Big salute to all the Veterans today! Also we would like to note that we have a BBR Extra Channel now live where we are going to post some of the more technical content or things that may be interesting to some of you that don't necessarily "make the cut" on our normal videos. For those of you who are into the CJ-7 build you should totally check it out because there is going to be a ton of Jeep stuff on that channel too! You can find the "BBR Extra" channel in the description or on the end screen in the video. Thanks!
a boost idea of mine no one has paid attention to for small engines: why NOT a brushless motor electric ducted fan used in electric model jet planes? they push a lot of thrust/pressure for being compressor type fans, the electronic speed controller can be programmed, controlled with a hall sensor on the throttle. you can program it's start point and it's RPM torque/boost curve with a 10 dollar (or less) card unit. it wouldn't involve all the "fancy plumbing" required by a real turbocharger either. if an air filter is large, a unit could fit right inside it, sneaky-sneaky! figure this, if the carb's throat is 26mm (pi R squared) and 531 square mm circle area, a 50 mm ducted fan is 1963 square mm total, minus 706 mm if powered by a 30 mm motor in its center, is 1257 square mm of compression surface area... roughly a 2.4:1 ratio between the push of the fan vs the carb throat. now the "fun" stuff.... the things are rated for how many pounds of static thrust they deliver, they usually DON'T tell how many CFM, or how much pressure they can develop.... like: 50mm being about 2" diameter, if its mounted to the end of a 2" pipe with a 1" outlet.... how much pressure in the 2" section? how many CFM (and at what pressure) is available at the 1" outlet? what is the max pressure it can develop before the compression fan blades are stalled? -like when ya put your hand over the hose of a shopvac and it revs up, basically. (there's still suction but the amount of flow gets choked off) I do think one would more than keep up with a small engine's intake/exhaust/displacement flow anyway, also possibly delivering at least 4-5 lbs of boost pressure, very easily and inexpensively too, like under 50 bucks. what might it do for a 212 size engine? lets think "oxygen"... if normal sea level air pressure is about 14 PSI, then 4 lbs of pressurized intake is trying to stuff about 276cc worth of oxygen into that 212cc displacement (30% more). kinda same strategy as a turbocharger or blower, it's already compressed when the piston is bottomed.... THEN the piston compression multiplies THAT. anyhowz..... that's "the long version" why I think it'd work out nicely once the speed/power controller is correctly programmed (oh hey, electronic management almost like the big boys!). edit: if the ducted fan is fuel proof, it could go behind the carb.... but its probably a better idea to go an EFI arrangement, which could also be controlled and programmed similarly to a ducted fan, maybe even from the same hall sensor for throttle position input, and tachometer (flywheel+coil).
impressive hydrodynamic pressure system you guys are running, - its really similar too an automobile turbo setup. , as an engineer, i simply couldnt resist the opportunity too blow in heaps extra fuel with a massive pump and an old civic injector. pulsed with one of these badboys. www.amazon.com/HiLetgo-12V-40V-Controller-Switch-Module/dp/B00QVONO20/ref=sr_1_5?ie=UTF8&qid=1542113193&sr=8-5&keywords=pwm+module . great videos. i wanna see this thing smoking on boost
Like said before your not going make any boost without a load. You definitely need stronger valve springs. I would tee off the boost reference and pressurize the fuel tank also into the vent. When the float drops enough and the needle unseats, the boost will just push the gas back into the tank.
Yep, need to add a hose to the tank vent. goin to run the bowl dry and go lean then melt the piston. the pressure in the carb might keep the needle shut.
Yes do this, and as for the tuning goes, my best guess is do not over enrich it to much. Make sure it revs out and runs great without boost with that carburator, the increased fuel pressure under boost will add that extra fuel you will need (small adjustments are needed here)
Mikuni's don't work as a blow through. Put it on the suction side with a hobbs switch that turns on the electric fuel pump when it starts to go from vacuum to boost. One fuel line from the fuel tank with a check valve fed to a y connector and another fuel line fed from electric fuel pump to the other side of the y to feed the carb under boost. The carb can keep up as long as it has enough fuel. Change the gear ratio to keep the RPM's low and the motor will live. If you were making boost and the motor coughed you would be replacing the piston fairly soon. 2-3 pounds of boost is the most you want otherwise the boost will keep the intake valves open. Try that blueprint.
Blow thru’s not just harder to tune also requires a little more complicated fuel system, like he stated hob switch and small electric perk pump along with some better valve springs.
A way i have done this before is to use an electronic fuel pump and a 1:1 rising rate fuel pressure regulator, use the electronic fuel pump to pressurise the fuel bowl and put the fuel pressure regulator between the pump and the carb. you have to set the regulator to near its minimum setting about 1-2 psi of base fuel pressure and then when the regulator sees boost it ups the fuel pressure with a ratio of 1 psi of boost = 1 psi of fuel pressure. This always keeps 1-2 psi in the fuel bowl no matter what the boost or vacuum is being produced. This worked perfectly for me and ran as it did before turbo, just with alot more power :). If you keep your current setup i would suggest putting a 1 way valve on the line between the turbo and the fuel bowl as any vacuum between the turbo and the carb will be trying to suck fuel out of the bowl, this is why it runs better when on boost. This will also help there to be less stuttering between going on and off the throttle. The type of 1:1 fpr is something like this, but i would try to find one with a guage to make it easier to set up :), hope this helped. www.ebay.co.uk/itm/Adjustable-Fuel-Pressure-Regulator-1-1-Rising-Rate-100-psi-7-bar-Select-Colour/332257912040?hash=item4d5c1d64e8:m:mlqe9MZfE1Kn8yd6vDGsCyA:rk:1:pf:0
Good job guys, your not floating the valves, however your tank needs boost pressure too, that way the fuel can flow into the carb, you have a lean breakup, and when you let off it fills the bowl and works right, pressureize your tank and fry some tires youve got the rest done.
