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+--- Thread: Con rod query (/showthread.php?tid=2039)
RE: Con rod query - Zetomagneto - 26-11-2018
(26-11-2018, 02:12 PM)Colin Wilks Wrote: Thanks both.Dealer would say that wouldn’t he, that way he gets 2 bites at the cherry, sells car as is, later sells engine on it’s own. If I was looking for a sports seven I would want one with a correct engine and would pay a premium for it.Probably pay more for one with new crank.I would not run a sports engine with an original crank, not worth the risk, neither would I buy an original Nippy crank I consider them worthless.How things change, a Nippy crank was a must have in the 70s!
I shall be getting the crank and flywheel balanced so may well ask them to lighten the flywheel at the same time.
As an aside, I was talking to a "posh" classic car dealer last week and I asked him the question "If I offered you my Type 65 with its original engine, would you prefer this on a pallet, entirely unaltered, or in usable form in the car?" He replied he'd like to see it on a pallet.
I think this is symptomatic of what's going wrong with classics - the idea that you keep a precious artefact but don't use it seems very sad to me, although probably financially sensible.
I am hoping my plan will give me the best of both worlds - a usable original engine that is hopefully unlikely to destroy itself, but retaining the original crank, rods and camshaft gear on the shelf so that my children can give the market what it wants when I'm dead (always assuming we're still allowed to drive cars with petrol engines in years to come).
RE: Con rod query - Barker - 27-11-2018
With Shell Bearings on a 1.5" Phoenix splash fed crank and rods, what harm would be done if the shells were beveled slightly at the joins, (between the cap and rod), to allow the flow of oil across the width of the journal ?
All the other modifications for reducing the oil inlet holes to the front and rear cam shaft bearings, two o rings for the front cam bearing, up-rated oil pump, and most importantly the alignment of the oil jets to the inlet galleries of the crankshaft would have to be undertaken. If oil can't get out of the journal, how can it get in ?
John Barker, Nelson NZ
RE: Con rod query - Colin Wilks - 27-11-2018
Shells or white metal? I discussed this last night with my mentor Nick Turley. Nick made the point that white metal is much more forgiving than shells when it comes to the crud that inevitably circulates in a traditional splash fed set up. As I do not want to get into fitting an oil filter I have decided to stick with white metal.
RE: Con rod query - Zetomagneto - 27-11-2018
(27-11-2018, 12:06 PM)Colin Wilks Wrote: Shells or white metal? I discussed this last night with my mentor Nick Turley. Nick made the point that white metal is much more forgiving than shells when it comes to the crud that inevitably circulates in a traditional splash fed set up. As I do not want to get into fitting an oil filter I have decided to stick with white metal.
Nick is absolutely right, I would not use shells without a filter.With white metal it has greater thickness and therefore the ability to absorb foreign matter.
RE: Con rod query - JonE - 27-11-2018
Zeto, So are Austin 7 standard three bearing engines essentially flawed, or do their shells have slightly different characteristics? Or are you just considering sports useage?
RE: Con rod query - Charles P - 27-11-2018
(27-11-2018, 06:24 PM)JonE Wrote: Zeto, So are Austin 7 standard three bearing engines essentially flawed, or do their shells have slightly different characteristics? Or are you just considering sports useage?
Don't they usually break the crank before the shells start to wear out?
C
RE: Con rod query - Hugh Barnes - 27-11-2018
Not in my experience Charles, having campaigned my Pearl with a 3 bearing engine for the last 15 years or more (including 2 Eurotours).
RE: Con rod query - JonE - 27-11-2018
I thought the crank breaks were just as a result of inadequate assembly in the first place, and that proper alignment resulted in, like Hugh accounts, a damn good engine. (All this of course just from reading stuff, so hence my interest in hearing from other experience)
RE: Con rod query - Charles P - 27-11-2018
(27-11-2018, 06:55 PM)Hugh Barnes Wrote: Not in my experience Charles, having campaigned my Pearl with a 3 bearing engine for the last 15 years or more (including 2 Eurotours).
It was tongue in cheek Hugh!
RE: Con rod query - Bob Culver - 27-11-2018
Unless finished in place all shells are made with an exaggerated clearance at the parting line although it may not be obvious.
Many cars with shells ran without filters ie late s.v Minx. Some makes had shells with the w.m just a few thou thick but even with these, grade for grade, I doubt if embedibility for normal dirt was altered. Life is much extended with thin w.m
My stock Seven original crankshaft is about .001 out of round at 100,000 miles, nearly all that on oils of API SB rating or less.
In ages past pratice at overhauls was to significantly take up cast bearings and re scrape . This exposed clean new metal.
In my observation with various cars over the decades, for the same oil, debris in the oil is hugely related to ring gaps and to consumption and consequent carbon formation.