Detonation? (vid)

[cv67]

Was fooling around with a go pro and after listening to this Ill be darned if it doesnt almost sound like pinging around 3:00 entering 2nd and 3rd more I listen to it. (you know how that goes!)

Never heard it in car but the mics can pick up things the ear cant. Youd think if it was it would be plenty audible and always listen for it
Not hearing it after the 4:50ish mark........sure hope Im wrong here dont need to be hammering the bearings out of a new motor. 4:50 not in secondaries at all, 3:00 "Just" dipping into them a tad. OCD...lol

Timing this is a pain, crafstman light I have doesnt play nice with this msd marks dance a lot been a problem since day 1 even before it was stroked.

Plugs seem to look fine.

https://www.youtube.com/watch?v=oOZFtGkcfgc&t=186s

[bentvalves]

can't hear anything, your not even really in it at the 3:00 mark.

anyways, make yourself a simple set of DET cans using some ear defenders and have a real listen.

[amc fan]

I could not hear anything. You are grannying it .If its going to rattle it put in 5th gear at 20 mph and floor it you n will hear it then... if its going to rattle!

[cv67]

Yup, not in it at all as the gas isnt really too fresh. Have put it in 4th and opened it up at lower speeds, nothing.
Strange how cameras can affect sound. Last one I had made the valvetrain sound like a guide was coming out. lol

An extra set of ears never hurts.

[stevek]

The keychain smacking into the dash between gear changes doesn't help.

[F-BIRD'88]

You can make up simple mechsnical acoustic or electrc amped "mechanics ears" to listen to the engine block while driving. A simple pick up transducer is a simple crushed short copper pipe drill a hole in it and screw it to the side of the engine block down near the frost plugs.
Niw either attach a hose to it and listen thru doctors stethescope or attach a lil mic to the copper tube andcrun the wire inside to a lil head phone amplifier. Listen with the head phones. Normal engine sound can be heard. Detionation can clearly be heard.
The lil mic/headphone amp l:stener alliws you to record the sound too.
I built one for abiut $30 using a hacked/McGivered Radio Shack personal amp listener..
All you are doing is removibg the internal microphone and remoubtibg it under hood onto the copper pipe transducer on the engibe block.
Run a extension mic cable (shielded audio cable) from the lil mic to the lil head phone amplifier. Keep the mic cable away from exhaust heat etc.

Get a friggin timing light. Does your light false trigger just at idle or does it stabilize when above 3000 rpm.
(No multi spark above 3000 rpm)
Where and how the timing light pickup is on the #1 spark wire matters.
With this you can hear the cylinder walls ring clearly from engine knock ping...
Splat splat splat! And not confuse with exhaust leaks and car rattles etc.

You glue the lil microphone to the copper transducer with epoxy glue. I glued mine to a decent aligator clip...

You can also use your smart phone to both listen and record the sound as a wave file.
You can hack McGiver a $15 smart phone head set with built in mic for this. Just steal the lil mic out of it and run a audio extenstion cable to the lil mic under hood.

[F-BIRD'88]

If the gas is old gas ,drain it and refill with fresh gas.
Yiu will damage that motor with old flat gasoline.

[hoodeng]

In the 80's when electronic ignition became standard on my area of work , some models would show spark scatter when setting the timing ,as it was electronic this was highly unlikely ,and proved to be. To correct the problem we were advised to use a Snap-on digital timing light and dial back a couple of degrees,worked every time, all you had to do for the final number was mark 3.5mm [in this case] along from the designated mark.Mind you a couple more degrees on a stock motor would sharpen things up a bit ,it wasn't till the 90's and dyno's become the standard tune tool that this would be the norm.A lot of timing problems on this product stemmed from the owners hearing some tune magic at 11pm in the pub and applying it to their bike the next day, it was nothing to see a timing pickup plate with screw cinch marks the whole length of the adjustment slot.[the photo is one i kept]

Another note on detonation ,when questioned about what a customer is hearing ,a lot will tell you the dets go away after 3000+rpm, this is usually not the case ,what happens is the dets go into an audible range your dog can hear and you can't.Dets happen over a number of degrees of rotation, as the engine speeds up the time the dets happen over shortens till you can't hear it.

Fresh tank of fuel and a process of pulling a few degrees at a time using the exact same load test each time will help to confirm or eliminate your concerns ,,,or if bucks allow a trip to the dyno.

Cheers.

[tresi]

If you want to tell if you're detonating pull your spark plugs. Look for purple/black fly specs.

[cv67]

The mark keeps on moving. Its been sitting for years will have to ck it again.
Timing light is a dial back, tdc is marked (fluid dampner I had on a 350 that never had that issue)its set at 0. Will have to check it once more.
perhaps its some goofy frequency the camera is picking up cause you sure cant hear anything in car. Motor has less than 100 mi on it.

[Olds455]

The keychain smacking into the dash between gear changes doesn't help.

That's the only thing I heard at 3 minutes and you can only hear it if you rewind the vid to around 2:55 and start from there instead of where it starts you from @3:04

[benno318]

one of my young customers new to racing was reporting detonation when running his race car on a test day - I was there so I got in and did a lap - well I simply could not believe it, the noise was as close to violent detonation as you would ever hear, but didn't correspond to throttle position. found that at certain places the gearstick would vibrate making the noise, and by holding it the noise went away. told the young fella well done, as that was exactly the noise he was to listen out for, but usually it would be responsive to throttle input.

[cv67]

DET cans using some ear defenders and have a real listen.

Explain please, never heard of it.
Didnt Jacobs used to have some kind of knock sensor deal with a light, or waste of time with a solid valvetrain?

Need an 02 sensor..keep suggestions coming. Gas (even with additive) is coming out, time to get some vp in it, retime & start over.
(and find somewhere to run it!!!)

I will say this timing mark thing is super irritating. Its not endplay, the oil pump etc and dont have $300 to buy a secret sauce timing light.
Had Bob Jennings rebuild a brand new dist, put it on a sun machine reads perfect...put it in the car and timing (scatter) persists.
My oil pump drive does not stand up straight when I pull the dist out (has the steel collar) could this contribute?

only reason I got this msd was due to a ton of overlap Id hope this would help prevent any fouling but woulndt buy one again .Rant off

[CGT]

The mark keeps on moving. Its been sitting for years will have to ck it again.
Timing light is a dial back, tdc is marked (fluid dampner I had on a 350 that never had that issue)its set at 0. Will have to check it once more.
perhaps its some goofy frequency the camera is picking up cause you sure cant hear anything in car. Motor has less than 100 mi on it.

I may have missed this, but your timing light, is it digital dial back?

[F-BIRD'88]

I have found that the Equus Brand INNova brand
Timing light with the mechanical/analog advance dial
Read correctly with msd ignitions and the advance works too. Do not buy the Electronic Digital Advance version.
This cheaper basic analog dial timing light is better and it works.