I need a set of ears, long post and not a normal noise

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My427stang
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I need a set of ears, long post and not a normal noise

Post by My427stang »

So engines come and go, but this one doesn't want to leave my engine stand. Worst part is, the customer is a deadbeat....me, it's in my own F100.

This engine is a 445 inch FE, scat crank, solids, probe pistons, all new at build, has a ticking noise that sort of sounds like a loose rocker on a stud type rocker, but improves when hot and doesn't care what i do to the valvetrain, I have been working on it for literally years and I haven't found the noise yet, despite 2 full tear downs and that is to include some good old fashioned, hate to admit, dummy type part replacement.

I have three videos, first is just to give you the idea of what idle sounds like, nice and quiet. The next two videos I will try to point out the noise using the time in seconds on the video

Quiet idle - https://www.youtube.com/watch?v=Uf3D5c9ZZfs

So far, in search of this noise, the truck has had countless ears on it, and keep in mind, I have two of the best ears I know, especially on FEs and this truck I have owned and built/rebuilt for near 30 years. It has had acoustic tools on it, all valve train replaced at least twice and parts taken off used elsewhere successfully, the engine was re-blocked (built it loose and though maybe piston slap).

Different valve covers, cam, lifters, pushrods, rockers, crank magged, different clutch assembly and flywheel, fuel pumps, water pumps, timing sets, balancers, even had the heads magged to see if we could find a broken guide that wasn't showing up by eye. Pistons measured and remeasured, but never zyglo'd (new Probes when this started, still look new). and, furthermore, all bolt on parts are on a temp replacement bench build engine that is in the truck (flywheel, clutch and all the front of motor, alt, PS, etc)

The key is, the noise is NOT there at idle, makes MOST noise cold, get quieter hot but is still there, but I can find no evidence of anything that would make the noise, seems worse under initial light load, but truck is real strong and when you put your foot into it, it revs real quick and ois likely still there but loud pedal makes it harder to hear. Definitely quieter when hot though

Please listen to this video and focus on "tapping" , noise happens under light load at :29, :45, :50-:52 and 1:08 ignore the grind you hear at the end, 1:22, my daughter leaned on the transfer case shifter while filming

https://www.youtube.com/watch?v=gnSd_lMyFNM

Here is a second video. shorter, :06, :16, :26

https://www.youtube.com/watch?v=VlHIl9hafYA

Now, if I had to sum this up, all that is left, a piston with a crack, likely in a pin boss, but I have it apart now and no evidence (I am going to Zyglo all the pistons) or something in the head casting itself, it had iron guides put in by a reputable porter and the heads were magged.

Any ideas? The replacement bench build runs so nice and quiet, but this isn't a cheap garage decoration and I hate to throw more at it without logic

Some things to keep in mind, absolutely nothing like: adjusting the valves wrong, or fuel pump or rockers hitting valve covers or baffles or bad fuel pump, it's got to be something a bit unusual, lot's of times inside and all replacement parts have gone to live happy lives :)

Thanks
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Re: I need a set of ears, long post and not a normal noise

Post by n2xlr8n »

I had a side oiler long ago that sounded like that.

It was the oil pump drive rod rattling- I replaced both it and the oil pump and it went away.
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Re: I need a set of ears, long post and not a normal noise

Post by My427stang »

n2xlr8n wrote: Mon Feb 19, 2018 3:26 pm I had a side oiler long ago that sounded like that.

It was the oil pump drive rod rattling- I replaced both it and the oil pump and it went away.
Interesting, I'll take a look, it has an aftermarket pump drive and a Melling M57HV, and that is one part I would not have suspected but if it was hitting something it should have left a mark. Distributor moved to bench build, so it would have to be the bottom side or shaft itself making noise
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70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
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Re: I need a set of ears, long post and not a normal noise

Post by grant6395 »

Sounds like a" forged piston rattle" to me. Collapsed( slightly) skirt maybe?
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Re: I need a set of ears, long post and not a normal noise

Post by Casper393W »

Have you pulled one plug wire off at a time to try and isolate it to one cylinder?

