Re: response from Jim Adney re jerky acceleration

[Chris Wright <Christopher.Wright@Sun.COM>]

<x-flowed>Hi all,

Many thanks and please keep the ideas flowing.  I picked up a new dizzy 
cap this morning and hope to try it later.
My answers are below each of your suggestions in caps.
Rgds chris

On 26 Sep 2005 at 21:08, Dave Hall wrote:

>  
>
> > > I wonder if another possibility is that what you're feeling is a slight
> > > pinging. Have you tried higher octane gas? Upping the displacement from 1500
> > >      
> > to
> >    
> >
> > > 1600 would also up the compression ratio a bit, and this could be blindsiding
> > > you.
> > >      
>
>  
>
> > Maybe if it was previously a 1500 single carb, but the 1500S twin carb had a
> > much higher CR than the 1600.
> >    
>
> I believe that he has rebuilt a 1500S into a 1600. Dropping the domed pistons 
> would reduce the CR, but the 1600 displacement into the original 1500S heads 
> would push it back up again. I'm not sure where it would end up, especially 
> since we don't know the details of what was done and what parts were reused, 
> but there is the possibility of ending up with 1500S CR or even higher.
>  
THIS IS A GOOD QUESTION.   THEY USED A PAIR OF NEW 1600 SINGLE PORT 
HEADS AND 1600 FLAT TOP PISTONS.
I  IMAGINE  THAT THE CR IS NOW SLIGHTLY LOWER THAT A 1500S.   WERE THERE 
ANY T3s IN 65-66 WHICH HAD THIS 1600SP THAT WOULD GIVE ME A GUIDE TO THE CR?

NO, THERE'S NO PINKING AT ALL UNDER ANY CONDITIONS AND I ALSO TRIED 98 
OCTANE FUEL, BUT NO CHANGE.
CAR IS FINE WHEN YOU GET TO 4TH AND THERES NO PROBLEM WHEN THE PEDAL IS 
FLOORED IN ANY GEAR.  IT ONLY HAPPENS WHEN DRIVING REASONABLY, IN 2ND 
BETWEEN 20 AND 25 AND SLIGHTLY IN 3RD AT 25-35.   WHEN REALLY HOT, IT 
GOES AWAY.

> Either outcome could lead to some difficulty.
>
> OTOH, I just noticed that he says he has no problem at full throttle, so ping 
> is probably not the problem.
>
>  

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