Help identify this piston - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Witt51 · 01-08-2018, 08:07 PM

This might be hard to see but only Pic I have. From the picture does this look like a oem replacement piston or is this a domed pistons?

Long story short new rebuild and making a knock. Pulled the heads to check it out. It's supposed to be an oem replacement but I sent the picture to another speed shop and he said it's a domed piston. It looks domed to me but I wanted an opinion before I raise hell.

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zz430camaro · 01-08-2018, 08:09 PM

WTF that is something.

Witt51 · 01-08-2018, 08:43 PM

Quote:

Originally Posted by zz430camaro

WTF that is something.

Ya I don't know what to do about it I know that both speed shop and machine shop will just blame each other . The car was finished over a year ago and only 700 miles after rebuild. I've had some life issues happening so it went on the back burner and now I'm trying to get it fixed.

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zz430camaro · 01-08-2018, 08:52 PM

Those are not factory pistons, someone pulled a fast one and probably threw in something they had laying around to make some money. Sucks to have scum bags out there doing this stuff.

Makes you want to kick someones ass. Those are some type of aftermarket small dome piston, what brand is anyones guess.

Witt51 · 01-08-2018, 09:00 PM

This entire build cost almost 9 k and they had the car for 9 months. I complained about issues and I was blown off cause they already got my money. I sent the oil off to Blackstone and waiting for results. Most likely I will be rebuilding this myself. No wonder why I noticed this shop reputation is going down hill and I've seen more and more complaints

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Talladega · 01-08-2018, 10:12 PM

Keep us updated to what happens.......

Witt51 · 01-08-2018, 10:21 PM

They will act dumb but I'm putting a nasty review on the speed shop and machine shop. Just talking to both shops about the knock they blamed each other and the speed shop said they can pull the motor again for me but I will pay for it.

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Witt51 · 01-08-2018, 10:25 PM

I will. I made a post about the speed shop and how I was treated before and someone called and told him about it. He brought it up to me when I talked to afterwards.

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Witt51 · 01-22-2018, 06:15 PM

I'm going to post this here. I put everything together on the engine. On startup I get this knock. After warmup it dies down quite a bit. I was told it was piston slap by the shop. Cam and lifters looked fine. The oil was sent off to Blackstone and found a little bit of lead but said it could be from fuel additives. Nothing else showed up. The engine has less than a thousand miles on it. This car has turned into a pain in the ass for the past few years. http://cloud.tapatalk.com/s/5a667d3f37f81/34129.mp4

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go_go_gadget88 · 01-22-2018, 06:29 PM

1st, yeah that is definitely not an oem piston! Take a look at my cam swap post a coiple down and you can see a stock one is flat on top.

As for your video..If it goes away when warm, it most likely IS piston slap. However, that sounds a lot louder than the piston slap I usually hear. Did the pistons physically feel loose in the bore when you had heads off? And was there a noticeable cross hatch in the cylinders still? Makes me wonder if they didn't just stick some random pistons in there and said good enough.

Witt51 · 01-22-2018, 06:40 PM

They felt tight and I checked cross batch on them. On one cylinder it looked slightly smooth on the one bore. I figured that was from the piston slap.

The noise gets a lot quieter but of course I can hear it but most people probably can't.
The heads are shaved by. 030. The cam is a custom grind from Brian tooley. I don't know if all that will matter when it comes to making noise. It had a good amount of carbon build up on heads but I cleaned that up and put a catch can. I was wondering if my gas wasn't high enough octane and detonating.

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Synner · 01-22-2018, 08:46 PM

Knock could be in the tune, check measurements of pistons vs bore, view all the bearings. What oil and weight and how full? Valves make noise initially on startup with certain oil weights and higher fill levels. Could you be confusing that with piston slap? What was your oil pressure? You can also use a handheld or demand your tuner log knock sensor files while driving. What octane are you using vs what was it tuned for? There should be ZERO noticeable piston slap on a stock bore stock style piston build. Just tossing out theories since hands-on is the only way to know. And with that much oil I'd be looking at your valve seals.

