[torqhead]

Originally Posted by 69 Limelight

I don't see how what I'm about to submit could possibly be because it was gone over by builder and went through dyno cell but, is there any possibility that the cam is ground with a 7-4 swap and therefore the firing order would be 18736542? The cam I currently have is a 7-4 swap and if I hadn't asked when I ordered it from cam company I wouldn't have known. No where on cam card or paper work does it say such.

Back on posts 719, 720 & 730 the posters are confident it's spark knock and proper timing would get rid of knock.

At this point seems like everything has been checked and something's double and triple checked as well as a lot of parts replaced and money thrown at it by owner and not much left so I'm throwing it out there. 18436572 firing order when it should be 18736542 would certainly make it shake and run rough like it does.

I thought of this earlier in the string, but I would think the builder would have that on the build sheet and assumed it would have been brought up by now. Anyway at this point, good to bring up everything!!! Reminds me of a pontiac motor I helped someone with recently it was popping out the exhaust regularly. It had two plug wires swapped.

[Va68goat]

This is the build sheet that I received.

[Sun Tuned]

Pulling plugs and have a look see might be good.

We've fooled with way more engines up the street in the last two years than I care to count. If I understand correctly this engine went back and was "held hostage" for how long?

The missing thing is what I'm zeroed in on right now. It looks the same as at least 4-5 cars we've worked on I can remember lately. All had same issue. Somewhat stale gas sticking valves. One in particular,a yenko 427 stuck two and bent a valve and tagged the edge of another.

This engine have bronze guides in it?

Any chance the gas is same age as how long it took to get engine back the second time??

Let's let the ignition thing be for awhile and look at some plugs.

See the deal with stale gas or gas that is starting to go bad is it may not smell. It will go back to its paragon base the older it gets. My dad demonstrates this to customers in this way...

He will pour about a half cup on shop floor and light it. The flame will if it will burn at all will have what looks like an acetylene smoke rising off the top.

This soot is not good at all.

The fresh stuff quickly goes poof and scares the hell out of everyone standing there. No acetylene like soot off of it.

Very direct and understandable.

Maybe I'll get an answer before I can't access site again, been messed up for a few days on my end.

[Sun Tuned]

Not paragon base, stupid spell check, I meant "Paraffin base"

[Sun Tuned]

My guess on the other is that the bushing in original msd has crapped the bed and a bunch of that debris went through the bearings and the oil filter mostly through the bearings. That's what I would say happened first.

Bottom bushing should not have trashed itself that fast.

I saw that deal here not but 6 months ago on a friends 455.

[HWYSTR455]

Originally Posted by gtofreek

….I pulled the distributor when I got the engine back from dyno. I checked the busing which was fine and I restabbed the distributor BUT had no way of setting the timing. That is why I wrote on a piece of tape on the carb plate that the timing needs to be reset. It was only close enough to get the engine to start and run.

You need to get the idle RPM up and not down at 400-500 RPM. That's just ridiculously slow for an engine with this much cam in it. I only hear the knock at this really low idle. Pick the idle up, set the timing as I wrote on the tape, and disconnect the vacuum advance for the distributor and plug the vacuum port on the carb., then see if the noise is still present. I bet it won't be there.

.

Ok, this makes a lot of sense, there was a discrepancy of whether the timing was set and ready for starting as shipped.

Sorry I haven't posted, biggest reason was I was unable to get in until tonight.

When I visited Thursday, first thing I did was pop the driver's valve cover, turned the engine over by hand, watched the #1 intake open, close, then brought the balancer zero mark up to the 12 on the timing cover. Then popped the distributor cap, and viewed the orientation of the rotor. It was half way between the #1 post and the #8 post, so I would say it was around 15-20 degrees advanced or more.

So I squared the rotor with the #1 post, put the cap back on, removed the IGN 12v wire from the + coil side, and ran a wire directly to the batt. Attached the timing light, and to get it ready to start.

Then I checked the carb, made sure the idle speed screw was about a half a turn or so from where the butterflies were closed, checking the screw I could see where it was lifting off the arm, made it to where it just touched, and added the half or so turn.

Then I went on to the idle mix screws, found all were different, one was like an 1/8 or less from being closed, one was about a turn and a 1/4, the rest were in between. I set them all to 3/4 of a turn.

It ran slightly rough when it initially started, but smoothed out some with a little run time. It was idling a little high, but it idled, revved freely, but still had an occasional miss. Let it reach operating temp, checked water temp and oil psi, it was fully warmed up, @ 185 degrees, had about 45-50 psi at idle, and to me, the knock was much less pronounced, and really felt it was only the typical crower rocker sewing machine type noise.

Joe mentioned it was idling high, so I turned it down some, which later he said after checking was about 1050. (I was not there for that). We shut it off, and for grins, we put the original IGN wire back on the coil +, and started it again. We didn't let it run long that time, but it appeared to not be affected by the original wire. I did notice though that there was a wire spliced into it, and I commented that it should be a dedicated wire, and to consider correcting that.

