Is a cheap piston ($$) a bad piston?

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dfarr67

Active Member
Shop wants to us Sealed Power/Speed Pro hypers DDP, on Ebay these are going for $120 a set...I've read nothing bad about them- is it a function of Federal Moguls vast manufacturing? Don't need to spend more than I have to for sub 6k rpm perfromance at 9.8:1 but I was expecting to pay more for a quality piston.
 
Like most things the application has a lot to do with the suitability of the component selection and use, hypereutectic pistons work rather well, as long as you stay out of detonation and under about 4000 feet per minute in piston speed.\in fact they tend to run quieter and burn less oil getting past the rings as clearances tend to be tighter than forged pistons, Ive used the pistons you linked to here in the past on several 383 engines I've built that were matched to automatic transmissions and 2.87:1-3.08:1 gearing where I knew they would seldom see high rpm use.
obviously you'll want to get the ring gap ,quench and side clearance matching the manufacturer's suggested clearances, and verify the piston to valve clearance.
without knowing the compression and gearing ETC. I can,t really suggest a correct matched cam, but youll generally want a 383 with those pistons to operate under 5800rpm, and under 9.0:1-9.5:1 compression so a cam in the 210-218 intake duration range is a common selection, for similar combos.
obviously a long detailed talk with several cam manufacturer's before selecting a cam may be useful
detdam.jpg

detonationbvc1.jpg

GET THE RING END GAP TOO TIGHT ,OR PISTON SIDE CLEARANCE TOO TIGHT,OR NOT PAY ATTENTION TO THE LUBE SYSTEM DETAILS,AND WHEN THE RINGS EXPAND WITH ENGINE HEAT THE ENDS TOUCH THE RINGS LOCK IN THE BORE AND THE PISTON LANDS SHEAR OFF, it RESULTS IN EXPENSIVE FAILURES GET THE GAP A BIT TOO LARGE AND YOU MIGHT BURN A BIT MORE OIL OR LOOSE SOME COMPRESSION, YOU'LL SEE A CHART LATER IN THE THREAD, BUT GENERALLY YOU'LL WANT .0045-.0065 PER INCH OF BORE DIAM. FOR A RING END GAP
http://www.ebay.com/itm/SBC-383-SMALL-B ... 00&vxp=mtr

viewtopic.php?f=53&t=110&p=137#p137
 
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You started a thread on towing over the Rockies, this is some questions on component choice. I've had KB's in the past- wouldn't know HOW they functioned but I guess no problems means they were OK.

- cam of choice is actually your first suggestion of Crane- 109671 seconded by the shop I'm dealing with- I presented 6 choices. I'm thinking of going for the 4/7 swap as it's no extra charge and with the intake- 7 seems constricted, but mainly for cooling the cylinder.

Other piston choices are SRP/JE 4032 forgings +16cc dish $580, and Probe SRS $490- these are all 9.5-9.8:1.
 

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I HAVE ALWAYS PREFERRED FULL FLOATING PISTON PINS
(that way you can self assemble the piston on each connecting rod)
(which comes in handy when you need to change piston deck height/quench, and side clearance etc.)
AND CUT TO FIT RINGS
(which allow a true custom fit)
and if possible forged pistons
(which are more durable and less subject to as rapidly occurring damage from detonation)
now I have zero problem using hyper-eutectic pistons in the proper applications because they work as well or at least as well as required with little or no down side if you remember the previous stated limitations
 
I'm getting fussy about where things come from- Mexico, China, India are not on the list. What have you found to the most value effective piston?
 
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