Webber 750 engine

brlcla

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I am ready to buy the three gear now.... just ready for testing to be done.

Love the fact its a three gear because I maintain the same rotation as the crank... and also the larger offset.... should be great on an airboat.

Neil,

Flanged crank or tapered? Is the prop hub available in an SAE II pattern? By the looks of the size of the bell housing, I can take a guess you are using the same size as the stock flywheel or very close to the stock. That housing looks like it is the same diameter as the marine housing.
 
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WHY

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It is my understanding that the "3 gear" re-drive shown in the pictures is a "custom dedicated order" but the "standard 2 gear" also fits the adapter housing and will be available after testing, while the "3 gear" has "exstensive testing" yet to be done and will take somewhat more time before release.

Tony
 

brlcla

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The two gear and three gear universal are both a standard product of Neil to my understanding.... both will require some testing.

Also I think I answered my own question. I think Neil swapped to the flanged crank as you can see the tapered crank that came out of the engine on the bottom shelf of the table next to the alternator.

Neil,

Are you going to develop a bed mount for the Weber also? I would be interested in that also.
 
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brlcla

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Well I have my good news... Neil emailed me yesterday stating that the he can build his box with an SAE II Flange and he has a bed style mount available.... looks like his box will give me everything I need for my boat upgrade with the least amount of effort....

Now just wait till testing is done...
 

WHY

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Hey Mark

Sunday afternoon here and have been on the internet for the last 2 or 3 hours studying O2 sensors on the Microsquirt forum and am getting a little education. Seems like there are basically two types, Narrow band and Wide band. Both types can have different numbers of wires.

Some info on the Microsquirt forum stated that the narrow band is not as accurated at idle or low speed engine loads and the wide band is, but that sounds to me like it would be just fine for our use since the only time we are at idle or low engine load is when we are taxing out to the runway or on a decent to final approach, so a narrow band would just be fine for our use and they are a lot less expensive -------BUT------- it looks like you have to have a wide band to tune the parameters of the Microsquirt (Megasquirt??) ECU so the ECU will have a program to refference the narrow band to. Looks like a narrow band may cost around $40 to $50. WWW.diyautotune.com has a wide band that is mentioned a lot in various posts, called the --- LC-1 , their part number is #3769 complete with controller at $200. The only value I see for using a wide band O2 sensor in our application, is that it can also feed a guage so you can monitor your AFR all the time.

If the O2 sensor is doing what I need at WOT and 75/80 percent throttle, then a narrow band is all I will probably run even though I will have to get a wide band to calibrate and program. If you do the same, before you would order a wide band, check with me, and I would loan you mine if I have already purchased one. No need to order another one if they are only going to be used for programming.

Tony
 

WHY

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Anyone out there with some past experience on O2 sensors and EFI that would be helpful, Jump in with both feet and let us hear about it, willing to listen to it all !!

Tony
 

JEFF TIPTON

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Does any of the following help?

Wideband zirconia sensor

A variation on the zirconia sensor, called the "wideband" sensor, was introduced by Robert Bosch in 1994, and has been used on a lot of cars[3] in order to meet the ever-increasing demands for better fuel economy, lower emissions and better engine performance at the same time. It is based on a planar zirconia element, but also incorporates an electrochemical gas pump. An electronic circuit containing a feedback loop controls the gas pump current to keep the output of the electrochemical cell constant, so that the pump current directly indicates the oxygen content of the exhaust gas. This sensor eliminates the lean-rich cycling inherent in narrow-band sensors, allowing the control unit to adjust the fuel delivery and ignition timing of the engine much more rapidly. In the automotive industry this sensor is also called a UEGO (for Universal Exhaust Gas Oxygen) sensor. UEGO sensors are also commonly used in aftermarket dyno tuning and high-performance driver air-fuel display equipment. The wideband zirconia sensor is used in stratified fuel injection systems, and can now also be used in diesel engines to satisfy the upcoming EURO and ULEV emission limits.

Wideband sensors have three elements:

Ion oxygen pump
Narrowband zirconia sensor
Heating element

The wiring diagram for the wideband sensor typically has six wires:

resistive heating element (two wires)
sensor
pump
calibration resistor
common

[edit] Titania sensor

A less common type of narrow-band lambda sensor has a ceramic element made of titanium dioxide (titania). This type does not generate its own voltage, but changes its electrical resistance in response to the oxygen concentration. The resistance of the titania is a function of the oxygen partial pressure and the temperature. Therefore, some sensors are used with a gas temperature sensor to compensate for the resistance change due to temperature. The resistance value at any temperature is about 1/1000 the change in oxygen concentration. Luckily, at lambda = 1, there is a large change of oxygen, so the resistance change is typically 1000 times between rich and lean, depending on the temperature.

