2 stroke Shifter kart engine questions

[thisismyusername]

Alrighty so i've actually changed my plans up, and if i can get my hands on a 125cc or 250cc two stroke race bike engine, im going to build a shifter kart based on that. If not i will use a lifan 200cc, but i have a few questions about the cooling systems on the two strokes.

So i'm actually very familiar with these engines as I've raced a Honda cr125 for the past several years, but my question is about the water pump for the coolant. I've seen people route their radiators on the opposite side of their karts, far above their engine, etc.

My question is, what are the possibilities for mounting the radiators away or a above the engine. On the dirt bikes they are right next to the engine with very small travel distance for the liquid, but would the stock water pump be able to push the coolant a farther distance across or up with longer radiator hoses or are these people upgrading their waterpumps?

Any info would be appreciated thanks

 

[itsid]

kart engines usually have external pumps directly mounted to the radiator (or very close by)
driven by a belt (toothed or twisted nowadays) directly off the rear axle.

That's certainly a viable route in case you worry about the original pump's capabilities.

But as long as there's no air trapped in the cooling system I don't see too much of an issue.
on race karts that is..
if you mount the radiator high up, you might run into problems.. but horizontal distance isn't a problem
then again high up driving the kart pump is causing yet another problem (routing the belt)

So yeah, if you talk shifter kart (i.e. race kart) I wouldn't worry too much,
keep an eye on the temp (a simple radiator mounted temp gauge will do)
and in case you suspect the pump not being powerfull enough, add a kart pump..

Since you say you'll add a bike engine, chances are it comes with an alternator;
so you might not only be able to help the radiator with a fan, but you could also try to find an electric pump with low enough power and high enough capacity to fit;
that could be installed even if the radiator is roof mounted on a buggy (given it's powrfull enough of course)

'sid

 

[thisismyusername]

kart engines usually have external pumps directly mounted to the radiator (or very close by)
driven by a belt (toothed or twisted nowadays) directly off the rear axle.

That's certainly a viable route in case you worry about the original pump's capabilities.

But as long as there's no air trapped in the cooling system I don't see too much of an issue.
on race karts that is..
if you mount the radiator high up, you might run into problems.. but horizontal distance isn't a problem
then again high up driving the kart pump is causing yet another problem (routing the belt)

So yeah, if you talk shifter kart (i.e. race kart) I wouldn't worry too much,
keep an eye on the temp (a simple radiator mounted temp gauge will do)
and in case you suspect the pump not being powerfull enough, add a kart pump..

Since you say you'll add a bike engine, chances are it comes with an alternator;
so you might not only be able to help the radiator with a fan, but you could also try to find an electric pump with low enough power and high enough capacity to fit;
that could be installed even if the radiator is roof mounted on a buggy (given it's powrfull enough of course)

'sid

Here's a video of something similar to what ill be doing. It doesn't look like he has an external pump anywhere
https://www.youtube.com/watch?v=KGOVAXL9kMA
He has the radiator mounted on the left side of the kart. You dont think this much horizontal distance would affect the stock cooling?

 

[Kaptain Krunch]

Should be fine. Worst case aftermarket high flow pumps are available for most bikes.