Hi Guys
Just purchased an old SR3 fitted with carbs on an rpe engine.
Used car once on circuit at Cadwell park but had overheating issues which ended my day early on.
After going over a few things i ended up replacing head gasket and also fitting a replacement rad as the old one had ballooned & was leaking.
Car also had no thermostat fitted so obviously must have had issues in past, so i fitted a stat amongst other things i could see that were not right or missing.
Issue i have is as follows:
whilst car is idling i noticed the temp goes up fairly quickly to around 107 deg even with fan switched on constantly, the orange warning light on the digi display is triggered at 98 deg.......Is that the correct trigger temp? Please bare in mind that i have not yet run the car on circuit since i replaced hg so car has no air flow to aid cooling and ambient temps have been around 30 deg of late
From what i have read the busa motor runs at 105 deg before fan is triggered which should drop temp to 100 deg so in that case the dash temp warning light would still come on : /
I am at Brands hatch on the 4th August and obviously do not want any issues with car boiling up so was hoping someone on here could shed some light with this possible issue
Thanks guys
Hi Bob,
If you are running a dry sump engine then there is more changes that you need to do other than just fitting a thermostat - you will need to fit the bleed so that hot water is still circulating and then activating the thermostat to open, sounds like this has not been done which is why you are seeing the temps you are.
Radical do not fit a thermostat as standard so this is not something that has been removed in the past.
Ignore the standard Suzuki temps, about 98° is good for a warning, ideally you dont want to be running above 100° for any period of time.
Ah right thanks for the reply Dan didn't know they never ran with a stat
I shall remove it again & see if that keeps temps down. This one us not dry sumped if that makes any difference, also warning light comes on at 96 deg not 98 as i originally thought
G'day @bob,
I thought I sent an earlier reply post, but now can't see it... I'll try again (apologies if it's a duplicate!)
I'm not sure if the older generation SR3's are the same as the newer RSX's, but thought I would share what I have learned about the coolant system on my car, hoping it might help....
- The ECU is programmed to turn the thermo-fan on in my car at 92 degrees C, and it runs until the water temp drops to 88 degrees C.
- The high temp alarm in my car is set at 95 degrees C, and there is an ECU trip that stops the engine at a higher temp, but I'm not sure what temp that is set to.... maybe others will know. So if yours is set at 98 degrees, that's slightly higher than 95 C,.... but probably still OK.
- As @rlm-dan has said, there isn't a thermostat fitted to my 1500cc engine.
- I recently changed coolant and was surprised that the system only held a bit less than 4 liters of coolant.
- You mentioned your engine warms up to 107 C quite quickly. I've never timed it, but I would be very surprised if my engine took less than 15 minutes to reach around 90 degrees C when just idling... even though I run my dry sump oil heater at the same time which would put extra energy into the system (not sure if you have an oil heater?). My car takes at least around 10 minutes of idling just to get to 60 or 70 degrees C (and engine oil is above 50 degrees C) and the car can be driven on track to complete the oil/coolant warm up.
Hope that helps....
@bob Lots of useful info there from RJ but do keep in mind, providing it has not been changed, your car will be on an early DTA or ignition only MBE.
As I believe you are on a after market management system the fan wont be controlled be the ECU as per the Hayabusa bike, I am guessing it will its own temp sensor somewhere to activate it. This can make things difficult to monitor when you have an ECU reading one temp, a separate sensor for the dash and another again for the fan!
I imagine you also have a large spacer on the thermostat housing with a temp sensor in? These early systems do not data stream to the dash like the newer cars.
If you are running a wet sump you will be running the standard mechanical water pump and this will have the bleed in needed for the thermostat (its the pipe from under the cylinder head to water pump on your car) so it could be worth replacing/inspecting the water pump to make sure this working correctly.
I would also assume that your car does not have an electric water pump fitted which can help massively, especially with heat soak once switched off.
@rjbender the water temp trip in the newer cars on Life is 120°C.
