Bongo Fury

dandywarhol wrote:

veebug74 wrote:Bigger isnt always better,you will more than likely introduce lag ,The gains will if any be marginal .
Whacking up the boost pressure would make the biggest difference ,providing the fuelings there.

Like adding a light spring to he actuator rod (assuming the boost isn't already at max)

Hi,thought this may make some sense after our conversation about other factors that can contribute to head failures,the heads i have seen on the forum failed around the valve area in the said to be weak spot

Source; http://en.wikipedia.org/wiki/Intercooler
After Coolers,
As well as allowing a greater mass of air to be admitted to an engine, intercoolers have a key role in controlling the internal temperatures in a turbocharged engine. When fitted with a turbo (as with any form of supercharging), the engine's specific power is increased, leading to higher combustion and exhaust temperatures. The exhaust gases passing through the turbine section of the turbocharger are usually around 450 °C (840 °F), but can be as high as 1000 °C (1830 °F) under extreme conditions. This heat passes through the turbocharger unit and contributes to the heating of the air being compressed in the compressor section of the turbo. If left uncooled this hot air enters the engine, further increasing internal temperatures. This leads to a build up of heat that will eventually stabilise, but this may be at temperatures in excess of the engine's design limits- 'hot spots' at the piston crown or exhaust valve can cause warping or cracking of these components. This effect is especially found in modified or tuned engines running at very high specific power outputs. An efficient intercooler removes heat from the air in the induction system, preventing the cyclic heat build-up via the turbocharger, allowing higher power outputs to be achieved without damage.

Compression by the turbocharger causes the intake air to heat up, rather than the air being heated by contact with the hot turbocharger itself, the vast majority is through the act of compression (ideal gas law) plus added heat due to compressor inefficiencies (adiabatic efficiency). The extra power obtained from forced induction is due to the extra air available to burn more fuel in each cylinder.

Rhinoman wrote:The purpose of the EGR is to reduce combustion chamber temperature so its probably not a good idea to blank it off. I shouldn't think that the intercooler has anything to do with overheating, on a petrol engine the rise in intake temperature can cause detonation but on a diesel I would think that it would be quite trivial compared to the heat generated by the combustion process itself. I doubt if many people here are running full boost for any length of time so the engine should be well within its design parameters
When a head cracks its invariably around one of the valves as this is the weak area on all heads.

Rhinoman wrote:Well strictly speaking the purpose of the EGR is to reduce NOx emissions however it does that by reducing combustion temperatures. I probably should have qualified my statement by saying its not a good idea to blank it off if your cooling system is marginal.
You are correct that the intercooler is there to make the air more dense by reducing its temperature, the question is how much can be gained by a bigger intercooler? I think I should take some temperature measurements. First task is to find the engine, I looked under the bonnet but it was nowhere to be seen