Slant Six Build Ideas

Slant 6 Engines

  1. John Martin

    John Martin Well-Known Member

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    It was lost in the last thread, but I was asking about the AussieSpeed Evil Stick.
     
  2. Johnny Dart

    Johnny Dart Well-Known Member

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    From what I got, you want to build an economical slant that is reliable, and can be driven everyday. The slant in "stock form" is already just that. Shaving the head/block, building a cylinder head, fancy stall converter, gears, etc etc would not be economical. Sounds like you've been on .org ?

    I would suggest a stock rebuild of the motor, electronic ignition, and a free flowing exhaust. Economical, reliable, daily driver. Done.
     
  3. volaredon

    volaredon Well-Known Member

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    Nothing wrong with .org.
    And the deal with the comp cams being not as good as they used to be isn't usually something that can be seen just on inspection upon taking it out of the box. The problem is with the makeup of the metal it is made of.hardness, etc. You can't just look at something and tell that.

    I don't blame anyone for wanting "a little More" out of a slant or a. 318. And to a point you can without hurting driveability or mileage. But it's all in how you go about it as to whether you get what you wanted to out of it when finished. But yeah, things like that higher stall in this case will not be necessary
     
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    • John Martin

      John Martin Well-Known Member

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      Improving on the design is absolutely economical. There is horsepower on the table with a slant six, it just needs help opening up.

      I guess you didn’t see the part where I am looking to get back power from the accessories the engine will have bolted to it.
       
    • RustyRatRod

      RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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      Thank you.
       
    • RustyRatRod

      RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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      Which is exactly what I suggested on his original thread and he got his feelings hurt.
       
    • RustyRatRod

      RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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      Getting it in and out. That's what it's all about. Super six carburetor, or small four barrel, mild camshaft, headers or modded opened up exhaust and bigger exhaust pipe. Milled head and or block for more compression. It's like any other engine, really with the exception that if you only do one thing, they payoff is much, much less, simply because you're working with less in comparison to a V8. Less bore size. Less bore numbers. Less cylinder head all the way around. Less port volume. Less valve sizes. Depending on how far you want to go, you can have the head ported and larger valves installed. That's getting pretty costly, but will add even more. Even an air cleaner designed to straighten and smooth the incoming air can make a difference. All of these things together will make a pretty big difference with a slant six.

      It's entirely possible with smart modifications, to add a solid 100 horse power from the stock highest rating of 145 and remain fairly streetable. Difficult naturally aspirated, but not impossible. Here is the latest cylinder head I am working on I just recently got back from my head porter. Completely ported, polished and modified for 318 valves. He was able to get from 99 CFM on the exhaust to over 150.That's an improvement I'll really be able to feel. As I said, it's costly. You just have to decide "how far" you want to go.

      CLOSED CHAMBER PORTED2.jpg CLOSED CHAMBER PORTED1.jpg CLOSED CHAMBER PORTED.jpg
       
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      • RustyRatRod

        RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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        Also, you should make sure to use whatever matching valve sprAngs you need to whatever camshaft you choose. Every single cylinder head I have (six) all have room for at least a big block Chrysler 1.550 diameter spring plus a little more.....all of course except the closed chamber head I pictured above. Its spring pockets I had to open up to the Comp 911 big block sprAngs I am using. Of course. That's how my luck runs. I'm a little rough around the edges, but I am excellent at making something from nothing and I guarantee you I can help you with your build.
         
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        • Ricks70Duster340

          Ricks70Duster340 Well-Known Member

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          Beautiful!!
           
        • RustyRatRod

          RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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          Here is the manifold mod I spoke of. I suck at using a grinder. I have lots of respect for those who can. My friend Freddie who lives five minutes away is one of those people. This thread outlines what he did to the manifold I have on Vixen now. He's done a second one I have on the engine in the picture. He got the outlet on it up to 2.5". I never would have imagined there was enough meat there to do it, but there is. I am going to get him to do another one for an engine I am building for a member here and probably a couple more for me just to have, since I have several more. It's a combination of small things like this that will add up and make your slant six a lot of fun. Here is the thread.

