steve McCulloch

Being a non-techie I wanted to know:

1. What are Bearings in an engine
2. Why do they tend to go if you add shed loads of power

Thanks

Steve

Trout

iTrader: (1)

Steve,

a non-techie answer...

...the Boxer engine layout means that the centres of the pistons are closer together than in 'normal' four cylinder car or even a V arrangement.

I don't know what the technical term is, but what is boils down to is that there is less ability to stiffen the crankshaft and so it is relatively flexible. It is this flexing that can be one cause of bearing failure.

It is however, flexible within the limits of the manufacturing budget (the Scoob in the land of origin is a cheap car) and the designated power output 276 bhp.

You can have a stiffer crankshaft at a (high) cost, again within the limits of the fundamental engine design.

Another, potential cause of bearing failure is a poorly tuned car (or an Sti V on a cold day) running lean consistently causing the piston to overheat - sometimes it is then possible for this heat to be transferred via the conrod to the bearing, cooking the oil and again causing failure.

So, basically, it is a budget performance engine that has limits of tuning inherent in the manufacturing cost, and ultimately the inherent design of the engine.

Rannoch, now awaiting many more knowledgeable gentlemen to correct me!

eggy790

iTrader: (20)

bump, lets see what answers people have 9 years later

STI_Baly

iTrader: (23)

Anywhere else it could be 18 years.