Just something I wonder about now and then. I've read on coolcats that the stock pistons won't work with performance mods like super charging or even a stronger cam than HO which is what I'm using now. A supercharger isn't too likely at the moment, neither is a cam change since it's lots of work and I'm lazy :hick: But I might be looking into 1.7 roller rockers later on which will increase the lift of the valves. Should I worry about that? Just what are the differences between my pistons and the Mustang HO pistons, I know they're dished but are they cut lower for more clearance? Is there a compression issue? I haven't seen 5.0 Mustang pistons up close but I've seen 94 3.8 pistons which were dished and judging with my eyes, the dish displaced about as much as the 4 valve reliefs on my stock pistons. Just curious.
'85 to 92 Mustang pistons were forged (the HO rollers) and from 93-95 they used hypertuecitc (or however it's spelled;) ) pistons. If you have valve reliefs in your pistons I *think* you should be ok with 1.7 rockers. You'd have to measure piston to valve clearance to be sure though. The Birds and Cats with a 5.0 from 86-88 had cast flat top pistons with no valve reliefs.
A few people have reported running an E-303 cam with the stock 1986-88 Cougar/T-Bird 5.0 block, and not having to have pistons with reliefs. Obviously every motor is different, and you should always measure first, but you might get lucky. I think your pistons have reliefs cut in, don't they? You're still running the 1983 block?
i wouldnt try it myself. some people dont know what they really have so they may accually have had vale releifs.
hypereutectic :P
Yep. Still have the 83 block with stock crank and pistons. My pistons have 4 valve reliefs cut into them, though obviously 2 of them aren't good for anything. I had to scratch my head on that one when rebuilding the engine....
The cylinder heads you run also have an impact on the cam you can run with flat top pistons. TFS heads with flat top pistons give plenty of clearance for a lot of performance cams. Which heads do you plan on running?
I'll probably have the E7 heads for a good while yet, atleast until I get a good deal on some GT-40 heads.