Knock/pinking after acceleration

[powermyster]

Just took the car for a run today to a show. I rarely drive it hard but decided to open the throttle on the way back after filling up

Afterward I let up she was pinking for a min, I took it easy and it went away. Thought maybe it could of been exhaust gasket but it seems to have gone away so mush have been detonation.

Any ideas??

Engine is 383 with 750cfm steer demon

 

[moes]

did it ping before you gased up the car? If not you might have got some bad gas. What octane rating of gas do you use?

 

[powermyster]

No but it seems to go out of it. It's all 95 here

My initial thoughts were the timing shifted slightly with the hard acceleration. Maybe the clamp wasn't fully tight but obviously if that was the case it should have kept up.

I'll check the timing tomorrow and see what it shows.

 

[Kern Dog]

All 95? I understand the European standard of octane is different than ours. Our 91 is supposed to be equal to a RON of around 94-95?
Regardless...You only have ONE grade of fuel ? You guys don't have 3 grades like we do ?

 

[powermyster]

We used to have 98 but hasn't been for sale for a long time.

 

[demonram]

I'm having a problem with my car. I moved to Az. from Il. in November. In Illinois we had 93 gas, in the Phoenix area the best I've seen is 91. I've got 10.5 with aluminum heads on a 451. I never had a detonation issue in Il. I have backed the timing down, added octane boost all to know avail. If I get on it it's there. What am I missing? I know there are guys running bigger higher comp engines not having issues. Could it be something else? I did put a new firecore distributor in before I left with a male style cap, new e3 plugs and wires. I know dist was set right, set timing. What if anything should I check? Thanks, Howard

 

[Ski 61701]

Since Illinois is anywhere from 450 to 900 ft above sea level, and now you are in Phoenix not sure what elevation is there , you are probably going to have to monkey with carb jetting due to thinner air. Not sure which way you will need to go with jetting