I had a engine one time that came in my shop it was a 4.6 2v in a mustang. It sounded like it had a rod knocking on the 3 cylinder.... Pulled the engine down and couldn't find anything that look to be the cause of the noise. I put a new rod on that piston and new bearings got it running and guess what the same noise was on the same cylinder! I took it back apart and replaced the piston..even though it looked perfect my guess is it had a crack in the pin boss area..

I wish you luck! Hopefully it is something simple
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Re: I need a set of ears, long post and not a normal noise

Post by MadBill »

Maybe it's my low-grade speakers, but I really can't hear any abnormal engine sounds. There is an erratic tick, but it sounds like it's from the passenger compartment.
However FWIW, a 380" SBF engine (squeezed into an 8.2" block) I was helping assemble had a regular clunk that we traced to a little flashing on a couple of counterweights contacting the bottoms of some pistons...
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Re: I need a set of ears, long post and not a normal noise

Post by kimosabi »

I have the same sounds at cold start up. Goes away when hot and it's my forged pistons slapping a little before everything is warm and nice. I have 1.125 pin height Mahle 3.75 crank.

Did you check piston to wall clearances? Mic the bores and pistons?
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Re: I need a set of ears, long post and not a normal noise

Post by mag2555 »

Sounds like piston slap to me!
I had a Olds 350 once that was doing that.
I had rebuilt it with its stock Bore and stock size cast Pistons, and all of the Pistons had the same tad loose Bore clearance and after racking my Brain on it for months with it I came to the conclusion that due to water flow pattern in the block the one cylinder with the noise was just warming up faster and in turn expanding faster then the piston.
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Re: I need a set of ears, long post and not a normal noise

Post by My427stang »

Thanks everyone.

As far as your questions, I re-blocked the motor because I had it real loose the first time (from memory, .0075), knowingly built that way, as I needed a tight block for a customer engine and hadn't had a lot of negative experience with piston slap before. So I figured that was my noise, clearance at assembly with the second block was right at .0045, no measurable taper and exactly where Probe said they wanted it. No change in noise. Last time I mic'd all pistons (actually every time, but first time was just to have bore gauge reference, next round was measuring at multiple points looking for damage) and saw nothing that didn't match the others, but I had some other things to do this weekend and didn't mic them since I tore it down this time.

It's likely got 500 miles on it and hard to tell, but I think it may have gotten a bit louder, or I am tuned into it now, so I will look for indicators again.

As far as pulling one wire at a time, great recommendation, I was hoping I could do something like that, but at idle there was no noise. I even went as far as pulling a wire and I have an old clamp-on spark plug that I picked up somewhere to check for spark and moved it from wire to wire and took it down the road, but it was inconclusive, truck got warmer as I did it, and no single cylinder gave me a dramatic change I think because of that.

I will measure a couple points on the skirts, see if I can see any trends, and I will likely have the pistons Zyglo'd, (as well as looking for something hitting near the oil pump) but seems like everyone keeps coming back to pistons, which seems logical to me too

These are Probe SRS 14785 pistons, I had never used them before, but they are 4.08 bore, 17.5 cc reverse dome, 433 grams, 1.33 CH, 2618-t61 forged, I usually run Diamond in my strokers and they tend to be silent, even cold, but run tighter at .0025 on the street and are made from 4032.

Could that noise be as simple as the material with the clearance at .0045? It seems pretty loud to me, and I used to run old loose TRWs at up to 10 thou clearance on old bone 427s and never heard a ticking like that, modern Speedpro forged are 4032 as well, but what about the old TRWs that we had to run real loose? Of course 427s had quite a bit more compression height/taller piston too

FWIW, SCAT FE cranks were known for a couple runs to have a counterweight hit the piston, I have close to .250, can't imagine anything happening there. I looked for rod to cam clearance, just seems wide open, and I have never seen any cam interference on an FE stroker but I will keep looking and report back. Thanks!
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70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
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Re: I need a set of ears, long post and not a normal noise

Post by MadBill »

