I've looked for improvements in lap times and haven't found anything
-----Original Message-----
From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net] On Behalf
Of William G Rosenbach
Sent: Saturday, July 31, 2004 1:23 PM
To: Guyots3@wmconnect.com
Cc: sbarr@mccarty-law.com; jerrybarr@charter.net; fot@autox.team.net
Subject: Re: ARP rod bolts etc
Leon wrote...
>>MSD ignition stuff is always useful.
Has anyone documented any significant power increase with the MSD on the
dyno where you can switch between standard ignition and MSD enhanced
ignition?
Bill
On Sat, 31 Jul 2004 03:26:47 EDT Guyots3@wmconnect.com writes:
> On Thu, 29 Jul 2004 13:42:52 -0500
> "Barr, Scott" <sbarr@mccarty-law.com>
> Wrote: Subject: ARP Bolt Failure?
>
> I pass along the following for whatever interest it may generate. A
> couple of weekends ago at Road America, my new Spitfire motor blew up
> in a pretty impre$$ive manner. My first thought was that a rod bolt
> on #2 had broken -- the
> #2 rod cap was seriously damaged and one of the bolt holes in the cap
> is now D-shaped -- clearly, the ARP rod-bolt was not in its hole when
> that damage occurred. But, these being ARP rod-bolts, I concluded
> that there must be some other explanation -- that it had been starved
> of oil or something.
>
>
> On disassembly, however, none of the other bearings show any real
> wear. My dad (with 40-some years of experience in the engine building
> business) took a
> look at the mess and concluded an ARP rod bolt broke. He showed the
> mess to a Caterpillar Certified Failure Analysis Instructor, who
> concluded an ARP rod bolt broke. See below for that discussion.
>
> Anyone else have experience of ARP rod bolts failing?
>
> Scott
>
> Hi Scott,
>
> An interesting story.
>
> What puzzles me though is your choice of Spitfire 1500 engine for
> racing?
>
> According to my recollection, the 1493cc engine has heavier
> Crankshaft, heavier (TR6) Con-Rods, heavier flywheel, a longer stroke
> and wider
> (TR6) bearings
> with increased drag, none of which lend themeselves to high RPM.
>
> In this particular case, bigger is not always best.
>
> I would recommend that for your replacement engine, you seek out a
> 1967-1969
> Spitfire Mk.3 1296cc engine, (FE engine prefix in the USA?), perhaps
> bored out by 40 thou to accept GT6+ pistons, (this raises the c/r to
> 10:1).
>
> A decent camshaft from say Ted Schumacher, (running in cam bearings),
> an alloy flywheel from perhaps Fidanza, a tuftrid-hardened crankshaft,
> plus duplex timing gear, a free flowing exhaust and a fresh set of ARP
> bolts etc would produce an engine of around 100 bhp+ at 6,000 rpm,
> with much more relaibility and
> an eagerness to rev.
>
> MSD ignition stuff is always useful.
>
> In Short, use all the strongest bits, build it very carefully, get the
> (cold) air in and out efficiently, lots of (cool) gas, and good strong
> sparks and you will have it sorted.
>
> Best Regards and Good Luck
>
> Leon
>
> (been there, done it)
>
> ps. just bought a set of Aviation grade X-rated bolts from Coastal
> Fabrications for my Vitesse Driveshaft/Propshaft. (as recommended by
> Chris Kantiarjiev in SF). In the interest of increased reliability.
> They certainly look to be of very high quality.
>
>
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