<VV> Points to ponder

[Tony Underwood]

At 01:51 hours 10/28/2005, Rad Davis wrote:
>The "real men" trick I learned was a piece of vacuum hose behind the 
>points.  It worked too, although it was and is a crappy, short-term 
>hack with bad consequences for the rubbing block on the points.
>
>I'll agree that there's a place for "ultra engineering" a certain 
>class of old car.  But "ultra" and performance tend to be mutually exclusive.
>
>Re the point bounce on the distributor machine - the *best* 
>combination of parts I could come up with had point bounce at 
>4800.  The first one I tried went into bounce below 4000.
>
>I would have been incredulous, except that I had experienced exactly 
>this on my first "performance" corvair - a '65 140 Corsa coupe.  It 
>would rip right up to about 4500 RPM and fall on its face.  I 
>cleaned carburetors, zero-lashed valves, changed points (several 
>times).  What cured it was changing to an ignitor.  It also 
>cold-started better.
>
>It's distinctly possible that the point springs for the 6 cyl chevy 
>distributor we use have gotten weaker in the generic replacement 
>parts of decades later.  I'd be curious to try an original set of 
>DELCO points from the '60s on the distributor machine.  I would also 
>wonder if DELCO spec'd in different points for the 140 from the 
>factory, but didn't list them as replacement parts.  It seems like 
>it would be awfully hard for the dealership to sell a 140 corvair 
>(with the additional expense involved) if the thing wouldn't 
>actually pull harder above 4000 than a 110 would.
>
>Rad Davis




I had (still have, just not as many) a batch of Delco points that 
I've been using up, and they worked up to 6000 rpm in the Spyder and 
the 140hp ragtop, which also floats valves at ~6000.   But the Spyder 
would pull up through 6 grand with nary a misfire although I was 
really leery of pushing it past that point.

It hasn't been my experience that the "good" Delco points would 
bounce at 4000 rpm.   Hell, cruising at 70 on the Interstate with 
short radial tires, the '60 4-door's engine is buzzing around 4100 
rpm (dreamwheeled figure considering tire circumference and gear 
ratio) and it still would go up to 85 mph if I really pushed it, 
before the valves would float, and you know it when the valves 
float.   Clatter.  And *that* engine runs the old style points with 
the long arm, albeit also Delco manufacture.   Got several more sets 
of those as well, still in the cute little Delco "spam can" boxes.

The 140 hp engine in the ragtop floated valves, as mentioned, at 
around 6000 rpm (with the big valve heads which admittedly had fresh 
springs, currently has 95 hp heads on it) and it got  *real* noisy as 
well when it happened, shuts down right now when it does, along with 
the racket; something I really try to avoid.   I've kissed a piston 
with an intake valve before, can cause grief.


I wouldn't be surprised if aftermarket points would indeed float at 
less than 5 grand.


tony..