[Mgs] Piston Broke (was Picking a head)

[Eric Erickson]

On 15/02/2008, at 7:17 AM, Rick Lindsay wrote:

> You know, the other possibility is that when they
> installed the new rings they did not correctly set the
> end gap - if they set it at all!
>

Nahh, just put my past ramblings down to disappointment :-)

I am quite prepared to believe the issue was caused by a detonation  
issue.

She was tuned pretty finely as far as the octane levels of fuel she  
needed and if that octane level dropped any she would ping.  I  
thought I kept an eye on that but in the heat of the moment and the  
noise of the track (at 6000 rpm) who knows what was happening.

Anyway, the damage looks like detonation damage (and blown apart top  
ring).

I have bitten the bullet and decided to drop the compression on the  
engine to a sensible point for a some-time street car so I can run it  
on Premium Unleaded.

Now I just need to look elsewhere for whatever power and/or speed I  
lose by doing that.

In the end this has probably just forced my hand a little.

I have found some nice "slightly" dished pistons that I will use and  
we will see what the end result is after a really thorough refresh of  
the poor engine.

Budget racing is fun, isn't it?



Thanks all,



Eric
'68MGB MkII
Adelaide, South Australia