What pistons are these?
- Thread starter TireFryer
- Start date
- Joined
- May 28, 2001
These??
www.summitracing.com
Sealed Power H899CPA Speed-Pro Hypereutectic Pistons | Summit Racing
Free Shipping - Speed-Pro Hypereutectic Pistons with qualifying orders of $109. Shop Pistons at Summit Racing.
- Joined
- Aug 1, 2003
trw L2481F
TireFryer
The New Kid
- Joined
- Dec 21, 2001
Sweet. Are they good or bad lol. I see it’s the heaviest piston pin ever. So I assume it’s bad because you don’t want to be throwing around weight.
SCOOBY DOO
BASED CANADIAN PATRIOT!!
- Joined
- Feb 18, 2007
I used them in an engine I had with zero issues. I always had the rotating assemblies balanced in my engines.
TireFryer
The New Kid
- Joined
- Dec 21, 2001
I’ll be getting it balanced for smooth revving
Turbo Archie
Active Member
- Joined
- Feb 2, 2018
The pins are heavy to help match the weight of factory pistons. Replace with lighter ones if you are going to re balance.
In theory you wouldn't have to add heavy
What Turbo Archie said plus they have a lower compression height because they anticipate you cutting down the decks to achieve your desired compression ratio. I didn't know this years ago when I rebuilt my original engine and just installed them without measuring anything. When I removed the engine to install my current engine, I measured the combustion chamber volume and how far down in the bores they were and discovered that my static compression ratio was 7.88 to 1. The correct way to chose pistons is to do all the machine work first then order custom pistons that will allow you to achieve your desired compression ratio while removing a minimum amount of material from the decks to keep them as strong as possible..
TIMINATOR
Well-Known Member
- Joined
- Jan 26, 2020
With liteweight tool steel pins you can save around 100 grams of weight per cylinder! You can also lighten up the actual piston forging an easy 20 grams + without compromising strength.
While you are at it, have the shop completely remove the small end balance pad of the heaviest rod, then match the weight the other 5 rods. You can also do this to the big ends and save more weight, but the small end eod and piston weight reduction helps more because it is reciprocating.
You start it at the bottom, stop it at the top, then start it at the top and stop it again at the bottom. Every revolution.
Saved small end pin , piston, and rod weight is usually around 140+ grams, x 6 piston assys. = 840 grams.
That may not seem like much, but there are 454 grams per pound. If you beam detail and polish the rods too, you can easily save over TWO POUNDS of reciprocating weight!
Then, because I am really anal, I spend hours grinding/ lightening the casting or forging flash and machining targets on my crankshaft too. On my old 454 chevy CRANK, I removed 7 POUNDS! Not to mention the rods and pistons,
With TRW pistons and stock rods and crank, my bobweight was pretty close to a normal 350 chevy small block bobweight!!
This is not only rotating and reciprocating weight, but also dead weight that you are also moving that 1/4 mile.
I also didn't mention that I do the casting and lightening thing on my block, heads, intake, and all accessory brackets too.
Or, you can just turn the boost up, use more fuel, make more heat, more exhaust back pressure, get closer to detonation and have shorter engine life.......
Ever get yer ass kicked by someone with a smaller cam, turbo, boost, and fewer bolt ons?
JMHO
TIMINATOR
P.S. This partially explains price differences between machine shops on "identical" engines....
While you are at it, have the shop completely remove the small end balance pad of the heaviest rod, then match the weight the other 5 rods. You can also do this to the big ends and save more weight, but the small end eod and piston weight reduction helps more because it is reciprocating.
You start it at the bottom, stop it at the top, then start it at the top and stop it again at the bottom. Every revolution.
Saved small end pin , piston, and rod weight is usually around 140+ grams, x 6 piston assys. = 840 grams.
That may not seem like much, but there are 454 grams per pound. If you beam detail and polish the rods too, you can easily save over TWO POUNDS of reciprocating weight!
Then, because I am really anal, I spend hours grinding/ lightening the casting or forging flash and machining targets on my crankshaft too. On my old 454 chevy CRANK, I removed 7 POUNDS! Not to mention the rods and pistons,
With TRW pistons and stock rods and crank, my bobweight was pretty close to a normal 350 chevy small block bobweight!!
This is not only rotating and reciprocating weight, but also dead weight that you are also moving that 1/4 mile.
I also didn't mention that I do the casting and lightening thing on my block, heads, intake, and all accessory brackets too.
Or, you can just turn the boost up, use more fuel, make more heat, more exhaust back pressure, get closer to detonation and have shorter engine life.......
Ever get yer ass kicked by someone with a smaller cam, turbo, boost, and fewer bolt ons?
JMHO
TIMINATOR
P.S. This partially explains price differences between machine shops on "identical" engines....
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