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Thread: Crank shaft size

          
   
   
  1. #1

    Default Crank shaft size

    Hello everyone!

    I am trying to stuff my .32 surefire into my newly acquired redcat earhquake. The mounts fit right up, but the cranks are different sizes and the clutch bell doesnt line up correctly. What are my options to make this fit?

  2. #2
    Throttle, Brake, Dammit!!!! Revolauncher's Avatar
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    Default Re: Crank shaft size

    You would probably need a clutchbell, flywheel, and clutch setup for the Surefire, like from a HPI savage MT, then line up with the spur. The Savage is probably the lowest profile setup I could think of vs. the long pinion on the redcat. You can't flip the diff. because of the chassis cutout on the redcat....I had an Axial .28 on a redcat monsoon and that worked with the above parts....The surefire crank is the industry standard, the redcat is a little wonky.
    -some say I am the Stig, but I'm just a New York cousin.

  3. #3

    Default Re: Crank shaft size


  4. #4
    Throttle, Brake, Dammit!!!! Revolauncher's Avatar
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    Default Re: Crank shaft size

    No, that is small block, you need big block clutch kit. http://www.ebay.com/itm/HPI-Savage-X...EAAOSwH09ZHEaf
    Last edited by Revolauncher; 06-21-2017 at 06:37 AM.
    -some say I am the Stig, but I'm just a New York cousin.

  5. #5

    Default Re: Crank shaft size

    Quote Originally Posted by fastenough View Post
    Hello everyone!

    I am trying to stuff my .32 surefire into my newly acquired redcat earhquake. The mounts fit right up, but the cranks are different sizes and the clutch bell doesnt line up correctly. What are my options to make this fit?
    One is a standard crank and the other is a pilot crank shaft. You will need a different clutch nut and a different flywheel and possibly bearings.. The clutch belll and clutch are standard. Make sure you use the same pin style flywheel to match the clutch shoes.
    IF you can't handle the TRUTH jusk keep on TRASH talking. The one who can't prove Im a FAKe is the real phoney!

  6. #6

    Default Re: Crank shaft size

    So the redcat avalanche uses a .28 with the same shaft as my surefire. I might try to put the clutch/flywheel combo for that on there and see if it fits. Looks very similar to hp 4.6 savage setup. If it still doesn't line up correctly, do I just need to drill out the holes in the chassis to make it fit?

  7. #7

    Default Re: Crank shaft size

    There are different flywheels for different style cranks. The motor mount block hole may be different as well. You have to find the right match when changing different motor and sizes.
    check the threads on the shaft to see if the are the same(1/4-2 with a nut. If both are the same then all you need is a different flywheel. Measure the shaft size. If the sizes are different then you need a whole new clutch kit for the engine with the bigger shaft size.
    Last edited by Monstertrucker14; 06-22-2017 at 07:41 AM.
    IF you can't handle the TRUTH jusk keep on TRASH talking. The one who can't prove Im a FAKe is the real phoney!

  8. #8

    Default Re: Crank shaft size

    Got a new flywheel clutch and bell. Still trying to figure out a way to move the motor far enough up to mesh with the spur properly. Right now with it as forward as it can go it's only maybe 1/4 on the spur gear.


    Do they make adjustable motor mounts? If I drill the slots on the chassis they will be too wide I think. If I do drill it out to move it forward, if I use a larger washer to keep the bolt from going through the chassis, will it still hold it tight? I'd be afraid going that big that it will move around and just strip spur gears
    Last edited by fastenough; 06-25-2017 at 05:38 PM.

