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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #11
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    I thought about automatics...the older I get the more I like the idea of putting around without shifting, but it is another 100lbs on a buggy.

    My idea is to cut a plate that will basically seal the bell housing area with a very heavy bearing in the middle. Then have the splined sleeve from a clutch friction plate pressed and welded into a 1.5" keyed shaft that feeds through the bearing with a sprocket mount immediately on the other side. This would make the input shaft only see rotational torque, and the heavy bearing and bell housing will take the brunt of the side load. If that ends up being still too much for the bearing the plate on the bell housing can have an additional bracket and bearing welded to it to support a longer shaft, and then the side load will taken up almost entirely by the bell housing. When I'm shooting for less than 125hp in a 1000lb buggy, I think that kind of arrangement should be safe.

    I think, as you say, the biggest issue will be supporting the input shaft properly. I think that's why people who swap meaner engines into the Chinese shafty minibuggies explode those gearboxes while people, such as myself, have no problems feeding the chain drive buggies. I've been throwing 100hp and 60lbs of torque pretty hard at my GK13 and the gearbox handles it just fine because all the bearings are properly supported. It doesn't see side load...just rotation. While I get what Iggsy is saying in that the RPM range changes a lot of things, you can in no way divide the 80lbs of torque a GSXR1000 is producing into a greater force than the 106lbs of torque a D16 is producing.
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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #12
    Millenium Member nutz4sand's Avatar
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    I think you are spot on on the tranny plate idea as thats quite silimiliar to which I hope to do.

    The 80ftlbs of torque (IF its crank torque) is first multiplied by the geardown at the clutch and crank THEN again in the trannies gears. So the primary geardown at the crank by whatever first gear ratio does multiply into some pretty mean numbers at the bike motors sprocket.

    But considering the low weight of a mini buggy combined with loose traction offroad it should not be to big a deal. You will always have some slip.

    I have seen turboed hondas revving to the gills and sidestepping the clutch with all that engine rotational weight and the entire clutch weight thru wide sticky tires on asphalt with the trannies taking the abuse in stride. (Yes I have seen failures too. But show me anything fail proof) That shockload has to be tremendous.

    I will also add in my one dislike of the RPM. The noise. I hate how the gears sound (straight cut) when spun fast or under load. The car trannies will not do this.
    Now that NOBAMA has PROVEN he is the absolute WORST president in the history of history Jimmy Carter can thank him for stealing the dunce crown.

    Lets hope the next guy repeals NObama care along with the rest of the stupid crap this blight on our windshield has done.
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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #13
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    80lbs of torque a GSXR1000 is producing into a greater force than the 106lbs of torque a D16 is producing.
    Mate, just an example, using your figures and assuming worst case loadings (peak torque and low gears).

    D16 peak torque is 106 ft lbs. No primary reduction so the civic gearbox sees 106 ft lbs on the input shaft (ignoring losses in the clutch etc.)

    GSXR peak torque 80 ft lbs. Assume you are using the motorbike gearbox for all of your shifting. You are currently in the bikes first gear. From the net, primary reduction is 1.553:1 and 1st is 2.687:1. Gives you a total of 1.553 x 2.687 = 4.173:1. Therefore your torque on the input shaft of the civic box is 80 x 4.173:1 = 333 ft lb on the input of the civic box (ignoring losses in the motorbike gear train).

    The bike engine is capable of putting three times the torque of the Honda engine into the civic box due to the reduction in speed!

    The civic box would possible work, proving you selected bike gearbox ratio of nearly 1:1 and used the civic box for all of your shifting. If you use the bike gearbox for shifting, you can put in some serious torque.
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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #14
    Millenium Member nutz4sand's Avatar
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    Quote Originally Posted by Iggsy View Post
    Mate, just an example, using your figures and assuming worst case loadings (peak torque and low gears).

    D16 peak torque is 106 ft lbs. No primary reduction so the civic gearbox sees 106 ft lbs on the input shaft (ignoring losses in the clutch etc.)

    GSXR peak torque 80 ft lbs. Assume you are using the motorbike gearbox for all of your shifting. You are currently in the bikes first gear. From the net, primary reduction is 1.553:1 and 1st is 2.687:1. Gives you a total of 1.553 x 2.687 = 4.173:1. Therefore your torque on the input shaft of the civic box is 80 x 4.173:1 = 333 ft lb on the input of the civic box (ignoring losses in the motorbike gear train).

    The bike engine is capable of putting three times the torque of the Honda engine into the civic box due to the reduction in speed!

    The civic box would possible work, proving you selected bike gearbox ratio of nearly 1:1 and used the civic box for all of your shifting. If you use the bike gearbox for shifting, you can put in some serious torque.

    I'll play ball.

    First off first gear should be for slowly crawling thur pits and campsites. (Sure you might be able to / could try to break it like this if you built it JUST to break it)

    Second gear is a whole another world. I am too lazy and at work so you do the math again please. What kinda torque in second?

    Third your forgetting that some of these BUILT hondas are making WAY more power than that stock. WAY MORE. Through the stock tranny.

    Fourth there is always going to be slippage off road.

    Fifth unless you build a friggin tank for a buggy its going to weigh a lot less than the car.

    Sixth even though the torque is high in lower gears. The rpms are not there. Remeber how many RPMS a honda engine is buzzing when a street dragger sidesteps the clutch at what 7 or 8 or 9 grand. You take crank weight and flywheel weight and a good clutch and how much torque do you think that tranny is dealing with in that moment? Flywheel weight adds KILLER foot lbs per RPM. Thats all to forgotten and IS being forgotton here.

