Hypereutectic Pistons

[Orange302]

This was a tread that i read at the corral. Thought i would bring it over here because i found it interesting.

pistons - Corral Forums

There is the link to the thread. Please take into consideration this is a forum and some people (including me) dont know exactly what they are talking about.

Also here is a link to what the chemical makeup of the Piston is:

Hypereutectic piston - Wikipedia, the free encyclopedia


They put SILICON in them.... Maybe everyone knew that, but i just learned it and found it interesting.

[shakes]

the joys of owning a stock bottom end 93-95 5.0.

[Orange302]

Originally Posted by shakes

the joys of owning a stock bottom end 93-95 5.0.

93-95, what type are in the 92 and previous?

[The Fox Master]

Originally Posted by Orange302

93-95, what type are in the 92 and previous?

Forged TRW boost/juice friendly man pistons

[Telsite]

True the 93-95 are not juice or boot friendly... but if your car is set up right and your compresion ratio is not above 10.5-1 you can run some... Friends of mine have run 125 shot and 6-10 lbs of boost... just make sure your are running good cause detonation will easily destroy them.

[Orange302]

Detonation=bad no mater what you you are running. That sucks that we didnt get forged pistons....

[black sunshine]

In my 86 cobra i run a stock short block with factory true flat top forged pistons 9.2:1 (86 only)verse the 9.0:1 there after. With E7TE heads and permatorqued gaskets it gives me a 9.8:1 total compression,because of smaller combustion cambers,after the clearence checks with putty they almost kiss each other,but as long as i do not blow a shift past 5000 rpm,which 5.0L due not produce there after anyway unless equipped with gt40 heads,valve relief drilled pistons and related hardware,there is no harm.overall hp is a whopping 320hp with minor add ons(exhaust,intake system,computor minipulation,underdrive pulleys and electric fan),not bad for speed density,pushing it to the limiits poor man style and back to the subject forged rocks over hyper any day,unless you have lots of money and no worry's..chew me if you want to,but i have results with no reliabilty issuses.also leaving the top of the hyper piston head at the top of the cyl is common hands down!

[Telsite]

I have no plans on adding boost or spray to my current motor so I went with the Hyperslugs due to they are lighter and lighter rotating assembly will help it spin up faster. So for the average joe if you plan on spraying or boosting be safe go forged.

[The Fox Master]

Originally Posted by black sunshine

In my 86 cobra i run a stock short block with factory true flat top forged pistons 9.2:1 (86 only)verse the 9.0:1 there after. With E7TE heads and permatorqued gaskets it gives me a 9.8:1 total compression,because of smaller combustion cambers,after the clearence checks with putty they almost kiss each other,but as long as i do not blow a shift past 5000 rpm,which 5.0L due not produce there after anyway unless equipped with gt40 heads,valve relief drilled pistons and related hardware,there is no harm.overall hp is a whopping 320hp with minor add ons(exhaust,intake system,computor minipulation,underdrive pulleys and electric fan),not bad for speed density,pushing it to the limiits poor man style and back to the subject forged rocks over hyper any day,unless you have lots of money and no worry's..chew me if you want to,but i have results with no reliabilty issuses.also leaving the top of the hyper piston head at the top of the cyl is common hands down!

320 hp sounds extremely optimistic with those mods if you are talking rear wheel HP, can you back that up, or is that a guestimate of flywheel HP?

also leaving the top of the hyper piston head at the top of the cyl is common hands down!

??? What on earth do you mean?

[Orange302]

I agree with FM it seems a little bit of a strech. As well, detonation is bad either way, and i am planning on running a modist amount of boost on my hyper pistons, i think that it is all in the tune.

[The Fox Master]

Originally Posted by Orange302

I agree with FM it seems a little bit of a strech. As well, detonation is bad either way, and i am planning on running a modist amount of boost on my hyper pistons, i think that it is all in the tune.

Boost? Didn't know you planned on supercharging it, when did this happen? You gonna sell the nitrous kit?

You are right, making a power adder live with hypercraptastic pistons on the street is very much in the tune, but the failures more often than not come from those little failures you never take into account, like overboost on a turbo due to a controler problem, or stuck wastegate. I blew head gaskets once because my Boost Retard box failed and didn't retard the timing at all. With nitrous a bad fuel solenoid or pump, or even a stuck solenoid can all of a sudden cause a huge lean spike and that is what kills ya. Another case that is especially prelivant to boosted cars is a bad part throttle tune - most tuners can nail down a WOT tune pretty easily, but at light cruise heading up a hill the computer can be commanding a stoich AFR of 14.7 which is great for economy on a N/A car or something with very little low RPM boost, but with pos. displacment setups and turbos you are into boost so early just climbing a hill can cause minor detonantion. With a forged piston setup you may never hurt it in this sort of situation, but with a Hyper piston that tiny little bit of tip in detonation can be enough to start pitting of even melting the piston, and THAT is why hypers suck

[Dagz]

good to know thanx for the info. No boost on the 95 and as much as i can get away with in the 67 with a stock 91 short block.

[Orange302]

EDIT*** by boost i ment nitrous. It is boost still too in my mind, just not constant.

[black sunshine]

flywheel hp.and i used a on line dyno program by filling in the blanks that was the resullts it gave me,but i guess it does not mean it's correct.but the before and after resullts were very impressive.no detonation detected.as for hyper pistons,they had a problem i was reading in one of my articles about the piston tops breaking off.might have been a bad batch,can try and find article if your interested,but i have a pile of mags,don't know witch one top of my head.

[The Fox Master]

Originally Posted by black sunshine

flywheel hp.and i used a on line dyno program by filling in the blanks that was the resullts it gave me,but i guess it does not mean it's correct.but the before and after resullts were very impressive.no detonation detected.as for hyper pistons,they had a problem i was reading in one of my articles about the piston tops breaking off.might have been a bad batch,can try and find article if your interested,but i have a pile of mags,don't know witch one top of my head.

The only dyno programs that are truely accurate are ones that demand head and intake flow numbers and calculate power based on flow. Performance Treds Engine Analyser is the only one I know that builders use, and provide quite accurate results. Desktop Dyno and the like are usually pretty optimistic.

320 flywheel out of E7TE heads is posstible but it takes some very good porting and a perfectly match cam such as trophy and factory stock NMRA racers use.

Anyhow, Hypers in Naturally aspirated applications with 10:1 CR or less on pump gas they should last forever.