which you refer?
The sensor is at the lake. I will measure the sensor resistance next trip.
02-23-2006 | 04:39 PM
#60
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Re: Programmable knock control systems
That sensor is "non resonant", meaning that it's not tuned to a particular frequency. It responds to all frequencies, up to about 20kHz.
The filtering is done electronically, inside the Mercruiser ECU. This way, manufacturers need to stock only one sensor, but they need to customize the electronics for each application.
The filtering is done electronically, inside the Mercruiser ECU. This way, manufacturers need to stock only one sensor, but they need to customize the electronics for each application.
