Ron:
If you haven't read Kas Kastners dissertation on TR-6 crankshafts, you
need to. There is a harmonic in the crank that occurs in the 6-7K rpm range.
It is a function of the design of the crankshaft and going to a billet crank
will not eliminate it. The bottom line is that even if the crank doesn't
break, the vibration will destroy lots of other bits in the engine. Smart
TR-6rs limit reve to 6000 rpm.
John Prie
----- Original Message -----
From: "ron meek" <rmeek8@juno.com>
To: <fot@autox.team.net>
Sent: Monday, May 17, 2004 11:02 PM
Subject: Crankshafts
> Hi all,
>
> So I'm thinking of the next TR-6 engine I'll be building for Walt
> Holowell and I'm wondering what the crankshaft options are,
> besides Moldex (c'mon Walt, buy me a Moldex).
> His current combo runs a stock crank and rods (polished,shotpeened,arp
> bolts) and has put down 135rwhp which should him at
> about 170-180 at the crank(I figure his od tranny is responsible for a
> few extra percent loss even though it's not engaged on the
> chassis dyno).
> I'm no Triumph expert, so at what point does the stock crank become a big
> liability, I expect this engine to rev to 7000-7200 rpm
> and hopefully put out about 210-220 at the crank,is this too optimistic?
> Since Walt attends southwest regional events and does not chase national
> points I don't want a short fuse, what will be the expected maintenance
> intervals on such an engine(rings,bearings valve guides)?
> Probable combo: Pauter rods
> PRI cam and lifters
> 12:1 JE or CP pistons
> Big valves and lots of porting
> Goodparts roller rockers and tubular pushrods
> well baffled sump as per current engine(3 trap
> doors courtesy of Stanley door hinges)
> 40mm DCOE's or possibly PRI's Keihin setup
> Did I miss anything Walt?
>
> All input would be very welcome.
> Ron Meek
> Alb. NM
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