Help w/ combination

[MikeDe]

Hope someone can help me with this one. Trying to come up with a combo. What is better for reliability? Less boost more static CR OR more boost less static CR? I remember reading an article about a British Engineer who felt more the more boost scenario was actually easier on the engine since the load on the pistons/rods/crank were constant were as in a low boost or normally aspirated scenario the loads alternately hammered the bottom end more.

Any thoughts?

 

[patprimmer]

In my experience, more boost, less compression is more unreliable as:-
The engine makes more power, thus increasing loads on most parts, including inlet valve springs, crank, rods, pistons gudgeons, cooling system, ignition system etc etc etc.
The increased boost increases charge density (that's how it makes more power). This then burns more fuel and air each fireing stroke, making more heat and more cylinder pressure. More heat and pressure means more likely to break.
The lower compression makes starting harder.
Low compression high boost makes plug selection harder, as you need a hot plug when not under boost, and a cold plug when under boost.

These problems are easy to solve to a point, that is if you don't take it to far.



Regards
pat

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