Overheating VFR400 NC30

[vagrant]

You should be able to flush it without taking the end tanks off. If it is that bad, try Kumue radiators. The place looks a complete mess but he does great work. Rebuilt the racekit rads for my RC30 after the couriers pretty much stuffed them.

The other thing you could try is fitting an electric waterpump (like this one)in place of the engine driven one. It will give you a higher flow rate than when the engine is at low revs, and you can leave it and the fans running after you shut the engine down.

[lostinflyz]

hey man,

before you go too far on fixing up stock rads, they are borderline on a hot day if they are perfect and your ringing the nuts off them.

Fixing a radiator will prob cost you little less than buying a proper race radiator (top only) that will cure all issues. RB imports in aussie sell them for 475 AUD, usually they have them in stock. When i talked it through with them basically they found these to be the best option for there forumla 400 class in aussie head.

HRC did an oil cooler for them as well to keep them cool in Japanese F3 competition use. You can retrofit other bikes(cbr600f4 is common) oil coolers without tooo much hassle.

but again man 100+ or boil over is not really an issue if its only on dummy girds or when you make it back to the pits. If it doesn't overheat during the race alls good.

[I14]

Its about pressure.

Water at amospheric pressure boils at 100 degrees C.
In a system with a 14psi Radiator cap the boiling point becomes around 125 degrees C.

The restriction of the thermostat in the system can raise pressure behind it to 30-40psi above that thus raising the boiling point in the hotter parts of the engine.

Without that restriction it doesn't get the localised pressure build up and will begin to boil in the hottest areas, thats a bad thing.

OK that makes sense thanks, I'll stick the thermostat back.

[I14]

You should be able to flush it without taking the end tanks off. If it is that bad, try Kumue radiators. The place looks a complete mess but he does great work. Rebuilt the racekit rads for my RC30 after the couriers pretty much stuffed them.

The other thing you could try is fitting an electric waterpump (like this one)in place of the engine driven one. It will give you a higher flow rate than when the engine is at low revs, and you can leave it and the fans running after you shut the engine down.

Thanks for that. I'll try it now its vanes have been cleaned and keep the website if that fails. I like the magnetic drive design, no seals to fail and stuff up a day's racing! I guess you just take off the mechanical pump and blank off the drive?

[I14]

hey man,

before you go too far on fixing up stock rads, they are borderline on a hot day if they are perfect and your ringing the nuts off them.

Fixing a radiator will prob cost you little less than buying a proper race radiator (top only) that will cure all issues. RB imports in aussie sell them for 475 AUD, usually they have them in stock. When i talked it through with them basically they found these to be the best option for there forumla 400 class in aussie head.

HRC did an oil cooler for them as well to keep them cool in Japanese F3 competition use. You can retrofit other bikes(cbr600f4 is common) oil coolers without tooo much hassle.

but again man 100+ or boil over is not really an issue if its only on dummy girds or when you make it back to the pits. If it doesn't overheat during the race alls good.

No it didn't overheat in the race so I think the cheapest fix is to fit a higher pressure rad cup to cope with it getting a little hot when back in the pits. With the motor turned off then you wouldn't think you could do any damage! Last resort a bigger Oz rad.

[koba]

No it didn't overheat in the race so I think the cheapest fix is to fit a higher pressure rad cup to cope with it getting a little hot when back in the pits. With the motor turned off then you wouldn't think you could do any damage! Last resort a bigger Oz rad.

I was working on a photo but havn't had a chance but I had a fan off a bike mouted on a stick and hooked up to a freshly charged 12volt battery when I was running a special that had an NSR radiator hooked to a KLR600.
It worked a treat on the dummy grid and after the race.

This was an exceptionally small radiator for the cooling requirements of the engine though, and even then it took a bit for it to boil over.

I find it hard to believe the standard NC30 radiators aren't up to the job if they are in good nick, on the hottest day of the year after a 20lap race maybe but do look over the whole thing carefully and make sure everything is all good.