Hey there. Just want to help. I would pressurerise the fuel from tank in to the carb. This is why: If you have 14.5psi fuel pressure from the atmosphere (fuel tank pressure) going in to the carb and the pressure in the carb is what ever boost the turbo is making, let’s say 14.5psi to make it easy. Then your relative fuel pressure becomes 0 psi that’s why you see the fuel getting pumped back up through the fuel line. Therefore you need 2-5 extra psi of fuel pressure before the carb. So to recap if you are making 14.5psi of boost and the atmosphere is also 14.5 psi you are effectively making 29psi of boost. Then you need 33-35psi fuel pressure to overcome the pressure difference. Keep in mind the fuel is already 14.5 psi of pressure in atmosphere. I hope it was helpful. Good luck.
there is no additonal 2-3 psi fuel pressure with a carb. he just needs to pressurize the fuel tank with the boost line from the compressor housing so that the whole system is pressurized to the same psi,
I have the same problem with a turbocharged lawn tractor I made, I took a turbo from a 14 Chevy Cruze and modified it to sit on my 12hp Tecumseh lawn tractor engine but every time it builds boost it will just push the gas back through and die, I’m hoping to resolve this issue by either using a pump with a regulator or equalizing pressure in the tank with the boost.
I have a question. Do you have the exhaust running through the turbo and then back through the carb? There's a inlet for the exhaust to enter the turbo and a outlet that runs to the carb. I can't really tell how you have it hooked up on the motor.
you need to add whats called a pitot tube, you run a tube perpendicular through your boost pipe with a hole facing air flow, connect the tube to a line pressurizing the carburetor float bowl, this will allow main jetting to remain close to stock, you can also box in the whole carb and pressurize it, carb doesnt care about boost so long as you keep it equally pressurized, problem comes when some areas and circuit are at atmospheric and others are at pressure, youll also need a rising rate fuel pressure regulator or referenced fuel pump to add a pound of fuel pressure for each pound of boost otherwise fuel cant get in to the bowl
This is exactly the right way to do it, or at least has worked for other people. A pitot tube, an enclosure for the carburetor (the enclosure must be air tight w/ a fitting for boost ref) a fuel pump, and a boost referenced fuel regulator would be recommended. Aeromotive and Magnafuel make these regulators but they are pretty pricey.
Have you guys tried running check valves on the boost reference (pressurizing the carb) and also on the fuel line. You can use it to keep pressure in the carb and stop fuel from pushing back out. Just a simple thought.
I think you might have better luck if you were to build that 212 up and make it safe to run in the higher rev range. You can only move so much air out of that exhaust port to spin the turbo, so if you put stronger internals in, did some head work, and took off the governor, then I can almost guarantee you’d see a lot more advantage out of the turbo.
We might do that in the future, but I think efi would be first if we went that route but a built engine would definitely crank out some more boost for sure!
Build Break Repeat I partially agree with him/her^ it would definitely be beneficial to remove the governor, but at the same time it might not be the smartest thing before building the engine if you’re already getting valve float. The biggest thing I wanted to get across with my original comment though, is that since you’re highly limited on the volume of air you should instead focus on the speed in which the engine is pumping it out. Either way, this is an awesome build and I’m enjoying it quite a lot. Can’t wait to see the next episode. 😃
@@Genesis385 everything is going to change as soon as they run it with a load. It wont rev right up, itll make more boost the air/fuel will be different. So really it's all moot until they drive the thing. Pick a setup, ballpark the settings and then tune it as they drive it.
Carbs can work as blow thru... You need a boost reference fuel pressure regulator. It turns up the fuel pressure to accommodate and cancel out the positive pressure in the carb and float bowl. Idk if the mikuni will work with it, but carbs can be used with blow thru boost. They do it on cars all the time.
Get a wideband o2 sensor so you know how rich/lean it actually is. And get a boost gauge that also reads vacuum. Tune for maximum vacuum at idle and go from there. Pretty neat little project!
Needs a boost gauge and is this a twin scroll hotside turbine housing? because if it is I know a way to get the turbo to spool up way faster and make more psi. Let me know thanks!
