[Va68goat]

dataway,
Ok..... I can handle a bet (Great idea!!). For those that want to put a little money on it....I'm game! I don't want half of the proceeds though. I say winner takes all. Lets make it $10.00 a guess...I'll keep a list of participants. Losers send the money to me and I'll send the money to the winner. Whomever doesnt pay up gets called out on this thread. You have to be specific in your answer. Winners split the money!
- $10.00: My inexperienced / rookie guess is the flexplate. It's the only thing that hasn't been replaced or reconditioned by Paul on this build. I think the noise goes away after replacing the flexplate.


Holeshot71,
We didn't see any signs of a leak on the manifolds. No hint of carbon etc.

STEELCITYFIREBIRD,
I'm hoping to be able to work on the car this coming weekend. I will ensure we test what you suggested. I think thats solid advice. Thank you!

[Holeshot71]

Originally Posted by gtofreek

The brand new manifolds out of the box were warped BAD! When I set them on the granite slab, there was probably a .040" bow in them. This has been the case with most of these manifolds I have installed new. So we took them and surfaced the gasket surface until they were flat. The steel gasket should work fine with them. Out of the box I could see you having to use the Fel-pro blue header gaskets or some Remflex. After surfacing them, they were flat so there should have been no need for special thick gaskets.

What I meant by surface mismatch was the exhaust ports were not lined up with each other and the gasket didn't crush. I believe it was a corner of one of the end ports.

I'm not saying this is the problem, it's just something I came across on the 455 I just built and thought it might be something to check.

When I'm listening for noises I prefer to use a 3' section of 3/8" rubber hose, one end to my ear. It really helps to isolate surrounding noises and helps to pinpoint where a noise is the loudest.

[Sirrotica]

Originally Posted by Holeshot71

What I meant by surface mismatch was the exhaust ports were not lined up with each other and the gasket didn't crush. I believe it was a corner of one of the end ports.

I'm not saying this is the problem, it's just something I came across on the 455 I just built and thought it might be something to check.

When I'm listening for noises I prefer to use a 3' section of 3/8" rubber hose, one end to my ear. It really helps to isolate surrounding noises and helps to pinpoint where a noise is the loudest.

As you have come late to this post, On page 13, post # 249 I also suggested using a length of hose to pinpoint the source of the noise. Using a length of hose I'm fairly certain they at least will pinpoint the exact portion of the engine transmission assembly where it is coming from. I've been turning wrenches for close to 50 years and have used this method when other methods were inconclusive.


My post from page 13:

As long as you have the new balanced flexplate by all means install it. I really have little faith it's going to cure the noise though. I feel you're in the right area, but if the noise gets cured by changing the flexplate it would be some other issue other than a crack, such as too much run out touching something on the rear side of the engine.

I'm not sure if you've tried a stethoscope, or used a rod to listen for the noise, but it sometimes will point you in the right direction. One other thing I have used to listen to automotive noise is a 1/4 inch piece of vacuum hose placed in your ear, and moving the other end of the hose around to pinpoint a noise. This method is probably better for getting you in the area where the noise is loudest, than listening with a rod or a stethoscope.

Just thought of one more thing, the welded lugs on the torque convertor. I have seen an instance where the lug was fractured. The car was a race car, actually the middle picture in my signature, 67 GTO, so with open exhaust no telling if there was a noise or not. The lug actually finally pulled a section of the torque convertor out, and caused all the ATF to leak out and burn on the hot exhaust system. One of the tack welds on the lugs could have broken off and caused a noise from the movement. Not likely, but this isn't a common noise either.

Hopefully the crew will be assembled this next weekend, and the mystery can be put to bed. I'm sure everyone that has money and time invested will be exceedingly happy to see the noise corrected.

[dataway]

I don't think I can bet against flex plate.

But using my calibrated ear I'm hearing 5-6 beats a second, which would be 300-360 beats a minute ... or 300-360 rpm if a crank related, or 600-720 rpm for anything that would resonate every 2 revolutions ... cam/cam chain/fuel pump/exhaust/dist/etc. Although, flex plate could conceivably be reacting to the pulse from a single particular cylinder firing.

Va68Goat ... no fair taking the most likely cause first

[dataway]

Ok, I'm going off the deep end now (as if I don't have my own engine problems).

Extracted the audio from the video, ran it through a processor/editor.

Here is a 4 second clip .... this represents TWO SECONDS of the audio slowed down to 50% speed so it's 4 seconds long.

https://youtu.be/Vb2wNs5zQsU (just used a pic of my engine because you can't upload just audio to YouTube)

You'll count six pairs of clicks/knocks ... actually the full audio file exactly 2 seconds was 7 pairs. So we'll go with 3.5 pairs of clicks per second.