          Exhaust Manifold Mod

          I have extended the olive branch and continued to offer help to you. It's up to you how you react, not me.
           
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          • Ricks70Duster340

            Ricks70Duster340 Well-Known Member

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          • RustyRatRod

            RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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            And that is a very possible and probable goal. I'd say you can get a good bit more than your goal as long as you approach it in a systematic approach as I've tried to outline and not just one piece here and one piece there..
             
          • Ricks70Duster340

            Ricks70Duster340 Well-Known Member

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            The slant is really under rated in my opinion. With the long stroke, it can be a great street engine. Back in the early 60's, the hyper pack really was a head turner!
             
          • RustyRatRod

            RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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            Here is the cylinder head after I cut the guides to the diameter of the seals I am using and also opened the springs up to accept the Comp 911 springs. A note of worth.....do NOT machine the spring seats DOWN into the head. They are pretty thin in that area. If you need more spring height, do like I did and use the 318 valves. They are about .300" longer than the stock valves and allow for more spring height and open the door for more spring to handle a camshaft with more lift. Using them also opens the door to having to have the rocker shaft assembly relocated. Nothing to it other than paying Mike at B3 Racing Engines to make custom shims for the rocker shaft. It's only money. With the mods you're wanting to do, I seriously doubt you'll need to go that far. Here is the top side of the head where you can see the guides and spring seats after I cut them.

            CLOSED CHAMBER SEATS AND GUIDES CUT.jpg
             
          • RustyRatRod

            RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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            The long stroke is the 225's biggest advantage. If people would throw away the notion of building them for "horse power" and build for torque, they would have a much better outcome.
             
            Last edited: Apr 7, 2021
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            • Johnny Dart

              Johnny Dart Well-Known Member

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              I guess I'm not sure what you mean by economical ?
              Are you talking economical as in money or fuel economy ?
              I was thinking economical as in money. Building one of these engines for power adds up real quick.
               
            • RustyRatRod

              RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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              Yes it does. Ask me how I know. lol It's a lot of fun, though.
               
            • DodgeLad

              DodgeLad Victim of Circumstance

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            • Johnny Dart

              Johnny Dart Well-Known Member

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              Ask me how I know. :eek:
              Never again. Small Blocks for me.

              Car pics 004.jpg
               
              Last edited: Apr 7, 2021
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              • RustyRatRod

                RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                Oh I already knew you knew it. lol

                Always gotta brag on any of your engine bays man. You're attention to detail is fantastic.
                 
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                • RustyRatRod

                  RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                  It turned out petty good, didn't it?
                   
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                  • John Martin

                    John Martin Well-Known Member

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                    I guess that when I said I want to build an economy slant six it was pretty unclear huh?

                    I am looking to increase the power of the engine to make up for the fact that it will be driving an A/C compressor, and a power steering pump, in addition to the water pump and alternator. I estimate that the car would only have around 90 net hp at the crankshaft with all the stuff on the engine and installed. I would like to have about 160 net hp more or less with everything on the engine.

                    I know I can get some free horsepower back with improvements to a stock 225. I have had two Darts with 225s and 2.76 rears. They are dogs around town, and shine on the highway.

                    The car will be going to Florida when I have finished with it. It will need to go 70-80 mph consistently. 3.23 gears are a good compromise between the 2.76 highway gears and a 3.55 acceleration gear.
                     
                  • Ricks70Duster340

                    Ricks70Duster340 Well-Known Member

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                    John, 3.23 gears are my favorite for all around driving too. If you maintain the stock tire size, you will be winding that guy up pretty high at 80mph with 3.23's. Slant sixes don't like to be revved up high because of the long stroke. The engine will last longer if you keep the R's on the lower side too.
                     
                  • Johnny Dart

                    Johnny Dart Well-Known Member

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                    70-80 considently ?
                    Stock lower end.
                    Super Six
                    Free Flowing Exhaust
                    Electronic Ign
                    2.76
                     
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                    • DodgeLad

                      DodgeLad Victim of Circumstance

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                      :yawn:
                       
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