| Author |
Message |
    
Patrick Lockyer.
Grand Master
Username: pat_lockyer
Post Number: 195
Registered: 9-2004
| | Posted on Thursday, 30 December, 2004 - 07:57: |    |
Have heard of the ignition timing being set to the correct degrees for octane fuel and a good distributor etc,then the car tested up a hill under load for pinging and pinking with the distributor retarded to eliminate the pinking when heard.
This is where the problems start.
First the engine will be down on power using more fuel the engine will run hotter[retarded]
The real problem in most cases is caused by the inlet valve seals leaking oil through the valve guides with the resulting build up of carbon deposits glowing hot on valves.
This is a cause of premature detonation,engine damage will occur if left uncorrected.
Ie exhaust valves burnning out,holed pistons etc.
Confirm with internal inspection through the spark plug hole.
|
David Gore
Moderator
Username: david_gore
Post Number: 355
Registered: 4-2003
| | Posted on Thursday, 30 December, 2004 - 09:17: | |
Hi Pat,
Point taken however I have used this procedure on engines ranging from a 1.3litre twin OHC multivalve to a 5.7litre Ford Cleveland V8 for many years without any problems.My driving has always involved frequent long trips [500/1000Km+] at the prevailing speed limits so engine carbonisation has not been a problem - I did check my Falcon V8 after 300,000 miles with a borescope and the combustion chambers were almost free from deposits.
Cars used for everyday city driving could encounter pre-ignition from glowing carbon deposits as you suggest. I used to have a problem with a 1.8litre Toyota Tarago [8 seat passenger van] leaded fuel engine pinging after filling up with lead replacement fuel at certain discount outlets; the engine timing was set for our 96 octane LRP however the discounters were not averse to on-site "blending" of the LRP with cheaper 92 octane unleaded fuel and this would cause pinging until the distributor was retarded using this rechnique and the fuel used. The engine settings had to be "spot-on" if you wanted to keep up with the traffic!! The engine lasted nearly 400,000Km before the body rusted out and I scrapped the vehicle.
(Message edited by david_gore on December 30, 2004) |
|