If Crankshaft related ... if each PAIR of clicks is a single event ... that would be 210 RPM - 3.5 x 60sec (unlikely). If each PAIR of clicks is two events that would mean 7 events per second, or 420 RPM still kind of unlikely.

Half Crankshaft speed (cam, exhaust, dist, lifter, timing chain etc.)
if each PAIR of clicks is a single event that would be 420 RPM
If each PAIR of clicks is TWO events that would be 840 RPM (more likely)

However ... obviously the clicks are not evenly spaced, you can hear them in PAIRS ... then a gap, then another PAIR. Sounds a lot like 2 out of 3 converter bolts tapping on something, but just doesn't seem fast enough to be crank related, or anything attached to the crank... that would be a steady, even click for every rpm. Engine sounds like it was idling at least 500 rpm. I have no idea ... maybe two cylinders leaking exhaust ... that doesn't seem likely. If I knew the exact rpm of the engine when the video was taken it would easier to narrow down the timing.

You will also notice, that in each PAIR of clicks, each click has a slightly different sound, again, what a person might expect from two different converter bolts tapping something ... but it's just not fast enough to be converter bolts I don't think. But ... with engine power pulses with each cylinder firing ... jeez, who knows what could happen with all that going on.

Below is a picture of the 2 second (expanded to 4) audio extraction from the last quarter of the video posted on page 11. Doesn't really tell you much as the clicks are kind of buried in the mix and don't appear to correlate with the spikes as far as I can tell. All you can really see is the quiet between Lopes of the the cam.

I should have been down in the shop working on my engine, but I spent a couple of hours playing around with this.

Update: Here is the sound slowed to 1/3 of original .... spacing of clicks sounds much more even. I time them about 0.15- 0.166 seconds apart. 360-400 rpm .... still too slow to be crank rpm ?
Don't let the lower pitch fool you into thinking it's a "Knock" ... it's not ... way more of a click.

https://youtu.be/hVk_SibKX0k

[JSPONT]

Originally Posted by dataway

Ok, I'm going off the deep end now (as if I don't have my own engine problems).

Extracted the audio from the video, ran it through a processor/editor.

Here is a 4 second clip .... this represents TWO SECONDS of the audio slowed down to 50% speed so it's 4 seconds long.

https://youtu.be/Vb2wNs5zQsU (just used a pic of my engine because you can't upload just audio to YouTube)

You'll count six pairs of clicks/knocks ... actually the full audio file exactly 2 seconds was 7 pairs. So we'll go with 3.5 pairs of clicks per second.

If Crankshaft related ... if each PAIR of clicks is a single event ... that would be 210 RPM - 3.5 x 60sec (unlikely). If each PAIR of clicks is two events that would mean 7 events per second, or 420 RPM still kind of unlikely.

Half Crankshaft speed (cam, exhaust, dist, lifter, timing chain etc.)
if each PAIR of clicks is a single event that would be 420 RPM
If each PAIR of clicks is TWO events that would be 840 RPM (more likely)

However ... obviously the clicks are not evenly spaced, you can hear them in PAIRS ... then a gap, then another PAIR. Sounds a lot like 2 out of 3 converter bolts tapping on something, but just doesn't seem fast enough to be crank related, or anything attached to the crank... that would be a steady, even click for every rpm. Engine sounds like it was idling at least 500 rpm. I have no idea ... maybe two cylinders leaking exhaust ... that doesn't seem likely. If I knew the exact rpm of the engine when the video was taken it would easier to narrow down the timing.

You will also notice, that in each PAIR of clicks, each click has a slightly different sound, again, what a person might expect from two different converter bolts tapping something ... but it's just not fast enough to be converter bolts I don't think. But ... with engine power pulses with each cylinder firing ... jeez, who knows what could happen with all that going on.

Below is a picture of the 2 second (expanded to 4) audio extraction from the last quarter of the video posted on page 11. Doesn't really tell you much as the clicks are kind of buried in the mix and don't appear to correlate with the spikes as far as I can tell. All you can really see is the quiet between Lopes of the the cam.

I should have been down in the shop working on my engine, but I spent a couple of hours playing around with this.

Update: Here is the sound slowed to 1/3 of original .... spacing of clicks sounds much more even. I time them about 0.15- 0.166 seconds apart. 360-400 rpm .... still too slow to be crank rpm ?
Don't let the lower pitch fool you into thinking it's a "Knock" ... it's not ... way more of a click.

https://youtu.be/hVk_SibKX0k

Damn nice work! Yes I tend to think converter bolts, or like I said before, flex plate bolts a little to long and sticking thru the back of the crank.

[dataway]

Note that even slowed down that much it's a distinctive click/tap ... not a scraping sound. Slowed down that much if it was a scraping sound it would end up as a hiss. This sounds like a relatively small part, tapping something for a very short period of time.

