212cc and 420cc exhaust with O2 sensor bungs for tuning.

[Jfive]

Is there any interest in these if I made a few. Would be setup for inexpensive tuning. One wire standard or Bosch sensor and use a volt meter to read air to fuel ratio. Would let you know basic idle ratio and wide open trottle.
Idea came after looking at modded race karts that have an open manifold with a bung and plug. I'd need to buy a bender and recoup the cost over a number if I made some. Have three engines as Guinea pigs for mock up. 196cc lifan. 212cc hemi and power land 16hp 420cc.
Have a job, not looking to make money just help others that wanna try and change for elevation reasons or because of using carbs and or modifying the air or fuel ratios and don't want to foul plug (rich) or burn up a piston (lean).

 

[bob58o]

i almost went to Fry Electronics to buy the parts for the LED display but
My soldering is garbage.

How far away does the sensor go?
Does it matter?
Anyway to test or calibrate in a "one off" application??

---------- Post added at 02:19 PM ---------- Previous post was at 02:15 PM ----------

DMM are free at HF with a $5 purchase all the time

 

[mckutzy]

IM guessing here...
In order to calibrate the device to be used, you would have to do an exhaustive test to determine the correct mixture(plug tests for a whole bunch of jets and given air filter setup) and what the reading is.... Then of course all the inbetween's to get the range. Rich-Right amount-Lean.

 

[Tangiblestar]

What kind of price point are you thinking?

 

[Jfive]

Really depends on how many I could make. The O2 bungs are the most exspensive depending on how many u purchase. As cheap as 3.00 a piece to 10.00 depending on if it has the plug or not stainless or mild recessed or not. I am thinking about using 3/4 steel coated conduit for 212 or 196 clones and 1" for the 390/420. O.D of the 3/4 is .992 so a small flare would make a tight fit in the 1" hole I punched on some test pieces. Looks like that's the common size used on 6.5s. I'd like em to be like 28.00 shipped with sensor bung and header and flange welded or not in case it's for a mini bike or something where it needs to be test fitted first. I'd like to make a small run. The bender is exspensive and the only cost I'm gonna try and recoupe a part of. There like 40 to 80.00 but to make the manderal bends it's needed. I have a two tigs or may try mig for ease. Gonna make one here this week first to show what I can do. Just putting a feeler out really.

 

[Jfive]

Made a flange to make the first one. 212cc hemi version 1.0. Took factory muffler off and cut the flange to make another. Took a comparison to show just how much restriction the factory has just at the flange.

 

[KartFab]

Is there any interest in these if I made a few. ...I'd need to buy a bender and recoup the cost over a number if I made some...
...Have a job, not looking to make money just help others...

That sounds like a conflict of interest right there lol.

Alright, please take constructive criticism. Think of the customer you are trying to do this for. So the need you are saying is getting the right mixture.

So you have a bunch of gearheads and inexperienced kids that are pimping out their engines.

So for the gear heads, they are already thinking, oh crap that is going to interfere with flow. Or are you saying that you are making a seperate manifold that you have to put on an engine, then remove after you get mixture correct? In that case, they might think well.... thats great, but its easier to remove a plug and i can just do it the old school way, so how is this even any better? It seems like more effort.

Now for the inexperienced engine people, how are they going to know that this is even beneficial? I for one am inexperienced, and I do understand that getting the mixture right or a little rich is great. However, using a multimeter and being able to read it is a theory, and I am not connecting the dots. Being able to do something in theory is not practical. How can this be something that is plug and play, like get this manifold and this plug and it shows you if its too rich or too lean. Right now it just sounds like a great theory thats too complicated to even bother with as an inexperienced person to even bother with.

In short, gearheads want it to give them a benefit, and not interfere with flow. Inexperienced peeps want it plug and play kit with no complicated BS that you gotta go through.

So how are you going to answer these questions?

