EGR - Anybody here mechanical minded?

Joe_Horner

jaydeeuk1 wrote: »

But if the the valves and cylinder walls were made of the same material from previous gen diesel engines that didn't have EGR's (quite likely imo - why change a component that works), they therefore would haven been designed to work at these temperatures anyway?

That's probably true fairly early in the life of the design. But EGR has been in use for so long now that it's unlikely it's still the case for many engines.

This is supposition to a great extent but it's not a big revision to change a material spec so at some point, as non-EGR versions leave the roads, the savings in material costs would make a change economically sensible on the basis that the new material will be suitable for almost all the current fleet.

Car makers are well known for shaving the pence because (say) 1p per valve, over 8 valves per engine, over 5 million engines is a handy bit of cash!

red_eye

lee678 wrote: »

At the risk of repeating myself the result of blanking off the egr will be much higher combustion chamber temperatures. This will a) stress the valves and seats much more, and b) cause pinking, which the ECU will deal with by retarding the ignition, so the engine will not be working at it's optimum designed parameters. You probably won't notice this until a valve burns out, a piston or spark plug melts or you get overheating problems. in fairness the problems are less prevalent in a diesel engine as the running temperatures are quite a bit lower to start with, the engine internals are tougher, and by definition they don't suffer from pinking, so removal is much more risky in a petrol engine, in my garage if asked to blank off a egr the answer if you cant afford a new egr then you shouldnt be running a car, imagine the scenario if a plug melts and they come back "well you blocked the valve" ! its not all about performance and economy and a lot of you need to recognize that fact .

so what you saying is that valves and pistons are now lower grade then on non egr engine?