  9. #9

    Default Re: Crank shaft size

    Trying to put a pilot style motor in a older nitro that uses a standard crank is nothing but problems. The shaft is too short. The best option is finding the correct style crank shaft like the other engine and using the old style clutch shaft with the correct flywheel. I have seen what happens when you start to mess with the chassis mounts holes. Ofna make an adjustable motor mount that allows you to slide the motor forward. $20. But that may still not be enough. The other problem with moving the motor forward is clearance for the flywheel with the center diff mounts. The correct flywheel will be longer moving it forward. There are some flywheels kits with add spacers to accommodate both style cranks. You can make spacers. Last option is to cut the crank and put on the old style pilot clutch nut. Again there man not be enough threads to support the nut. I had a engine just this way. It had the wrong flywheel and I put the correct one on and to my surprise only one thread to tighten the nut. So my conclusion was the engine must have had a pilot crank shaft. Check before cutting crank.

    http://www.nitrohouse.com/Hyper-18-A...79_p_5535.html
    Last edited by Monstertrucker14; 06-26-2017 at 07:20 AM.
    IF you can't handle the TRUTH jusk keep on TRASH talking. The one who can't prove Im a FAKe is the real phoney!

  10. #10

    Default Re: Crank shaft size

    If I take out the reinforcement plates the engines fits and covers half the spur but is cockeyed to get the proper mesh and still only covers half of the spur. I'm thinking this might be too big of a project and money pit for me. I may just rebuild or send my stock engine to redcat for a replacement. The sleeve got scored during break in somehow and the pull start spring broke, and I figured I would try to repurpose my surefire 32.

  11. #11

    Default Re: Crank shaft size

    Rebuilding the engine will cost you $100+ for parts and a new engine would be $136 http://www.ebay.com/itm/Redcat-Racin...8AAOSw2gxYzwoe The problem with the bigger engine is the style crank shaft. Did you install a fuel filter on the damaged motor????? Fuel with more oil lube will protect the engine better. I use Wildcat with 18% oil lube. Other option is finding a used engine red cat for less?/ All I run is Os and Kyosho so I can swap out parts easily. I have tried many different ideas on trying to put a pilot shaft engine in and nothing has worked. Pilot shaft engines only work on the newer style buggies with smaller main gears.
    IF you can't handle the TRUTH jusk keep on TRASH talking. The one who can't prove Im a FAKe is the real phoney!

  12. #12

    Default Re: Crank shaft size

    No fuel filter installed. The sh engine only has 7 tanks ran through it. I was having air bubbles in the fuel line so maybe it starved it of fuel and caused the damage. I replaced the fuel lines and tested the tank. So I wasn't sure where the bubbles were coming from. I was trying to diagnose it, and that's when the pull starter broke. I thought it was the one way, but the spring came unraveled.

  13. #13

    Default Re: Crank shaft size

    Crap in the carb needle can ruin a engine fast. A fuel filter is the safest prevent to fixing the problem. The engine had a super lean run causing the damage
    IF you can't handle the TRUTH jusk keep on TRASH talking. The one who can't prove Im a FAKe is the real phoney!

  14. #14

    Default Re: Crank shaft size

    Will definitely install the fuel filter before I break in a new motor next time. Would an air leak from the carb or exhaust cause the bubbles in my line? I pressurised the tank under water and didn't see any bubble come out. I'm assuming that it's good

  15. #15

    Default Re: Crank shaft size

    Air bubbles are from an air leak. Use new fuel line and check the pressure tap on the exhaust to make sure it's not blocked. Use 6-32 size pressure fitting.
    IF you can't handle the TRUTH jusk keep on TRASH talking. The one who can't prove Im a FAKe is the real phoney!

  16. #16
    Silver Level BYT Member cbaker65's Avatar
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    Default Re: Crank shaft size

    I missed this ,most people cut the crank an add a clutch nut assembly!!!....DAH....
    Just bash it!..

  17. #17

    Default Re: Crank shaft size

    Quote Originally Posted by cbaker65 View Post
    I missed this ,most people cut the crank an add a clutch nut assembly!!!....DAH....
    The engine in question is a pilot shaft engine. You don't cut them.
    IF you can't handle the TRUTH jusk keep on TRASH talking. The one who can't prove Im a FAKe is the real phoney!

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