Radiator Cap Alternative

[Claviger]

I started and allowed the bike to heat cycle fully with the new cap on with the Radiator totally full and the bike level. Reservoir was empty. It did push a little fluid out when shutdown and then sucked it back in when it cooled so working as it’s supposed to.

 

[joesoap]

I started and allowed the bike to heat cycle fully with the new cap on with the Radiator totally full and the bike level. Reservoir was empty. It did push a little fluid out when shutdown and then sucked it back in when it cooled so working as it’s supposed to.

 

[Idaho Red Rocket 3]

Tusk 1.8 High Pressure Radiator Cap Temperature Gauge KAWASAKI KX450F 2006-2016 | eBay

 

[warp9.9]

I started and allowed the bike to heat cycle fully with the new cap on with the Radiator totally full and the bike level. Reservoir was empty. It did push a little fluid out when shutdown and then sucked it back in when it cooled so working as it’s supposed to.

Is this a test you ran with the oem one also. For comparrison of functionality?

 

[Idaho Red Rocket 3]

What is the OEM pressure rating of the cap ?

 

[Claviger]

Is tjis a test you ran with the oem one also. For comparrison

. It wasn’t going back into the rad after cooling previously.

What is the OEM pressure rating of the cap ?

1.1 bar.

 

[warp9.9]

. It wasn’t going back into the rad after cooling previously.

1.1 bar.

Ok thanks was kind of hoping it was acting up. I still wonder if a good oem pressure rating would work with your build?

 

[Claviger]

It’s not the cap that’s the problem really, it’s the water pump design. It’s not meant for sustained high rpm use, so it’s causing the head to get too hot, which then causes coolant to boil out. For me it was exacerbated by the cap sticking and not sucking fluid back into the radiator.

 

[barbagris]

It’s not the cap that’s the problem really, it’s the water pump design. It’s not meant for sustained high rpm use, so it’s causing the head to get too hot, which then causes coolant to boil out. For me it was exacerbated by the cap sticking and not sucking fluid back into the radiator.

Hmm - That does not explain why mine only pukes out into the tank when it's stuck at tickover in traffic. The cap design of the "new" one looks more substantial too somehow.
I will ask my mate to order me one of each. Trade price and no sales tax. And I've dropped the fan switch to 98°C

 

[Claviger]

The heat atidle is because the pump is spinning very slowly so low flow. It’s an inherently crap design carried forward for more than 100 years that finally automakers are starting to get away from.

Sitting still you need the pump to spin fast and help cool the bike since there’s no/little air moving over the radiator and the fans no where near equal to when your at speed.

Then at cruise RPM it’s all working as it should, then at high RPM the terrible impeller design falls short because it’s a stamped metal piece similar to what Chevy put in SBC 350s circa 1955.

Old Chevy impeller, stamped impeller just like the Rocket, intended for long periods of time at cruise RPM: