TRW forged pistons (340)

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ir3333

ir3333

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..lots of guys trash talk these heavy old school forged pistons (L2316-30)
..How much difference will lighter, newer style forged pistons or hypereutectics make?
 
ir3333 said:
..lots of guys trash talk these heavy old school forged pistons (L2316-30)
..How much difference will lighter, newer style forged pistons or hypereutectics make?
Click to expand...

Hi,

I have a set of these and I'm planning on using them. L2316 and @ .030 over as well. Lightly used. Price was my main consideration on them and they were 100 bucks and no shipping charges because they were local. Piston travel/speed in a 340 is lower than in many other mills (chev 327 and 302 are exceptions) so heavier slugs may not be as much of an issue. Maybe lighter pins, if there is such a thing will help some as well.

If price is a concern for you, then I'd use them. Especially if you already own a set. My understanding is that they worked well back in the day despite the weight so I see no reason to not use them now. I plan on doing so... Eventually.

Hyperucraptics.. No thanks. And even they are a bit pricey.

Paul

Edit: Mine are actually 2332P 030 but researched the crap out of them and they cross to 2316's.
 
Lighter weight = less stress.

It may not make a difference in the way it drives or your experience. Lighter is better when it comes to moving parts in most every performance piston application.

220 grams is ~1/2 pound * 8 that's 4 pounds the crank and rods don't have to deal with.
 
KB 243 Weight Piston/Pin: 588/132

L2316F weight shows 735 ..dont know if that is with pin or not...
 
Faster revving, less stress.

Mike at MRL had some custom racetech pistons made for mine (they weren't even that expensive) and I used the K1 h-beams. Took a ton of weight out of the rotating assembly. It's a very docile engine yet made 470hp.

The other thing to consider is those old TRW/FM pistons are the type that stick out of the deck. In reality you're better off with a zero deck piston and a quench combustion chamber like the normal edelbrocks, magnum heads, etc.
 
I agree completely with Notch's response. These heavy slugs were being spun up to 7000 rpm with factory rods and held up very well. I see no problem with them unless you plan on going all out race.

I also have a set of these in my 340 motor.
 
ir3333 said:
..lots of guys trash talk these heavy old school forged pistons (L2316-30)
..How much difference will lighter, newer style forged pistons or hypereutectics make?
Click to expand...

Standard Bore

Stock 340........................... 719 Grams + 154 Grams {Pin}

Speed Pro Forged ............... 723 Grams + 154 Grams {Pin}

TRW Forged ....................... 720 Grams + 154 Grams {Pin}

Keith Black Hypereutectic ..... 585 Grams + 132 Grams {Pin}

Arias Lightweight ................. 514 Grams + 125 Grams {Pin}

Give or take a few G's.
 
69 Cuda 440 said:
Standard Bore

Stock 340........................... 719 Grams + 154 Grams {Pin}

Speed Pro Forged ............... 723 Grams + 154 Grams {Pin}

TRW Forged ....................... 720 Grams + 154 Grams {Pin}

Keith Black Hypereutectic ..... 585 Grams + 132 Grams {Pin}

Arias Lightweight ................. 514 Grams + 125 Grams {Pin}

Give or take a few G's.
Click to expand...

Those 'Speed Pro' and 'TRW' Forged Pistons may be heavy, but they are
near indestructible.
 
If you have the trw pistons already, run them

If not, I'd buy something that doesn't double as a nice heavy weapon. Those heavy slugs are in the 550 range last I looked. About the same as a diamond or other lighter piston.

Hypers work fine if set up correctly.
 
Just like cam technology, piston technology has come light years from when heavy forged pistons were the norm. So much more has been figured out about reciprocating mass and its effects than was known 30 plus years ago. As stated, if you have them, use them. But I tell you what. I'll be danged if I would buy them. And I am also a big fan of hypers. Almost without fail, if they have a failure, it is due to incorrect ring gaps. They have very specific ring gap specs and they must be adhered to......at least the KBs do. The Speed Pro hypers do not require special ring gaps.
 
