Why are Speed pro forged pistons so cheap compared to other brands? Are they good? Anyone here boost them, I am onlyu planning on about 10-12 psi, A blower car. I have had good luck so far with my speed pro hyper pistons for 2 years, but I detonated one cylinder and now I have only 70 psi of compression on that hole and a small tick/knock from that hole, am building it up now with a different cam and lower compression. I am choosing TRW-L2446F30 from summit they are only 40$ a piece. then the next decision is what rings? is gapless worth it?? or just run plasma moly??

 

what did you have to do for a fuel system to run a supercharger on top of a carb 351w?i am building a 1995 351w with vic jr heads,vic jr intake,h beam eagles and .030 block with flat top forged trw pistons.do you build the carb the same way you would build it for a turbo blow thru set up?what kind of boost are you running with your compression ratio?

 

They are rather heavy...compared to something from Ross, JE, CP, etc.
And in a more serious car, the piston, pin, and ring package mass is VERY IMPORTANT.

In a street/strip car keeping RPM under 6500, it's not as critical.

 

Have you checked out theprices for the Ross piston/ring combo. It isnt that much more if you check threw Summit

 

Im using the same exact trw pistons your using with a set of SCAT Ibeams and im making 612RWHP on my stock block combo @ 8PSI

 

I used those pistons long time ago as well as Brent on this forum. They at that time were 2488 part number. I broke a lot of things with my S-Trim but them. My set up was TFS twisted wedge heads, 1087 wolverine cam, GT-40 intake, Full weight 87 GT, 306, AC, ETC. Many passes at 127 to 130 mph. A older guy at the machine told me sure I could pay the cost of a lite better piston but he never had a set of those fail him yet. So I took his advise being this was my only way to work.

 

Well I hope they are good, I just got them today, they look good, no high spots or sharp edges, not sure about the valve clearance, they have a 13cc dish, And i noticed a very thick top ring land, which is good for handling boost. The crazy thing is that is says it only need 1.5-2.5 thousands clearance, that is tight for forged, My local machine shop suggested the looser fit for forced induction, The other odd this is is that the hyper pistons can either be press or float but the powerforged are only press fit. Since I am sticking with stock rods thats OK. they are factory forged rods with football head rod bolts, tho I might upgrade bolts if I can get them reasonable.

 

Run them, there good pistons!
I beat the crap out of a set for
2-3 years @ 18-20 lb's on pump
gas in a 3800 lb 9.70@140 ride.

Don't get caught up in that gapless
ring crap, I've run them both save your
money!

 

Weren't the forged 5.0 liter motors from 87-92 factory forged made by TRW? If yes, we all know how much abuse those tolerate.

 

i had a pair on my 302 they were nice for the price no complaints.

 

They're heavy, but they take a serious beating. I've seen TRW's come out of motors in one piece when nothing else in the motor or valvetrain did.

 

actually from what i have seen all 1986 5.0s were packin TRW Forged flat tops, when i say flat, i mean FLAT. if you check AFR's site they specify that 1986 motors are the only ones that need to be clearanced for AFR185 heads. i think a few early 87 motors had them too.

The 86 motors were zero decked motors also, a shitty head design called for said pistons and decking, its hard to call it a GT mustang if it only puts out a measly 189 flywheel hp.

I had valve clearance issues with an F-cam with 1.94/1.60 69' 351w heads. i used some releif tools i found online you can notch them in the car etc with an old head and a drill.