You got a few options that would fix your problems , perhaps easiest would to get a fuel pump and some controls that tune fuel press with turbo boost , also run capped line as a return fuel line to tank . It might also be possible to just stay strictly mechanical by sealing gas cap and running pressure line you got running to carb instead to tank thereby pressurizing fuel as boost builds but you would need a blowoff valve to prevent over fuelling at low rpms , but you def need boost gauge and some controls either elec or mech to control the difference of fuel demands . It would even be possible to salvage an injector from a tbi from old car and nix the carb all to gether and make a trip to autopart store and radio shack and slap proper controls on , but once you get a set up that works be prepared for something to break . You just need some thinking cap time and you will suceed . Hope you have a blessed day
You've got 2 options to get this to run properly. Either build a proper box to go around the carby or go to a suck through design. Either way you probably need to get an air fuel ratio guage and play with the main jet sizing aiming for around 11.5 to 1 under load on pump fuel. Good on you for getting this far though 👍
All you have to do, is Tee off the boost reference,and go tank vent, and Tee of to the carb drain (on the bottom) and the fuel/air will stay the same as boost builds/drops. And when you said 'I tightened the screw but fuel still sprays out' ……. that it just a drain, pull the plug out to drain the carb for winterizing the motor. the gas was getting pumped out the *overflow* and get 20lb valve springs before you blow the thing up. hehe
drive it every time you tune its different with no load and try taking the exhaust off to see if it will spool faster also maybe pressurising the fuel tank so it forces fuel at boost.👍
Ever tried changing the jets/needle? Pilot jet affects low, main affects high end, needle adjustment affecta the entire rpm range. Or am I just thinking dirt bikes?
Right now, when the turbo boosts a little the carb stops deliver gas........ You must put the carburetor before the turbo! Remove de carb from the midle. Basicaly do this: Carb --> Turbo --> Engine air intake.... (just like that!)
hey guys nice work looks good so far. you may want to put vaccum from the input side of the turbo to the waste gate solenoid otherwise it will build full boost all the time and mess with the air fuel mixtures.
I like your video's and nothing wrong with some trail and error, but its simple. Carb = vaccum , Turbo = Boost (positive pressure)I would get a rising rate FPR and fuel pump (don't waste money on EFI) - exactly as a dude a few days ago said :)
Have you guys thought of trying an efi conversion for it and removing the carburettor to be able to get it tuned better and actually be able to make boost. Also now that it’s turbocharged you will probably need more fuel pressure and not just a gravity fed fuel system
If you don't equalise fuel pressure with a blow through setup, you are going to continue to have issues. You can also enclose the carb in a box and pressurise the whole box. That way the pressure outside the carb is also at boost pressure and that should stop the fuel being pushed out of the overflows.
you will have to make a plenum around the carb to properly blow through on that carb then use a one way air valve to the fuel tank to compensate for the boost also will have to be sealed,connect to the turbo also the plenum box around the carb
Please try putting the boost into the tank vent (but make sure tank is sealed). Thay way you wont surge for fuel when the boost pushes it out of the carb
You really need to build an enclosure that basically puts the entire carb under boost, then run a pressure line to the tank so fuel still flows under boost. Remember carbs work when they suck and they can't suck when there is more pressure inside the carb than in the fuel supply.
whats the build on the current engine? billet rod and piston? heavier valve springs? im curious. ive wanted to turbo my 212 DB so these videos have been awesome to follow
Your welcome!! But like I said with this setup.. on boost you'll be runing on the just the bowl, unless you get the fuel pressure higher than the boost pressure!
If you try attaching a lever arm to the idle or air fuel mixture screw then attach that to the throttle and you would have Progressive air fuel mixture. Also adding a fuel regulator
If you're using blow through setup, fuel pressure must be more than the boost pressure, thats why you have problems. You can use battery powered cheap fuel pump to solve the problem
Okay, please listen, you're gonna blow that engine up if you don't change the valve springs, get a billet rod, and a billet flywheel. A few nice things to have would be stronger pushrods too but they aren't exactly necessary. Any one of those parts are going to fail, especially the valves without valve springs. Build the engine right, the stock engine is great but it WILL NOT hold up to being turbocharged.
BJ Jongejan I forgot to mention that it does have 18lb valve springs. But yeah if we were going for extreme durability rod and flywheel would be essential. Thanks.
I’m quite sure once they get the basics of making the turbo system work, a built engine will come next. Building an engine without a working and tunable turbo system would be pointless
You need a higher psi fuel pump and use a boost reference fuel pressure regulator, and for ever psi of boost add one psi of fuel. Maybe tap and plug the carb vent and over flow and use the boost reference you currently have going to the carb on the fuel pressure regulator.
Pull the turbo and weld the waste gate shut. If it’s non gated, then it’s a VGT turbo. Supply a boost reference to the VGT actuator. This should bring boost in earlier and provide a more usable torque curve
The amount of boost that this thing is making (possibly none) would never overcome the weight of the Waste gate spring. So it would be a waste of time to weld it shut.
You know when I built my turbo 250cc pep boys baja dune buggy I used a gt15 Garrett turbo and ran a boost signal line to the fuel tank and the carb vent. With a MBC I was able to achieve 18lbs of boost under full load, one needs to learn how to set up a blowthrough carb
Also get a boost gauge and electric fuel pump and regulator and set your fuel pressure to .25 lb higher than your boost pressure to equalise the pressurization of the fuel bowl
Typically itll backfiring out the exhaust when you have too much timing. Whenever you add cyl pressure your spark becomes more volatile so the fuel burns faster which you need to back timing down
My opinion gotta tee off the the boost reference from the turbo one goes to the wastegate and the other to the Gas tank . Add a bov in between the turbo and carb , tap the intake manifold for vacuum reference for the bov.