Also, if you look at all the companies making performance exhaust systems, almost all of them get their flanges laser cut in bulk. Might not be worth the cost up front, but if these do end up selling well, then you will save rediculous amounts of time and money to get a 4'x8' sheet of steel lazer cut out of all the flanges you can dream of. Also, there are differences between box stock, predator, clone etc engine flange patterns, so watch out for that. (bolts clearing welds, bolt spacing)

 

[Poboy kartman]

And this friends....is KartFab GAB....something I've only seen thisl

Whatever.....Poboy is ALWAYS.....READY TO DEFEND...His position....OR.... HOMEbring it chumps....but make your peace beforehand,

Jest saying....

 

[rk970]

O2 sensor bungs are 18x1.5mm just get a nut and weld it on.
Take a look here. Do not waist time with a narrow band O2
http://www.14point7.com/pages/products

The problem with short head pipes (single pipe under 20") is the possibility of fresh air reversion at lower rpm causing dilution of the exhaust. If you move the sensor to close to the exhaust port it can over heat it.
If you get the small issues sorted out it is a good tuning tool.. It becomes a great tuning tool when you add in MAP, RPM and the ability to data log. It is not so safe to be looking at a afr gauge while driving a cart at WOT.

 

[CoroTheCat]

Well its certainly an interesting idea, looking forward to see where this is heading.
From what I can read it shouldn't be complicated to read the voltage from the plug, you could feed it to a microprocessor and it could write the info on a display or something. Pretty simple stuff.
I'm guessing that you are going to use a wideband sensor?

 

[Poboy kartman]

Here we go:MAMA....: "If your friend jumps off a bridge, would you?"

Bob: ...."Well...factoring in the acceleration rate of 32 seconds per second
per second...and not having an exact height or the exact compression rate outside of the substrate below...I'd say no...I'd have to research this...."

 

[Jfive]

That sounds like a conflict of interest right there lol.

Alright, please take constructive criticism. Think of the customer you are trying to do this for. So the need you are saying is getting the right mixture.

So you have a bunch of gearheads and inexperienced kids that are pimping out their engines.

So for the gear heads, they are already thinking, oh crap that is going to interfere with flow. Or are you saying that you are making a seperate manifold that you have to put on an engine, then remove after you get mixture correct? In that case, they might think well.... thats great, but its easier to remove a plug and i can just do it the old school way, so how is this even any better? It seems like more effort.

Now for the inexperienced engine people, how are they going to know that this is even beneficial? I for one am inexperienced, and I do understand that getting the mixture right or a little rich is great. However, using a multimeter and being able to read it is a theory, and I am not connecting the dots. Being able to do something in theory is not practical. How can this be something that is plug and play, like get this manifold and this plug and it shows you if its too rich or too lean. Right now it just sounds like a great theory thats too complicated to even bother with as an inexperienced person to even bother with.

In short, gearheads want it to give them a benefit, and not interfere with flow. Inexperienced peeps want it plug and play kit with no complicated BS that you gotta go through.

So how are you going to answer these questions?

Also, if you look at all the companies making performance exhaust systems, almost all of them get their flanges laser cut in bulk. Might not be worth the cost up front, but if these do end up selling well, then you will save rediculous amounts of time and money to get a 4'x8' sheet of steel lazer cut out of all the flanges you can dream of. Also, there are differences between box stock, predator, clone etc engine flange patterns, so watch out for that. (bolts clearing welds, bolt spacing)

So I am a gear head correct. I personally never liked looking at a plug and cross referencing it to a chart of pictures to see how something is running. I once bought accell 5.00 a piece spark plugs for a SBC motor I built just too find out I would have been better with the 1.88 two pack autolights from Walmart. They fouled out and eventually made the engine run like crap.

Now I have been getting into turbocharging and also into tuning and ECU's ect. Narrowband 02s are for N/A engines where you gave a narrow band you wanna keep your air to fuel ratio at. In turbo charging its a wider area hence the wideband setup Posted above. I have too innovative Motorsport LC1 wideband setups. I like 14.7 though and am familiar with there stuff and actually reference them a lot when people want a low budget unit and don't mind soldering.