Since it still had an occasional miss, I suggested if it continued to have that miss, to change out the plugs, and if it still missed, to change out the wires. Also mentioned that it of course will require some additional tuning, idle mix, advance curve, etc, once he has the miss taken care of.

I was satisfied with the results, and felt the original 'knock' had subsided, but due to the high idle, he felt the results were inconclusive. Since we didn't have a tach, I suggested he have it checked before making any other changes, and if it was high, turn the idle speed to 850-950, due to the size of cam.

Joe, maybe for comparison purposes, post the vid of that day? That may help if others can chime in and determine if it was just drowned out or masked by the idle speed.

.

[aceaceca]

I have followed this thread for some time. It just dawned on me you could have an idle circuit that is dead. My AFB four barrel car developed a knock at idle out of the blue. I was stunned as the engine had been fine for a long time. The knock was loud enough to be very disconcerting. After much fiddling I determined that one circuit of the carb was not functioning. You know this when a mixture screw does nothing. I swapped a different carb on there and presto, the knock was gone. To be frank, I was bloody amazed. After all these years you think you have been there and seen everything related to rogue engine problems. Not so. Keep on learning.

Another give away to non functioning or way too lean idle mixture is that you have to turn the idle speed screw way in to keep the thing running. To such a point that the venturies start to drip fuel to run the engine. When you see the dripping venturies you think the floats are too high or the needle and seat is not working. When you eliminate that probable cause, you are back to non functioning idle circuits or ones that are too lean for the engine combo. Been there done that on my new tripower set up. Just drilled the air feed and fuel feed locations on the idle circuit but have not lit it off yet.

You also need to be sure your throttle linkage has enough travel to enable the butterflies to fully close. If you do not, the carb will stay on part throttle operation and not go onto idle circuit.

[TedRamAirII]

Just thought of something. Pull the distributor, and watch the cam gear as someone is cranking the engine over. it could be out of round, and the noise you hear is the oil pump shaft hitting the hole in the block. For sure check the lower distributor bushing , see if its tight or loose again. I know Paul checks the cam for being straight, but I doubt he would check concentricity of the gear. Maybe the gear isnt cut right, like one of the grooves not deep enough. Really look the dist gear over and see if its worn abnormally.

[Va68goat]

Sun Tuned,

When the motor was first delivered several years ago, I literally stopped by the gas station on the way to where my car was, got fresh gas and put it into the brand new gas tank, started it up and the knocking noise was present. The knocking I hear now sounds exactly the same. The gas that is in the tank now was put in the tank right before the motor was last sent to Arizona.

HWYSTR455,
Here is the video when you were over at the house-
https://www.youtube.com/watch?v=LqcT7q1UKFY

Here is a video when the idle was brought down-
https://www.youtube.com/watch?v=RUnO9Fwj0qQ

Here is the video of the first start-
https://www.youtube.com/watch?v=kHLshwwe-Tc

The knocking noise can't be heard as well with a high idle. A higher idle masks the noise but it can still be heard. If this is a ignition issue, plugs, plug wires etc why wasn't it heard on the dyno the 4 times it's been on the dyno. When using a listening device, we get a signature at the distributor...again. That makes me believe that the distributor bushing is the result of another problem that wasn't discovered.

1) Why has the knocking noise been the same for two years? Even after changing the rockers, lifters, push rods, flex plate, thicker oil, heads inspected?

2) If the plugs, plug wires are suspect, why couldn't the knocking be heard in Arizona on the dyno?

3) If the distributor bushing was the source of the knocking noise, why was the bushing replaced and it's still sounds the same?

Believe me...I hope it's an ignition issue but to me and most of the guys that have helped me with this car, it doesn't make sense. These are the same plugs that were just used on the dyno..actually they are the plugs that were in the car when the motor first started. Same thing with the wires. I'll get some plugs and try that but replacing new parts with new parts is going down the path that I went through before.

[HWYSTR455]

Listening to the vids is diff than being there, but yeah, I still hear it in the second vid.

It still sounds like a rocker to me, and it's a noticeable miss. It's like it's resonating under the cover. It seems more localized now, but maybe I'm mistaken, but it sounds like it's focused on that #8 & #6 cyl area.

Hm. Well, process of elimination, make sure the ignition is right, try the new distributor and plugs, maybe pull that #8 and/or #6 wire, see if it changes. If it doesn't change when pulling the wires, maybe it is still something with the dizzy.

.

[Va68goat]

HWYSTR455,

We know it's not the rockers because the rockers were replaced and the same noise is present. Yeah..we'll recheck ignition next and even try another distributor. It would be hard for me to believe that the distributor could be the culprit because it was knocking prior the the damage being discovered to the bushing. If the bushing or distributor are damaged now, I would assume it was caused by something else. Paul just inspected the distributor, had the bushing fixed and the knocking is still present. Again, I hope it's an ignition but it doesn't seem possible.