Try putting the air filter on it to where the turbo has to try a little harder to breath and it may cause just enough pressure to build boost but I'm new to the turbo thing lol
One more thing, you are going to have to run an electric fuel pump also because usually the fuel is gravity feed and with boost it pressureise it and basically stops the flow of fuel to the carb so it must be pressurized in order to work. Idle the waist gait will solve it but if u get an electric fuel pump and run it on a relay and hook it to the throttle so when u start on the gas, up have to play with when it turns on but it will kick on and pressurize the fuel because the boost is basically just forcing it back into the tank so u need to over come that witch that is not a big deal at all. So your waist gate needs to be working and u need fuel pressure. Sounds simple witch it is but it's just different on a small engine like that. But I can say confidently that is your issues and again I hope you read these!!
You need down the clip of the needle, to rich on the middle range, get a big jet pilot, the main jet is only on a ¾ to full throthle, get a air hose to the thank
To actually get anywhere you need a more automotive style carburetor with some kind of secondary that way it can be leaner down low and richer at wide open when it’s really needed
Hello, you have to close the little holes in the admission of the carburetor because if you blow high pressure from there the fuel will flew away... Trust me that's the problem
You are forgetting one thing the regulator valve on the side of the turbo has nothing hooked up to it you need to have vacuum up to it so that way it controls your boost your going to just be chasing your tail until you fix that situation a little diaphragm on the side of the turbo that controls the butterfly that opens for the exhaust that's why you're having a mixture problem because it keeps trying to spool the turbo if it's closed or it's not spooling the turbo if it's open
Just make you an equal length split manifold then you just have to sync them to where you have a primary for your idle speed. Tap manifold for a vacuum port on each runner, that why you can tune off vacuum. Which will at least get you to a better setting than ya'll are now.
Why did you only make the left wheel spin? I think thats not good when you drive. Both wheels need to spin. Put an another axle on itso both wheels will spin. It will drive much better. Also put an blow off valve on it so the extra boost can go away when you release the accellerator
420 would be pretty good but if you don’t wana worry about power issues go 670. The biggest thing I’d worry about is getting a proper tav settup. A 420 with a 40 series from GPS would be good.
Build Break Repeat I didn’t notice a boost gauge. This seems to be the new thing on TH-cam. Everyone trying to boost go karts. I can dig it. Almost wish someone would boost the biggest engine harbor freight has that I’m pretty sure is fuel injected.
N1ck0145 Garage . I was thinking of turboing my built 670 golf cart. It goes thru belts the way it is tho. haha. I built the header with a turbo in mind.
Hey Daniel, I'm a fellow Tamu student here in town, and I've got some projects under my belt, I've got the opportunity to build a pretty ridiculous kart right now, think you'd have any interest in being a part of it?
Only way to get these small engines work with turbo is install carb in turbo intake. There is no living person who has made one cyl run properly with normal slide carb with pressure. And when installed in turbo intake, low rpm drive is probably going to be horrible cuz you have to tune it so rich, otherwise it goes way too lean when and if you manage to gain some boost.
have you tried adding some kind of valve in the line to pressurize the bowl where you can adjust how much air goes into the bowl also try adding a blow off valve so you arent putting strain on the carb
Big salute to all the Veterans today! Also we would like to note that we have a BBR Extra Channel now live where we are going to post some of the more technical content or things that may be interesting to some of you that don't necessarily "make the cut" on our normal videos. For those of you who are into the CJ-7 build you should totally check it out because there is going to be a ton of Jeep stuff on that channel too!
You can find the "BBR Extra" channel in the description or on the end screen in the video. Thanks!
Build Break Repeat Second Channel right here! Make sure to subscribe!
And its blowing out air at d bottom because that's we're u hook up your boost gauge from run a hose from there into a gauge
a boost idea of mine no one has paid attention to for small engines:
why NOT a brushless motor electric ducted fan used in electric model jet planes? they push a lot of thrust/pressure for being compressor type fans, the electronic speed controller can be programmed, controlled with a hall sensor on the throttle. you can program it's start point and it's RPM torque/boost curve with a 10 dollar (or less) card unit. it wouldn't involve all the "fancy plumbing" required by a real turbocharger either.
if an air filter is large, a unit could fit right inside it, sneaky-sneaky!
figure this, if the carb's throat is 26mm (pi R squared) and 531 square mm circle area, a 50 mm ducted fan is 1963 square mm total, minus 706 mm if powered by a 30 mm motor in its center, is 1257 square mm of compression surface area... roughly a 2.4:1 ratio between the push of the fan vs the carb throat.
now the "fun" stuff.... the things are rated for how many pounds of static thrust they deliver, they usually DON'T tell how many CFM, or how much pressure they can develop.... like: 50mm being about 2" diameter, if its mounted to the end of a 2" pipe with a 1" outlet.... how much pressure in the 2" section? how many CFM (and at what pressure) is available at the 1" outlet? what is the max pressure it can develop before the compression fan blades are stalled? -like when ya put your hand over the hose of a shopvac and it revs up, basically. (there's still suction but the amount of flow gets choked off)
I do think one would more than keep up with a small engine's intake/exhaust/displacement flow anyway, also possibly delivering at least 4-5 lbs of boost pressure, very easily and inexpensively too, like under 50 bucks. what might it do for a 212 size engine? lets think "oxygen"... if normal sea level air pressure is about 14 PSI, then 4 lbs of pressurized intake is trying to stuff about 276cc worth of oxygen into that 212cc displacement (30% more). kinda same strategy as a turbocharger or blower, it's already compressed when the piston is bottomed.... THEN the piston compression multiplies THAT.
