I was on the BMW forums and noticed that the 1M actually uses the same radiators as the 135 however it has a add on mini radiator to improve cooling.
Instead of using a swirl pot and tank, couldn't we simply plumb in an extra mini rad?

Hi,

there are several ways to improve the cooling, but an extra radiator make things not easier (space), the same for the header tank and swirlpot

more tomorrow if you are interested

greetz

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KEEP COOL UNDER PRESSURE

street legal?.....perhaps in tschibuti

When we designed the cooling system for my ST205 track build we decided against fitting bleed lines as the coolant flow is very unpredictable, particularly so with a competition car where the coolant temps and pressures are a lot higher than in road use. I've seen some very sophisticated bleed line setups but the manufacturers and/or teams have probably spent a lot of time and money to design the system so it works properly.

This doesn't of course preclude fitting bleed nipples so you can bleed air from the end tanks etc. after filling with coolant and running the engine up to operating temperature. This is quite sensible and will help avoid airlocks.

The acid test will be when we fire the engine up and actually observe how the coolant system functions after this substantial redesign. Fingers crossed!

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Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp

Please expalain? I have more space and better idea to install a extra small rad then swirl pot and extra tank.
Whats the down side to this?

Also here's a thought. The throttle body has a water feed which many by pass because we don't need it. Instead of bypassing it, how about plumbing a small rad there? Will that not help lower the temp?

Hi,

ok, here we go,

- get a 40mm or 50mm alu radiator with fans (like spal), the oem shroud lowers the air flow and you just need the fans in the city or on stages with much curves and high power

- built a hard pipe instead the hose from the radiator to the thermostat housing, once the thermostat opens and in high revs (=high water pump flow) the hose can/will pull together
in extreme situations up to a 70% lower water flow as possible, one of the best mods i did turbo and engine say thanks becouse this are the situation you and i like to drive

- and then comes airflow through the radiator package, get as much possible pressure before it (by panels that do not allow the air to flow a different way as in direction radiator) and as low as possible beding them (air escape on the bonnet and on the under panel)

-you can plump the TB heater, and if you realy want a header tank then you can use the conenctor on the stainless pipe coming from the TB that retours to the water pump and mount the header on the tower bar (use a header tank like my one it is big enough and compact), then comes the radator cap mod as talked before and a line from the radiator to the header tank

so now the package is compact and pretty overkill
you can find pictures in here viewtopic.php?f=1&t=2908

- the next is a uprated oem water pump, but my one isn't tested currently so i have no feedback for you, just the "how to" if you are interested......

greetz

_________________
KEEP COOL UNDER PRESSURE

street legal?.....perhaps in tschibuti

Hi,

http://www.6gc.net/forums/index.php?showtopic=88531

i saw that comment from Special_Edy on 6gen.celica forum, you have to cool also the buttom/piston bores, you should not use any epoxy you simple isolate the water from the heat and lower his surface, be carefull!
the one he is in right is "faster water flow" or in other words -> cicles per time unit, one cicle = heat the water in the block and cool it in the radiator, more of this per time unit and you raised the cooling performance
thats why i did a uprated water pump mod, but this ins't free of risks, a higher water flow can youse cavitation -> lower pressure before the water pump and higher water flow in the block -> Mr. bernulli explained it

http://en.wikipedia.org/wiki/Bernoulli%27s_principle

a further way to improve the system i forgett to wrote is the water itself, alcohol or anti freeze dramatically reduces the heat transfer to the water and water has the highest specific heat capacity, go for a higher amount of water (i use a 2/3 water and 1/3 anti freeze), no one ever developed a better fluid for cooling purpose then water!

greetz

_________________
KEEP COOL UNDER PRESSURE

street legal?.....perhaps in tschibuti

From the 6gc forum.




The thermostat is a linear proportional device which goes from slightly open to fully open over a span of a few degrees. It effectively mixes uncooled water from the bypass pipes with cooled water from the radiator and will adjust it's opening amount to give the correct temperature of 'mixed' water. The colder the water coming from the rad, the more closed the thermostat will be. This is slightly self-defeating in that reducing the flow through the rad will lead to the water cooling more and will then close the thermostat further, etc. etc.
The upshot is that an over-efficient radiator will reduce the flow through the engine substantially, and will reduce the pressure at the pump inlet potentially leading to cavitation at high RPM. ( http://en.wikipedia.org/wiki/Cavitation ) Also, if the temperature of the water from the radiator is much colder, there is the chance of rapid temperature variations of the water going in to the engine, as pressure surges due to RPM changes cause different mixing. Another good reason to drive gently until everything is properly warm.

Another common mistake is to think of the water entering the engine as 'cold' and the water leaving as 'hot'. Provided the flow rate is high enough the water coming out of the engine should only be slightly hotter than that going in, and likewise the water shouldn't be in the radiator long enough to cool massively. The water is effectively just conducting the heat from the engine to the radiator metal surface where the heat is transferred to the airstream. The faster the water flow, the less temperature differences throughout the sytem, and this is desirable. Temperature gradients, and especially rapid temperature changes, are what cracks blocks and heads.

As regards the turbo outlet, I haven't measured temperature but I would expect flow to be sufficient to prevent it getting too hot. Even if it were, it returns to the main flow through the radiator and has plenty of time mix. If the flow is small compared to the main flow, it's effect on overall temperature is negligable. Provided the main radiator copes with ALL the heat produced by the engine, there is no problem.

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If at first you don't suck seed, try drier grain.

Probably more important than the water cooling is oil cooling.

Oil is squirted over the pistons all the time, and will therefore provide much of the cooling for the pistons. If the pistons overheat while the block stays cold, you will potentially have a 'heat seize'.

The standard water - oil cooler is useful as it also helps heat the oil quickly during warm up, however it should be supplimented on a high power engine by an external cooler. This should ideally be thermostatically controlled to maintain a constant oil temperature.

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If at first you don't suck seed, try drier grain.

Thanks guys. I think I've learnt quite a bit over the few forums. There are many theories to take into consideration and ultimately I do wander if this mod is worth doing or not.

Like what Nial pointed out in the past, maybe the charge cooler should be more of a productive focus when it comes to cooling.

Chargecooling is a separate issue, and very important. Cooler charge not only contains more oxygen leading to greater power, but also increases the margin before detonation allowing more ignition advange / greater efficiency. It has very little to do with keeping the engine cool though.

IMO a header tank is a quick & easy mod. and is very worthwhile as it helps prevent local boiling on cool down laps which can lead to a cracked block.
The alternative would be to run evans coolant, however AFAIK this is not so good at transferring the heat. Enough big power engines do run it to make me think it's good enough though.

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If at first you don't suck seed, try drier grain.