Who knows how the timing gets screwed up taking the video, pulling the sound file, processing it ... if my timing is in error and the taps are closer to 0.12 seconds apart... it could mean an rpm closer to 500-525 .... so possibly crankshaft speed. Again, not knowing what the RPM was in the video makes it tough.

Besides the tap ... wonderful sounds coming from that engine, the sound of an engine that has all the right pieces in it.

[400 Lemans]

I think its a leak at the head pipe where it is attached to the manifold. Sounds just like when the donut gaskets would start going bad on the older cars.

[Squidward]

I can't believe Dataway's Audacity! The nerve of some people...

[dataway]

Originally Posted by Squidward

I can't believe Dataway's Audacity! The nerve of some people...

Pretty nice piece of software .. FOR FREAKIN FREE

[promptcritical]

Like Jonesee in Hunt for Red October. Magma displacement...not.

[Va68goat]

Holeshot71,
Would there be any evidence of residue on the manifolds itself?

Sirrotica,
I'm hoping to have the car on my buddy's lift this weekend. I'll make sure we do some testing before we just replace the flexplate. I like that idea of using a hose to listen for the noise. I used my buddy's stethoscope and it was a little deceiving because of the vibration with the car running.

dataway,
Thank you for taking the time to do all of that...that's some CSI stuff. Hahahaha. I will share this information with the guys working on my car this weekend. This is great information. Thank you again.

[TedRamAirII]

Originally Posted by gtofreek

I seriously doubt that unless it's external.

I hope it is too. I hear a "double tap" and I dont think there is anything else that can cause it. Especially after the converter bolts have been checked/verified. I would think if its flex plate related, you would see some sign of a crack, like a rusty spot or be able to push or pry on the plate in a way to make a noise.

["QUICK-SILVER"]

Is the oil filter by-pass (in the filter adapter) still intact and functional?
IMO As it should be for a street car.

And why do people keep posting "no metal in oil"? Where is that info coming from?

Wish all the videos were back up and people would try to cypher through relevant posts and pictures by the OP and the hands on folks that have been helping him.

Also, while this car is in the air...please check crank end-play and turn the engine by hand to feel for that loud clunk clunk that happens when the engine gets cut off.

Tryin' to be nice
Clay

[Va68goat]

QUICK-SILVER,

This is the oil filter that was on the car when I received the motor. The oil wasn't changed after being on the dyno. To make it easier on everyone helping me...When I get home tonight. I will repost all the videos and pictures on one thread.

[dataway]

Here is the sound sample cleaned of 90% of the normal engine noise, with mostly just the tapping left.

Gotta say ... if the tap is crank speed the engine was running at 320 rpm ... which I don't think is likely.
If the tap is at half crank speed .... rpm 640 ... far more likely.

I'm going with something turning or firing at half crank speed.

This sample is running at 50% of real speed.

https://youtu.be/44IBBGRU3VM

[Va68goat]

dataway,

What does that mean? "turning or firing at half crank speed." What causes that?

I just got home and I'm going to post the videos from when the motor was first started to the last few tests that were conducted.

[mgarblik]

I'm hoping to have the car on my buddy's lift this weekend. I'll make sure we do some testing before we just replace the flexplate. I like that idea of using a hose to listen for the noise. I used my buddy's stethoscope and it was a little deceiving because of the vibration with the car running.

Something the guys helping you can try. If the stethoscope is too sensitive and they are hearing too many other sounds, have them insert a 2" piece of small vacuum tubing over the end of the stethoscope probe end. The vacuum tube will filter out lots of the outside noise and let them zero in on the knock much easier. Hope this helps.

[dataway]

Half speed would be anything turned/moved by the camshaft, or anything triggered by a cylinder firing. Camshaft turns at 1/2 crank speed, as does cam sprocket, distributor, fuel pump, oil pump. Also ... an individual cylinder fires at half crank speed (every other revolution of the crank) ... so for instance an exhaust leak at the exhaust port would "sound" at 1/2 crank speed. Or anything trigger/vibrated by the power pulse from an individual cylinder would "sound" at 1/2 crank speed.

However, with all the resonant vibrations that take place in a V8, numerous things can imitate these different sounds. Exhaust can be very tricky as the various exhaust pulses combine in the manifolds and do strange things.

It sure sounds like something in the flex plate/converter area, but the tapping just seems too slow for that. However add some resonate vibrations and there could be something on the flex plate that only "sounds" every other revolution, despite the fact that it turns at the same speed as the crankshaft.

In other words ... I have no idea what it is But I'm extremely curious.

[Va68goat]

- 1st start:
https://www.youtube.com/watch?v=kHLshwwe-Tc

To make this easier, you can just look at the videos under my (Joe Crespo) that is associated with the above video. I think I made them all "public"