anyhowz..... that's "the long version" why I think it'd work out nicely once the speed/power controller is correctly programmed (oh hey, electronic management almost like the big boys!).
edit: if the ducted fan is fuel proof, it could go behind the carb.... but its probably a better idea to go an EFI arrangement, which could also be controlled and programmed similarly to a ducted fan, maybe even from the same hall sensor for throttle position input, and tachometer (flywheel+coil).
impressive hydrodynamic pressure system you guys are running, - its really similar too an automobile turbo setup. , as an engineer, i simply couldnt resist the opportunity too blow in heaps extra fuel with a massive pump and an old civic injector. pulsed with one of these badboys. www.amazon.com/HiLetgo-12V-40V-Controller-Switch-Module/dp/B00QVONO20/ref=sr_1_5?ie=UTF8&qid=1542113193&sr=8-5&keywords=pwm+module . great videos. i wanna see this thing smoking on boost
do efi
Like said before your not going make any boost without a load. You definitely need stronger valve springs. I would tee off the boost reference and pressurize the fuel tank also into the vent. When the float drops enough and the needle unseats, the boost will just push the gas back into the tank.
Omg... I said this on the last video. Lil idiots don't read long comments. Lol
Yep, need to add a hose to the tank vent. goin to run the bowl dry and go lean then melt the piston. the pressure in the carb might keep the needle shut.
Yes do this, and as for the tuning goes, my best guess is do not over enrich it to much. Make sure it revs out and runs great without boost with that carburator, the increased fuel pressure under boost will add that extra fuel you will need (small adjustments are needed here)
@@thegenerousdegenerate9395 I said that two weeks ago lol. i wasnt surprised.
Mikuni's don't work as a blow through. Put it on the suction side with a hobbs switch that turns on the electric fuel pump when it starts to go from vacuum to boost. One fuel line from the fuel tank with a check valve fed to a y connector and another fuel line fed from electric fuel pump to the other side of the y to feed the carb under boost. The carb can keep up as long as it has enough fuel. Change the gear ratio to keep the RPM's low and the motor will live. If you were making boost and the motor coughed you would be replacing the piston fairly soon. 2-3 pounds of boost is the most you want otherwise the boost will keep the intake valves open. Try that blueprint.
Uncle Muir 👏🏼👏🏼👏🏼
Blow thru’s not just harder to tune also requires a little more complicated fuel system, like he stated hob switch and small electric perk pump along with some better valve springs.
A way i have done this before is to use an electronic fuel pump and a 1:1 rising rate fuel pressure regulator, use the electronic fuel pump to pressurise the fuel bowl and put the fuel pressure regulator between the pump and the carb. you have to set the regulator to near its minimum setting about 1-2 psi of base fuel pressure and then when the regulator sees boost it ups the fuel pressure with a ratio of 1 psi of boost = 1 psi of fuel pressure. This always keeps 1-2 psi in the fuel bowl no matter what the boost or vacuum is being produced. This worked perfectly for me and ran as it did before turbo, just with alot more power :).
If you keep your current setup i would suggest putting a 1 way valve on the line between the turbo and the fuel bowl as any vacuum between the turbo and the carb will be trying to suck fuel out of the bowl, this is why it runs better when on boost. This will also help there to be less stuttering between going on and off the throttle.
The type of 1:1 fpr is something like this, but i would try to find one with a guage to make it easier to set up :), hope this helped.
www.ebay.co.uk/itm/Adjustable-Fuel-Pressure-Regulator-1-1-Rising-Rate-100-psi-7-bar-Select-Colour/332257912040?hash=item4d5c1d64e8:m:mlqe9MZfE1Kn8yd6vDGsCyA:rk:1:pf:0
Check out the efi kit that boosted boiz have for their shopping cart would probably be something good for u to look into
You took that engine to the next level. I’m getting better at fixing go karts every time I watch cool videos like this.nice job.
Awesome dude! I want to do that to my go kart now!!
Your clutch seems to be walking in and out on the shaft.
Brooks Pearce Yeah gotta tighten those set screws
I noticed that too.
Good job guys, your not floating the valves, however your tank needs boost pressure too, that way the fuel can flow into the carb, you have a lean breakup, and when you let off it fills the bowl and works right, pressureize your tank and fry some tires youve got the rest done.
Carburators dont Works in positive pression, use in sucçion tube of turbo
Hey there.
Just want to help. I would pressurerise the fuel from tank in to the carb. This is why: If you have 14.5psi fuel pressure from the atmosphere (fuel tank pressure) going in to the carb and the pressure in the carb is what ever boost the turbo is making, let’s say 14.5psi to make it easy. Then your relative fuel pressure becomes 0 psi that’s why you see the fuel getting pumped back up through the fuel line. Therefore you need 2-5 extra psi of fuel pressure before the carb. So to recap if you are making 14.5psi of boost and the atmosphere is also 14.5 psi you are effectively making 29psi of boost. Then you need 33-35psi fuel pressure to overcome the pressure difference. Keep in mind the fuel is already 14.5 psi of pressure in atmosphere.
I hope it was helpful. Good luck.
there is no additonal 2-3 psi fuel pressure with a carb. he just needs to pressurize the fuel tank with the boost line from the compressor housing so that the whole system is pressurized to the same psi,
I have the same problem with a turbocharged lawn tractor I made, I took a turbo from a 14 Chevy Cruze and modified it to sit on my 12hp Tecumseh lawn tractor engine but every time it builds boost it will just push the gas back through and die, I’m hoping to resolve this issue by either using a pump with a regulator or equalizing pressure in the tank with the boost.