Now the O2 sensor would eventually come out and be replaced with a plug. Not hindering flow after tuned. If you have a tunnable carb you'd tune the engine then take the sensor out and plug it and now you just have the header at less than the cost from someone else.

Now I am not looking to make 100 or so units so using a metal worker punch like I did only took 1min to make one flange lol. I'd do water jet over laser anyways. Just cause its better in my opinion. If it was stainless maybe laser. I can mig weld and not cover the bolt holes or tig with er70 filler if need. I ordered one O2 to try this out first. Cost 5.50 shipped.

Flange was a piece of scrap. Free. 1min of time maybe two mins with cut disc and grinder to copy the outside if the flange. One flange is 12.00 on eBay maybe laser cut. My 5mins is worth 12.00 I think. Not what I'd charge lol. I have a few multimeter's from harbor freight. They are free from time to time. I'd suggest the same to others. Bought zip ties get free multimeter. They had one on the latest ad locally infact. Usually the flashlight.

Shouldn't be hard to read the sensor IMO. Its one wire (positive/red). Ground to header (black). Set rear of kart on a block and start and let the sensor warm up then see how it runs at idle and at full throttle. No permanent gauge or any thing just simple tune up then pull the sensor and plug and go. Not trying to add to the expense most don't want to spend. Heck plugs get expensive and to a novice that over tightens a plug heads and gaskets could get expensive plus plugs if your buying 6.00 performance ones. My way you leave the plug alone.

I am just putting this out to see if anyone would like to try it. See threads on people having issues with engine running weird and i think having the ability to see what its running like vs. Guessing would be better piece of mind.

 

[chancer]

I like it. DIY and 5 mins beats buying it on Ebay!
I think part of the difference of theory between you two is...
Kartfabs website is attempting to appeal the masses. (nothing wrong with that) but K.I.S.S. is kinda mandatory.
Where as J5 is offering his advice to Forum members only. With the assumption we have more than a clue, and the support network here.

 

[Jfive]

Went to Lowes and picked up two sticks of conduit. 1" and 3/4". The 3/4" is a perfect match for the 212cc hemi with a 1" hole on the flange.

 

[Poboy kartman]

Well, .......

I just gotta say.....

Sometimes I get flack for the way I post...

But it HAS to be easier to read than this:

XX_XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

 

[Jfive]

Well, .......

I just gotta say.....

Sometimes I get flack for the way I post...

But it HAS to be easier to read than this:

XX_XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Fixed

 

[bob58o]

I read that the sensors have a 30mm long threaded part. I think the long bungs are 25mm.
The sensor would extend 5mm into the tube (~1/5" of an inch).

Not much of a difference between tuning and when it is removed. You could cut some threads off if you wanted it to protrude more.

Maybe it works right out of the box, the voltage as described in the link you gave me, but maybe not.

I think trial and error and manual tuning would also be required. Check stock AFR voltage, Check With upgraded Air Filter and stock jetting voltage, check multiple jet size voltages (both lean and rich). Find perfect Jets and find that voltage. Base "lean" or "rich" voltage after you find the voltage of the perfectly jetted carb.


I might like to keep something like that installed with a display on my dash. A kind of warning letting me know my AFR is off and I should stop doing donuts.
Where's sid on this one? Seems like his department???

 

[Jfive]

narrow band guages are cheap. If you have a electric start and a battery it wouldn't be hard to do. Unfortunately I have the pull start. I do have a 12v small battery I could setup to try it out though. I'd even possibly buy a guage to try it out.

 

[Iron John]

I dunno, maybe for all-out racing this instrumentation is worth it, but for 100 years folks just read their spark plugs.

 

[bob58o]

I dunno, maybe for all-out racing this instrumentation is worth it, but for 100 years folks just read their spark plugs.

For 1000's of years people thought the world was flat.
For one week, I thought I was going to run my 420 stock.
For two days, I thought I had a date with Missy.

Just saying...