losing compression

[F7R-R5]

its got new rings and the bores were de polished

 

[sparky33]

but you are clearly still getting blow by, you have proved this yourself.

 

[F7R-R5]

but i dont understand why thou, from all the things done it shouldn't

 

[sparky33]

As stated, it can only be down to the bores or the rings, the rings are not sealing the bores. (the oil does though), so this indicates blow by.

 

[stan]

what were your ring end gaps, and piston/bore clearances?

 

[F7R-R5]

i cant remember off the top of my head but i know they were still in torerances

 

[F7R-R5]

just an undate, today i fired the car up after its been stood for a few days and for some strange reason it seems to be running fine idling fine no strange misfire, i had it running for about an hour as i was on my lunch break, do i (A) finish putting it back together and drive it about and hope it doesnt play up ( carry on letting it tick over a few more times to try getting it to play up

 

[Neal R19]

if its a fresh rebuilt engine with new rings and refinished bores, the last thing you want is for it to sit there idling for hours on end, you need to drive it and give it plenty of load to force the rings into the cylinder walls and bed them in before the bores glaze up. Idling will just glaze the bores over without bedding them in. The hour you have already idled it for is less than ideal really.