[cdrookie]

Originally Posted by abefromen

It's interesting that you replied here because I never said who did the work.

No worries though. Like I said in my email to you, after it's torn down and everything measured I will update this thread with what is found be it good or bad.

What's interesting is he only did the short block and I don't remember you saying that you did, or had done, the whole rest of the engine. Since you are going to tear it apart, why not do it in front of Calvin? You can measure everything with your calibrated mics and bore gauges, and let Calvin use his. It sounds like you're close enough not to do it that way. And with him posting here, letting everyone know he built this short block, sounds like he's confident in his work.

[abefromen]

Not sure yet.
I've taken a break from everything for the time being.

I also never said I was the one who is going to tear it apart. It may be an impartial shop who doesn't have a dog in the race.

[lust4speed]

To be blunt, some of the advice tossed out above is terrible. Won't pick on anyone but a lot of it sucks and is totally incorrect. So let the reader sort through the advice carefully.

If there is garbage in the oil - is it from a seasoned engine builder that only built out the shortblock, or might it be from the heads or more likely a poorly cleaned used valley pan? Engine is the sum of its parts, and any one of those individual parts can cause problems.

Forged pistons at operating temperature do not slap at .005" cold clearance. Included is a section of the spec sheet from my order of Ross pistons last month calling for .0045" clearance. Ross knows the expansion characteristics of the aluminum alloy they use and what clearance is needed, and the same for other piston manufacturers. Both the forged piston with larger cold clearance and the stock cast with tight clearance will have the same piston/wall clearance when at operating temperature.

Just because an engine has a small cam doesn't mean that piston temps are going to be low. That small cam, higher geared axle ratio, and low RPM grunting up a grade on a hot summer day will have very high combustion temperatures. Hotrod engines bleed off a lot of combustion heat that stays trapped in more conservative builds. That's why longer duration cams are recommended to ward off detonation - and detonation is nothing but excess combustion temperatures. Set piston to wall clearances too tight and you might be in for an abrupt stop up the next long grade.

[1969400HO]

A lot of things said are from ppl that built engines professionally, seen as much as any big names person in any car race industry the last 50+ years too!
Or been next to it to see also.
I work in HIGH TECH indusrtry, and troubleshoot FAR beyond basic car engine dynamics and read it all here, it all posts is things to ponder look at and about any point CAN easily be correct and cause “collateral” issues. Masking other “root cause” issues.
What Always is the issues ppl have never really lived the dynamics so their confusion about it reigns supreme usually in the opinion poles until ppl open the thing up and find what was said THAT 95% of the time is right.
“what point:” did it begin to fail from!
Sometime everything is so destroyed its a mystery!!
What I post and also read comes from probably a thousand engine rebuilds, troubleshooting and diagnosis. And I was 100% right on everything I posted at some point.
ROOT cause could be Dozens of different things! or more!! Easily.
I can always tell when ppl have NEVER ever been in a machine ship to realize all that can occur and does.
I loved it when ppl broughT in a crank, That got so stinkin HOT it was BLUE half way to the other end then said “Oh i only “just started it it up and turned it right OFF”.....

[geeteeohguy]

Originally Posted by 1969400HO

A lot of things said are from ppl that built engines professionally, seen as much as any big names person in any car race industry the last 50+ years too!
Or been next to it to see also.
I work in HIGH TECH indusrtry, and troubleshoot FAR beyond basic car engine dynamics and read it all here, it all posts is things to ponder look at and about any point CAN easily be correct and cause “collateral” issues. Masking other “root cause” issues.
What Always is the issues ppl have never really lived the dynamics so their confusion about it reigns supreme usually in the opinion poles until ppl open the thing up and find what was said THAT 95% of the time is right.
“what point:” did it begin to fail from!
Sometime everything is so destroyed its a mystery!!
What I post and also read comes from probably a thousand engine rebuilds, troubleshooting and diagnosis. And I was 100% right on everything I posted at some point.
ROOT cause could be Dozens of different things! or more!! Easily.
I can always tell when ppl have NEVER ever been in a machine ship to realize all that can occur and does.
I loved it when ppl broughT in a crank, That got so stinkin HOT it was BLUE half way to the other end then said “Oh i only “just started it it up and turned it right OFF”.....

???? I think teardown and inspection of the OP's engine will show excessive clearances which are causing his noises. Simple as that.

[tom s]

If I was the builder I would want to be the guy to listen to and check the engine before being pulled and would insist I would be the one to open the engine.JMHO,Tom

[NeighborsComplaint]

Originally Posted by lust4speed

Forged pistons at operating temperature do not slap at .005" cold clearance. Included is a section of the spec sheet from my order of Ross pistons last month calling for .0045" clearance. Ross knows the expansion characteristics of the aluminum alloy they use and what clearance is needed, and the same for other piston manufacturers. Both the forged piston with larger cold clearance and the stock cast with tight clearance will have the same piston/wall clearance when at operating temperature..

Depends on the piston's construction and alloy. Venolia, for example, calls for .010" clearance for a forged 4.1060" forged piston. I've had them, set to manufacturer's specs and they clattered like a diesel on cold startup at the recommended clearance.. Then again, they were race pistons with lateral gas ports and thin ring pack so were expected to rattle. The OP's pistons (Ross) called for .020-.025" clearance for his bore size, If installed to that spec, the motor would be quiet as a mouse. The clearance was doubled and of course they slap as the pistons were designed to expand less.

