Im sure this topic has been discussed on here before but I cant manage to find anything about it through the search engine now that there is no tech forum anymore (not overly happy about that) As title says this is my problem, my kid got 15 laps in sat night and pulled off track because temp was 240, he melted the stator in dodge city 4th of July weekend where it hit 270, that's been replaced motor runs great no missing no steam out pipe not pushing out anymore coolant than normal when they get hot. Ive heard a lot of different ideas on plumbing and restricting coolant line from t-stat housing to top of radiator, im running 1"id hose through out the whole system with a reducer where it enters radiator at, the radiator is 14 1/2" tall and 19" wide normal core with side tanks, one thing that is a little different on my car, t-stat hose goes to bottom of radiator on right side of car, water pump house goes to top of rad. on left side of car. Im still running stock t-stat and housing, im quite sure I have bled off all air in system, ive got coolant reservoir mounted way up the fire wall, im running 50-50 mix prestone coolant. Should I dump the t-stat and housing and run say a 10an fitting out the pipe on top of motor with smaller hose all the way to rad. to restrict it some, im also planning on replacing rad. with one of the fat core radiators from Foz to see if that does the trick? Could a slightly plugged injector be causing problem if it is leaning out some? Motor has tons of power no missing runs great. Any ideas folks? "Honest Dad" where are ya? You haven't steered me wrong yet! Thanks in advance! Dave

Is it on alcohol or gas?

Dave

Sounds like you have been reading "Smokey's" Book and are trying out reverse cooling>. I never cared for cross flow radiators but hot should go in top and cold out the bottom. It sounds like your radiator bungs are located on wrong side for your motor and you hooked them up the shortest way possible. Add a couple of feet of hose and run hot water (outlet thermostat) to the top of the radiator and cold water from the bottom of the radiator to the water pump (inlet) and you should fix your problem. My next advice would be to get a radiator with top and bottom tanks. Stand it straight up in the wind, protect it with a rock guard and if you are running gasoline get an electric fan to help cool it.

With the cross flow radiator as soon as the coolant drops below the top bung all the pump will pump is air. The cross flow's big advantage is if you get a hole in the top of the radiator the coolant drops below the hole and doesn't flow out any more and you don't loose all of your coolant but with top and bottom tanks a hole anywhere will empty your radiator. With the cross flow you still have to pump off the bottom.

One other little trick, for lazy racers (us). Get a small plastic bottle, zip tie it to the down tube beside the radiator (oil can bottle works nice) but clear is better. Stick your overflow tube in the top of your bottle, it will catch your overflow and when the radiator cools down the expelled coolant will be drawn right back into the radiator through the vacuum relief valve.

Honest Dad himself

Sorry I left out it is on alky and I do have an electric fan, another question, should we be racing with fan on or off? Once again thank you for info "dad" gonna order up new radiator right away, top and bottom tank. The radiator they sell is 16x16 with fat core, rad. ive got now is 14.5x19 wide, should I have them build me a rad. that is the full 19" wide and 16" high with top & bottom tank?

I always turn fan on second i hit the track and never go over 240 but i'm running a 04 gsxr also make sure the fan is always going when switch is on a friend of mine was having a switch problem and the fan would always shut off even when switch was on and was hitting around 270 and over heating. Also make sure you have a good size fan we used to over heat with are old radiator and small fan.

Dave

The bigger the better, watch out for rocks, the more you cover the sides and direct the air the better off you will be.

BUT on Methanol the std rad should work fine with a 20+ pound cap50 /50 wont boil to 260 Deg +. Actually the hotter the better as long as you can hold coolant the Toyotas are running even hotter than 260.

Make sure you have bungs on the way they should go and if you are running 12AN hoses get 12 AN bungs welded in Radiator sure beats clamps.

For the time being putting hoses in order should do the trick.

Honest Dad himself

So how hot is ok for one on gas. Some friends of mine here in town are having overheating issues with theirs. They've cooked one motor this year already

Bad

Too hot is when you boil all the coolant out. I have seen them run 5 or so laps with no coolant and survive. What do you mean by cooked.

Honest Dad himself

Trashed two ring lands and had the gasket blown on cyl 3&4 they said it got up to 250 at putnamville sat night and boiled all the water out. It has a 26 lb cap. I'm wondering if it's not plumbed backwards like the original posters car. The fan on it is a bit chincy and has no shroud. They had it flow tested earlier this and it was plugged so they had it flushed now it flows good. At least according to the radiator shop. Thanks again buddy!

Bad

Seems to me like the bungs on the old Honda motors was reversed from Yamaha, I remember switching some of them around to get it right. If a guy is really pushing an R1 they have a heating problem. Not many guys run them that hard especially starting out. Make sure the thermostat is opening, borrow a pan and water from mama put it on the stove and see if it is opening. These motors are much more intolerant of installing parts out of specs. Sticking rings sounds like they may have been a little loose in the lands and fluttering.

Check out them hoses, and remember the most important rule when laying down sod "Green Side Up" These motors are very tuff and like I said several laps with no coolant doesn't usually hurt them.

Honest Dad himself