In the 80's and early 90's mustangs with the 302's when did they switch to hyper. pistons? Also, which pistons would stand up to NOS the best and how big of a shot could be used without blowing it up?
Brett

 

Forged is the best, not sure about what year on any Hyp. pistons.

 

I think they switched to the hyper pistons in 93 on the HO.. The forged are better for NOS...Lew

 

Forged pistons, like said above, would be better for NOS.

 

yeah like lew said, in 93 they switched to hypers. i think 88-92 in the ho motor was forged. Forged will stand up alot longer to NOS.

 

On the 5.0 motor the rod bolts are the weak link for high rpm and power adder apps, but that said the stock rotating assembly seems to reliable up to around the 400hp range.

 

I think it sucks the weakest link in most engines are the rods.

I had a 490-510 horsepower (crank) highly modified twin turbo (upgraded 15G turbos) Stealth R/T TT. Ross forged pistons. Aftermarket forged steel crank (came with a cast iron crank).

Stupid part on my part was the stock rods I left in there. Spun a bearing 3 times, threw a rod through two blocks. Was a few years back, I learned a lesson there. You can have the best crank and pistons in the world, but the rods are the weakest link if you aren't careful.

 

..Are the rods ok or is it just the bolts ?? I guess a set of ARP rod bolts would be a good up grade... Lew

 

Yes ARP bolts are the fix.. though by the time you buy the bolts, have the old ones pressed out.. new ones pressed in.. and the rods true'd again, you could have bought an aftermarket set with ARP fasteners installed.

 

Thanks thats good to know.... Lew

 

So, somewhat off subject, but what do you think the limit is for my stock '86 EFI 302? I do know it pulls to 5000RPM and can pull farther, but I never take it passed there. Is 5000RPM too high? Just curious, I know it doesn't mean much.

I know 5.0's are great revving motors with the 3" stroke, so can the stock rods and bolts take 5k RPM pretty easy?

 

Yeah 5k is no problem.... 6k+ is when things get hairy. I'll add that with an all stock '86 truck motor you're really just making noise reving it that high, the whole powerband is below 4000rpm.

 

92 was the year that they made the switch. Some of the 92 302s have forged pistons and others are hyper.

 

According to specs and a few other people on the board, that is true. I'll make a vid, though, it pulls harder up to 5k RPM, and would pull farther, but I'm 'scared'. Off subject again, but when I used to use Castrol GTX 10W-30, 5k would die off in power, then I tried GTX 10W-40 for one oil change, and it died in power around 4700RPM (yes, I watch closely). I went back to 10W-30... but now all year I've been running Rotella-T Synthetic 5W-40, and I don't notice a difference except that 5K RPM is not a 'wall' anymore. It wants to go on. I'm sure the engine is stock, though, but I'll have to take a picture/vid for you guys showing it pulling to 5K in 3rd (NP435) doing over 65MPH. It really winds out.

 

http://www.youtube.com/watch?v=qfrr0RC1SS8

Just one of my 5 vids or so. Just showing it goes to 5k easy.

Yes, I'm spinning all through 2nd gear. I just held it at 5K RPM.