Iain's 20XE Trackday Nova

[House]

Hope you get it fixed soon, don't want to let Mr House out on track alone now do we...

I don't believe they would actually let me book on without Iain!!!

[Plug]

I reckon a rings come free or a piece of a ring in cylinder 4, or like you said Dave somethings come down out of the inlet but if that had happened id expect damage to a valve

[Iain]

Head on the bench for inspection



And quickly discovered the issue. There's a piece of inlet valve guide missing, and one bit loose and freely sliding around the valve stem causing the rattle.



Looking at my options now, it'll either be a light hone and spare 86mm piston fitted and new head, or a complete new engine.

[Plug]

I've got a spare gm head in the garage if needed mate

[scott.parker]

Wow... That's an odd one! I don't know how you keep your enthusiasm to keep rebuilding and progressing, but fair play, carry on.

[Iain]

Cheers Plug. Got a complete engine coming from House as a backup, and I'm popping out to look at a tall engine locally tomorrow night. I'm also getting a quote on fixing the current head although I doubt that'll be economical to do.

I've stripped the bottom end a little further to investigate whether honing is an option. Offending piston out:



It's squashed the compression ring solid from the impact:



I have spare early pistons, so my preference is to maintain this bottom end as the other 3 are good, give #4 a hone and pop this replacement in with new rings:



The bores are ever so slightly scored from the 'event' but you can't really feel anything with your nail so optimistic won't cause a problem:



The original sealing ring gaps at 0.6mm which is 0.1mm above tolerance... Maybe new rings will reduce it down, or maybe the bore's just worn. I'll see what a new set of rings gap like before proceeding:

[Iain]

Wow... That's an odd one! I don't know how you keep your enthusiasm to keep rebuilding and progressing, but fair play, carry on.

I suspect the enthusiasm will not last too much longer if the engine pops again At least I have two failure ornaments in my glass cabinet now

[Southie]

Nice damage, it's a nightmare though when engines let go so hope you get it sorted cheap enough

[nova_stee]

Looks next to nowt that mark in the bore .

[House]

spare spare engine will be on a pallet tomorrow and ready to be shipped to you.