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Cheapest rev limiter possible

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 84_Chevy_K10, Jan 1, 2003.

  1. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I am just going to put together a mild small block if I don't put a used motor in my truck this time. The thing is, I always find myself out in the woods over-revving my truck doing something stupid. That's all fine and dandy, but I managed to blow it up once. I want my truck to be more dependable. I really haven't got to do much 'wheelin lately, just repair stuff.

    So...

    Task:
    Limit RPM to something safe (5000 or so)

    Conditions:
    Given a beat up, rough, 4wd Chevy shortbox pickup, 9" of lift, 35" BFG M/Ts, 3/4 ton axles, and 4.10 gears with a gov loc rear and open front with a 4 speed and 205.

    Standards:
    Must be cheap and reliable.

    What do you guys got for me?
     
  2. Pure Insanity

    Pure Insanity 1/2 ton status

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    MSD 6AL has a limiter in it. Its the same as a 6A but has a rev limiter.

    Or use a tach w/ shift lite. When I hit 6000 I get a big orange lite in my face thats a bit hard to miss. /forums/images/graemlins/crazy.gif
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I have a stick. I'm not gonna lift even if I do see my tach going crazy because I won't be able to upshift in the mud anyway.

    6AL is $220. I was hoping there was a cheaper way. The 6AL is what I had in mind though.
     
  4. Pure Insanity

    Pure Insanity 1/2 ton status

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    TMK the 6AL may be the cheapest ay to go. Check Jegs and see if the list any stand alone limiters.

    The beauty of the shift lite is you dont even have to be LOOKING at it, it grabs your attention. /forums/images/graemlins/eek.gif

    Unless your willing to work w/ it tho, a limiter if definately for you. /forums/images/graemlins/rotfl.gif
     
  5. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Well when I blew my motor up, I knew it was screaming so I looked down after I lifted at the end of the pit. The tach said 7,000 after I'd already lifted. Did you know a stock-bottom ended 305 would spin that hard?

    By the time that light comes on its too late anyway. Jeg's doesn't list a stand-alone limiter, but I was hoping someone had another idea.
     
  6. Pure Insanity

    Pure Insanity 1/2 ton status

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    Stand alone rev limiter

    I did it the old fashioned way, looked it up in the catalog then punched up the part #. /forums/images/graemlins/deal.gif

    I do have to disagree on it being too late by the time the lite comes on. When mine hits 6 its on and stays on till I lift.
     
  7. Pure Insanity

    Pure Insanity 1/2 ton status

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    As a side note....if youve never heard a motor bouncing of the rev limiter, it sounds strange and youll think your done till you get used to it.

    You cant just stand on it and let it bounce off the limiter. Youll have to back out. What they do is drop the spark to alternating cylinders to keep the RPM at the selected point. So more or less your losing power by riding the limiter.
     
  8. Sandman

    Sandman 3/4 ton status Author

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    That is exactly the reason I went to the auto. The stick was great getting me out of the hole but it would top out and sometimes people would get me on a long pit. I killed my 400 by over reving it in a race.
     
  9. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    SM 465's aren't that useful in mud...the only time my old 350 ever saw 5500+ was in the mud. I looked down and saw the tach a little over 6000 and got out of it instantly. That 350 had a slight tick ever since.

    Rene
     
  10. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Yeah well I was in 4 low and 2nd gear...I just should have picked a higher gear but I thought the mud was deeper.

    I know it's not good to let a motor bounce off the rev limiter but it's still safer than for RPM to continue to increase. Plus, when I'm out in the woods, the throttle is only short spikes like that. At the mud bogs every year of course, it's about 10 seconds of that.

    Oh, I had no idea that an MSD soft touch rev control could be used itself. That's what I'm going to buy then. I thought you needed an MSD ignition to hook the rev control up.

    Now that's what I need! A $95 box to save a $300 motor! Either way it saves quite a bit of labor.

    As for the auto vs. manual debate, I'm not sure. Me and my friends all used to be automatics and went 4 speed (either by swapping or buying a different truck, three of us swapped) and we're all happy. There are downfalls to both, and flat out bogging is one of the downfalls, but honestly that's the only time I miss my automatic.
     
  11. 87sm465np208

    87sm465np208 1/2 ton status

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    cheapest rev limiter = a peice of wood under the gas petal /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif /forums/images/graemlins/rotfl.gif.

    /forums/images/graemlins/usaflag.gif /forums/images/graemlins/truck.gif
     
  12. 84_Chevy_K10

    84_Chevy_K10 Banned

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    LOL!! I need one! Make mine a 4x4!
     
  13. HarryH3

    HarryH3 1 ton status Author

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    I was thinking that swapping to a small 2-barrel carb would work also. /forums/images/graemlins/wink.gif
     
  14. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    here is a backwoods idea....
    RPM switch set up to open a relay to cut power to your distributor. RPM switches are fairly inexpensive. it would work, but it isnt the best way.
    Grant.
     
  15. HarryH3

    HarryH3 1 ton status Author

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    With a carb, it will still be dumping fuel into the engine while the spark is turned off. The raw gas accumulates in the exhaust system. Then when the spark comes back on, BOOM!!!! One hell of a backfire. A buddy in high school used to turn off the key for a couple of seconds in his F-100, then when he would turn it back on you'd think that a tank had just fired a round under the truck. Then one day it built up just a little too much and blew the seam on his muffler open about 4 inches. /forums/images/graemlins/eek.gif

    That's the main reason that modern rev limiters cut spark to only a few cylinders at a time. /forums/images/graemlins/cool.gif
     
  16. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    yeah, a little toyoat heliux i knew of used to do that. like i said, not the best way, but a way. i do like the newer soft touch rev limitrs by MSD. mine was nice, i would use it to keep my foot out of it from time to time. Grant
     
  17. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Muffler bombs are the oldest trick in the book. That's why I have straight pipes and if I didn't, I'd have straight through mufflers.

    I'm going to buy an MSD soft touch box, now that I know it'll work with stock HEI.
     
  18. imiceman44

    imiceman44 1 ton status

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    I have 2 trucks, one for speed with a th400, and one for slow go with a 465.
    I like the auto for keeping the momentum going and the manual for the easy engine breaking in low gear.
    I tried my 465 with the diesel in the mud and snow and I almost got stuck when I was upshifting because you loose the rotationnal force on the tires and the wide ones drag and stop.
     
  19. 84_Chevy_K10

    84_Chevy_K10 Banned

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    You have to pick the right gear first. If you choose too low of a gear, you over-rev your motor like a mad man. If you choose too high, you bog down. I've never had a great motor so I always go too low. You can't try shifting in the middle of a pit.
     
  20. imiceman44

    imiceman44 1 ton status

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    Well I was in a snow run on a long steep slope and I couldn't just keep going in first for 500 feet.
    /forums/images/graemlins/grin.gif
    Luckily with great tires and dual lockers, I didn't get stuck and the diesel can pull in second or third from almost standing still. /forums/images/graemlins/thumb.gif
     

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