How street able are these 340 stroker motors?

Small Block Mopar Engine

  1. OldmanRick

    OldmanRick Well-Known Member

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    I think i'm understanding better now.

    This article may shed a little light as far as your project is concerned. I'm not recommending any particular parts or brands, but the 2nd engine here (scroll down) looks very close, although you will have the 3x2 intake. You also would probably be well served to spec out a custom cam just for your application.

    http://www.hughesengines.com/TechArticles/10408416strokerdynotestingsept2002.php
     
  2. moper

    moper FABO Gold Member FABO Gold Member

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    The owner of this engine is a wrench and part owner of a very successful NMCA Mustang and has many race cars under his belt. I built the shortblock and degreed the cam. He added the top end and dyno'd the engine. I wasn't aware he was testing anything and while I'd question many others' results just as you did - I have learned after talking to him there's no reason to question this guy. The numbers may be a little off accounting for typical dyno shenanigans, but the change was significant and very apparent. These were both tuned on the pump although i don't think they tried to wring every last ounce from the Air Gap combo because he was going with the six pac regardless. Tune all you want - the intake is restrictive on a 4" stroke engine. It's reality - not pessemism.
     
  3. michformulaS

    michformulaS Well-Known Member

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    I wanted Torque for the street so I went with the following set up and am very happy with the results.
    416 Scat forged internals, zero deck with -20.5 dish (9.7:1) with 68CC X ported heads.
    Air Gap w/ 750 Speed Demon and smaller 1 5/8 Hooker headers (power steering) so probably not too far off 340 manifolds. 236 dur 108 LSA .500" lift cam with 2500 stall converter and 3.23 gears. This thing pulls real nice and drives great as a summer DD with power steering and power brakes. I figure if I ever want to trade streetable torque for more horsepower all I have to do is redo the top end and cam. So far I am going on 4 years of really enjoying this setup.
     
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    • DA4AD

      DA4AD Well-Known Member

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      Sweet, that's what I wanna hear.
       
    • moper

      moper FABO Gold Member FABO Gold Member

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      Another build - like Mich's - same build but 587 castings ported, another 10° of duration @ .050 in a hydraulic cam, and a Holley Avenger 870VS. In a 3800lbs E body and 3.23s it gets 17mph and runs 12.80s @ 109 in the 1/4.

      The 4" stroke smallblock A body combo is the ultimate street combo IMO.
       
    • fishy68

      fishy68 Tyr Fryr's Inc. FABO Gold Member

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      Curious as to the findings of the article referred to in the Mopar Muscle magazine I see the test engine is a 360, not a 4" stroke 408/416. It wouldn't surprise me to see a much larger difference in power production than the article shows when comparing them on the much larger cube stroker. JMHO
       
    • autoxcuda

      autoxcuda Well-Known Member

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      Mine is similiar. I feel it's real streetable.

      416 Scat cast, 9.8:1 with edelbrock ported heads
      M1 Single plane w/BG 750 Silver Claw
      TTI 3/4" stepped headers X-pipe and full 2 1/2" TTI exhaust
      274S Comp mechanical cam 236/242 @.050, .502/.511, and 110 seperation.

      I was looking to trade low rpm torque for hopefully more high rpm HP/TQ. Still spins tires at will on the street anyways.

      [ame="http://www.youtube.com/watch?v=HfJI_CQ98C4&feature=share&list=UUt4XUw2IBPxheMcJX5CdnuA"]416 Drive away - YouTube[/ame]

      [ame="http://www.youtube.com/watch?v=-8QSTlvdqSs&feature=share&list=UUt4XUw2IBPxheMcJX5CdnuA"]416 Idling sound walk around - YouTube[/ame]
       
    • DA4AD

      DA4AD Well-Known Member

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      Is it cheaper to buy a kit or buy the parts seperatly?
      I priced out the steel crank from dodge - $1000.00.
      Whats the best choice for rods and pistons? hoping the block cleans up at .040. Can I use stock rods ?
      Pulling the motor Friday night!
       
    • flyfish

      flyfish C8H18+N2O = :-D

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      The price of the crank is a little steep. I have not checked prices lately, but when I built my stroker 4 years ago I got a Eagle steel crank for $650. As far as rods go, it is hard to beat the Scat I-beams for the money...4340 steel, light, strong, and relatively cheap (I got mine for $260 off Ebay).

      Here is my build for my street/strip car if you are curious...and YES, it is very street-able in my opinion...but opinions vary.

      360 block, 410 ci, pump gas, 10.8:1 compression
      Eagle 4.00 steel crank, Scat I-beams, Diamond pistons, total seal rings (file fit),
      ARP main/head studs, Edelbrock heads stage II ported by Ryan J @ Shadydell,
      Small solid roller 248/254 duration w/ .576/.582 lift, Victor intake, Proform 750 dp
      4.10 gears, spool, 35 spline axles, Caltracs, Mono’s, Calvert shocks
      727, manual valve body, 8” converter, 28x11.5 Hoosier QTP
      3200 lbs, street trim and with 3 inch Flowmasters.

      My car runs mid 10’s…but you could do something similar with a hydro roller, less converter, and non ported heads to make a nice low 12/high 11 second street car.
      Basically, all you need is a plan and a goal in mind before you start, and build accordingly.
       
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      • autoxcuda

        autoxcuda Well-Known Member

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        I used a cast Scat rotating balanced assembly I bought from Brian at IMM Engines. Everything measured spot on. Brian could have sold me a unbalanced kit and then charged me to balance it, but he said he has checked them and they were fine for my street/strip application.

        Cast is fine for street strip car around 500 HP or less. Got about 6,000 hard miles on it so far.
         
