dwcopple
backyard hooligan
gran pann did you remove your internal governor then? what did you do about the gasket? cereal box?
Bronda engine
- Thread starter KartFab
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KartFab
Active member
Yea governor is removed. I just used the old gasket and some gasket maker. When I clean the engine up I will put a new gasket on. I'd rather pay for a new gasket than make one.
KartFab
Active member
Bought a tachometer to put on the bronda engine. Revs to valve float around 5600-5800 rpms. Engine was not under load. Made a little video of it. Seems simple enough. Going to put this engine on the steaker go kart I have laying around.
http://youtu.be/cziW03Wc3Wc
The equation i have shows the max speed at 5500 rpm at 66 mph.... kind of hard to believe... but the math is correct.
Makes me wonder if the drag from the tires/weight/etc may reduce the top speed. will be a 6:1 ratio with 22" tires... we will see lol. Ill have the tach on it and a little gps app to see if everything matches up..... now i just gotta restore ANOTHER go kart before any updates haha.
http://youtu.be/cziW03Wc3Wc
The equation i have shows the max speed at 5500 rpm at 66 mph.... kind of hard to believe... but the math is correct.
Makes me wonder if the drag from the tires/weight/etc may reduce the top speed. will be a 6:1 ratio with 22" tires... we will see lol. Ill have the tach on it and a little gps app to see if everything matches up..... now i just gotta restore ANOTHER go kart before any updates haha.
Drag from tires, the inherent inefficiency in a clutch, and a chain and sprocket, wind resistance, whatever lift you might experience from the air getting under the kart causing loss of traction, literally any other interaction between two different things.
You might not see the calculated amount but you'll see a nice high speed
firemanjim
Just kartin' around....
great video..... Out of curiosity, do you think it's possible to run 2 3hp briggs off of one big carb?
KartFab
Active member
The gx620 honda engines have 2 cylinders, 1 carb. Gotta try it out to see?
2SlickNick
American Minibikes @ FB
Hey Gran_pann,
I want to do the same set up with the carb as you. I just ordered this.... http://www.ebay.com/itm/261444841235
Could you please tell me tube size you used, which gasket I would use to make manifold, size plate you used for flanges, and any other suggestions.
thanks.
I want to do the same set up with the carb as you. I just ordered this.... http://www.ebay.com/itm/261444841235
Could you please tell me tube size you used, which gasket I would use to make manifold, size plate you used for flanges, and any other suggestions.
thanks.
KartFab
Active member
I tig welded it it's all stainless.
7/8 ID tube for intake/exhaust.
45 deg elbow for exhaust
1/4" plate for flanges
For engine side I used new briggs gaskets.
I made the flanges by simply tracing the exhaust gasket and engine side of old carb
For the carb side of the flange I used the carb gasket to trace out the flange.
#36 jet, 140 e-tube
Performance intake adaptor/air filter for the predator 212cc
Two 1/4"x 3 3/4" grade 8 bolts to mount the carb.
Also, no idea how to hook up throttle mechanism. It's going to need a spring to avoid damaging butterfly if you floor it. You are on your own there since I haven't even figured it out.
7/8 ID tube for intake/exhaust.
45 deg elbow for exhaust
1/4" plate for flanges
For engine side I used new briggs gaskets.
I made the flanges by simply tracing the exhaust gasket and engine side of old carb
For the carb side of the flange I used the carb gasket to trace out the flange.
#36 jet, 140 e-tube
Performance intake adaptor/air filter for the predator 212cc
Two 1/4"x 3 3/4" grade 8 bolts to mount the carb.
Also, no idea how to hook up throttle mechanism. It's going to need a spring to avoid damaging butterfly if you floor it. You are on your own there since I haven't even figured it out.
OzFab
Well-known member
6:1 on 22s sounds like a bit of a stretch; just saying...
KartFab
Active member
6:1 on 22" is a huge stretch for a cent clutch.
Torque converter? I cannot explain in words, but spend 1 min 30 seconds watching this and you will see
1) 6:1 ratio
2) 22" tires
3) 196cc greyhound engine, all stock.
4) torque converter
Rest is self explanatory. Gotta see it to believe it sometimes right? I agree it is a bit of a stretch, but only on very steep hills.
https://youtu.be/__EfI0MB1ls
Torque converter? I cannot explain in words, but spend 1 min 30 seconds watching this and you will see
1) 6:1 ratio
2) 22" tires
3) 196cc greyhound engine, all stock.
4) torque converter
Rest is self explanatory. Gotta see it to believe it sometimes right? I agree it is a bit of a stretch, but only on very steep hills.
https://youtu.be/__EfI0MB1ls
firemanjim
Just kartin' around....
Great action video. That's how you sell it!! That's @6:1 on a 196cc?? Wow, very impressed!