Witt51 · 01-22-2018, 09:26 PM

Quote:

Originally Posted by Synner

Knock could be in the tune, check measurements of pistons vs bore, view all the bearings. What oil and weight and how full? Valves make noise initially on startup with certain oil weights and higher fill levels. Could you be confusing that with piston slap? What was your oil pressure? You can also use a handheld or demand your tuner log knock sensor files while driving. What octane are you using vs what was it tuned for? There should be ZERO noticeable piston slap on a stock bore stock style piston build. Just tossing out theories since hands-on is the only way to know. And with that much oil I'd be looking at your valve seals.

I've talked to the tuner when I initially had the issue and he swore that the computer will adjust for knock and is set to a 14.7:1 a/f. I use the mobile 1 suggested oil and I've changed the oil level a few times to see if that's the issue also. My oil pressure is around 60 at startup and stays around 32 or so at normal Temps. At that time the noise is almost gone. Just loud enough that I can hear it but of course I'm focused on finding it. I also thought I've had a bad tank of gas and it's tuned for 93. I just recently added race gas to see if it helps but I'm not sure how long that takes to adjust. I had alot of oil in the intake manifold before I removed the heads. The speed shop said it was carbon build up that was causing detonation and since that I put on a catch can on. The seals were tested also when it was rebuilt. The builder also told me that with the headers, the cam and shaved heads it's going to be louder but before that my other builds were never that loud. I had the crank walk and everything was replaced. So everything was brand new

The machine shop had no answer to why those pistons were put in. They don't look stock or the oem replacements I asked for. I'm starting to feel like those pistons are the key to this. I was already running a 12:1 compression with stock pistons and the domed ones have me worried that compression is too much. I've thought about putting thicker head gasket in there. I don't know if this different piston would have a slap to it but doubt that.

Also like to add that this build was completed a year and a half ago. I started working to fix it but I was kind brushed off by the machine shop and speed shop. I then shortly had emergency back surgery and I'm just now starting to really recover from that. That's why it's taken so long to get back on it.

I did the disconnect the coils from each cylinder and no change at all. I probably need to do a leak down and compression test on it.

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Synner · 01-22-2018, 09:34 PM

I understand emergency back surgery. 11 screws and steel rod in May, garage is filled with parts waiting to be installed and night stand covered in pills waiting to be taken that don't help. 2 injections today, another in 2 weeks.

Based on that I'd look at the tune, combustion volume, and piston rings. You don't get so much oil it causes knock unless they dorked up the rings or valve seals. Catch can has nothing to do with it.

01-08-2018, 08:07 PM	#1
Witt51 Drives: Black 2ss Join Date: Aug 2011 Location: Illinois Posts: 232	Help identify this piston This might be hard to see but only Pic I have. From the picture does this look like a oem replacement piston or is this a domed pistons? Long story short new rebuild and making a knock. Pulled the heads to check it out. It's supposed to be an oem replacement but I sent the picture to another speed shop and he said it's a domed piston. It looks domed to me but I wanted an opinion before I raise hell. Sent from my SM-N950U using Tapatalk

01-08-2018, 08:09 PM	#2
zz430camaro Drives: 2015 1LE Join Date: Oct 2015 Location: Cleveland, OH Posts: 1,485	WTF that is something.

01-08-2018, 08:52 PM	#4
zz430camaro Drives: 2015 1LE Join Date: Oct 2015 Location: Cleveland, OH Posts: 1,485	Those are not factory pistons, someone pulled a fast one and probably threw in something they had laying around to make some money. Sucks to have scum bags out there doing this stuff. Makes you want to kick someones ass. Those are some type of aftermarket small dome piston, what brand is anyones guess.

01-08-2018, 09:00 PM	#5
Witt51 Drives: Black 2ss Join Date: Aug 2011 Location: Illinois Posts: 232	This entire build cost almost 9 k and they had the car for 9 months. I complained about issues and I was blown off cause they already got my money. I sent the oil off to Blackstone and waiting for results. Most likely I will be rebuilding this myself. No wonder why I noticed this shop reputation is going down hill and I've seen more and more complaints Sent from my SM-N950U using Tapatalk

01-08-2018, 10:12 PM	#6
Talladega Drives: 2013 Camaro SS Join Date: Oct 2016 Location: Arvada, CO Posts: 686	Keep us updated to what happens.......

