Joined: Aug 2017 Posts: 1,713 Threads: 47
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
That sounds plausible Colin, has anyone experience of how the baffles improve or not the consumption in a heavily worn engine?? My own personal experience of removing them is only in engines I have rebuilt and have resulting good bores and rings. In the past (25+ years ago) there were some fairly poor pistons and rings on the market, these often smoked, the couple I encountered, it was only two engines, had baffles fitted and the problem was immediately cured with good quality rings.
Black Art Enthusiast
Joined: Aug 2017 Posts: 272 Threads: 18
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Location: Deepest Norfolk
Thanks Colin - at least I now know why they were introduced, even if the jury is still out on how effective they are.
Note to self: Must make the effort to buy Sharrat's book!
Rick
In deepest Norfolk
Joined: Aug 2017 Posts: 2,748 Threads: 31
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Location: Auckland, NZ
Provided light cannot be seen past the rings what distinguishes poor quality pistons and rings, other than actual performance?
“Skill”, or established tricks, can make a difference with worn parts but for reasonably unworn or new, provided rings are not broken, what scope is there for skill to make a difference? Especially with iron rings which bed.
Austin seemed to battle with oil consumption, but the now conventional one piece grooved and drilled iron oil ring was late to appear. I am not sure when honing became standard. (Cyls were commonly finished with an orbiting grinder) As illustrated in the parts book, for a while about 1933 the 2nd ring had drillings behind so the car functioned with effectively one compression ring!
Is anyone still running the original wide compression rings? Used with one conventional grooved and drilled iron oil ring these could give near nil oil use.
Prior to Colin above I wondered if the baffles were somehow supposed to work with the drillings in conrod, which must flow oil both in and out.
It seems odd that baffles were fitted to pressure fed engines. Perhaps it was less confusing for the production line.
From experience with other makes oil consumption can be a puzzle. For many mechanics, customer cars disappear out the door and, except for cock ups, they seldom learn the accurate long term outcome.
I found with new rings in several moderately worn Javelin engines oil consumption on trips seldom below 1 pint per 400 miles. Yet a 170,000 mile Hillman, with shells so corroded they rattled, and most original top rings broken, barely reached this figure.
