Your theory or Surtee's theory would be valid if there were no exhaust stroke..
Give it some thought.. every engine cycle there is exhaust stroke with no real
pressure above the piston so you are still in the unsafe condition you describe
for 50% or the time. As far as making it easier to drive with high gear only..
My answer is get another driver that will deal with it, the car will go much
faster with a transmission in it. The funny thing about being the best is that
you are the best relative to everyone else at the time, and your methods are the
best at the time you used them. That does not mean that better ways to do things
will not come along or better drivers and engines. It is all relative to the
date the records is set. It makes it all fun to see things evolve and you need
to grow with the new information. This does not ever discount what someone has
done in the past but does allow for growth and new thinking. Oh and you dare
wrong on the over rev in a sporty car.. they bang those things off the limiter
endlessly..and we do get errors on occasion that they have exceeded the limiter
by 8 or 9 hundred rpm in a set of tight corners with lots of downshifts.. Some
of these are engines with the limiter set at 9000 or more rpm also.
Dave Dahlgren
ardunbill@webtv.net wrote:
>
> Dave, we're talking about one of the all-time Masters of Bonneville
> here, the record book is full of Lattin-Gillette team Ardun records.
>
> As to the con-rod breakage risk, that is a fact, not a theory nor an
> opinion. We're talking about a situation where the conrods are running
> right at their limit of ability to hang onto the pistons and not break
> under the small ends. The stress on them is close to the snapping point
> due to the rpm, piston speed and piston weight. If the throttle is
> snapped shut, the gas pressure over them which has been partially
> offsetting the inertia load, partially balancing it if you will, is
> suddenly cut off so this represents the instant of maximum stress on the
> rods. Elmo told me they'd had it happen, just like that.
>
> For many years I followed the British road-racing motorcycle sport very
> closely, in the golden age of high-performance singles. They were
> developed right to the limit of reliability with endurance. Numerous
> experts mentioned in articles that con-rods were most likely to break
> when snapping the throttle shut on the over-run. The great bike and car
> World Champion John Surtees mentioned this himself in one of his books.
> For years at the start of his career, he built his own racing equipment
> in his garden shed.
>
> Let me quote from Surtees, for everybody's enjoyment: "It is when you
> ease the throttle at really high revs - say, for a fast curve - that a
> connecting rod is most likely to go. Inertia loading on the rod goes up
> as the square of the engine speed but so long as you are on full
> throttle there is some gas pressure above the piston to offset part of
> the upward load. When you ease the throttle you ease the gas pressure -
> and that is when you should be ready to whip out the clutch like greased
> lightning at th first sign of a locked engine." ("John Surtees on
> Racing" London, Iliffe and Sons Ltd. 1960. P. 39).
>
> The sports cars to which you allude, true, they constantly snap the
> throttle open and shut as a part of driving and braking technique.
> First, they have the finest con-rods available, second I daresay they
> don't constantly have their engine at the red-line on the over-run. Or
> do they?
>
> Keep in mind, Elmo never used anything but original Ford stock rods by
> preference and to keep costs down, and they're no Carrillos. You have
> to look after them.
>
> Elmo told me they like a high-gear only push start at Bonneville,
> pushing with the truck up to a speed fast enough for the car to chug
> away in top gear, because it's easier for the driver. I'm quite sure
> that a standard part of the shut-down is to shut the fuel cut-off on the
> injection at the same time you start to throttle back, to avoid danger
> of hydraulicing. Cheers Bill
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