<VV> PG engine break up at 4400 rpm

[BobHelt at aol.com]

Well, it appears to be weak valve springs. But may I suggest  that you be a 
bit more definitive. 
 
First you say that the engine breaks up and then you say it  stops 
accelerating. As I read it, these are two different things.  The  first would 
indicate to me that the engine starts running rough as might be  caused by 
intermittent ignition failure. Something that you might be able to  hear in the 
exhaust.
 
That, while the second description indicates that the max rpm  is being 
reached and that the engine just doesn't have any power to go beyond  that rpm 
but that it is still running smoothly. That it just peaks  out.
Bob Helt
 
 
In a message dated 4/16/2016 7:01:09 A.M. US Mountain Standard Time,  
virtualvairs at corvair.org writes:

I  will be running my PG 140 at the New York Safety Track again this year. 
Last  year when accelerating down the straight in low, the engine pulled 
well until  about 4400 rpm where the engine seemed to just stop  accelerating. 
(heads milled to .035 squish, balanced forged pistons  and con rods. OTTO 
20 cam, etc.)

I am running igniter ll and the  recommended  flame thrower coil. I just 
changed the spark plug wires to  8mm and new AC 44F. Timing set at 16. running 
87 octane.  Same  4400  results in test run yesterday.
My Fitch with similar internals, I can  shift at 5500 with ease with it 
still pulling.
Any  ideas??