I have a SB350 with 10.5:1 compression. I use high octane fuel and it knocks a little when under acceleration. How long before the knock causes damage? I don't want to keep test driving to detect it.
Timing is around 8-10 degress BTDC.
you can't it is an action related problem.
The engine needs to be under stress in order to create the situation that it happens in.
If it is happening you need to use a higher grade of gas.
The recommended grade in your manual is for driving at sea level.
So if you live at a higher altitude you can get away with using a lesser grade gas, it is basically 2 grade points for every thousand feet.
Example: In northern Utah you can get gas in the 85 grade and at being 4500 ft have no problems with knock even under heavy stress. But if we travel to LA we need to 89 in to make sure it doesn't knock
What do you mean by spark knock? There is Rod knock and it is most noticeable between 2500 and 3100 rpms.
Any type of diagnostic work usually has to be done with the car on.
You cant the car needs to be under driving conditions, if you use the proper grade of gas (Octane) it should not knock. Newer cars adjust for this.
that is difficult to make happen because of the cause of that knock. if it is temp related, or if it is timing related or even if it is mixture related you need to load up the engine to make it happen. if you had a dynomomoter, that would be ideal but who has a 45,000 tool just sitting in their garage?
You have a knock sensor in the car(most likley) and if the thing is EFI you have a diagnostic system of some type. Obd1 up to 1995 and obd2 after 1995 it is a obd2
Throw a respectable tester on it and see what you receive. Then work from there.
Here check this out
"Pinging" is caused when a fuel charge is ignited before the spark ignites it, or it is ignited too early.
This says it all in a few words.
a lean condition will cause this as well, make sure intake is bolted down, make sure pcv valve is working properly, and hose is ok, vaccuum booster line tight, carbureautor gasket doesnt leak. An easy test is spray with carb cleaner in small burstsaround the gasket, if idle changes your sucking the fluid into the problematic vaccuum leak in the area.
I wouldnt raceor be rough on it till its fixed if its your only transportation, if it isnt, find problem asap. The knock is never good no matter how it happens. Its damaging your pistons slowly. I laid over ring gaps because i thought i could cheaply fix it by adding octane booster..... four pistons down!