Why a 4/7 SWAP CAMSHAFT?? - HOW TO calculate your RPM and Speed!

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  • @benrossbach6501
    @benrossbach6501 4 місяці тому +15

    There may be 39 million channels but yours is one of only afew automotive channels worth watching. Thank you sir.

    • @TRAVISVANZUIDEN
      @TRAVISVANZUIDEN 4 місяці тому +4

      Completely agree

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому +4

      Very nice compliment, that motivates me to keep digging. Thanks Ben and Travis. AG

  • @alleyoop1234
    @alleyoop1234 4 місяці тому +4

    Back in the 80's I worked at a carb shop in Prince George, BC, which of course we also did all ignition work. When hooking a car up to the scope, often I would hook the inductive pickup to #6 instead of #1.
    I had SO many guys try to tell me I was doing it all wrong and I had no clue what I was doing, lol!

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks alleyoop, you are correct. That would work exactly the same. AG

  • @SalterRacingEngines
    @SalterRacingEngines 4 місяці тому +4

    All the tests that I've done with 4/7 swap cams on similar engine builds it seems to smooth out the torque curve more so than a traditional firing order
    It will be interesting to see if your results come out the same

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому +1

      Thanks for watching and commenting Brian. You have been busy too! AG

  • @dondotterer24
    @dondotterer24 4 місяці тому +4

    Congratulations on the win and fast time. You showed them that you could beat them with basically a street car engine when they where trying to go all out. Thanks for the videos!

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks for watching and commenting Don. AG

  • @edpetrocelli2633
    @edpetrocelli2633 4 місяці тому +3

    I got to hand it to ya, your shop is super clean and a motor can`t be too clean, I just cant keep mine in that condition. Now my assembly room is a different story. but nowhere as sanitary as yours, where my machines are its a bit dirtyer. Your place looks as clean as a kitchen. I keep looking for a pool table and a bar. I did see A/C. Very nice. I enjoy your videos and look forward to them. Congrats to your son`s checkered flag

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks for the nice comments Ed, and good to hear from you.AG

  • @DavidB7474
    @DavidB7474 4 місяці тому +2

    I hate to admit that algebra would play a part in hot rodding, but it’s finding the variable. It’s a really basic formula. I learned it in hot rod magazine in 80’s. In my first 74 Camaro the speedometer didn’t work. But I figured mph based on rpm. Now they have calculators on line.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks David, there are easier ways to do it, but always better to understand it.AG

  • @clarkkent5076
    @clarkkent5076 4 місяці тому

    I have watched all your posts since around one year ago. I probably know about 75% of the stuff that you talk about. But the 25% I am missing is probably the most important stuff. If I had built an engine with my 75% knowledge, it would most likely have been destroyed. Thanks for sharing your knowledge.

    • @goldsgarage8236
      @goldsgarage8236  3 місяці тому

      Thank you for watching and commenting Clark.AG

  • @MVPisME383
    @MVPisME383 4 місяці тому +4

    Thank you for sharing your knowledge. Nice looking paint jobs on those.

  • @harryhicas
    @harryhicas 4 місяці тому +1

    Respect to you for being a noble man.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому +1

      Thanks Harry, I even showed this one to my wife. Comments like this keep me motivated. Much appreciated. AG

  • @keithiverson6687
    @keithiverson6687 4 місяці тому +1

    Safety lock wiring on bolts is done a lot on tracked military armoured vehicles, the vibration running through the driveline will rattle anything else loose.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks Keith, makes sense. Thanks for the info.AG

  • @Carl_Jr
    @Carl_Jr 4 місяці тому

    Great formula on the RPM and speed calculations. One suggestion: Multiply the outcome by .95 to account for converter slip. The average high-po converter has about a 5-8% slip at speed. 👍

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому +1

      Good point Carl. i was just thinking 4 speed with final 1:1 drive but you are correct. Thanks for contributing to my channel. I am not sure the the correct number is but .95 sounds reasonable. AG

    • @Carl_Jr
      @Carl_Jr 4 місяці тому

      @@goldsgarage8236 Gotcha. 👍
      A manual transmission would be perfect for this formula. The .95 would vary depending on the torque converter slip, which can't truly be measured. Any company worth their weight will give the approx amount in the specs.
      Thank you for such great content. I've learned a lot more from you than you have from me. 😁

