detonation.
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I know its abit different bit the vvc metro boys swear by jacking up the drivers side (where the header tank is) of the car while bleeding the system tl get all the air pockets out, I have always done the side with the header tank just to try and get any other bits of air out (seems to do the trick)

Do the 16v/twin cam people have problems with hot points as well? What about the 7 ports and stuff too?

Drives
-Ford S-max Mk2 Ecoboost
-Rover 100 VVC #2 - track project

Searching is all you need on TurboMinis

Nice thoughts Robert and many correct ones, one to note is always IMO use the heater take off and circulate. This in a ring main, there's no dry decking and fooking about like that unnecessary!

Plumbing in the heater take off reduces detonation in the cooling department

I tend to agree Steve,I also have the heater matrix and aux.pump in the ring.
Having said this,went to start it today after fixing manifold (stripped) studs,rattly tappet etc.and got 3 cyls on cold start-sure sign of h/g failure coming.Went out anyway,because it's been ok before like that,mile from home,small squeeze of pedal and suddenly on 2 cyls.Limp home,comp check shows 1&2 blowing badly between them-not seen this one before.Ho hum,head off AGAIN tomorrow... :-

'Where does the engine go?'

i had to go a long way to keep temps down,
keeping on top of the temp rise when on boost in the inlet and coolant is critical
in the end to get a stable temp i ended up blocking the heater take off tap but i had a pipe that went from above the thermostat into the top of the header tank ( highest point by about 4 inch) the header tank outlet went down into the bottom hose
i also had a pipe that came out from bellow the thermostat that went through a valve into the bottom hose ( basically an adjustable bypass )
on my build (100% Dry decked) i had to keep the coolant flowing even when cold only by a tiny amount or it would never get warm, if i stopped the coolant flow ( eg closed thermostat) the coolant in the head would boil before getting to the thermostat, i could hear bubbling and pressurising the coolant system what this seemed to do was cause an airlock in the head = no coolant flow at all
once i got the coolant sorted and kept on top of the inlet temps it let me really wind the boost up
on mine i ran bpr6es, never went higher even on 25psi / no water+meth
the pistons came out like new

Yes i moved to the darkside

Instagram @jdm_brett

I've never been a fan of the electric water pumps. I know there are a good few that use them with success.

The main reason I don't like electric pumps is that they cannot generate the same head (pressure) against that thermostat as a mechanical pump can. It has been said that the mechanical pumps can push 30psi into the cooling jacket behind the thermostat. This cannot be said for any of the electric pumps available.

So what is the benefit of that extra pressure in the cooling jacket.......... Coolant boils at a much higher temperature under pressure. This allows the coolant to pick up more sensible heat before it boils (nucleate boiling) and when it boils it absorbs heat as latent heat (Change of state) those small nucleate bubbles will collapse sooner transferring that latent heat back into the liquid coolant again as sensible heat and away from the hotter coolant by convection. This nucleate boiling is important in transferring the heat to the coolant since the heat energy required to boil a liquid to a vapour is considerably greater. Without pressure, nucleate boiling happens at a much lower temperature transforming rapidly into transition and or film boiling that creates a insulating bubble of steam that dramatically reduces heat transfer. This steam bubble prevents liquid coolant contacting the hot metal surface preventing the important nucleate boiling. The result is a hot spot in the combustion chamber that propagates detonation.

Now that is not to say that the electric pumps don't work, they just work in a different way . If the electric pump can supply enough flow through the head to move the hotter water away from those hot areas of the combustion chambers quickly, the possibility of these large ’bubbles’ of steam are reduced. This type of system needs as little restriction as possible and the thermostat is a big restriction.

On a dry deck setup with an electric pump I'd remove the thermostat or sleeve in an effort to achieve the highest flow around the system in an effort to reduce the chance of transition or film boiling resulting in those bad steam bubbles, mainly as a result of the lack of 'head' (pressure) in the system. You’ll have to find another way to control engine temperature such as using a bypass thermostat which maintains full flow around the coolant jacket.