01-08-2018, 10:21 PM	#7
Witt51 Drives: Black 2ss Join Date: Aug 2011 Location: Illinois Posts: 232	They will act dumb but I'm putting a nasty review on the speed shop and machine shop. Just talking to both shops about the knock they blamed each other and the speed shop said they can pull the motor again for me but I will pay for it. Sent from my SM-N950U using Tapatalk

01-08-2018, 10:25 PM	#8
Witt51 Drives: Black 2ss Join Date: Aug 2011 Location: Illinois Posts: 232	I will. I made a post about the speed shop and how I was treated before and someone called and told him about it. He brought it up to me when I talked to afterwards. Sent from my SM-N950U using Tapatalk

01-22-2018, 06:15 PM	#9
Witt51 Drives: Black 2ss Join Date: Aug 2011 Location: Illinois Posts: 232	I'm going to post this here. I put everything together on the engine. On startup I get this knock. After warmup it dies down quite a bit. I was told it was piston slap by the shop. Cam and lifters looked fine. The oil was sent off to Blackstone and found a little bit of lead but said it could be from fuel additives. Nothing else showed up. The engine has less than a thousand miles on it. This car has turned into a pain in the ass for the past few years. http://cloud.tapatalk.com/s/5a667d3f37f81/34129.mp4 Sent from my SM-N950U using Tapatalk

01-22-2018, 06:29 PM	#10
go_go_gadget88 Drives: 2010 Camaro 2SS/RS ABM 6M Join Date: Jul 2017 Location: Kansas Posts: 617	1st, yeah that is definitely not an oem piston! Take a look at my cam swap post a coiple down and you can see a stock one is flat on top. As for your video..If it goes away when warm, it most likely IS piston slap. However, that sounds a lot louder than the piston slap I usually hear. Did the pistons physically feel loose in the bore when you had heads off? And was there a noticeable cross hatch in the cylinders still? Makes me wonder if they didn't just stick some random pistons in there and said good enough.

01-22-2018, 06:40 PM	#11
Witt51 Drives: Black 2ss Join Date: Aug 2011 Location: Illinois Posts: 232	They felt tight and I checked cross batch on them. On one cylinder it looked slightly smooth on the one bore. I figured that was from the piston slap. The noise gets a lot quieter but of course I can hear it but most people probably can't. The heads are shaved by. 030. The cam is a custom grind from Brian tooley. I don't know if all that will matter when it comes to making noise. It had a good amount of carbon build up on heads but I cleaned that up and put a catch can. I was wondering if my gas wasn't high enough octane and detonating. Sent from my SM-N950U using Tapatalk

01-22-2018, 08:46 PM	#12
Synner Drives: cars Join Date: May 2011 Location: Oversneeze Posts: 4,544	Knock could be in the tune, check measurements of pistons vs bore, view all the bearings. What oil and weight and how full? Valves make noise initially on startup with certain oil weights and higher fill levels. Could you be confusing that with piston slap? What was your oil pressure? You can also use a handheld or demand your tuner log knock sensor files while driving. What octane are you using vs what was it tuned for? There should be ZERO noticeable piston slap on a stock bore stock style piston build. Just tossing out theories since hands-on is the only way to know. And with that much oil I'd be looking at your valve seals.

01-22-2018, 09:34 PM	#14
Synner Drives: cars Join Date: May 2011 Location: Oversneeze Posts: 4,544	I understand emergency back surgery. 11 screws and steel rod in May, garage is filled with parts waiting to be installed and night stand covered in pills waiting to be taken that don't help. 2 injections today, another in 2 weeks. Based on that I'd look at the tune, combustion volume, and piston rings. You don't get so much oil it causes knock unless they dorked up the rings or valve seals. Catch can has nothing to do with it.