[TR] Dieseling and pinging

[Chip19474 at aol.com]

Wayne,
 
I'm sure there's a thread lurking around somewhere on the List regarding  
whether it's necessary to use high octane fuel with TR motors but, in your 
case,  consider what you've observed......your engine "started with high 
octane fuel  and ran fine".  I think you'll fine that most owners of these cars 
use high  octane fuel because the cars perform better and achieve better fuel 
 economy.  Not wanting to get into a discussion on compression ratio and  
octane/pinging relationships, back in the 60's, we used high octane fuel 
because  we were advised that the cars required it and, indeed, they ran better 
with  it.  With today's pump fuel octane levels "not what they used to be", 
using  higher octane fuel is an even better choice.
 
So, the simple answer to this portion of your post is to refill your tank  
with high octane (93) and tune to it rather than trying to dial-in your 
motor to  87 or 89 octane.
 
My advice is to go with 93 octane and adjust your timing and carbs to that  
fuel.  As far as agonizing over trying to get a textbook timing reading,  
forget it!  Anytime you do modifications to the engine, the timing setting  
offered in the service manual is a good place to start but the final timing  
setting is where the engine performs strongly without pinging under  
load.....
 
Chip Krout
Delaware Valley Triumphs, Ltd.
Skippack, PA
1976 TR6  CF57822U