2SlickNick
American Minibikes @ FB
You are right, the throttle hook up is a pain. I bought some levers and it became a hassle like having the stock set up again. My wife always tells me less is more, so......... I had an 
The direct throttle hook up can cause the butterfly to bend if you floor it, right.....
So....What if you put a spring with just a little bit more strength/stiffer than the return spring - between the throttle and throttle cable?
That way if you floor it, you are only stretching the spring and not bending the butterfly.
Or.... Just have one pivot point with a rod connected to throttle like this( scroll down 3/4 to pic with red shroud ) http://www.affordablegokarts.com/throttle-linkage.php
The direct throttle hook up can cause the butterfly to bend if you floor it, right.....
So....What if you put a spring with just a little bit more strength/stiffer than the return spring - between the throttle and throttle cable?
That way if you floor it, you are only stretching the spring and not bending the butterfly.
Or.... Just have one pivot point with a rod connected to throttle like this( scroll down 3/4 to pic with red shroud ) http://www.affordablegokarts.com/throttle-linkage.php
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2SlickNick
American Minibikes @ FB
Question: When you bought that air filter it looks like the 2-7/16" ID... right?
Was it real snug when you slipped it on the adapter? or did you have to tighten it down alot?
I ask because I need to get a shorter filter like this.... http://www.ebay.com/itm/42mm-Air-Fi...12655947&tpos=top&ttype=price&talgo=undefined
Thanks in advance.
Was it real snug when you slipped it on the adapter? or did you have to tighten it down alot?
I ask because I need to get a shorter filter like this.... http://www.ebay.com/itm/42mm-Air-Fi...12655947&tpos=top&ttype=price&talgo=undefined
Thanks in advance.
just out of curiosity...
KartInfo by kartcalc.net:
Code:
[FONT="Verdana"]
[B][U]KART[/U][/B]
[INDENT][I]RW diameter[/I]: [B] 22 in | 55.88 cm[/B]
[I]Total weight[/I]: [B] 330.69 lbs | 150 kg[/B]
[/INDENT]
[B][U]ENGINE[/U][/B]
[INDENT][I]Original HP[/I]: [B] 5[/B]
[I]Asummed HP[/I]: [B] ~5.58[/B]
[I]Torque[/I]: [B] 7.29 ft lbf | 9.89 Nm[/B]
[I]RPM[/I]: [B] 5500[/B]
[/INDENT]
[B][U]TRANSMISSION[/U][/B]
[INDENT][I]Final ratio[/I]: [B] 6:1[/B]
[I]TC type[/I]: [B] series 20 7" driven[/B]
[I]Lowest ratio[/I]: [B] 18.78:1[/B]
[I]Highest ratio[/I]: [B] 8.4:1[/B]
[/INDENT]
[B][U]PERFORMANCE[/U][/B] (estimated)
[INDENT][I]Max Wheel Torque[/I]: [B] 136.99 ft lbf | 185.73 Nm[/B]
[I]Min Wheel Torque[/I]: [B] 61.28 ft lbf | 83.08 Nm[/B]
[I]Acceleration[/I]: [B] 8.56 ft/s² | 2.61 m/s²[/B]
[I]Top Speed[/I]: [B] 42.85 mph | 68.97 km/h[/B]
[/INDENT]
[/FONT]it say series 20 7" driven, that should be about the same as the maxtorque TC you have (more or less)
I can't see how you end up with 66mph *shrugs*
Also you can't
Pm = m * g * Cr * v + 0.5 * Da * Cw * A * v³
assuming you and your kart weigh ~150kg
you're on a leveled asphalt road and your kart as a wind resistance of 0.7 (race karts are ~0.64) with a frontal area of ~0.9m² (9.7 ft²)
150 kg * 9.81 m/s² * 0.02 * 29.5 m/s + 0.5 * 1.2 kg/m³ * 0.7 * 0.9 m² * (29.5 m/s)³ = 10572.34275 Watts or 14.4HP
you think it can provide 14 horses?
'sid
KartFab
Active member
I'll have a 30 series 6" driven that I was using in the equation.. Also, my equation just goes off tire size, gear ratio, engine rpm, and torque converter low/high ratios. It does not account for any forces like drag, torque etc.
Sorry for the confusion. Obviously not going to get to 66 but am wondering out loud how fast before it tops out. Only one way to tell for sure is to test it out, which won't happen for a while.... Kind of like my 1997 honda civic, I got it up to 125 mph on a flat, recently paved road, but didn't want to go any faster for fear of dying by hitting a pebble on the road. I'm sure I could get it up to 50 mph but who would want to do that? It's not a race kart, but has a wide stance and low center of gravity. *contemplates death scenarios* I originally thought about putting it on a mini bike with a different ratio but the brakes suck so not even going to try to get to the top speed with that.