Also consider that most of the heat of combustion in the cooling system comes from the combustion chamber, not the bores, and is why many top fuel drag engines only run coolant through the heads. Granted those engines are pretty much one run scrap affairs, but if bore cooling was a prime cause of detonation, I'd think they would be cooling them.

The thing with dry deck is that the flow over all four combustion chambers is the same, it is the total flow in the system. In a wet deck, total flow is distributed across all four combustion chambers and in an ideal situation would be %25 of the total flow over cylinder 4, %50 over cylinder 3, %75 over cylinder 2 and %100 over cylinder 1 where it then exits the head. either way cylinder 1 chamber would perhaps still be exposed to the hottest coolant ? (in general terms). That is to say, that the hot water always exits at cylinder 1. In localised terms on a wet deck cylinder 4 would run at a higher localized temperature since it only ever sees %25 of the coolant flow. What if it could see %100 of the flow as it does in a dry deck? Its local temperature would be lower but cylinder 1 would still be the same as it was before with a wet deck?..........

Taking my babblings into consideration I was asked to look at an engine for a friend. He participates in competition rally’s and built a 16v 1380 engine for it. He used an electric pump and electric cooling fan on a side mount rad. On a drive around, the engine temps were marginally acceptable and the cooling fan was always on, but it just couldn’t cope with any load on the dyno without overheating, taking this as a good indication of what might happen on a long stage on a rally. I suggested he put the mechanical pump, thermostat and fan back in to eliminate any issues with the engine and get it tuned. Instant transformation! Overheating no more, not even on the dyno. The question still remains why this is the case on this engine when others seemingly have great success? Now I’m not saying my suggestion in using the mechanical gear was the final solution, but it did resolve the problem at least temporarily with the thought of reliability of an original design that’s worked well for well over 50 years, must be worth it if it means finishing that rally stage?

We do that to the brake and coolant systems at work, halerious when it goes wrong stuff shoots everywhere!

Drives
-Ford S-max Mk2 Ecoboost
-Rover 100 VVC #2 - track project

Searching is all you need on TurboMinis

so far no mention of deck height and quench . running too much room gives cause for detonation as well . and that would be about where mk1 pistons where eaten

not all castings have good coolant galleries (just bad casting). if you have one odd cylinder overheating/detonating/eating gaskets all the time it might just be a problem with that particular head or block.

top fuellers probably get a fair amount of cooling from the ridiculous amounts of fuel they manage to slosh in .

has anybody used dry ice on the ic and fuel cooling for drag use ?

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

I had a thought earlier is it possible to fit a bleed valve to a head to make sure there are no pockets of air? Please inform me if I am being a douche but surely its a sensible idea?

Drives
-Ford S-max Mk2 Ecoboost
-Rover 100 VVC #2 - track project

Searching is all you need on TurboMinis

Ive seen bleed valves in thermostat housings

I seriously doubt it!

that's where mine is paul.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Marina's had bungs on to of the 'stat housings.

I'd be careful of where you attach bleed hoses, you could ruin any syphon effect. The higher the header tank the better.

Cooling's about maintaining temperature differential and coolant mass. The original water jacket might have biased flow to the pump end but it will have included heated water from the other end, reducing the temperature differential. Letting hot water out of the heater tap would also take heat away from the cylinders at the at the other end.

Chamber shape won't only aid the burn to spread faster, it will improve fuel distribution in the mix.

Has anyone running a leccy pump tried reversing the flow direction? It'd maximise the temperature differential where most heat is generated.

Seems to me Robert made an important point earlier about time on full load.A quick dash up the strip lasts 10-15 secs,nothing like enough for coolant considerations to have an effect.Even the pistons will not reach stable temps.Circuit/hillclimb/sprinting is a different matter,with 30-50 secs at least on full load.So on the strip I think mixture,inlet temp,timing and octane are critical for a given setup.For this reason I always use 97 RON plus an octane improver (ok I know I run NOS as well)

'Where does the engine go?'