TRW L2452F for $300 . . . Worth it?

Discussion in 'Small Block Tech' started by patwhac, Oct 16, 2018.

  1. patwhac

    patwhac Well-Known Member

    There's a guy who wants to sell me a NOS set of TRW L2452F .030" over forged pistons for $300 shipped, including wrist pins. Does you guys think it's a good buy or would the $700 Autotechs be better even if I can't afford them right now?

    I believe these TRW pistons are listed as stock replacement for non turbo V6s and the Buick 350. They are like the low compression version of the old TRW L2343 pistons. The specs are supposedly as follows:

    1.825" compression height.
    0.231" deep dish
    3.070" dish diameter
    (dish is 28cc if my math is correct)

    In my dream plan I would use these for a medium (6 to 12 psi) twin turbo 350 with 73+ capscrew rods. However a static compression ratio calculator is showing me 7.3:1 SCR assuming a deck height of 0.100", 58cc heads, and 28 cc dish. That seems pretty low even for boost.

    These are all theoretical numbers, I'm not able to measure anything yet!
     
  2. alec296

    alec296 i need another buick

    Deck height with those is more estimated .068. So I got 7.83 compression.
    .030 off block for a .038 in hole would net about 8.21.
    I would try to bring up compression over 8 even for boost. The turbo 6 guys are running 9.0-10.2 compression on the big power engines. Makes greater torque curve.
    I would consider it a fair price as the federal mogul coated skirt pistons are still obtainable . L2481. Similar specs. 24 cc dish. And if you shop around you can get 8 for about 400 ish. Autotec used to carry a je grand national piston. Which they may suggest.
     
  3. 300sbb_overkill

    300sbb_overkill Well-Known Member

    Would be closer to .080" in the hole, so do the compression math with that number, that should help out a little. Also if the block's deck is milled .030" that should bring you to around .050" in the hole.

    Have the heads milled with just a clean up cut and run the steel shim head gaskets(.020" thick instead of .040" thick) and you should be around 8.5:1 to 9.0:1, I would guess without doing the math?

    BUT, the deck milling will cost around $150 to remove .030", more than that there is an extra charge.

    The steel shim head gaskets costs about $50 more than the composites do.

    Mill heads around $100

    You'll need shorter push rods for sure now, $?.

    With all these extra machining costs how much are you saving?
     
  4. alec296

    alec296 i need another buick

    Even at 7.7 compression and turbos it should have power.
    And 300 for pistons, 150 for .030 deck. Measure for pushrods.
    Vs 700 for pistons and rings.
    The savings can pay for other block work or balancing.
    But are the autotec pistons better, yes. And customizable to your needs and with higher compression height.
    Autotec probably are lighter also.
    Hard call to make unless you just look at cost factors.
     
  5. Mart

    Mart '71 350 GS, almost stock

    Have Jason Cook talk to the guy and you'll get them for $5:D
     
  6. patwhac

    patwhac Well-Known Member

    Thanks for the insights! $5 sounds great, who is this Jason Cook haha? :p

    I agree that the only way I'd really be saving any money is if I ran these pistons with nothing more than "normal" machine work to the block. Meaning normal .020" or so cleanup on the deck same on the heads. Those are things you have to do during any rebuild right, even if I had the sacred Autotechs?

    Attached is the SCR calculator assuming .080 deck height. I've seen various people posting numbers from .055" to .100" so I guess all this is sort of pointless until I actually measure the deck height. Is that something I can do with a dial indicator or does the rotating assembly have to be removed?

    Thank you all for talking with me about something that's so far only a dream in my head . . .
     

    Attached Files:

  7. 300sbb_overkill

    300sbb_overkill Well-Known Member

    Oh yeah, forgot to add on rings because if you order the AutoTecs from Scott Brown they come with rings for $699.

    So a set of rings for the TRW pistons are around another $60 for the lessor expensive ones.

    Plus, if you went with composite head gaskets, if the deck isn't to bad which usually they're not you could skip the deck milling.
     
  8. Swagon

    Swagon Well-Known Member

    you would be leaving a lot of power on the table with only 7.7 static compression. To me its not worth putting turbos on that engine with that compression. personable Id shoot for a compression around 9.3-10.1. compression isnt bad for a boost engine, just run less timing/boost. It takes less effort to make power with compression. you could safely run 10psi of boost with like 12 degrees of timing with pumpgas and makes like 600hp. Dont be scared of compression.
     
  9. patwhac

    patwhac Well-Known Member

    It looks like in the end I wouldn't be saving that much to end up with less powerful engine that's sluggish off boost. Thanks for helping me decide you guys!
     

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