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        • DA4AD

          DA4AD Well-Known Member

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          Eagle kit w/ steel crank - $2,150.00 locally.
           
        • fishy68

          fishy68 Tyr Fryr's Inc. FABO Gold Member

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          You just gotta price around. I bought all my parts separately because I wasn't in a hurry to get it done and looked for the best deals. In every case I bought parts that someone else had bought and for one reason or another never used them so I got new in box parts for just a little more than half of what they normally sold for. The only exception was the rods in which case I went with new SCAT rods. Like Flyfish said their nearly impossible to beat for the price and value. You can use stock rods but they aren't as strong and will almost always need upgraded bolts (ARP bolts) installed along with re-sizing. That costs nearly as much as buying a new set of SCAT rods. Plus stock rods will usually hit the bottom pan rail on the block so the block has to be clearance for them. SCAT's use bolts instead of studs and nuts so they clear the block fine. Their also a good amount lighter than stock rods. Lighter rotating parts means a longer lasting engine (as long as their good parts of course).

          What horsepower level do you have in mind? I see a lot of guys recommend using a steel crank and it is of course the best but I agree with AutoX that a cast crank is fine up to 500 hp. That's what I have in mine and it's going on 6000 hard miles, but it is only about 450 hp so I'm not stressing the crank to the max.

          Pistons are another consideration. IMO when doing a stroker you should always go forged because the piston speed is so fast on them they take a beating. I used Wiseco Pro-Tru pistons and they are super light and along with the light SCAT rods allowed my machinist to internally balance the rotating assy. without using any Mallory metal (that stuff is priced like Gold!)

          If I were you I'd have the block sonic tested. Most will be ok at .040 over but you just never know. You want a good stable cylinder wall, not something flimsy that lets the piston rock around. You should also have it square decked. SB Mopar's are usually terrible on deck height accuracy.
           
        • frosty_the_punk

          frosty_the_punk Well-Known Member

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          A lot of motors lose horsepower when changing from a torker II to a Super victor or M1 too, but do we dismiss them as being generally inferior? No we don't.

          Every combination is different and I think there will be combinations where the six pack will work approximately just as well as any other dual plane.

          most strokers are built for power, obviously. But I don't believe that a well tuned six pack will guarantee a minimum loss of 20hp compared to any other off the shelf dual plane.

          To each their own.
           
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          • BrianT

            BrianT Let's go!

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            As far as deals go, I bought a complete forged Scat rotating assembly from Summit when they ran their 10% off deal earlier in the year. No shipping, no tax. I couldn't beat the price anywhere.

            Side note...when I opened the box that was drop shipped directly from Scat, someone had put H beam rods in there instead of the I beams it was supposed to come with. Bonus!
             
          • Art Clark

            Art Clark For Our Boys

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            Check out Nick on YouTube.
             
          • Brooks James

            Brooks James Dustoff

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            RRR you are correct. I agonized over headers vs manifolds my research showed that even on a mild plus street engine the difference was 20/30 hp
            I know that many will disagree with me but you won’t really feel 20-30 hp in the seat of your pants. Also consider heat production, fitting problems, burnt wires, gaskets, rust, low clearance etc.
            Not to mention that a really good set that doesn’t have high frig factor to fit is 400-500 bucks.! Don’t ever think my exhaust manifolds will wear out. I built my car to cruise not work on all the time
            I can street race at night and my wife can go to the grocery store in it the
            next day, and do it with 500 hp on tap
             
          • 12many

            12many Well-Known Member

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            Love a good thread resurrection. Ahhh things were so innocent and less complicated back then :rolleyes:
             
          • Scott Bender

            Scott Bender Member

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            I have the exact set up your talking about and I drive it on the street all the time. Never an issue.

            IMG_20201222_135403165_HDR.jpg
             
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            • Nat

              Nat Well-Known Member

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              you don't need a stroker to get 430+hp out of a 340 , i had a granny build 340 with 400tq 425 hp , and it was super streetable got 20 mpg+on the highway . am now going to build one again as the stroker gets 120mile to a tank used to get close to 300 miles on a tank @6.00+a gallon i'm tired of the stroker
               
            • flyfish

              flyfish C8H18+N2O = :-D

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              Hello 7.5 year old thread, how have you been!! :lol:
               
            • ir3333

              ir3333 Well-Known Member

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              resurrected...but i know guys with 408's that get a ton of effortless tire spin, cruise nicely on the street
              ...but none get good mileage.
               
            • autoxcuda

              autoxcuda Well-Known Member

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              neither will with a larger cam in a 340 making the same HP and TQ.
               
              Last edited: Mar 8, 2021
              • Agree Agree x 1
              • rumblefish360

                rumblefish360 So close, yet so far away FABO Gold Member

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                Now use a 318 & an OD trans.....
                Just saying...:poke:
                 
              • ir3333

                ir3333 Well-Known Member

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                I agree, but both need to have a cam with the most efficient lo speed torque value at the cruising rpm.
                The small motor should do better with careful cam selection.The stock 340 head is very efficient on the small block.Many stock 340's got 20 mpg.Geared for the cam they still do very well when built for power.Strokers...not so much.
                 
                Last edited: Mar 8, 2021
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                • furrystump

                  furrystump Well-Known Member

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                  I run 11.79 at 117 though stock 68 340 exhaust manifolds at 410 CI. I know of a 444 that runs 11.5’s at 121? Mph with a 6 pack and the same exhaust manifolds. Do they hurt sure, at street car level........ahhh not to most peoples idea of street car. I know the 444 put out a very conservative 450 on the dyno.
                   
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