[Scott Stoneburg]

Ok. I'll chime in. This has probably been checked too but just for redundancy sake.
1-What rockers are being used? Both initially and now? With poly locks?
2-what's the installed spring height? Stock or increase cor cam lift?
3- are you running spacers under those valve covers?

[Baron Von Zeppelin]

There used to be select machine shops that had an electric powered run-stand for new engine break-ins. The electric motor turned the engine for whatever length of time at selected rpm's. One of these would be your ultimate diagnostic venture.
IF the last of your in-car tests do not provide the answer.

These may have dinosaured out of existence. idunno
Floor space takes priority over machinery that gets seldom use.
Motor Supply Co. of Greensboro,NC used to have one - but they are no longer in business.

Someone else in the Greensboro area may have that machine now.
-- Or know of where one might still be in use.

DR. BO machine shop in downtown GSO - (336) 275-5883
(BO was the Head Man at Motor Supply machine shop for decades before it sold out to CarQuest - and then started his own place).
Bo's son runs it now.

Performance Enterprises /Alfred Williams machine shop on East Wendover Ave in GSO - (336) 621-6572
I think Alfred's son is probably running it now.

Would be 2 good sources of contact if you can't locate anything in your area of VA.
If they don't have the machine - they might know who does.

[HWYSTR455]

The rockers were replaced due to incorrect poly locks that were contacting the rocker body on the sides of the slots, and the replacement ones used were Crower stainless.

Yeah, I wasn't suggesting the rockers were 'bad', I was simply stating the noise sounds like rocker noise, which can be caused by a number of reasons.

.

[chiphead]

In latest vids, it's a little "heavy" a noise to be just rocker clicking. If it was just valvetrain noise, I'd say "run it". It does sound like it's in the rear of the motor/engine bay area.

My vote is piston slap. Does noise decrease after engine fully warms up? My motor made a similar noise when cold. I was at .0055" with 2618 alloy Ross pistons. It would click and "double knock" when cold. Noise would mostly go away when warm, but I'd hear it at idle if I listened closely. I ran that motor HARD for years and never had an issue with the pistons. Is your motor really at .0047", which is what the build sheet calls out? That would explain why the issue has never been found. Same pistons, same bore size, same clearance, same noise. Just about every part in the engine has been examined or replaced except for the piston skirt clearance, right?

In the video, you come around the driver side near the end of video. I hear a "double knock" sound at the 13 to 16 second mark, that sounded exactly like my motor.

What alloy pistons?

[gtofreek]

Originally Posted by TedRamAirII

Just thought of something. Pull the distributor, and watch the cam gear as someone is cranking the engine over. it could be out of round, and the noise you hear is the oil pump shaft hitting the hole in the block. For sure check the lower distributor bushing , see if its tight or loose again. I know Paul checks the cam for being straight, but I doubt he would check concentricity of the gear. Maybe the gear isnt cut right, like one of the grooves not deep enough. Really look the dist gear over and see if its worn abnormally.

Good thought, but I do check this also when I check the cam for bent. This cam only had .001" runout. Most cams I see have .002"-.003" runout and they have never been a problem.

[gtofreek]

Engine does not have a 4-7 swap cam in it. If it did, it never would have made 540 HP and 570 ft. lbs. missing like it is now.

[John Milner]

Originally Posted by chiphead

In latest vids, it's a little "heavy" a noise to be just rocker clicking. If it was just valvetrain noise, I'd say "run it". It does sound like it's in the rear of the motor/engine bay area.

My vote is piston slap. Does noise decrease after engine fully warms up? My motor made a similar noise when cold. I was at .0055" with 2618 alloy Ross pistons. It would click and "double knock" when cold. Noise would mostly go away when warm, but I'd hear it at idle if I listened closely. I ran that motor HARD for years and never had an issue with the pistons. Is your motor really at .0047", which is what the build sheet calls out? That would explain why the issue has never been found. Same pistons, same bore size, same clearance, same noise. Just about every part in the engine has been examined or replaced except for the piston skirt clearance, right?

In the video, you come around the driver side near the end of video. I hear a "double knock" sound at the 13 to 16 second mark, that sounded exactly like my motor.

What alloy pistons?

I bet you are right. I've set some forged pistons up around .005" and have had some make a noise similar to that. They also ran very hard. I have no idea what these particular pistons call for as far as clearance but if I was building a 550-600 horse engine I would want it set up on the loose side. A 550-600 horse 455 engine won't ever sound like a stock 455 engine.

I still think I would get the miss and timing figured out and run it to see how it does.

[gtofreek]

They call for .0045"-.0055" clearance. I originally set them up at .0045", It's been lightly honed now twice so it is now around .0047"-.0048" I can guarantee it's not piston slap. It would need .006"-.007" before you would really start to hear anything loud. Piston skirts still measured really good this last go round.

[Region Warrior]

Just came on board here.
The idle vid sounds just like what happens(but not near as bad) if an n2o system is activated on fuel side only.
Like really bad spark knock...