What engine?

[bread]

Hello, I already posted a thread about what I am designing and planning on building.

http://www.diygokarts.com/vb/showthread.php?t=27962

Now, I am wondering what engine is right for a vehicle of this size and weight. Pushing the vehicle and two 160 lbs passengers, I want to go 40-45 mph easily.

I was thinking of the 16 hp duromax coupled with a TAC 2 and geared pretty high.

I don't know if that will be enough hp/ torque however; and that is why I made this thread.

What engine should I use? Motorcycle? Small diesel? V-twin?

Attached is a pic of my final design

Thank you

 

[mckutzy]

I'm thinking that with those bigger engines, your COG is getting higher and there isn't alot of weight to counterbalance that at the front.

Diesels are going to be hard to use a cvt with as they are lower revving than what typically is used to engage the cvt with than gasoline engines.
As I recall there was a guy here who did just that and it didn't work right for him.

Putting the gas tank up front?

 

[bread]

Yea, I realized I wouldn't be using a TAC with the small diesels.

I haven't yet decided what I will be doing about weight in the front, I'll probably end up moving the seats forward about 6 in.

Do you think the 16 hp duromax with the TAC will be sufficient power for this vehicle?

 

[bread]

Also, I'd really like to use this 5.5hp tecumseh I have lying around the shop. If I couple that with a TAC will that provide suffiecient power?

 

[itsid]

that looks like a -what?- 80 lbs construction so we talk about a total weight of ~400lbs?

and you want to reach easily 45mph hmmm

okay first: a TAV2 is a series30 with a backplate.. that is limited to 8hp
(the backplate is the limitibg factor, without it it's rated for up to 13hp...)
a 16hp engine might be going through belts quite quickly...
and considering a belt costs the same as a ordinary cent clutch that's not actually something you'd want to buy every other month (or every fourth ride)

That being said.. I suggest a series 40 and your 16HP engine, you need a mild mod to get a bit more rpms to reach your speed goal

a 5:1 ratio might work (at least my calc isn't screaming) if it'S still powerful enough to reach topspeed IDK, at least it won't shred the belt right on spot but starts moving the kart

KartInfo by kartcalc.net:

[FONT="Verdana"]
[B][U]KART[/U][/B]
[INDENT][I]RW diameter[/I]: [B] 18 in | 45.72 cm[/B]
[I]Total weight[/I]: [B] 401.24 lbs | 182 kg[/B]
[/INDENT]
[B][U]ENGINE[/U][/B]
[INDENT][I]Original HP[/I]: [B] 16[/B]
[I]Asummed HP[/I]: [B] ~16.99[/B]
[I]Torque[/I]: [B] 23.34 ft lbf | 31.65 Nm[/B]
[I]RPM[/I]: [B] 4200[/B]
[/INDENT]
[B][U]TRANSMISSION[/U][/B]
[INDENT][I]Final ratio[/I]: [B] 5:1[/B]
[I]TC type[/I]: [B]  series 40[/B]
[I]Lowest ratio[/I]: [B] 12.15:1[/B]
[I]Highest ratio[/I]: [B] 5:1[/B]
[/INDENT]
[B][U]PERFORMANCE[/U][/B]
[INDENT][I]Max Wheel Torque[/I]: [B] 283.63 ft lbf | 384.55 Nm[/B]
[I]Min Wheel Torque[/I]: [B] 116.72 ft lbf | 158.25 Nm[/B]
[I]Acceleration[/I]: [B] 18.44 ft/s² | 5.62 m/s²[/B]
[I]Top Speed[/I]: [B] 44.98 mph | 72.39 km/h[/B]
[/INDENT]
[/FONT]

A MUCH safer suggestion would be a slightly more advanced modification (governor removal, rejetting, airfilter and highflow exhaust) to reach 5500 rpm and gear 7:1

KartInfo by kartcalc.net:

[FONT="Verdana"]
[B][U]KART[/U][/B]
[INDENT][I]RW diameter[/I]: [B] 18 in | 45.72 cm[/B]
[I]Total weight[/I]: [B] 401.24 lbs | 182 kg[/B]
[/INDENT]
[B][U]ENGINE[/U][/B]
[INDENT][I]Original HP[/I]: [B] 16[/B]
[I]Asummed HP[/I]: [B] ~17.84[/B]
[I]Torque[/I]: [B] 23.34 ft lbf | 31.65 Nm[/B]
[I]RPM[/I]: [B] 5500[/B]
[/INDENT]
[B][U]TRANSMISSION[/U][/B]
[INDENT][I]Final ratio[/I]: [B] 7:1[/B]
[I]TC type[/I]: [B]  series 40[/B]
[I]Lowest ratio[/I]: [B] 17.01:1[/B]
[I]Highest ratio[/I]: [B] 7:1[/B]
[/INDENT]
[B][U]PERFORMANCE[/U][/B]
[INDENT][I]Max Wheel Torque[/I]: [B] 397.08 ft lbf | 538.37 Nm[/B]
[I]Min Wheel Torque[/I]: [B] 163.41 ft lbf | 221.55 Nm[/B]
[I]Acceleration[/I]: [B] 25.79 ft/s² | 7.86 m/s²[/B]
[I]Top Speed[/I]: [B] 42.07 mph | 67.71 km/h[/B]
[/INDENT]
[/FONT]

slower yes, but less likely to fail

you will not find an industrial engine that will allow you to go 45mph without modifications.
mainly because if you gear high enough to reach that speed @ only 3600 rpm you will not be able to get it going from 0mph since even in idle the kart would need to run 20mph or something just to catch up with the clutch.. and that'll shred belts or clutches or both

'sid

PS rule of thumb: think about at least 100 rpm per mph to not melt your clutch/belt in an instant on take off