  • @danieldimitri6133
    @danieldimitri6133 4 місяці тому

    There are theories about 4/7. One is to separate 5-7 but when you do that you pair up 4-2 or 3-1 as in the ls firing order. Both banks also still have 90 degrees pairs no matter what firing order, it's just that the opposite bank won't have them adjacent. However with rear exit headers the 4-7 swap still puts the rear more of the cylinders in the 90 degrees pair ahead of the other which helps space out the wave timing giving things a little more room to flow in the collector. I also feel it makes a better symmetry in a dual plane manifold but the issue is that good manifolds are tested on standard firing order engines and may have been compensated in some way. When it was tested the dual plane manifold with a 4/7 swap ended up with poor fuel distribution compared to the standard firing order camshaft and was down on power so it's fine in theory but in practice it would need manifold development for a dual plane. I feel like for a fi setup with a front mounted throttle body it might help to have the air come in near the adjacent 90 degrees pair which would make both the 4/7 and 4/7+3/2 swaps something worth exploring. The 4/7+3/2 swap happens to be the same as an LS or a roller cam Ford Windsor but Ford also happens to number the cylinders differently so it's not the same on paper. Ford said this helped with making main bearing loads more even. There is also a theory about crankshaft dynamics. The 18436572 order jumps from end to end on the engine making criss cross patterns. But the 4/7 swap and the 4/7+3/2 swap, if you start at 8 go from back to front of the engine. 87365421 or 87265431. 3 or 2 are the only cylinder not in sequence. It's not possible to make it a perfect with a cross plane crankshaft but with a non mirrored flat plane crank like some of the coyote Ford engines it is. But short of a total redesign a swapped firing order gets you close and may vibrate the crankshaft less.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks for your very detailed comments Daniel. You obviously have put a lot of thought into the 4-7 swap. AG

  • @SalterRacingEngines
    @SalterRacingEngines 4 місяці тому +3

    Wow Allen I had no idea there was that many channels that's crazy

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому +1

      Thanks Brian, good thing they are not all about engine building. AG

  • @stuckinmygarage6220
    @stuckinmygarage6220 4 місяці тому

    Good info. FYI, 4/7 swap on old stock Chrysler RB iron (440/383) with dual plane doesn't like it. Makes sense, though

  • @rubeneliel2k
    @rubeneliel2k 4 місяці тому +3

    Thanks for sharing knowledge. 👋🇵🇷

  • @dondotterer24
    @dondotterer24 4 місяці тому

    KCMAXX says the the 4/7 swap cam on his BBC crank driven Procharger runs smoother and the bearings look better. And I have seen a Dyno test where it smoothed out the curves.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks for the info Don. All good to know. AG

  • @enginemechanic-fo8ie
    @enginemechanic-fo8ie 4 місяці тому +2

    Hello MR golds garage i like your channel because you answer questions in the comments. Spicer has a nice transmission gear ratio calculator online. In your carburetor test do you have the edelbrock vrs-4150 carburetor in other tests they seem to be pretty good carburetors thanks

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks for the nice comments The only Edelbrock carb I have is a 1406 which is 600CFM. As we will discuss in the test, the carb that makes the most power on the dyno is not necessarily the best one for the street. Smaller carbs provide better throttle response and sometimes drivability. AG

  • @davidreed6070
    @davidreed6070 4 місяці тому +2

    Ive tried the 4,7 swap cams. I couldnt tell any difference. An ls cam also has the 2and 3 swapped..people say the harmonics are better. But then 1 and 3 follow each other.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks David. We will just have to see how our 4-7 swap works out. AG

  • @JerryHelton-zo7dg
    @JerryHelton-zo7dg 4 місяці тому

    All Nissan 5.6 V8 engines came factory with th 4/7 swap. It's definitely a world class engine.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому +1

      Very interesting, thanks for the info Jerry. AG

    • @JerryHelton-zo7dg
      @JerryHelton-zo7dg 4 місяці тому

      @@goldsgarage8236 firing order for 5.6 Nissan V8. 18736542.

  • @ws2664
    @ws2664 4 місяці тому

    I can't wait to see the difference between the 1.5 and the 1.6 rockers, I'm thinking about doing this to my car but I'm worried about engine vacuum and my power brakes. Could you use a vacuum gauge while testing both, It's just a Sunday driver and I'm more concerned about losing my power brakes then I am about increasing horse power? Thanks.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Bill, don't worry about vacuum. Duration effects vacuum not lift. 1.6 rockers will improve lift and should help everywhere with negligible effect on duration. You will be ok. AG

    • @ws2664
      @ws2664 4 місяці тому

      @@goldsgarage8236 Ok, good, then I can't wait to see the results.