    Yet those honda trannies take it.

    Heres another one for you. Another X-memeber of this site has a Built VW Bus box. he is feeding a very healthy Hayabusa to it with a chain to move the power over (no reduction if I recall after the bike engine and a simple cush drive (that anyone could add to the honda setup easy enough) and his rail is a tad larger than most "mini's". This guy is a power monger and does not baby his ride. He has never had an issue with it.

    Now A honda tranny is tougher than a VW bus. But logic tells me that if you were to do this the bus tranny would pop. It MIGHT if all he did was full out drag racing launches. He does dune it hard though.

    But lets face it this is a budget setup for fun. I STILL would wager the honda over the VW setup.

    I have seen NO ONE who can PROVE the honda tranny would not live behind a Hayabusa if done right. NO ONE.
    Now that NOBAMA has PROVEN he is the absolute WORST president in the history of history Jimmy Carter can thank him for stealing the dunce crown.

    Lets hope the next guy repeals NObama care along with the rest of the stupid crap this blight on our windshield has done.
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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #15
    Senior Member whitedragon64's Avatar
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    Hi Nuts
    The reason i dumped the Honda trans after a year of perseverance with it
    Main issues was the drive line to it ( Finally sorted that out with a gear drive) this cost 2 civic gearbox's to sort out

    Then I detinated 2 Honda Trans in race conditions = stripped teeth on the gears
    Used 3,4 and 5 the gear in the Honda trans as gear ratios changes so shifted gears in the Busa where 1st and 2nd gears were was taken up with a steel housing with larger bearings to reinforce it

    All comes back to breaking and grabing traction = massive shock loads and the gear teeth part company

    If I remember correctly the Busa trans gears were larger than the civc gears
    Wider tooth and greater pressure angle
    I may be wrong cant compare them now as they went into the trash years ago

    Not saying it cant be done as I have see it done Just not for me , and it is a lot of work
    I was talking to a guy over here and he had one hooked up behing a GSXR 1000 back in the early 80's usen it in the dunes only and he had years of thrashing it with no issues
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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #16
    Millenium Member nutz4sand's Avatar
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    Quote Originally Posted by whitedragon64 View Post
    Hi Nuts
    Main issues was the drive line to it ( Finally sorted that out with a gear drive)

    All comes back to breaking and grabing traction = massive shock loads and the gear teeth part company
    Got any pics of the drivetrain? What gears were you stripping out? Even with a gear drive if it was not solid and straight 100% of the time NO tranny input would survive. Period.

    As for breaking and grabbing traction I understand that. Just like I understand the loads of a car engine on the floor and the clutch being dumped. This amount of shock is more than the Busa likely could make shy of a flywheel being added after its output.

    Anyone who doubts the hitting effect of a fast spinning flywheel I can show yah some expieriments that will make a beliver out of you (and likely break your arms at the same time)

    I would be willing to bet that the alignment was brought into question over the grabbing and breaking traction which caused flex and made the input not held straight.

    I could be wrong but I do not think I am.

    How was the tranny and the bike motor each mounted.
    Now that NOBAMA has PROVEN he is the absolute WORST president in the history of history Jimmy Carter can thank him for stealing the dunce crown.

    Lets hope the next guy repeals NObama care along with the rest of the stupid crap this blight on our windshield has done.
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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #17
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    I'll use busa numbers, mainly because its what I had in a spreadsheet.

    Peak torque on a busa = 102 ft lb. Assuming you could transmit all of the torque (no wheel slippage etc), here are the torque figures out the engine output (i.e input to the civic box). Gear ratios have the primary factored in.

    Gear Ratio ft-lb
    1st 4.2 426
    2nd 3.1 315
    3rd 2.4 248
    4th 2.1 209
    5th 1.8 185
    6th 1.7 170

    So even in 6th, you would put out more torque than a stock engine.

    When you consider shock loading, as a general rule of thumb the loads are multiplied by between 2 and 3. Not saying kit won't work, but it is a lot of load for a little box.
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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #18
    Millenium Member nutz4sand's Avatar
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    One thing I have not seen in too many of these setups is a cush drive.

    The amount of relief it could provide is great.

    The unit I described above has one and he swears by it that it helps the VW BUS box stay alive.

    If you wish to ride with him to see IT work he rides in Little Sahara Sand Dunes at Waynoka, Oklahoma a lot. I could set you up on the right date.
    He also goes to other dunes like St Anthonies and Glamis.
    Now that NOBAMA has PROVEN he is the absolute WORST president in the history of history Jimmy Carter can thank him for stealing the dunce crown.

    Lets hope the next guy repeals NObama care along with the rest of the stupid crap this blight on our windshield has done.
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    Re: Motorcycle engines and car transmissions....why ain't it done?
     

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    Re: Motorcycle engines and car transmissions....why ain't it done?
    #20
    Millenium Member nutz4sand's Avatar
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    Yup I remember that now and felt the same way then. And yes I do think that the gears put an unnatural side load on the input. Unless I am missing something it looks like the gear on the input does not have a bearing between it and the tranny?

    I also need to look at it better how it and the engine are tied.
    Now that NOBAMA has PROVEN he is the absolute WORST president in the history of history Jimmy Carter can thank him for stealing the dunce crown.

    Lets hope the next guy repeals NObama care along with the rest of the stupid crap this blight on our windshield has done.
    Reply With Quote
     

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