Since it's coming apart yet again anyway, why not try L2L's abradable coating? https://www.line2linecoatings.com/ At 0.008" +, my aluminum BBC had piston slap cold and hot. I had it deck plate honed to +0.005" and coated to ~ 0.000" and fully expect a huge improvement when I get it running again.
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Re: I need a set of ears, long post and not a normal noise

Post by DanE1 »

In 1973, I had a 460" 427 MR FE (.060" overbore with a .2" stroker crank) in a 1960 F100 SB that was set up for the power. Upon firing it up for the first time, there was a noise that sounded like a rod. Couldn't believe it. So, out came the engine and disassembled. One rod was just barely touching the windage tray as it cycled. One little hit with the hammer to the windage tray and problem solved.
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Re: I need a set of ears, long post and not a normal noise

Post by 77cruiser »

Have a windage tray? My 385 sbc had a similar noise never could find it, but 1 rod was just touching the windage tray.
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Re: I need a set of ears, long post and not a normal noise

Post by cjperformance »

With good headphones connected to watch your videos i will say 101% that you have piston slap- a lot !
I can hear it right from the get go.
Sometimes you can quieten excess clearance slap by backing the ignition timing down a few degrees, this gets the piston hotter and sees less cylinder pressure over TDC and will quieten the rattle for test purposes only!!
Report back with accurate piston to bore clearance and pin clearance in piston and rod small end.
What did probe reccomend for those pistons?
Do you have a vacuum advance unit hooked up?
What initial and total timing?
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Re: I need a set of ears, long post and not a normal noise

Post by rfoll »

I have had bad piston pins sound similar, also a set of main bearings that were out of spec for the advertised size and it sounded exactly like that.
So much to do, so little time...
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Re: I need a set of ears, long post and not a normal noise

Post by My427stang »

cjperformance wrote: Tue Feb 20, 2018 6:52 pm With good headphones connected to watch your videos i will say 101% that you have piston slap- a lot !
I can hear it right from the get go.
Sometimes you can quieten excess clearance slap by backing the ignition timing down a few degrees, this gets the piston hotter and sees less cylinder pressure over TDC and will quieten the rattle for test purposes only!!
Report back with accurate piston to bore clearance and pin clearance in piston and rod small end.
What did probe reccomend for those pistons?
Do you have a vacuum advance unit hooked up?
What initial and total timing?
I will check clearance again, hope to get to it tomorrow, but been a busy week and I want to do when I can go slow and give it the attention it deserves

When it went together last time clearance was .0045, that was Probes recommended spec with the pistons, however, for my bore size it says minimum .003, max .007. I do have wear marks on top and bottom of every bore, I will take pictures, leads me to believe things are moving around

I doubt it's a pin clearance issue, they feel real good but I will measure.

Initial is 14, total is 36, vac advance limited to 10 degrees on ported vacuum Of course though the engine is out and down to bare block with the crank hanging in it

These pistons do not have an offset pin either, but Fords typically can go either side for both old school forged and cast, so I'd be surprised.
DanE1 wrote: Tue Feb 20, 2018 5:16 pm In 1973, I had a 460" 427 MR FE (.060" overbore with a .2" stroker crank) in a 1960 F100 SB that was set up for the power. Upon firing it up for the first time, there was a noise that sounded like a rod. Couldn't believe it. So, out came the engine and disassembled. One rod was just barely touching the windage tray as it cycled. One little hit with the hammer to the windage tray and problem solved.
77cruiser wrote: Tue Feb 20, 2018 6:39 pm Have a windage tray? My 385 sbc had a similar noise never could find it, but 1 rod was just touching the windage tray.
I do run a windage tray, but have had it in and out, no difference, that being said, I'll set it on there one more time and look, can't leave a stone that's been turned already unturned :)
Bullock's Power Service, LLC
Plattsmouth, NE
70 Mustang, 489 FE, TKO-600, Massflo SEFI, 4.11s
71 F100 SB 4x4, 461 FE, 4 speed, port injected EFI, 3.50s
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