Just remember if you do change the pistons you will need to have the rotating assembly balanced.
 
ir3333 said:
..lots of guys trash talk these heavy old school forged pistons (L2316-30)
..How much difference will lighter, newer style forged pistons or hypereutectics make?
Click to expand...

Though the lighter Pistons will reduce the rotating-mass, that doesn't
necessarily mean more overall power.

But, yes the engine will rev quicker. And there will be less stress on the
internal engine components at high RPM's.
 
The lighter parts wont show up on the dyno...but the lighter parts will showed on the et slip...see quote below...
 
I am currently rebuilding my w2 340 that I initially built about 10 years ago around the speed pro version of this same piston and I am facing the same dilemma of whether to run this piston again. I have been upgrading some parts, namely the con rods to eagle h beams partially because of concerns of the piston weight and partially with a longer terml plan to build a stroker motor. I have also just installed the milodon four bolt main caps as well. For my intended rpm range of about 7200 rpm to get the w2s to work and with a stock stroke crank I will continue for now with this piston. But to build the stroker in the future I need a crank and new pistons. I think with the increased crank throw the trw piston is just too heavy. Some people say these old heavy slugs are darn near indestructible. But for a stock stroke the motor ran great with these heavy slugs.

Duane
 
...been too busy to be on line since i posted this. Lot's of great common sense info.
tx guys!
 
Duane said:
. Some people say these old heavy slugs are darn near indestructible. But for a stock stroke the motor ran great with these heavy slugs.

Duane
Click to expand...

I used those heavy slugs for years....then one day, the heavy slug and crank became disconnected from the crank via the stock rod....no more stock rods..

The last 360 engine I assembled.(71 Duster)..I used Ross pistons that weight 484 grams plus the Scat I beam rods at 585 grams...I bitched at my youngest daughter about hitting the rev limited in the water box...6000 rpm chip...

One day, at TNT I drove the car....and guess what I was hitting the chip also...plus i could not believe how fast the rpm came up...each cylinder is about 150 grams lighter then the one in 71 my Demon...and I can tell the difference in the engine acceleration.

H beam rods and old trw pistons should be able to with stand a first strike from a nuke and continue to live...LOL...For a every day driver go for it...
 
Tony I took yours and many others advice quite a while ago to change the stock rods out.
I agree by today's standards the trw piston is not ideal. Nowadays we have lighter weight and fancy skirt coatings. But sometimes you gotta use what you got. With an eye towards a future stroker build I figured to run the old heavy piston with a much stronger rod for now and upgrade to a new crank and nice light weight pistons on the next build. The Eagle rods could be used again on the next build and have already added four bolt mains. Block is going to the machine shop tomorrow for the line bore.
This plan should work as long as she survives the first strike as you say.
I did plenty of upgrades this year to my whole motor and trans, but I gotta leave some things for the next time.

Duane
 
I've probably had a hundred sets of those Pistons and wouldn't hesitate one bit to slap them in a motor and go. I love building fast stuff out of old junk and seeing how fast I can make something go real cheap. I've built a bunch of 340's with these Pistons, a 509 MP cam and a Holley strip dominator with a 750 double pumper that were pretty quick rides.
 
I have the 10.2/1 TRW's. I've run 7 lbs of boost at 7400 rpm, they seem pretty tough.
 
hemichuck said:
I've probably had a hundred sets of those Pistons and wouldn't hesitate one bit to slap them in a motor and go. I love building fast stuff out of old junk and seeing how fast I can make something go real cheap. I've built a bunch of 340's with these Pistons, a 509 MP cam and a Holley strip dominator with a 750 double pumper that were pretty quick rides.
Click to expand...

And that old school recipe right there ^^^^^ would waste most street driven chevys. LOL
 
I used some of them Heavy old slugs back when that's all you could get in forged piston.
lasted me 20+ years!

My new stroker, Yeah, went the much lighter, Ross pistons and Scat rods.

If i was to build a stock compression, on the cheap, I would go back to them slug, as i won't have to pay the extra expense of balancing the assembly.

If i was balancing, NOT A CHANCE!!!!!!!!! Malory metal is expensive!!!!!!:D
 
Live again!


Anyone still running these?

20220202_151652.jpg


20220202_151618.jpg
 
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