  • @SalterRacingEngines
    @SalterRacingEngines 4 місяці тому

    Hey Allen, did you ever dyno the budget 350 engine

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому +1

      Hello Brian. We are waiting for a dyno date, right now it is Oct12. If Darrell gets a cancellation it will move up. He is pretty busy right now. We also have a dyno date for Oct 5, but we will use that for Tony's 302. AG

  • @ronalddmeacham3722
    @ronalddmeacham3722 4 місяці тому

    Allan do you have an identical spec cam with a traditional firing order to compare to? Very interested to hear the idle sound

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks Ronald. Not exactly but the lift and duration etc of this cam are very close to the cams that we typically install in our 350 builds. AG

  • @itseithergonnaworkoritaint7852
    @itseithergonnaworkoritaint7852 4 місяці тому +6

    Supposedly the 4/7 swap is moreso for crankshaft load distribution than equaling the intake pulses. An even better thing to do would be to offer a sbc camshaft with an LS firing order. Then the intake pulses would be more equalized and the crankshaft load distribution would be better. The down side is it wouldn't sound like a sbc anymore.😁😎👍

    • @ericuncapher9922
      @ericuncapher9922 4 місяці тому +1

      Yes. Going to sound terrible.

    • @doomman700
      @doomman700 4 місяці тому +1

      It won’t change the sound as much as you think. Now a flat plane crank, different story.

    • @shadvan9494
      @shadvan9494 4 місяці тому +3

      A 4/7 swap cam has the same firing order as the LS/LT engines. I believe it’s a combination of 3 things. 1. Better crank harmonic as you mentioned, 2. Better cooling, since cylinders 4 and 2 fire after each other and the front of the block gets the coolest water with a 4/7 swap cam, and 5an7 are at the back and get the the hot pocket of water at the rear of the block. The factory motor had poor cooling in that area. Did ent matter on street motors, but if you look at pretty much all race motors, the had braided lines running from the back of the intake manifold to the front to improve water flow inn the block and improve cooling at the rear of the block, on an SBC 5and 7 always run hotter than the others,a 4/7cam also helps thar. And 3. The 5/7 intake charge issue cylinder 7 robs some intake charge from cylinder 5. Nd that leaves the hot cylinders on the engine lean. Which is not good for power and can lead to detonation issues. Where a 4/7 swap cam cylinder 2 is robbing cylinder 4 intake charge, but it’s going in to the cooler cylinders and has less of an effect. Of coarse that really only applies in single plane manifold and tunnel rams a dual plane would not be affected by it. On a street engine you probably won’t see a difference in performance. Maybe 5/10 tops. Depending on the engine size. But on something like a full race 540 big block Chevy, it could be as much as 20+ hp. And that could be the difference in cooling the lean cylinder better and no running into detonation as soon, allowing for more initial timing or even just from reduced tendency for detonation. Those are just my thoughts,

    • @itseithergonnaworkoritaint7852
      @itseithergonnaworkoritaint7852 4 місяці тому +1

      @@shadvan9494
      Thanks for taking the time to explain that, I had a feeling there was more to it.😎👍

    • @ericuncapher9922
      @ericuncapher9922 4 місяці тому

      @@shadvan9494 Thanks for information

  • @garylawson5230
    @garylawson5230 4 місяці тому +1

    Do you know if the air flow research BBC dual plane intake manifold is any good or wait to see if they improve it

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks for the question Gary. I don't have any specific knowledge about that AFR manifold. Eric Weingartner is the youtube expert on intake manifolds. Check him out. AG

  • @doomman700
    @doomman700 4 місяці тому +1

    4/7 swap harmonics on the crankshaft are better.

    • @goldsgarage8236
      @goldsgarage8236  4 місяці тому

      Thanks Doomman. I think you are correct and one reason for doing it. Thanks for commenting. AG

  • @markmcmullen1371
    @markmcmullen1371 4 місяці тому +2

    👍👍👍

  • @TheLonesometoad
    @TheLonesometoad 4 місяці тому +2

    Edelbrock... not Elderbrock.

  • @brrpbrrp7657
    @brrpbrrp7657 4 місяці тому

    We’ll that didn’t clear up anything