What Pistons are These? Have Lightning Bolt Stamp - See Pic

[Terbro]

Nick may be off the hook here. I did look again with the scope, and found a number starting with an L. The number is longer than the part numbers I see on Summit starting with L's, but...it's definitely an L as you can see in the pic.

It's hard to rotate the endoscope all the way around the rim (and pulling it too far back makes it too dark), but I got around most of the edge, and I didn't see any notches. But...I did also see an arrow on the dish. I'm thinking it serves the same purpose as the notches - indicating to position the piston toward the front of the motor.

What do guys think? Forged, yeah? As I put in my feedback, I absolutely do not want to misrepresent Nick. He's done enough misconduct already on his own. He doesn't need me adding anything inaccurate, so I'm happy to clear his name on this issue.

 

[Terbro]

What actually got me back down to the car, was the pic of this piston: http://www.gnttype.org/techarea/pictureguides/pistonguide/38SPhyperpiston.html

Its design looks most similar to mine, with that distinct lip with the sharper cut off, and the fact that they just don't look polished....just like those! So...I'm confused. I was virtually convinced those were what I had, and then I see the L. I don't get it, but the L does speak volumes, unless there's some possibility that the number on top could start with an L, and it doesn't mean forged, because it's not the same number on the bottom, which is the true part number? Not likely, right?

 

[earlbrown]

Federal Mogul has moved their pistons manufacturing facilities all over the place the last few decades. You really can't trust a pic that was taken years ago as the gospel when it comes to cosmetic nuances to identify pistons. From your last pic it looks like the laser etched part number starts with ''L'' which means forged.

I just dug out my 2005 Sealed Power paper book... A forged 3.8 slug is L2481F and a pair of digits for oversize in 30 or 40 over. A hyper is H521ACP with nothing for STD or a 20,30,40,50 at the end for oversizes.


Since our plugs point more downhill than something like a SBC it should be easy/possible to see the entire crown by moving the piston down in the bore and possibly using some supplemental lighting.

Granted, I know how it is when it comes to major effort and expense to do some little thing, but pulling the pan plug out to look at the bottom of your slugs isn't even a full oil change when it comes to effort.

Frankly if you've convinced yourself that you have aluminum foil pistons, is a premature oil change to put your mind at ease really that big of a deal?

 

[Terbro]

Federal Mogul has moved their pistons manufacturing facilities all over the place the last few decades. You really can't trust a pic that was taken years ago as the gospel when it comes to cosmetic nuances to identify pistons. From your last pic it looks like the laser etched part number starts with ''L'' which means forged.

I just dug out my 2005 Sealed Power paper book... A forged 3.8 slug is L2481F and a pair of digits for oversize in 30 or 40 over. A hyper is H521ACP with nothing for STD or a 20,30,40,50 at the end for oversizes.


Since our plugs point more downhill than something like a SBC it should be easy/possible to see the entire crown by moving the piston down in the bore and possibly using some supplemental lighting.

Granted, I know how it is when it comes to major effort and expense to do some little thing, but pulling the pan plug out to look at the bottom of your slugs isn't even a full oil change when it comes to effort.

Frankly if you've convinced yourself that you have aluminum foil pistons, is a premature oil change to put your mind at ease really that big of a deal?

No, I think I've concluded that they are forged. I googled buick speed pro forged pistons 3.8 and found this link: http://www.jegs.com/p/Sealed-Power/Speed-Pro-Powerforged-Buick-Pistons/755710/10002/-1 And it's got the same number you just mentioned. And what I originally thought was 636 is 030...with the crosshatch through the zeros. I took the best pic I could.

At one point with the scope, I saw an F, so I'm almost certain the number is L2481F 030. Nick told me he would be boring it 20 over, but apparently he had it bored 30 over. It looks like the 030 is stamped differently than the rest of the number, can't say for sure.

But the main point is - I'm virtually certain they are forged. I can clearly see the L2 the 81 I really can't see, but all in all...I'm convinced...and pleased.

 

[MAK507]

Look, your pictures look like hieroglyphics off of Aliens vs Predators. I can't make anything off of them but the logo. I'm a pretty good newb at this car, building it by using this site as a bible for it. Glad you're not bored 20 over. I have never heard of that

 

[Terbro]

Look, your pictures look like a hieroglyphics off of Aliens vs Predators. I can't make anything off of them but the logo. I'm a pretty good newb at this car, building it by using this site as a bible for it. Glad you're not bored 20 over. I have never heard of that

Dude...I looked at my pic, and...that got a huge laugh out of that. The problem is, I have to take a photo of my phone's screen with my Sony camera...so it doesn't come out as good as what I see with my eyes. It's still hard to see, but I see more in person.