The post of the other kart w/maxtorque was just to illustrate you can put a 6.5 hp engine w/ 6:1 on 22" tires which is within an acceptable balance if speed/torque (because the low end w/a torque converter is a multiplier to the 6:1, which I probably should have clarified)
Sorry for the confusion. Obviously not going to get to 66 but am wondering out loud how fast before it tops out. Only one way to tell for sure is to test it out, which won't happen for a while.... Kind of like my 1997 honda civic, I got it up to 125 mph on a flat, recently paved road, but didn't want to go any faster for fear of dying by hitting a pebble on the road. I'm sure I could get it up to 50 mph but who would want to do that? It's not a race kart, but has a wide stance and low center of gravity. *contemplates death scenarios* I originally thought about putting it on a mini bike with a different ratio but the brakes suck so not even going to try to get to the top speed with that.
The post of the other kart w/maxtorque was just to illustrate you can put a 6.5 hp engine w/ 6:1 on 22" tires which is within an acceptable balance if speed/torque (because the low end w/a torque converter is a multiplier to the 6:1, which I probably should have clarified)
Ahh yes.. thanks to 10% overdrive on a series 30 6" that's indeed a mathematical 66.66 mph
thanks for clearing that up.
well you can solve it the other way around too, it's much more complicated I'm afraid
but it should give you an idea at least...
150 kg * 9.81 m/s² * 0.02 * X + 0.5 * 1.2 kg/m³ * 0.7 * 0.9 m² * X³ = 4104 Watts (~5.6HP)
29.43 X + 0.378 X³ = 4104
(let me skip the nasty...)
X = 20.9722 m/s theoretical max speed
21 m/s are ~47 mph or ~76km/h
the bad news is, according to the internets the achievable efficiency with a TC is around 88% so the available power is 3612 Watts...
but that's only about 1m/s you loose on that
so 20 m/s (19.9988) ( 44.74 mph or 72 km/h)
still pretty good I think
Okay, to be fair.. I have no idea what hp the engine can provide I can just make a more or less educated guess, and I do not know your or your karts weight, the exact wind resistance or frontal area...
but at least that should give you hint to work with
IIWM I'd gear it 8:1 to lessen the pain for the engine, that still provides a theoretical 50mph
(above my estimation) and you can check if your engine can reach the max rpm at max speed before you gear higher. if it doesn't there's no point in trying without further engine modification, right?!
'sid
PS I'd love to see this kart to be tached with my calculator *wink wink*
thanks for clearing that up.
well you can solve it the other way around too, it's much more complicated I'm afraid
but it should give you an idea at least...
150 kg * 9.81 m/s² * 0.02 * X + 0.5 * 1.2 kg/m³ * 0.7 * 0.9 m² * X³ = 4104 Watts (~5.6HP)
29.43 X + 0.378 X³ = 4104
(let me skip the nasty...)
X = 20.9722 m/s theoretical max speed
21 m/s are ~47 mph or ~76km/h
the bad news is, according to the internets the achievable efficiency with a TC is around 88% so the available power is 3612 Watts...
but that's only about 1m/s you loose on that
so 20 m/s (19.9988) ( 44.74 mph or 72 km/h)
still pretty good I think
Okay, to be fair.. I have no idea what hp the engine can provide I can just make a more or less educated guess, and I do not know your or your karts weight, the exact wind resistance or frontal area...
but at least that should give you hint to work with
IIWM I'd gear it 8:1 to lessen the pain for the engine, that still provides a theoretical 50mph
(above my estimation) and you can check if your engine can reach the max rpm at max speed before you gear higher. if it doesn't there's no point in trying without further engine modification, right?!
'sid
PS I'd love to see this kart to be tached with my calculator *wink wink*
zbuck
New member
Very nice work on the intake and the exhaust. But I see a problem. With the gov'r removed, it would wise to change the oil slinger on the rod, to the nylon replacement/ a Raptor rod with the oil slinger built it the rod cap. As the sheet metal stock one will eventally crack in the 90 deg bend and explod when twisted above 3600 r's a few times. Therefore putting a nice window in the the block.
KartFab
Active member
So I basically have like $80 invested in this engine, and don't want to go overboard. Is it possible to just get a different slinger without a new connecting rod? If so please post a link of where to buy.
2SlickNick
American Minibikes @ FB
found this.... as we are in the same boat. Post # 3
http://www.diygokarts.com/vb/showthread.php?t=20615
http://www.jcspecialty.net/
zbuck
New member
Yes, I prefer the nylon for its light weight. Another thing, when you pulled the gov'r gear, did you remove the thrust washer? If not it will come of the shaft and wreck hovac inside the case.- Status