SN95 Block vs Fox Body Block

93 up had hyper crap pistons, 86-92 had forged, 86 are flat top pistons, 4.6s suck./story.

wytstang said:

No ones talking about 60's & 70's blocks....

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Sorry...thought the "doesn`t know what he`s talking about" comment was directed at me.

But still the late model 5.0L roller block are thinner in critical areas compared to the 60`s and early 70`s blocks...as a comparison.

As someone mentioned above...
Ford removed a lot of metal in the roller blocks compared to the blocks of the 60`s and 70`, along with the loss of nickle content over the years..

and if anyone actually looks for one, hypereutectic pistons started in late model year '91. It seems to be ~ the same time the FP relay moved under the hood.

What was the advantages of the Hypereutectic Pistons??

hypers are lighter and theres another advantage or 2 supposedly (i forget). but they suck

yeah, i hear they're not boost friendly at all

The only advantage was to ford they were cheaper..........

HISSIN50 said:

and if anyone actually looks for one, hypereutectic pistons started in late model year '91. It seems to be ~ the same time the FP relay moved under the hood.

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Not doubting you, but all the resource books state that Ford changed to hyper pistons for the 1993 Model year...whick also means these motors were probably assembled late 1991 thru 1992 to be used in 1993 cars.

xr8d302 said:

What was the advantages of the Hypereutectic Pistons??

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They are harder than forged which means the engine can be assembled with closer tolerances.

The cons are that they are much more brittle than forged which is bad for s/c or juice. They break under hard load.

The only Pro I can see is that when a hyper piston fails is does less damage than when a forged piston fails. The hyper won't expand from excessive heat; it breaks apart while the forged expands and eventually melts from excessive heat, causing much more damage to the block.

ChrisA#5 said:

hypers are lighter and theres another advantage or 2 supposedly (i forget). but they suck

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Hyper's don't expand with cold weather, and they are lighter. But they are not as durable as we all know.

hyp pistons have less piston to wall clearance, they have silicon in them to make em more flex, since there so rigid, they are better for longevity and emmisions. they CAN handle boost what they cant have is any sign of detonation, many people run these pistons with s/c and nitros w/ no probs. You tune needs to be 100% dead on for these aplications. there is nothing wrong with a hyp. piston from the factory's point of view.

87-92 MUStang 302 v8's should all be forged.

Paul, you are correct. I am down to typing with one hand right now. I meant to type '92 but missed.

Late '92 was when hypers started being used (it was not right at the model year change for '93, but rather a few months of production before). Most folks round up and say one is good through '92 (to get forged slugs). But if hunting, checking date codes is a good idea.