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I looked through most of the threads and wasnt too sure so I have a question, please exuse me if it is anyway a repost but I just wanted to make sure.

I am rebuilding my motor and two question, please keep in mind I am looking to make upwards of four hundred would like to do more so what do you suggest for both rods and pistons? I know that forged pistons are the way to go put who makes them for our cars? Please help I read so much on these sites but am still not sure what the best is.

Once again i apologize if this has been covered already and I missed it . Thanks in advance.
 

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Go with Diamond pistons... these are what Intense and 3800 Performance sell.

For rods, the stock rods aren't very weak, but if you want to upgrade them, put in a set of L32 rods.
 

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I agree with Jason on both counts. There are other piston manufacturers that make pistons for our cars, but I think it's safe to say that at least 90% of the 3800's that run forged pistons are using Diamond, and to my knowledge nobody has broken one yet. The nice thing about forged pistons is that it removes the piston as the likely failure point in the motor. When tuning mistakes do occur, you're looking at either melting a plug or blowing a head gasket, both much preferred over a chipped piston.

John
 

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johnt said:
I agree with Jason on both counts. There are other piston manufacturers that make pistons for our cars, but I think it's safe to say that at least 90% of the 3800's that run forged pistons are using Diamond, and to my knowledge nobody has broken one yet. The nice thing about forged pistons is that it removes the piston as the likely failure point in the motor. When tuning mistakes do occur, you're looking at either melting a plug or blowing a head gasket, both much preferred over a chipped piston.

John
Ah ha John. Im the other 10%...Im running Wiesco's....Your right. Its nice to find a melted plug rather than a chunked piston. Lean is mean. Too pistons that is.. :rolleyes: DUUUUUUUU
 

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Yep! I just melted a plug a few weeks ago, on a non-nitrous run no less. I blew out a vacuum line and my fuel pressure instantly went from 70 to 50. Good thing I had forged pistons. :)

John
 

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ko2461 said:
I looked through most of the threads and wasnt too sure so I have a question, please exuse me if it is anyway a repost but I just wanted to make sure.

I am rebuilding my motor and two question, please keep in mind I am looking to make upwards of four hundred would like to do more so what do you suggest for both rods and pistons? I know that forged pistons are the way to go put who makes them for our cars? Please help I read so much on these sites but am still not sure what the best is.

Once again i apologize if this has been covered already and I missed it . Thanks in advance.
Definitely FORGED for sure, and Diamond makes a very nice product! They were able to manufacture me a custom size for my bored block as well, so that was great. :)
 

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As I posted in another thread, magnifluxing and shot peening rods makes them VERY strong.
 

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The strength of any piece of steel or Iron is in the metalurgical make up of the material. The annealment and heat of the material determine the amount of hardness as well as the depth of hardness. Magniflux is a method of determining cracks in the material. Has no effect what so ever on the strength of the material. Shot peen on forged steel does add a very light form of density but, the main purpose for shot peening is to eliminate heat risers in the material. The type of material as well as the amount of carbon drawn on the steel at heat is what will determine the end result. An ideal rockwell (rockwell is how hardness is rated in steel/iron) for a piston rod is 35 - 39 rockwell. And the most expensive rods usually have a double annealment. The ideal material to make a con rod out of is 4140 pre-heat. For our 3800 engines, the need for aftermarket pistons and rods will be rare. Unless a person plans on shooting a heavy hit of NOS, or running lean to the point of danger. Stock lower end should be fine.
 

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tan said:
Magniflux is a method of determining cracks in the material. Has no effect what so ever on the strength of the material.
No kidding! :rolleyes: But if you are building a strong engine, you sure don't want rods that are cracked, now do you?
Shot peen on forged steel does add a very light form of density but, the main purpose for shot peening is to eliminate heat risers in the material.
A quote from Peening Technologies
"Shot peening is a cold working process used to increase the fatigue life of metal parts. Parts are bombarded with round steel, glass, or ceramic shot under controlled conditions to induce a stressed surface layer in compression. This surface layer inhibits the formation of tiny surface cracks which give way to fatigue failure."
This is a relatively cheap method of ensuring your rods won't break under extreme load. Magnaflux first, then shotpeen. Rods no break.
 

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After a part has been heat treated, any part not just rods, it is checked for cracks. That's what magniflux, does nothing more. Magniflux has been around for years. Shot peen is cold working the part but, in itself it's nothing. The material used is what determines the strength of the rod. If you take a piece of 1018 cold roll steel you can heat and shot peen until your blue in the face. That rod would break. The 18 in the 1018 is the carbon content. Very low. You could not draw enough carbon to harden the rod. When glass is used instead of shot it's called glass bead, not shot peen. The very best rods are rough machined, annealed, then heat treated, annealed, shot peened, then re-machined for accuracy, size and weight. Shot peen has also been around for years. No new technolgy there. It cleans the scale from parts after they come out of the furnace as well as act as a form of forge hammer, removing heat risers. With any piece of iron or steel the the type of material used and the proper heat treat will determine the affectivness of the part. I say this from experience. I'm a supervisor in a machine shop. We make, among other things, Performance engine parts including con rods for H******'S Cams . I guess what I'm trying to say is Magniflux is one of many ways to check for cracks and shot peening in itself is about 1% of the process for producing a quality reliable part. Neither magniflux nor shot peen in themselves or combined will make a part "VERY strong"
 

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I've also heard that after shotpeening, a rod must then be straightened, is this true?
 

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That Depends on the manufacturing process. Shot peen will not cause a part to need straightening. The heat treat process is what causes the part to twist and then need straightening. When a part is shot peened, it is usually put on what is called a wheel-a-brator. Then pellets are shot at it from all angles and sides under extreme pressure. If enough stock is left on the part for finish machining, the straightening process can be minimized.
 
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