Okay, so posting the pic was probably pointless. But I could just make out in person the numbers (having seen them previously on that link I mentioned helped). Nick's original explanation for boring 20 was to help align the cylinders. He said he didn't like going over 20 over because it compromises the strength of the block. So I don't know if I'm happy about going 30 over or not. More cubic inches, but I understand his reasoning...weaker block.

Someone please chime in here and support or deny that line of thinking. Is 30 over okay as far as block strength? I think a lot of peeps do it, yeah?

Anyway, time to update the signature.

 

[Boost231]

30 over is fine and the most common over bore imop. Now if we are talking 60 then it might be different

Sent from my SM-N910T using Tapatalk

 

[MAK507]

Dude...I looked at my pic, and...that got a huge laugh out of that. The problem is, I have to take a photo of my phone's screen with my Sony camera...so it doesn't come out as good as what I see with my eyes. It's still hard to see, but I see more in person.

Okay, so posting the pic was probably pointless. But I could just make out in person the numbers (having seen them previously on that link I mentioned helped). Nick's original explanation for boring 20 was to help align the cylinders. He said he didn't like going over 20 over because it compromises the strength of the block. So I don't know if I'm happy about going 30 over or not. More cubic inches, but I understand his reasoning...weaker block.

Someone please chime in here and support or deny that line of thinking. Is 30 over okay as far as block strength? I think a lot of peeps do it, yeah?

Anyway, time to update the signature.

I did tons of research on the bore. I was at STD when I blew the head gasket. The gashes in the cylinders made me go up without a choice. After going .030, when I got the block back, one cylinder had a gash from top to bottom. The guy apologized, and said it was already like that... Uh yeah bullshit. He had just done the job! So I had to get them rebored... Honing would not have gotten rid of that gash.

I met up with Kenny Duttweiler which is FAMOUS on these cars. http://www.hotrod.com/features/1502-take-5-kenny-duttweiler/

He did the bore job for the .040... Beautiful job.

He told me this motor was very safe to push .040, and that he personally would be ok even with .060 but that it is risky because the walls will be very thin and you're screwed after .060... Needing a new block.

 

[Terbro]

30 over is fine and the most common over bore imop. Now if we are talking 60 then it might be different

Great.

 

[Terbro]

I did tons of research on the bore. I was at STD when I blew the head gasket. The gashes in the cylinders made me go up without a choice. After going .030, when I got the block back, one cylinder had a gash from top to bottom. The guy apologized, and said it was already like that... Uh yeah bullshit. He had just done the job! So I had to get them rebored... Honing would not have gotten rid of that gash.

I met up with Kenny Duttweiler which is FAMOUS on these cars. http://www.hotrod.com/features/1502-take-5-kenny-duttweiler/

He did the bore job for the .040... Beautiful job.

He told me this motor was very safe to push .040, and that he personally would be ok even with .060 but that it is risky because the walls will be very thin and you're screwed after .060... Needing a new block.

Not that I'm an expert, but...looks good to me.

 

[MAK507]

I had a nightmare that I pulled my motor out to check the cylinder walls. I guess from this late talking about bore specs... Cylinders were all cracked [emoji31] I woke up in panic but thankful it was just a nightmare[emoji56]


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[earlbrown]

Any idea what the last stone used in honing process was? (and if you have moly rings?)

It might be the picture but that finish looks a lot rougher than I usually like.

 

[TURBOELKY]

That hone job looks crazy. What's up with that hole being threaded all the way up? Helicoil?

 

[MAK507]

Any idea what the last stone used in honing process was? (and if you have moly rings?)

It might be the picture but that finish looks a lot rougher than I usually like.

I don't want to hijack this thread, but in the interest of public information, (because I hate reading threads when something interesting comes up and no follow up occurs) the cylinders were smooth. The HD setting on the iPhone was pretty amped up to show more detail on the cross hatches. I would've flipped out if it was rough.

That hone job looks crazy. What's up with that hole being threaded all the way up? Helicoil?

Top near middle of the picture? It was already like that when I tore motor apart. No idea. Last three previous owners?

 

[ITSAV6]

what's up with all the "dumb" ratings on the posts?

 

[Terbro]

what's up with all the "dumb" ratings on the posts?

That would be ~JM~. He inundated all my posts on this thread and the one in the feedback section re: Nick Micale (well over 20...I stopped counting). He must still be in Jr. High. His way of respecting a person's honesty, a person's personal opinion, and the forum's rating system. I might retaliate and do the same thing if I were back in Jr. High. We don't get too many of his type here, I'm sure there are many more of his type on the Honda forums.

As result of your abuse of the forum's rating system ~JM~, I'm reporting you to the moderator.