I have a question. Do you have the exhaust running through the turbo and then back through the carb? There's a inlet for the exhaust to enter the turbo and a outlet that runs to the carb. I can't really tell how you have it hooked up on the motor.
you need to add whats called a pitot tube, you run a tube perpendicular through your boost pipe with a hole facing air flow, connect the tube to a line pressurizing the carburetor float bowl, this will allow main jetting to remain close to stock, you can also box in the whole carb and pressurize it, carb doesnt care about boost so long as you keep it equally pressurized, problem comes when some areas and circuit are at atmospheric and others are at pressure, youll also need a rising rate fuel pressure regulator or referenced fuel pump to add a pound of fuel pressure for each pound of boost otherwise fuel cant get in to the bowl
This is exactly the right way to do it, or at least has worked for other people. A pitot tube, an enclosure for the carburetor (the enclosure must be air tight w/ a fitting for boost ref) a fuel pump, and a boost referenced fuel regulator would be recommended. Aeromotive and Magnafuel make these regulators but they are pretty pricey.
Have you guys tried running check valves on the boost reference (pressurizing the carb) and also on the fuel line. You can use it to keep pressure in the carb and stop fuel from pushing back out. Just a simple thought.
I think you might have better luck if you were to build that 212 up and make it safe to run in the higher rev range. You can only move so much air out of that exhaust port to spin the turbo, so if you put stronger internals in, did some head work, and took off the governor, then I can almost guarantee you’d see a lot more advantage out of the turbo.
We might do that in the future, but I think efi would be first if we went that route but a built engine would definitely crank out some more boost for sure!
@@BuildBreakRepeat you should at least remove the governor if you haven't already.
Build Break Repeat I partially agree with him/her^ it would definitely be beneficial to remove the governor, but at the same time it might not be the smartest thing before building the engine if you’re already getting valve float. The biggest thing I wanted to get across with my original comment though, is that since you’re highly limited on the volume of air you should instead focus on the speed in which the engine is pumping it out. Either way, this is an awesome build and I’m enjoying it quite a lot. Can’t wait to see the next episode. 😃
@@Genesis385 everything is going to change as soon as they run it with a load. It wont rev right up, itll make more boost the air/fuel will be different. So really it's all moot until they drive the thing. Pick a setup, ballpark the settings and then tune it as they drive it.
Hi there, u could put your adjustable carb in some sort of a box to enclose it and run your charge pipe to that box.
Carbs can work as blow thru... You need a boost reference fuel pressure regulator. It turns up the fuel pressure to accommodate and cancel out the positive pressure in the carb and float bowl.
Idk if the mikuni will work with it, but carbs can be used with blow thru boost. They do it on cars all the time.
Get a wideband o2 sensor so you know how rich/lean it actually is. And get a boost gauge that also reads vacuum. Tune for maximum vacuum at idle and go from there. Pretty neat little project!
Needs a boost gauge and is this a twin scroll hotside turbine housing? because if it is I know a way to get the turbo to spool up way faster and make more psi. Let me know thanks!
build a box around carb thats air tight and have a fuel pump provinding fuel to the carb
You got a few options that would fix your problems , perhaps easiest would to get a fuel pump and some controls that tune fuel press with turbo boost , also run capped line as a return fuel line to tank . It might also be possible to just stay strictly mechanical by sealing gas cap and running pressure line you got running to carb instead to tank thereby pressurizing fuel as boost builds but you would need a blowoff valve to prevent over fuelling at low rpms , but you def need boost gauge and some controls either elec or mech to control the difference of fuel demands . It would even be possible to salvage an injector from a tbi from old car and nix the carb all to gether and make a trip to autopart store and radio shack and slap proper controls on , but once you get a set up that works be prepared for something to break . You just need some thinking cap time and you will suceed . Hope you have a blessed day
Good job!
You've got 2 options to get this to run properly.
Either build a proper box to go around the carby or go to a suck through design.
Either way you probably need to get an air fuel ratio guage and play with the main jet sizing aiming for around 11.5 to 1 under load on pump fuel.
Good on you for getting this far though 👍
All you have to do, is Tee off the boost reference,and go tank vent, and Tee of to the carb drain (on the bottom) and the fuel/air will stay the same as boost builds/drops. And when you said 'I tightened the screw but fuel still sprays out' ……. that it just a drain, pull the plug out to drain the carb for winterizing the motor. the gas was getting pumped out the *overflow* and get 20lb valve springs before you blow the thing up. hehe
drive it every time you tune its different with no load and try taking the exhaust off to see if it will spool faster also maybe pressurising the fuel tank so it forces fuel at boost.👍
Did you ever put the boost air pressure line into the fuel tank? that would keep fuel pressure high.
Ever tried changing the jets/needle? Pilot jet affects low, main affects high end, needle adjustment affecta the entire rpm range. Or am I just thinking dirt bikes?
Right now, when the turbo boosts a little the carb stops deliver gas........ You must put the carburetor before the turbo! Remove de carb from the midle. Basicaly do this: Carb --> Turbo --> Engine air intake.... (just like that!)
hey guys nice work looks good so far. you may want to put vaccum from the input side of the turbo to the waste gate solenoid otherwise it will build full boost all the time and mess with the air fuel mixtures.
