piston return springs?

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Mar 4, 2010 | 10:29 PM
  #1  
Okay now that youve fell in my trap i have a question!

How easy is it to tell if your car is detonating? Ive heard everything from popcorn sounding to bb's in a coffee can.. During the t56 swap i removed my distributor so i would in no way hurt it while the engine was tilting. After i first installed it, the car wouldnt start and shot smoke through the carb. I moved it 180 degrees and it fired right up.

I first timed it on the low side to be sure i wasnt detonating and had it at 8 degrees BTDC. Then i moved it up to 12BTDC. I still hear a little crackling in the exhaust, but im not sure if its detonating OR if its just because my exhaust isnt 100% tight (only have 2 bolts in each header, lost my bolts ). Plus my headers end right beside my shifter. I have advanced it higher and can hear a difference except for a metallic ringing. If i retard it any lower my car just stalls out.

I wouild really like some advice guys.. im really scared to drive my car. I dont wanna hurt my engine.. thanks
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Mar 4, 2010 | 10:45 PM
  #2  
Re: piston return springs?
Dont listen to the exhaust, listen to the engine itself.
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Mar 4, 2010 | 10:49 PM
  #3  
Re: piston return springs?
every single car ive ever heard detonating never sounded like "pinging", it has always sounded like a rattle type sound. Like loose metal rattleing against something.
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Mar 4, 2010 | 10:53 PM
  #4  
Re: piston return springs?
When driving i cant hear anything over the putting of the exhaust right below my hand. When its idling and im outside the car it sorta sounds like something rattling in the intake but i cant tell. This never stops though. Even when i retard it so much that it stalls out. Am i just paranoid?
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Mar 5, 2010 | 04:05 PM
  #5  
Re: piston return springs?
You've got A LOT of wiggle room there. If you put it "just barely" above stalling, you're about 30* away from detonation.
Detonation is VERY distinct. You've just got loud raspy leaky exhaust. Pay no attention to that. Detonation, even with open exhaust will be noticeable. It'll be like the engine just RATTLED. Like someone forced a bag of marbles, or wrenches into your combustion chamber. It'll drown out your exhaust.

Fix up your car though, driving it with two header bolts in will burn out your gaskets rather quickly...
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Mar 5, 2010 | 04:30 PM
  #6  
Re: piston return springs?
Thanks man, that was very helpful. Im going to buy the gasket set from advance auto parts in a few days. They come with all 6 bolts and the metallic gaskets. Again thanks, i feel alot better about driving my car now.
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Mar 5, 2010 | 04:45 PM
  #7  
Re: piston return springs?
Should have... 8 bolts? I don't remember, either way, good. Remember exhaust bolts are renowned for "self-loosening". If you want, buy special lock washers (nord-lock) or Super-8 or whatever those other ones are - or get used to re-tightening them after the first few heat cycles.
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Mar 5, 2010 | 05:46 PM
  #8  
Re: piston return springs?
6 bolts on each exhaust manifold/header.

I heard a car detonate on a dyno, you could definitely hear it above the exhaust on the outside of the car! You should feel some power loss also, like the car starts to hesitate.
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