Chinese oversized radiators?

[oldskool]

Bloke selling the oversized radiators on Trademe finally replied.
"hi there, you need make the fit, this radiator thicker than standard, thx."

Meanwhile I left a PC fan in a tub full of water overnight. Plucked it out this morning and sprayed it with WD40. Powered it up and it ran sweet.

[bogan]

Meanwhile I left a PC fan in a tub full of water overnight. Plucked it out this morning and sprayed it with WD40. Powered it up and it ran sweet.

Throw some river sand in the water and shake it around a bit, reckon it might not last so good then.

[L Rider]

Meanwhile I left a PC fan in a tub full of water overnight. Plucked it out this morning and sprayed it with WD40. Powered it up and it ran sweet.

I'd say it'll be like the wheel bearings on wee KTM 50's. They're not sealed/covered like on bigger bikes so they shit themselves regularly mainly due to waterblasting. Sometimes you'll get a decent amount of hours out of them other times not so many.

[oldskool]

804 grams give or take some. I'm happy with that. Tawny will be happy enough with the minimal increase in weight too if it means she can ride carefree without me being the overbearing dad!
I settled with a Jaycar Temperature sensor kit in the end. $26. Couldn't be bothered with isolating a micropic from ignition interference so I opted for a kitset instead of custom building one.
The batt is a 12V SLA from jaycar, $22. It fits in the airbox snug as a rug. I figure I clean the air filter every ride anyway so won't wire in a recharging socket to the side of the bike.

[dafydd roberts]

804 grams give or take some. I'm happy with that. Tawny will be happy enough with the minimal increase in weight too if it means she can ride carefree without me being the overbearing dad!
I settled with a Jaycar Temperature sensor kit in the end. $26. Couldn't be bothered with isolating a micropic from ignition interference so I opted for a kitset instead of custom building one.
The batt is a 12V SLA from jaycar, $22. It fits in the airbox snug as a rug. I figure I clean the air filter every ride anyway so won't wire in a recharging socket to the side of the bike.

Let me know how the field test goes if it still boils or not.

[oldskool]

Let me know how the field test goes if it still boils or not.

Yup will do. Field test wont be until next weekend. If it fails then I'll have to look at mounting a 120mm fan to the front of the rad.

[bsasuper]

Has anyone had any experience with these 'made in china' alloy radiators? Do they do as they claim? ie: 25-30% cooler engine temp.
From what I can see they have wider vanes which are double sided. How is their fitment and build quality? My factory coolant capacity is 1 ltr. Is it safe to say the fluid volume will increase to 1300ml with an oversized rad?

They wont have a 25-30% decrease in engine temp, they will just keep the engine temp "normal temp" for a longer period when slow riding(no air flow throught rads), the thermostat is what controls the engine temp.

[flyingcr250]

They wont have a 25-30% decrease in engine temp, they will just keep the engine temp "normal temp" for a longer period when slow riding(no air flow throught rads), the thermostat is what controls the engine temp.

MX bikes dont have a thermostat

[oldskool]

Okay just finished the final touches, ie: lacquer sprayed circuit board and fan circuits, fitted battery box and set thermistor into hollowed out bolt head. Ran it up to operating temp (hot to touch, throttle snaps responsive) and waited. Fans kicked in but don't know at what temp... I left my digital thermometer at work. I preset it to when the kettle boiled.
So it'll be a trial and error calibration for now. There's a trimmer pot to tweak for temp switching. Should be interesting. Bring it on!

[oldskool]

Now to wait for the weekend

[oldskool]

Let me know how the field test goes if it still boils or not.

Tawny rode it for 4 1/2 hours (engine hours) at the sandpit yesterday. A bit of everything. Did a few reds, some of Shane's specials, including slow unmarked hilly windy tracks. Fans kicked in every so often, especially when bike was on it's side and still running while she struggled to pick it up. They would run for a couple of minutes and switch off as the rads cooled. Didn't take much to keep them off the boil. Didn't lose any water.

Washed the bike with Dynamo last night, gave the fans a good drowning, ran a hairdryer over the sensor, fans fired into life after about 2 minutes of hot air. Battery still reading 12.56v (started at 12.75v)

Next test will be in wet clay. I've already sourced some IP68 rated fans so if these normal ones fail then the totally sealed IP68's will be the next step.

But for now I'd say the project so far has been successful!

[dafydd roberts]

Tawny rode it for 4 1/2 hours (engine hours) at the sandpit yesterday. A bit of everything. Did a few reds, some of Shane's specials, including slow unmarked hilly windy tracks. Fans kicked in every so often, especially when bike was on it's side and still running while she struggled to pick it up. They would run for a couple of minutes and switch off as the rads cooled. Didn't take much to keep them off the boil. Didn't lose any water.

Washed the bike with Dynamo last night, gave the fans a good drowning, ran a hairdryer over the sensor, fans fired into life after about 2 minutes of hot air. Battery still reading 12.56v (started at 12.75v)

Next test will be in wet clay. I've already sourced some IP68 rated fans so if these normal ones fail then the totally sealed IP68's will be the next step.

But for now I'd say the project so far has been successful!

Would they be these? http://www.youtube.com/watch?v=AbQILgx5KU8

[cheese]

You could probably add a LED to indicate close to boiling point too so you know you need to turn the bike off. Or a temp gauge?

[oldskool]

You could probably add a LED to indicate close to boiling point too so you know you need to turn the bike off. Or a temp gauge?

You mean something like this?

[scumdog]

An over advanced ignition, operating in 40 deg C temps or blocked radiator fins can obviously cause heating problems too.

An engine without enough advance (i.e. retarded) causes overheating.