7:50 have u screwed the pully on to the shaft because when u Rev it the full sprocket in the engine moves out like 10mm
Can you put the carb on the intake manifold and build a carb hat to hold boost?
Sick intro
I like your video's and nothing wrong with some trail and error, but its simple.
Carb = vaccum , Turbo = Boost (positive pressure)I would get a rising rate FPR and fuel pump (don't waste money on EFI) - exactly as a dude a few days ago said :)
Have you guys thought of trying an efi conversion for it and removing the carburettor to be able to get it tuned better and actually be able to make boost. Also now that it’s turbocharged you will probably need more fuel pressure and not just a gravity fed fuel system
If you don't equalise fuel pressure with a blow through setup, you are going to continue to have issues. You can also enclose the carb in a box and pressurise the whole box. That way the pressure outside the carb is also at boost pressure and that should stop the fuel being pushed out of the overflows.
you will have to make a plenum around the carb to properly blow through on that carb then use a one way air valve to the fuel tank to compensate for the boost also will have to be sealed,connect to the turbo also the plenum box around the carb
You should be pressurizing the tank with the same pressure going to the carb. Neutral fuel dressier for a blow through will work well.
Please try putting the boost into the tank vent (but make sure tank is sealed). Thay way you wont surge for fuel when the boost pushes it out of the carb
You really need to build an enclosure that basically puts the entire carb under boost, then run a pressure line to the tank so fuel still flows under boost. Remember carbs work when they suck and they can't suck when there is more pressure inside the carb than in the fuel supply.
I’d try to take that boost line and connect to fuel tank vent. Kinda like a boost reference fuel pump in a car
whats the build on the current engine? billet rod and piston? heavier valve springs? im curious. ive wanted to turbo my 212 DB so these videos have been awesome to follow
Yeah I want to 420 swap my daughters go cart and this video would help so I can eventually boost it
It's completely stock I believe
Your welcome!! But like I said with this setup.. on boost you'll be runing on the just the bowl, unless you get the fuel pressure higher than the boost pressure!
what king of go kart frame is it? I have the same exact kart. just dont dont know the name. Can anyone help me out?
If you try attaching a lever arm to the idle or air fuel mixture screw then attach that to the throttle and you would have Progressive air fuel mixture. Also adding a fuel regulator
You need fuel pressure higher than boost pressure, there are some special turbo carb fuel pressure regulators that can do that, and you need fuel pomp
The clutch slides side to side a bit is that even good?
now we begin to be on the right track! 👍🏻
If you're using blow through setup, fuel pressure must be more than the boost pressure, thats why you have problems. You can use battery powered cheap fuel pump to solve the problem
Okay, please listen, you're gonna blow that engine up if you don't change the valve springs, get a billet rod, and a billet flywheel. A few nice things to have would be stronger pushrods too but they aren't exactly necessary. Any one of those parts are going to fail, especially the valves without valve springs. Build the engine right, the stock engine is great but it WILL NOT hold up to being turbocharged.
BJ Jongejan I forgot to mention that it does have 18lb valve springs. But yeah if we were going for extreme durability rod and flywheel would be essential. Thanks.
I’m quite sure once they get the basics of making the turbo system work, a built engine will come next.
Building an engine without a working and tunable turbo system would be pointless
its not making that much boost dude
@@samsterstormhobbies Even performance N/A needs those mods 😝
Idk if you'll noticed but the clutch be moving in and out....you'll should get a bolt and tighten it down
You need a higher psi fuel pump and use a boost reference fuel pressure regulator, and for ever psi of boost add one psi of fuel. Maybe tap and plug the carb vent and over flow and use the boost reference you currently have going to the carb on the fuel pressure regulator.
I'd say you made some boost!👍
A turbo compresses air so if you put the carbie before the turbo then it's compressing air and fuel. That means less air to compress.
Pull the turbo and weld the waste gate shut. If it’s non gated, then it’s a VGT turbo. Supply a boost reference to the VGT actuator. This should bring boost in earlier and provide a more usable torque curve
The amount of boost that this thing is making (possibly none) would never overcome the weight of the Waste gate spring. So it would be a waste of time to weld it shut.
Stiffer valve springs, so they can close when they need to while air is forcing them open
You know when I built my turbo 250cc pep boys baja dune buggy I used a gt15 Garrett turbo and ran a boost signal line to the fuel tank and the carb vent. With a MBC I was able to achieve 18lbs of boost under full load, one needs to learn how to set up a blowthrough carb
maybe try use the mikuni for draw through set up. it might be better than the tilitson because of the bigger throat and also bigger jets will help.
If you add a electric fuel pump with a boost referenced fuel pressure regulator you might be able to remove the stumble at low rpm
Would love to see an efi kit on it that would help with boost and maybe heavier vavle springs if it don't already have a built motor
Also get a boost gauge and electric fuel pump and regulator and set your fuel pressure to .25 lb higher than your boost pressure to equalise the pressurization of the fuel bowl
Typically itll backfiring out the exhaust when you have too much timing. Whenever you add cyl pressure your spark becomes more volatile so the fuel burns faster which you need to back timing down
My opinion gotta tee off the the boost reference from the turbo one goes to the wastegate and the other to the Gas tank . Add a bov in between the turbo and carb , tap the intake manifold for vacuum reference for the bov.