As titania is an N-type semiconductor with a structure TiO2-x, the x defects in the crystal lattice conduct the charge. So, for fuel-rich exhaust the resistance is low, and for fuel-lean exhaust the resistance is high. The control unit feeds the sensor with a small electrical current and measures the resulting voltage across the sensor, which varies from near 0 volts to about 5 volts. Like the zirconia sensor, this type is nonlinear, such that it is sometimes simplistically described as a binary indicator, reading either "rich" or "lean". Titania sensors are more expensive than zirconia sensors, but they also respond faster.

In automotive applications the titania sensor, unlike the zirconia sensor, does not require a reference sample of atmospheric air to operate properly. This makes the sensor assembly easier to design against water contamination. While most automotive sensors are submersible, zirconia-based sensors require a very small supply of reference air from the atmosphere. In theory, the sensor wire harness and connector are sealed. Air that leaches through the wire harness to the sensor is assumed to come from an open point in the harness - usually the ECU which is housed in an enclosed space like the trunk or vehicle interior.
[edit] Location of the probe in a system

The probe is typically screwed into a threaded hole in the exhaust system, located after the branch manifold of the exhaust system combines, and before the catalytic converter. New vehicles are required to have a sensor before and after the exhaust catalyst to meet U.S. regulations requiring that all emissions components be monitored for failure. Pre and post-catalyst signals are monitored to determine catalyst efficiency. Additionally, some catalyst systems require brief cycles of lean (oxygen-containing) gas to load the catalyst and promote additional oxidation reduction of undesirable exhaust components.
http://en.wikipedia.org/wiki/Oxygen_sensor
 

Friendly

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Tony,
That is kind of you to offer the use of your O2 sensor, The Megasquirt program has both sensors. The firmware just needs to know which you are using to apply the proper value to the amount of voltage feedback. If your Os sensor is say 0 to 5 volts then the fuel will be distributed based on say 5 steps, If it is 0 to 10 volts the same fuel will now be distributed in 10 steps, giving you finer control . I already have the Wide Band Sensor so, I will remain with it. I have already down loaded the Megasquirt firmware to my processor. After I am sure about the rest of my sensors, I will re-flash the firmware with my updates and start the tuning process. Sounds like you are moving along nicely. I will finish my Megasquirt after while. I have some videos to edit and then I will get on the the Megasquirt.

Thank you Jeff,
You posted the same time, I did. I hope my example does not confuse anyone, it was meant to simplify what you so accurately posted.
 
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WHY

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Hi Jeff

That is a excellent explanation of the two types of sensors, thank you , Mark, that is good that the Megasquirt system comes with the sensors, no added expense. Will probably be at least a month or two before I would even think about sensors, got to build a exhaust system first, and have to finish the wiring before that and probably the oil system , haven't even thought about the cooling yet.



Tony
 

brlcla

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Why not use the stock wide band that comes with the polaris FST... you are talking about spending $50 for a narrow band.... the wide band is only $125

4011040
 

Friendly

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Hi Jeff

That is a excellent explanation of the two types of sensors, thank you , Mark, that is good that the Megasquirt system comes with the sensors, no added expense. Will probably be at least a month or two before I would even think about sensors, got to build a exhaust system first, and have to finish the wiring before that and probably the oil system , haven't even thought about the cooling yet.



Tony
Tony,
there is more information on the Megasquirt Web Page that may not be on the DIY web page. If you have not read the sensors and wiring, it may help a lot. The hard part about the Mega/Micro squirts is the instructions if for several units and they all sound alike, so you have to pay close attention or the manuel has jumped to a different version before you know it.

Here is the link for the O2 sensors
http://www.megamanual.com/PWC/
 
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WHY

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Hey Mark

Got caught by a friend of mine, was doing a serious case of Dumb A$$, was bolting all of the main ground leads inside the cockpit and out in the engine compartment to a common point for all grounds and engine ground as well (which is good) but thought I was really doing well by using a stainless bolt that would go thru the firewall, frame and connect everything at one point, but had failed to place a stainless washer between the copper (tinned) terminals and the aluminum frame. This would set up a serious electrolysis point by putting the copper directly against the aluminum. Some times you really feel stupid when you know better, it sure is nice to have good friends.

Tony
 

Friendly

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If weren't for mistakes, how would I know I was learning something?

Tony

Megasquirt site tells you how to load files into Megatune. It is really not user friendly. If you should have to re-flash or change your program, USE the program from DIY. It is simple download and execute file. I could not believe how easy it was after messing with the Megasquirt documentation.

I will be ordering the alum for the new face plate on the weber. This one will include the motor mount bosses and the relief cut into it for the flywheel. Then I hope to put some hours on the Weber.
 
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Friendly

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Tony,
Are you going to post any of your connections to the Microsquirt. I would be very interested in the difference in the Micro Vs Mega Squirt hook ups and pins. In particular, I would like to know how you are triggering the coils, if you are that far along already.

What are you doing to sync the firing of the coils with each cylinder? If they are not in sync, you have a 50/50 chance on the starting.
 

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Hi guys!!

Sounds like you are all making great progress!

PS:
I always like higher resolution sensors.
 
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