[tom s]

Pistons are NOT quiet on start up and rattle when hot!Just does not work that way!I have 2 cars with piston slap now and neither are noisy when hot. Tom

[mgarblik]

Originally Posted by tom s

Pistons are NOT quiet on start up and rattle when hot!Just does not work that way!I have 2 cars with piston slap now and neither are noisy when hot. Tom

Agree. That is why I suggested the extra thick oil test. That generally eliminates the pistons as the noise root cause as it did for the OP. He said the noise was louder when up to operating temp with the thick oil. That pretty much eliminates the pistons. Also the builder said in a post that he added .001 to the manufacturer's Piston to Wall recommendations. That is fairly common and does eliminate the possibility of skirt damage and gives a little insurance. .001 over minimum spec. would only be .0005" over max spec. So the piston to wall according to the builder is .0005-.001" over. Should be quiet and cause no issue. If this is correct, the noise is something else. Typically, noise like this that gets louder at operating temp is bearings, since the OP says the top is quiet. Very difficult to tell from little video's.

[KEN CROCIE]

I hope you mean .015" side clearance.

[Dragncar]

Originally Posted by NeighborsComplaint

Depends on the piston's construction and alloy. Venolia, for example, calls for .010" clearance for a forged 4.1060" forged piston. I've had them, set to manufacturer's specs and they clattered like a diesel on cold startup at the recommended clearance.. Then again, they were race pistons with lateral gas ports and thin ring pack so were expected to rattle. The OP's pistons (Ross) called for .020-.025" clearance for his bore size, If installed to that spec, the motor would be quiet as a mouse. The clearance was doubled and of course they slap as the pistons were designed to expand less.

If they were Ross at .005 he would be fine. But they are SRP. Ross call for .004-.0045. His pistons, SRP call for .002-.0025 at his bore size so they must be a alloy that does not expand as much as the Ross pistons.
Colossal mistake to run the SRPs at .005 with no hard block. Rattle city like he said.

[abefromen]

Originally Posted by mgarblik

He said the noise was louder when up to operating temp with the thick oil. That pretty much eliminates the pistons. .

Not exactly. Maybe my wording was misinterpreted.

Noise is pretty consistent Just not as bad when cold be it with the original break in 30W, some 10-40 after that as recommended by builder and then the 20-50.

Although it was never run at cold idle with the 30W.

[tom s]

Ken,did you get hold of Mark?Tom

[JEC3039]

OP - when the engine comes apart and if you are able to verify that nothing else is out of order internally and it comes down to piston clearance, as opposed to buying a set of custom pistons (although that would work) please consider the Line2Line company for their piston wall coating build up on your current pistons. This is not a thin-film low-friction flash coating like used for race engines (that wears off in relative short order), but rather it is a harder more substantial material that's meant for long-term mileage. Should you decide to close your clearance down from .005 to .003 or .0025, the Line2Line process is perfect for that. If you have access to a dyno so that you can control the breaking process very well, you can order the coating in a tight-to-the-bore condition and it will clearance itself when following their specific break-in procedure to the letter. If not convenient to use a dyno, they will prepare the coating thickness for drop-in and go assembly. That aspect is your call.

Line2Line is from the metro Detroit area, as am I, and I first became aware of them when I purchased a Butler 461 rotating assembly for a 400 block that required a 4.155 bore for the Ross pistons supplied in the kit. My machine shop missed the final hone a bit and it measured 4.157. I was pissed as hell. I was ready to order another set of pistons from Butler (would have been custom this time) when I was alerted to the Line2Line folks. (No I don't work there and have no skin in their game.) They built up my piston skirts with their abradable hard coating. My shop picked up the cost ($240) as a goodwill gesture for their mistake. Maybe Clay would consider the same.

I broke the engine in under dyno controlled conditions. After a few thousand miles I had a need to pull engine and replace the rear main (that's a different story) but it let me see the pistons first hand. Coating looked like new.

Check out their website in your spare time and call their tech line with any questions. You've got brand new pistons. Might as well try to keep them in service. Best of luck!

[NeighborsComplaint]

Originally Posted by Dragncar

If they were Ross at .005 he would be fine. But they are SRP. Ross call for .004-.0045. His pistons, SRP call for .002-.0025 at his bore size so they must be a alloy that does not expand as much as the Ross pistons.
Colossal mistake to run the SRPs at .005 with no hard block. Rattle city like he said.

Sprry, had Ross on the brain. The OP's Pistons are SRP and are too loose.

[Dragncar]

Originally Posted by abefromen

Not exactly. Maybe my wording was misinterpreted.

Noise is pretty consistent Just not as bad when cold be it with the original break in 30W, some 10-40 after that as recommended by builder and then the 20-50.

Although it was never run at cold idle with the 30W.

The piston part number shows press fit pins. But you said it has full floating pins. What happened there ? How was the conversion done, if at all ?

[steve25]

A quick way to see if the noise is related more towards a rotational issue or recipercating issue is to warm the motor up so its noisy, then shut her down and either pull off all of the odd number or even number plug wires, then jack up the idle speed a good amount and restart the motor and see if the noise heard has changed.

If the motor had roational noise issues then the motor will sound the same when running as before the plugs where pulled.

[abefromen]

Originally Posted by Dragncar

The piston part number shows press fit pins. But you said it has full floating pins. What happened there ? How was the conversion done, if at all ?

idk, that's a question the builder would have to answer.

I cut the second filter open yesterday and it was completely clean.

[STEELCITYFIREBIRD]

I hear a definitive exhaust leak.
Simple test with a helper/s is to plug up the tail pipe/s with a rag and sole of a shoe, the leak/s if present will hiss get louder or you won’t build any pressure at the tailpipe exit/s if large leak.
Simple and effective.
😎

[adynes]

Originally Posted by STEELCITYFIREBIRD

I hear a definitive exhaust leak.

I thought the same thing, in the first video.