Broke a piston on 17 lbs WHY!!!
That piston doesn't look burnt in that picture. Looks like the ringland just snapped off. That could just be from too much cylinder pressure for that piston. Could be from detonation. How did the plugs look?
I was surprised to see so many posts until KP's about the powerpak pistons...
You have far surpassed the capability of that piston. Its a 4032 alloy that I wouldnt run over about 8-10 psi on (600 rwhp would be my recommended limit for a converter/auto or maybe closer to 700 rwhp on a stick car).
You need to go to a 2618 alloy custom piston /w lowered ring lands, upgraded hell-fire or stainless top ring and upgraded tool steel pins.
You have far surpassed the capability of that piston. Its a 4032 alloy that I wouldnt run over about 8-10 psi on (600 rwhp would be my recommended limit for a converter/auto or maybe closer to 700 rwhp on a stick car).
You need to go to a 2618 alloy custom piston /w lowered ring lands, upgraded hell-fire or stainless top ring and upgraded tool steel pins.
If this is that piston you are talking about, then basicly those pistons are no better than stock piston's!!!
My 408 317 headed twin 76 blow thru was just sneeking up on running some good numbers went 5.06 140 then 5.05 140 .Then on the 3rd pass on 17lbs right in the lights made a noise went 5.10 136. Got it home took the head off and #2 has a hole on the side down to the first ring. piston is a Mahle powerpak which is forged alum.AFR was 6.6 on E85,timing was 21. Any ideas on this
Teching In
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i purchased the power for my build then heard some bad rumors about the powerpak pistons icallthier tech he told them my build an boost i planed to run (25--30)psi 6 boltsEptheads Lsx block. his word was dont use them but we can make you a set that will work i ended up useing Diamonds no problem yet i had used diamonds before on (20-25)psi car ran 540s at137-140 mph never aproblem till one day bang!!!!!
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Thread Starter
Teching In
Joined: Aug 2007
Posts: 47
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From: Greenville, South Carolina
I was surprised to see so many posts until KP's about the powerpak pistons...
You have far surpassed the capability of that piston. Its a 4032 alloy that I wouldnt run over about 8-10 psi on (600 rwhp would be my recommended limit for a converter/auto or maybe closer to 700 rwhp on a stick car).
You need to go to a 2618 alloy custom piston /w lowered ring lands, upgraded hell-fire or stainless top ring and upgraded tool steel pins.
You have far surpassed the capability of that piston. Its a 4032 alloy that I wouldnt run over about 8-10 psi on (600 rwhp would be my recommended limit for a converter/auto or maybe closer to 700 rwhp on a stick car).
You need to go to a 2618 alloy custom piston /w lowered ring lands, upgraded hell-fire or stainless top ring and upgraded tool steel pins.
what would a set of dish pistons and rings like I need cost? i have to see what I end up with head wise before i can tell you dish size the old ones were -12s
I was in the same boat, but I will tell you this. I detonated the **** out of my motor at 17 psi. I was running the Mahle Power Pak L92 pistons too!
The pistons held up great, there are a few pepper marks on almost all of them, but nothing broken. The coating held up well too. Totally reusable, but will put some 2618's in it and crank the boost way up!
Oh I ran 5.60 on that pass, but it didn't start detonating until high gear in the last 1/8th, still ran a 8.84 at only 151.
The pistons held up great, there are a few pepper marks on almost all of them, but nothing broken. The coating held up well too. Totally reusable, but will put some 2618's in it and crank the boost way up!
Oh I ran 5.60 on that pass, but it didn't start detonating until high gear in the last 1/8th, still ran a 8.84 at only 151.
Thread Starter
Teching In
Joined: Aug 2007
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From: Greenville, South Carolina
Yes 5.05 @ 140 in th 1/8 1.19 60'. The weekend before it went 1.14 60' but was going left. Fixed that and went on T&T night and could only go 1.19 60'. Your mustang has the engine like I need, But I dont want to do the time for robbing a bank. LOL!!! I was worried about lifting the heads and had a ticking bomb inside I guess i was lucky it didn't destory everything
Thread Starter
Teching In
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From: Greenville, South Carolina
Coils and a 6010 with a map.I did verify the timing on the MSD screen and put air on the map and watched it take it out. You could hear the engine change sounds as the timing came out.
Thread Starter
Teching In
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From: Greenville, South Carolina
If it was too fat there may have been unburnt fuel in between the ring lands. This then combusted in between the rings breaking the piston. To fat can be just as destructive as being to lean
I am not making near the power you are, but I am using a similar Mahle pistons on my vette.
19 psi (small turbos) and still holding up at the 750++ rwhp level. I am running a pretty loose gap.
Maybe your ring gap was too tight?
19 psi (small turbos) and still holding up at the 750++ rwhp level. I am running a pretty loose gap.
Maybe your ring gap was too tight?
Yes 5.05 @ 140 in th 1/8 1.19 60'. The weekend before it went 1.14 60' but was going left. Fixed that and went on T&T night and could only go 1.19 60'. Your mustang has the engine like I need, But I dont want to do the time for robbing a bank. LOL!!! I was worried about lifting the heads and had a ticking bomb inside I guess i was lucky it didn't destory everything
When I picked out the pistons, I called Mahle several times. I told them it would be boosted, they asked how much, I said 18-20 psi, they said no problem. I did go with a different ring gap, then what was specified in the sheet with the pistons. The tech guy gave me a spec he wanted to run, and I called back to verify, because it was different then what was in the sheet. I have it wrote down, but I believe it was wider on the second ring, which is opposite of what the sheet said. He was animate about it, and I think it worked well.
The 4032 piston may not be the best for an all out combo, but the Mahle overall are a great piston.
My datalogs didn't show anything out of the ordinary when it was detonating, so that still might be the cause of the broken piston.
The 4032 piston may not be the best for an all out combo, but the Mahle overall are a great piston.
My datalogs didn't show anything out of the ordinary when it was detonating, so that still might be the cause of the broken piston.
Thread Starter
Teching In
Joined: Aug 2007
Posts: 47
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From: Greenville, South Carolina
When I picked out the pistons, I called Mahle several times. I told them it would be boosted, they asked how much, I said 18-20 psi, they said no problem. I did go with a different ring gap, then what was specified in the sheet with the pistons. The tech guy gave me a spec he wanted to run, and I called back to verify, because it was different then what was in the sheet. I have it wrote down, but I believe it was wider on the second ring, which is opposite of what the sheet said. He was animate about it, and I think it worked well.
The 4032 piston may not be the best for an all out combo, but the Mahle overall are a great piston.
My datalogs didn't show anything out of the ordinary when it was detonating, so that still might be the cause of the broken piston.
The 4032 piston may not be the best for an all out combo, but the Mahle overall are a great piston.
My datalogs didn't show anything out of the ordinary when it was detonating, so that still might be the cause of the broken piston.
CSU- Kevin has been a big help
