Hey everyone i just picekd up my third 5.0 mustang and its a 93, i know the 93 dident use forged pistons. are they safe to modify? im lookin to do some nice afr heads ,cam, manifold, gears, fell exhust ect...
Of course you can...it just isn't as safe for the level of boost you can get with forged pistons...
Here in a month I'm going to start on installing my FTI cam, AFR heads, Performer Intake, and I already have the gears, full exhaust etc...so I'll let you know how it goes
prior to my big mods, my 93 was fine running a stock block and internals with a heads/cam/intake combo along with a full exhuast and all the other goodies aside from a big shot of nos and 8+lbs of boost.
93 mustangs used hyperutectic pistons which I believe have more silicon in them, although they provide tighter clearance between the piston and cylinder wall, and have a lower coefficent of heat expansion, they are more brittle and are less forgiving when not tuned properly. So there's less room for error when dealing with nos or boost. It can be done just have less room for error.
ok cool, i dont plan on running any boost or spraying so this is good news. i just dident want to spend all this money modding the car only to have it blow from week pistons!
The pistons are not necessarily weak. Hypereutectic pistons have been used on many Ford engines since the early '90's...even the modulars. Alternative Auto Performance used a '92 LX "mule" with a stock '96 DOHC modular (with hypereutectic pistons) and nailed it with 25-30psi...putting out roughly 650rwhp. It eventually blew the block apart after several 1/4 mile runs, but upon autopsy, it was found that the pistons literally ripped apart from high RPM (over 7000), not from air/fuel issues.
The thing with any engine with mods, especially those running boost, is to closely monitor and tune for a "safe" air/fuel ratio...sometimes that means custom tuning. If you are just planning a head-intake-cam combo, your '93 should do fine. A suggestion, though, is to check your compression across the cylinders to make sure you are going to get a good ring seal. No sense in modding to top end if your bottom end needs attention first.
I have roughly 550 on a non tuned motor to a more than capable ability of 600 with the botom end being all stock.I saw 10 to11psi of boost to get these numbers so basicly if the motor dosen't go lean under load and you keep it tuned to the safe side you shouldn't have any issues