What cubic inch can you stroke a 350 to?

Discussion in 'Small Block Tech' started by C.Rob, Feb 12, 2018.

  1. C.Rob

    C.Rob Well-Known Member

    Just wondering since there are so many options on the 455 what sizes have guys made the 350 engine?
    300sbb_overkill likes this.
  2. greatscat

    greatscat Well-Known Member

    Chris we stroked Sonny's Tweety about as much as possible and got 366 using chevy rods. Cam gets in the way.
    DBS and SpecialWagon65 like this.
  3. 300sbb_overkill

    300sbb_overkill Well-Known Member

    Chris, post Sonny, you can get nascar take outs(1.850" rod journal size) for pennies on the dollar that will yield a 370 CID with a .040" over bore and a 3.990" stroked sbb 350 crank!

    If in you're interested you can PM me for more details.
  4. DBS

    DBS Well-Known Member

    I thought you had it worked out to get up around 380+, but is that where rod/cam clearances become very close? I love reading all your 350 posts. Taking notes:).
  5. BrianTrick

    BrianTrick Brian Trick

    Cool info. Anyone use rods with the 1.88” Honda journal? Can’t get 4.00” stroke to fit?
  6. greatscat

    greatscat Well-Known Member

    Thanks for the update
  7. 300sbb_overkill

    300sbb_overkill Well-Known Member

    You can get 383 cubes with a block that sonic checks good enough for a .105" over bore and the 3.990" stroke. That's the hard part though, finding block good enough to over bore that far.

    gsjohnny has been using the 1.889" rod journal size nascar take out rods for the last IIRC 5 years.

    The 1.850" rod journal size doesn't really have under sizes so you can't go any further with the stroke, so 3.990" is it. The extra .010" less stroke is to make sure every journal cleans up.

    A 4.00" stroke would work, even a longer stroke could be made to work with a billet crank, but custom rods with the Mitsubishi rod journal size of 1.777" would be a good idea to use for more cam clearance with more than IIRC 4.200" of stroke. Also with a stroke that is from 4.00" to 4.200" a 1.850" rod journal rod would work but should be no longer than 6.350" so the rod will actuate more at the parting line of the main caps as it rotates the crank to help keep the rod to cam clearance in check.
    Last edited: Feb 20, 2018
    Nailhead Ronnie likes this.
  8. BrianTrick

    BrianTrick Brian Trick

    Good info. Never toyed with a 350,but I’ve thought about it.
  9. C.Rob

    C.Rob Well-Known Member

    Just thinking about a buddy who wanted to build a 350 and turbo it verses a 455 due to block strength. Thanks guys
  10. BrianTrick

    BrianTrick Brian Trick

    I’m sure you probably have a Buick 350,or ten,but if your buddy needs one,I have one.
  11. sean Buick 76

    sean Buick 76 Buick Nut Staff Member

    My plan is to stick with 355 cubes, with turbos you really don’t need huge cubes... I would rather thicker cylinder walls and no trimming the rods to make them clear the cam.

    I went with a block girdle, billet crank from King, Hershe stock spec rods, diamond pistons. Will top it with fully ported alum heads once TA releases them later this year. Using a belt driven oil pump, still wet sump, internal balance, 9:1, street combo, mild cam by Scotty Brown. I don’t think I need big cubes with the twin turbos.

    My roll bar is only good for 10.00 in the quarter and my car is 2980 pounds so I think I should be good with this small cube combo.

    Attached Files:

    Nailhead Ronnie and Julian like this.
  12. 300sbb_overkill

    300sbb_overkill Well-Known Member

    Wrong thread, the question was "What cubic inch can you stroke a 350 to?"

    Not why wouldn't Sean do it.
  13. 8ad-f85

    8ad-f85 Well-Known Member

    Somewhere in between the extremes are lessons in trade offs dealing with this or any engine's designs.
    DBS likes this.
  14. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Shouldn't this thread be in the Small Block Forum?:)
  15. Jim Weise

    Jim Weise GOT AIR?

    Yes, it should be.. done

  16. alec296

    alec296 i need another buick

    I know Odin von hammer had to clearance his rods for cam with 1.850 rods. But I think he has a roller cam.
  17. 300sbb_overkill

    300sbb_overkill Well-Known Member


    You mean Ivan? Goes by Extended power and has a pic of Beaker from the Muppets for his avatar here?

    He went with the 6.450" length rods, the longer the rod the less it actuates away from the cam. Would of had more clearance with a shorter rod, the shorter it is the more cam clearance it will have. Unfortunately the dam deck height is so long you need to try to stay around a 6.300" to 6.400" length to try and keep the piston weight down and get enough cam clearance.

    Or if one wanted to go with a longer rod length they could order the cam with a smaller base circle for more clearance there, like the sbc guys have to do with more than .333" of lobe lift with a stroke of 3.750" or more and that is with 6.00" rods! With a 4.00" stroke in a sbc engine, the cam needs to be a small base circle cam, the rods have to be 6.00" or longer AND the rods need to be clearanced for the cam! Machining cam clearance is NOTHING new when building a stroker engine, unless you building a small block mopar then it would be new.
    DBS likes this.
  18. Mart

    Mart '71 350 GS, almost stock

    Wasn't there a guy in Europe or Netherlands that had Molnars that needed clearancing?
    Was he running flat tappet or roller?
  19. 300sbb_overkill

    300sbb_overkill Well-Known Member

  20. 300sbb_overkill

    300sbb_overkill Well-Known Member

    Yes, IIRC his ID name is Juze.

    He needed to clearance his rods for a standard stroke sbb 350 using the aftermarket Molnar rods, AND they didn't look like they had the correct offset either, so the rod didn't look like it was centered in the piston when it was in the bore.

Share This Page