Piston slap poll

[KiLLeR2001]

Can anyone using Amsoil 5w-50 confirm/deny if they have it?

Thanks.

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[Deranged1]

I hear it when the engine is cold. I have noticed it's not as noticeable when I run higher quality, higher octane fuels. Ford said it was normal for engines with forged pistons but I never heard it in the Boss. I'm not very comfortable with it and feel it will shorten the life of the engine big time. Going back to a cross plane crank as soon as the next Mach or Boss comes out.

 

[Hack]

I understand. I'm just giving this some extra scrutiny as it's not a SUV engine, it's supposed to be a hand built, precision racing engine (maybe a little strong worded) so the question that I'm asking is why...or what is different between and engine that does and one that doesn't? If they all did it, it would actually make more sense to me.

Higher RPM engines are more likely to have piston slap compared to an SUV engine. The Voodoo has lightweight, forged pistons - both of those features improve the high RPM capability, but also increase the likelihood of piston slap.

The piston skirts are the area that does the most to prevent the piston from tipping in the bore. Lugging the engine by opening the throttle too much when the engine is cold or at low RPMs does put a heavy strain on the piston skirts. It's possible that if an engine has been lugged it's more likely to make a noise due to clearance between the pistons and their bores. I'm sure that Ford worked hard to make the pistons durable to withstand mistreatment as much as possible while keeping them light for high RPMs, though.

 

[Bingo13]

Can anyone using Amsoil 5w-50 confirm/deny if they have it?

Thanks.

I do not have it with the Amsoil, but did not have it with Motorcraft 5w/50. I have piston slap in my '00R so I know what it sounds like, but do not in my built '03 Cobra. I took the advice of that engine builder with this car and on my previous '12 Boss, which was piston slap free.

I let the car warm up to full operating temp before driving it off the lot. I had the GM come out thinking I had an issue with car, but explained what I was doing. He expected to see me back in five minutes or calling for a tow truck.

I drove the car for about a mile and then took it to redline and held it for about 15 seconds, then resumed a normal drive varying rpms on the freeway for 10 minutes and then took it to redline for 20 seconds, repeated it twice until I was holding redline for 30 seconds. I then spent about 30 minutes just varying the rpms on the freeway and in the neighborhood. Took the car home, let it idle for a few minutes and parked it overnight. I repeated the same process the next day and have no piston slap.

I do not know if this procedure actually worked in the particular instance or not, but I do know I am now 3 for 3 when it comes to a lack of piston slap with my Mustangs. That said I do have that slight vibration from 1900~2100 rpm at various times, but it is never consistent, which bugs the hell out of me.

 

[stanglife]

Higher RPM engines are more likely to have piston slap compared to an SUV engine. The Voodoo has lightweight, forged pistons - both of those features improve the high RPM capability, but also increase the likelihood of piston slap.

The piston skirts are the area that does the most to prevent the piston from tipping in the bore. Lugging the engine by opening the throttle too much when the engine is cold or at low RPMs does put a heavy strain on the piston skirts. It's possible that if an engine has been lugged it's more likely to make a noise due to clearance between the pistons and their bores. I'm sure that Ford worked hard to make the pistons durable to withstand mistreatment as much as possible while keeping them light for high RPMs, though.

I understand the mechanics behind it. Like I said - the question is why some do and some don't.

 

[nastang87xx]

It was 44 degrees out this morning but my car was in a heated garage prior at about high 60's. No slap. She's outside right now in the parking lot at the office so we'll see what happens when I fire it up later. I'm using Mobil 1 full synthetic. I use maybe 20% throttle at most in 6th and not up hill if I'm on the highway to pass. I broke it in by pretty much going to straight to autocross at 200 miles. Will report back. I'v heard very few strange noises from my car. Not even really any driveline lash unlike my last car. Sheesh, that thing clunked and clanked all the time.

 

[montreal ponies]

Can anyone using Amsoil 5w-50 confirm/deny if they have it?

Thanks.

I just did my first oil change just 2 weeks ago at 1400 miles using Amsoil 5/50 signature series and did not noticed any difference . It still slaps as bad as before.:tsk:

Whatever it is worth in the equation, i run 94 octane gas at all times.

 

[nastang87xx]

Oh something else i should mention is that I have slightly lugged my engine before in 6th, not often but whatever, it happens. It sounded like deep muscle car burbles. No clunk clunk clunk.

I think what would be better data points are how did you break your shizz in and for how long and are you getting slap or not.

 

[montreal ponies]

I do not have it with the Amsoil, but did not have it with Motorcraft 5w/50. I have piston slap in my '00R so I know what it sounds like, but do not in my built '03 Cobra. I took the advice of that engine builder with this car and on my previous '12 Boss, which was piston slap free.

I let the car warm up to full operating temp before driving it off the lot. I had the GM come out thinking I had an issue with car, but explained what I was doing. He expected to see me back in five minutes or calling for a tow truck.

I drove the car for about a mile and then took it to redline and held it for about 15 seconds, then resumed a normal drive varying rpms on the freeway for 10 minutes and then took it to redline for 20 seconds, repeated it twice until I was holding redline for 30 seconds. I then spent about 30 minutes just varying the rpms on the freeway and in the neighborhood. Took the car home, let it idle for a few minutes and parked it overnight. I repeated the same process the next day and have no piston slap.

I do not know if this procedure actually worked in the particular instance or not, but I do know I am now 3 for 3 when it comes to a lack of piston slap with my Mustangs. That said I do have that slight vibration from 1900~2100 rpm at various times, but it is never consistent, which bugs the hell out of me.

Wow, never heard of such a procedure, as matter fact, i didn't know the ECU would allow the engine to be ran at full throttle for that long. :shrug:

I'm sure that some 350 owners that have broken in their cars pretty agressively still have piston slap.

 

[Johnb-5.0]

My car does make some noise at idle, my thinking it's
the dual mass flywheel.

 

[stanglife]

My car does make some noise at idle, my thinking it's
the dual mass flywheel.

You wouldn't notice this at idle. Try in 2nd gear, 2500ish rpm, press the gas just enough to slightly accelerate.

 

[Clink]

Chin Motorsports - Sebring (DEC 10-11). I haven't signed up yet so hopefully there's some space once my PTO clears.

Just checked - novice class is full for Saturday, which is the day I'd like to go... I jumped on the waiting list.

I would also recommend The FIRM up in Starke, it's a very forgiving course and perfect for your first time out in the car. Check out the threads in the FL section.

 

[stanglife]

I would also recommend The FIRM up in Starke, it's a very forgiving course and perfect for your first time out in the car. Check out the threads in the FL section.

I'm going to the track attack and then to Sebring with the R. I have experience there and Starke is almost twice as far away from me. ;(

 

[Clink]

I'm going to the track attack and then to Sebring with the R. I have experience there and Starke is almost twice as far away from me. ;(

Ah ok understood, Sebring is closer to me also (Clearwater) and I usually stay in Gainesville if I'm going to Starke. Good luck and I hope to see your car at a meet one of these days!

 

[stanglife]

Ah ok understood, Sebring is closer to me also (Clearwater) and I usually stay in Gainesville if I'm going to Starke. Good luck and I hope to see your car at a meet one of these days!

I'm sure you will. I usually go to the local cars and coffee events. (Dupont, Reeves, Crowne).

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