before you think your pinging is tune related read this....

[The1]

higher flow by meaning of larger pintal diameter, perhaps drilling holes isn't a good idea as this defeats the thermostat's purpose, but i know with pc water cooling more flow is actually better for temps, less flow gives higher temps and would have to be less efficient and more load on the cooling system, water seems to be rather quick at extracting heat. The overall idea of getting the water circulating earlier being 82c instead of 92c is the idea and the higher flow would only come in over that temp. If the target is to reduce hotspots, then you need to keep it either cooler and give it more flow, if the coolant is hotter then you have less margin to play with for heat extraction to coolant. Obviously your cooling system plays a big part as well.

[immortality]

I think it's hard to compare a cars engines cooling system with that of a PC, total volume and flow paths are completely different.

I do agree though with the cooler thermostats used in cars. I've had a fair few discussions about it on various forums and the LS boys have spent enough time on dyno's to conclusively say that engines produce better power at 180° than the hotter factory fitted items.

I think it's also agreed that plain water is probably better then glycol based coolant, however plain water just won't do in extremely cool or hot climates and also doesn't have any anti corrosion properties which is the reason glycol products are the acceptable standard in coolant systems.

I think the trick with coolant systems is to maintain flow, at least this is what has been found with the 308's and the hot spot at the back of the head. I've also seen similar modifications done on SBC engines where the water jacket ports in the block deck are reduced in diameter to force more coolant fully toward the back of the block before it rises up into the head. It's also the reason I'm actually a fan of the VN s1 coolant system, the coolant only travels one way through the block (front to back) and then exits the engine so no reverse flow patterns with potential dead spots, it also has a bleed point at the front of each head at the coolant passage to bleed out any air. Unfortunately the stainless return pipe is a bit high and can get an airlock but i've never personally had any issues with it.

[Holden202T]

I've always seen a lot of the chev race car boys use speedflow fittings in the back of the manifold where its normally blocked off to filter more coolant from there directly to the thermostat housing to stop that hot spot issue.

[The1]

yeh i quote this from another forum. Decicrate who some may know.

I was doing some work for some speed way guys a while ago. They are using Buick 3800 and were constantly letting number 3 go or cracking the head in number 3. They worked out that for some reason the water cooling was an issue over the top of the chamber of number 3 and it would always get a lot hotter than the rest of the cylinders. They made some changes to the cooling system by adding coolant pipes at the back of the heads and the issue with number 3 disappeared. They think that because that cylinder was getting a lot hotter it was suffering from detonation and killing the piston, head gaskets and heads.

[Holden202T]

yeah that wouldn't surprise me, and apparently they aren't allowed to do that if I recall!

[immortality]

I've always seen a lot of the chev race car boys use speedflow fittings in the back of the manifold where its normally blocked off to filter more coolant from there directly to the thermostat housing to stop that hot spot issue.

Yep, seen that done too. Seen many done with fittings from the front and rear of the heads with a remote mounted thermostat housing.

[immortality]

yeh i quote this from another forum. Decicrate who some may know.

I was doing some work for some speed way guys a while ago. They are using Buick 3800 and were constantly letting number 3 go or cracking the head in number 3. They worked out that for some reason the water cooling was an issue over the top of the chamber of number 3 and it would always get a lot hotter than the rest of the cylinders. They made some changes to the cooling system by adding coolant pipes at the back of the heads and the issue with number 3 disappeared. They think that because that cylinder was getting a lot hotter it was suffering from detonation and killing the piston, head gaskets and heads.

Do you know which Buick 3800 they are using?

I had a issue with mine a few years ago, dodgy injector. I used a heat gun at work, checked which header pipe was running hot and changed that injector and it was running a lot better.

Unfortunately the Buicks also have issues with the rear cylinders running a little lean becuase of the nasty turn the air has to do from the TB/neck into the rear runners

[charlay86]

a lot of these cooling problems arise because the manufacturer uses the holes in the gasket to regulate flow through the heads, re-routing with the help of external pipework can significantly improve the flow through the engine.
faster moving water is better for cooling, as you are constantly introducing cooler liquid, having said that, the water pump actually produces a reasonable amount of pressure at high rpms (before it cavitates!) which increases the boiling point of the coolant which helps to stop it flash boiling in places where the temps are higher. GM picked the thermostat temp for best emissions and perhaps fuel economy reasons, if you raise the output of an engine it will have more heat to get rid of and the points where the flow is somewhat stagnant become very apparent.

[antus]

In the original article at the top of page 4 they mention "the traditional anti-freeze mix with water is very poor at the task" so Im thinking that the article is not really targeted at aussies.

[delcowizzid]

look up waterless coolant its great stuff.