smells like....

[hg70]

i spoke to a mechanic today about a rolling road and a tune, bla bla bla he said for every pound of air i squeese in under boost it adds 4 metric tonnes of stress on the crank?
i can smell something in the air and i don't think it's roses, is this true coz i find it really really hard to believe

 

[Loz]

I can believe it. An engine is subject to lots of large forces and all of them are trying to pull it apart, just think how much pressure that small explosion generates, its got to move all the rotating weight of the engine plus the rest of the drive train and the weight of the car on top of that. When you add all those forces together the resultant force on that small part of the crank has to be quite large.

 

[hg70]

from what he was saying and what my plans are there is already X mount on the crank plus another 20-28 tonnes that i'll be adding, i know a fair bit about strengths in steels from welding and years in steel yards, and i know if i hung 28 tonnes off my crank 1 of two things will happen, the bolts would pull clean out or just snap. or maybe i have not realised just how effective the crank counter weights are....thoughts?

 

[Loz]

I think its the bearing surfaces he talking about, I seem to recall that when talking about pressure on bearings it can quickly go into large numbers.

It is intriguing though, I'll have to try and find some more info when I get in.: D

 

[HDi fun]

Four cylinder engines especially are subject to huge forces and bearing pressures given that the whole thing effectively stops every 180 degrees. I don't think he's far out with the numbers he's quoting.

 

[gummy]

Thats a very interesting subject,never thought about the stresses and strains put on an engine and its components,i just take it all for granted!!.