I need some feedback on speed-pro hyper-tec pistons. I need pistons .040 over and they only make forged ones up to .030 over. Has anyone used these hyper-tec pistons. What are the pros and cons of forged vs. hyper-tec? Also has anybody used Diamond forged pistons? Your help is greatly appreciated. Thank you
Hyper-tec vs. forged pistons
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Intercooler
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Have to keep my eye on this one 
1000MileStylez
Black Sheep
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if you spray your motor, go forged, i hear diamond pistons blow
just my $.02
just my $.02
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I have them in my car. Didn't ask for them when it was rebuilt but that's what they used. I've done a little research and some like them some hate them. Seems like as long as you don't lean out you should be fine. I know guys who have melted fordged so anything is possible. My car is just a quick street car for the most part. I don't race it or anything like that. I did talk to one guy who is well into the 10's with them and liked them. Most of the old head engine guys are scared of anything new or different from what works. So these are different and new and you'll hear them bad mouth them but so far they seem to work fine for me. One guy described them as taking a hammer and tapping on a piece of glass.. what's going to happen after sometime... well my engine only has a few thousand miles on the rebuild so I'll post back around 50 to 100K 
Got this from the Federal Mogul site..
3. Hypereutectic
Contains 12.5 percent or more silicon content. Special melting processes are necessary to ‘super-saturate’ the aluminum with additional silicon content. Special molds, casting and cooling techniques are required to obtain finely and uniformly dispersed silicon particles throughout the material. Our hyper-eutectic material is also being used in light and medium diesel engines to replace some of the eutectic pistons with iron groove inserts used for additional heat and wear resistance of the ring groove. Heat and wear in the ring groove contribute to groove ‘pound-out
There are lots of hypereutectic alloys, some better than others for any give purpose. And the casting technique is also important. So there is no "quick" answer as to whether it is a good thing or a bad thing. "Good" hyper pistons CAN be as good as forged, or close, and cheaper. But you have to get "good" ones, in either case.
3. Hypereutectic
Contains 12.5 percent or more silicon content. Special melting processes are necessary to ‘super-saturate’ the aluminum with additional silicon content. Special molds, casting and cooling techniques are required to obtain finely and uniformly dispersed silicon particles throughout the material. Our hyper-eutectic material is also being used in light and medium diesel engines to replace some of the eutectic pistons with iron groove inserts used for additional heat and wear resistance of the ring groove. Heat and wear in the ring groove contribute to groove ‘pound-out
There are lots of hypereutectic alloys, some better than others for any give purpose. And the casting technique is also important. So there is no "quick" answer as to whether it is a good thing or a bad thing. "Good" hyper pistons CAN be as good as forged, or close, and cheaper. But you have to get "good" ones, in either case.
I have ran hypers on my 4.1. The ones from Poston. Cracked two of them immediately after the rebuild. Hypers are not made for naturally aspirated motors.They are too brittle and don't hold up under detonation and boost. I have heard some guys with no problems with them, but then there are many others cracked them like I did. I went with a set of forged pistons from CP. With a little research you should be able to find a forged piston for your motor. If you can't get .040 over stocked anywhere you can get a custom set from most piston manufactueres.
Intercooler
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Okay... I can chime in now 
I have seen them cracked. Usually it is explainable. What was your piston to wall clearance set at when they cracked and what brand? Myself and others all run them without problems. See a good deal of detonation too and they don't give up the ghost. Keep it tuned, install them right and they work like any other piston. Don't set them up right, let the tune get out of hand and they will fail if they were made of titanium.
I have seen them cracked. Usually it is explainable. What was your piston to wall clearance set at when they cracked and what brand? Myself and others all run them without problems. See a good deal of detonation too and they don't give up the ghost. Keep it tuned, install them right and they work like any other piston. Don't set them up right, let the tune get out of hand and they will fail if they were made of titanium.wall clearances are much tighter with hyper pistons, due to the fact that they are cast and the high silicon content means that tehy don't expand much, so if you run the clearances loose they will rock in the cylinder, and if you detonate they rock real bad, and they shatter, but if they are used properly with tight clearances they will last, detionation kills all, it shatters hypers, burnes holes in forged, i ran hypers in a nitrous engine with no problems for years, i would use hypers in a street engine, due to the hardness of the hypers they don't scuff as badly and the warmup time isn't as much ase forged, if you run forged you have to warm the engine up good and you will need to replace them more often due to wall scuff, if you run forged on the street you might wana think about a skirt coating such as swain tech anti-friction coating, thats my take on the issue
grant
grant
Intercooler
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That's a very good post! My observations also! I had some pretty intense scuffing with J&E's. Hypers are much better. Piston to wall varies somewhat by the amount of heat generated. Something along the lines of .002"- .0025" seems to work well.
BEATAV8
The Engine Whisperer
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My old engine has hypereutectic pistons in it. I had it running 11.6x @ 116MPH at 25-26 PSI on 100 octane. I removed the engine because I figured to go faster reliably I would need steel main caps and head work and light weight pistons blah blah blah... Anyways it is still in good shape with no problems.
I have no complaints about the hypereutectics. They look just fine after running at ~450HP for several years in my car. FWIW I tune for 1-2 degrees of knock at most, especially at high boost.
The new motor has Diamonds in it. These were recommended to me by ANS. I know a few others in Chi-town using them too. It will be starting up and breaking in soon.
I have no complaints about the hypereutectics. They look just fine after running at ~450HP for several years in my car. FWIW I tune for 1-2 degrees of knock at most, especially at high boost.
The new motor has Diamonds in it. These were recommended to me by ANS. I know a few others in Chi-town using them too. It will be starting up and breaking in soon.
.40 over motor
hey guys
I have a .40 over motor in my gn. The motor has about 6k on it now and it runs like a champ. The only problem i have heard of with a buick v-6 being .40 is heating issues. But i seem to have no trouble with that also and it's a street conntender with the A/C blowing cold.
hey guys
I have a .40 over motor in my gn. The motor has about 6k on it now and it runs like a champ. The only problem i have heard of with a buick v-6 being .40 is heating issues. But i seem to have no trouble with that also and it's a street conntender with the A/C blowing cold.
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