Try putting the air filter on it to where the turbo has to try a little harder to breath and it may cause just enough pressure to build boost but I'm new to the turbo thing lol
link for the fuel pump?
One more thing, you are going to have to run an electric fuel pump also because usually the fuel is gravity feed and with boost it pressureise it and basically stops the flow of fuel to the carb so it must be pressurized in order to work. Idle the waist gait will solve it but if u get an electric fuel pump and run it on a relay and hook it to the throttle so when u start on the gas, up have to play with when it turns on but it will kick on and pressurize the fuel because the boost is basically just forcing it back into the tank so u need to over come that witch that is not a big deal at all. So your waist gate needs to be working and u need fuel pressure. Sounds simple witch it is but it's just different on a small engine like that. But I can say confidently that is your issues and again I hope you read these!!
You need to adjust your idle jet because it does the low end of the throttle
Wait is that engine un the front of the go cart or the back?
If it is un the front
you really wanna get toasted
You need down the clip of the needle, to rich on the middle range, get a big jet pilot, the main jet is only on a ¾ to full throthle, get a air hose to the thank
There is a kit. That make the carburetor to a injection one. So you can tune all the maps
Like man
To actually get anywhere you need a more automotive style carburetor with some kind of secondary that way it can be leaner down low and richer at wide open when it’s really needed
You need to build a low speed by pass like people in the comments are suggesting. This should eliminate the stumble.
For every lb of boost you're supposed to increase fuel pressure by 1 lb. A boost reference regulator would fix everything with an electric pump.
Hello, you have to close the little holes in the admission of the carburetor because if you blow high pressure from there the fuel will flew away... Trust me that's the problem
You are forgetting one thing the regulator valve on the side of the turbo has nothing hooked up to it you need to have vacuum up to it so that way it controls your boost your going to just be chasing your tail until you fix that situation a little diaphragm on the side of the turbo that controls the butterfly that opens for the exhaust that's why you're having a mixture problem because it keeps trying to spool the turbo if it's closed or it's not spooling the turbo if it's open
Just make you an equal length split manifold then you just have to sync them to where you have a primary for your idle speed.
Tap manifold for a vacuum port on each runner, that why you can tune off vacuum.
Which will at least get you to a better setting than ya'll are now.
Definitely read your plug. It will tell you a lot
Most people wouldn't know anything by looking at a plug. But if you know what your looking for its like reading a book
Why did you only make the left wheel spin? I think thats not good when you drive. Both wheels need to spin. Put an another axle on itso both wheels will spin. It will drive much better. Also put an blow off valve on it so the extra boost can go away when you release the accellerator
What do you think is the best go kart engine for a 4 seater go kart.
440cc snowmobile Engine
420 would be pretty good but if you don’t wana worry about power issues go 670. The biggest thing I’d worry about is getting a proper tav settup. A 420 with a 40 series from GPS would be good.
@@BuildBreakRepeat or you go with a sled engine and your getting 60+ HP and you have a torque converter that comes with it
Do the tct or tfb cuz it’s larger and doc a pull through.
Set up your boost by gear that might help? 😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂jokes.
I don’t think it’s making any boost with no load. Also Remember....leaner is meaner ;)
Chesapeake Outdoor Brothers Haha yeah, it made slight boost but when we drove it it was a completely different animal 😏
Build Break Repeat I didn’t notice a boost gauge. This seems to be the new thing on TH-cam. Everyone trying to boost go karts. I can dig it. Almost wish someone would boost the biggest engine harbor freight has that I’m pretty sure is fuel injected.
N1ck0145 Garage cars and cameras are always messing with those engines. Maybe they can do a turbo build
N1ck0145 Garage . I was thinking of turboing my built 670 golf cart. It goes thru belts the way it is tho. haha. I built the header with a turbo in mind.
Boost reference line goes to the tank
Put a jet into the charge pipe for fuel pick up. All it (injector)needs is 12v and fuel.
You might try hooking up the waste gate
You should probably hook that waste gate before you break the engine or the turbo
put another carburetor at the entrance of the mikuni and go changing the jets until it is
ecotrons efi kit would make this so much easier
Hey Daniel, I'm a fellow Tamu student here in town, and I've got some projects under my belt, I've got the opportunity to build a pretty ridiculous kart right now, think you'd have any interest in being a part of it?
LMAO why does your clutch shifts on the engine shaft when you rev??
Watch the clutch at 7:50 when he reves
Anti lag boi
U got a lot going in but u gotta think about the OUT EXAUST make it bigger
take the intake and carb you have on and put it on the turbo the run the turbo right to the motor then tune from there need long throttle cable
Try using a pulse pump to create fuel pressure
It's breaking up a bit in high R P M close your spark plug gap a little.
Only way to get these small engines work with turbo is install carb in turbo intake. There is no living person who has made one cyl run properly with normal slide carb with pressure. And when installed in turbo intake, low rpm drive is probably going to be horrible cuz you have to tune it so rich, otherwise it goes way too lean when and if you manage to gain some boost.
have you tried adding some kind of valve in the line to pressurize the bowl where you can adjust how much air goes into the bowl
also try adding a blow off valve so you arent putting strain on the carb
Looks like its just going to back the fuel back up into the tank
The carb should be on the inlet side of the turbo if you use fuel injection it would go after the turbo