Increased displacement

[dc240969]

l was having a gander through pistonheeds a while back and came across this RS4 or RS6. The engine displacement had been increased to 4.0 liters. Now l was having a think to my self while l was out driving and the subject breezed past. Im all up for conventional after market mods, like l have and alot you of as well, but lm also up for something beyond. So l would like to ask some of you meccies , or those in the know, what does increasing the displacement involve and what would be the potential gains? Is the motor up to it?

 

[RobinA3]

You can increase the displacement by either increasing the diamter of the bores but you'll only gain a small amount due to the oil and water jackets or you could stroke it to give you the extra displacement. Either way you'll be looking at a fair chunk of money, the first option you'll need new pistons, the latter you'll need new rods and crank.

To be honest you are looking at a few grands worth of work for little gain, you get more gain for less money by going for a bigger turbo etc.

 

[samuelt]

Land Rover did this big time, they took the V8 from 3.5 to 3.9 and this was ok then to 4.0 and again to 4.6 the last two engines had so many problems with cracking between bores and water jackets.

The French are into Displacement Increasing as they are not aloud to modify there engines so increasing the displacement can a 'hidden' mod.