[Mgs] Piston Broke (was Picking a head)

[Eric Erickson]

On 15/02/2008, at 1:09 AM, WSpohn4 at aol.com wrote:

> I doubt you had a piston problem due to RPM, Eric. There are lots  
> of people that rev MG engines much higher than you do without  
> incident.  I'd look to something else.  Were you getting  
> detonation?  I'd worry about timing and mixture.
>

Well it looks like the issue was caused by a broken top ring (the  
rings on the JE pistons are pretty fine) - and using AVGAS with the  
high compression generally mean no detonation.  I will try and take  
some shots but the damage was pretty certainly done by the broken ring.

As far as over revving - on the track I take that thing regularly up  
to 5500 to 6000+ revs but can remember the odd "issue" (missed gear  
related, or high-speed "off"... ) where it has gone well over that on  
a couple of occasions.

I was told she could handle 7000 revs but never really found any  
advantage going much over 5500 - it was only the odd error that would  
see the needle bounce that far past the old redline.

Anyway - I have a lead for some flat-tops and I will be chasing that  
on Friday.


Thanks,


Eric
'68MGB MkII
Adelaide, South Australia