Heymow - Lawnmower Racing Forum

Mower Building / Setup Help => Drag Mowers => Topic started by: TractorMan11 on April 19, 2012, 11:39:35 pm

Title: gearing for a drag mower
Post by: TractorMan11 on April 19, 2012, 11:39:35 pm
i need a little help with figuring out my set up for drag racing my mower  i have a 11hp Briggs flat head, peerless 724a trans axle i need to figure out engine pulley size trans axle pulley size  trans axle sprocket  and rear axle sprocket?  :confused:

Title: Re: gearing for a drag mower
Post by: royalblu68f100 on April 20, 2012, 08:29:32 am
The 724 should be a transmission.  A transaxle has the transmission and axle built into one housing.  The main thing you need to keep in mind is how many rpm's your engine will be able to produce and how far you will be racing.  Tell us this and we may be able to help more.
Title: Re: gearing for a drag mower
Post by: TractorMan11 on April 20, 2012, 12:08:45 pm
ok yes thanks you for correcting me, and up here the only class to run is 1/8th mile with the Jr. dragsters thats what the owner of the drag strip told me, and im not sure how many rpms my engine spins im guessing 5500 - 6000
Title: Re: gearing for a drag mower
Post by: Johnson Mowersports on April 20, 2012, 12:53:44 pm
is this a stock motor if so it want spin but 4500 maybe a little more
Title: Re: gearing for a drag mower
Post by: royalblu68f100 on April 20, 2012, 01:01:43 pm
Hmmm,I would get a centrifugal clutch.
Title: Re: gearing for a drag mower
Post by: TractorMan11 on April 20, 2012, 01:19:19 pm
the motor is stock except for the original owner took the Governor out and i think i figured out the pulley set up now just need to work on the sprocket set up  plus im still im mock up stages and should i go with solid mounting for my suspension or should it have some give ?
Title: Re: gearing for a drag mower
Post by: royalblu68f100 on April 20, 2012, 01:24:16 pm
Solid, you do not want things moving around.  My mower went 52mph in the eight with wrong gearing it would have easily went 60 with the proper pulleys.  It had a 820 transaxle, an OHV Briggs single and a lot of motor work.  It only made 2 passes under hard launches, pushed the cases apart.
Title: Re: gearing for a drag mower
Post by: Rooster on April 20, 2012, 01:34:44 pm
Can you go RAGB?
Title: Re: gearing for a drag mower
Post by: TractorMan11 on April 20, 2012, 01:41:27 pm
well im trying to do the best i can with a stock motor but more work focused on the chassis because if i can get my chassis set up ill work on the engine later plus im on a budget because my wife total hates my tractor and making them go fast in general so i do what i can. but what set up did you have as far as pulleys and sprockets because i would like to break the local record of 48.78 mph
 
i have no clue on where to find one plus the ones from EC are expensive and i don't see me spending 200$ on my tractor getting away with it :noplease:
Title: Re: gearing for a drag mower
Post by: Rooster on April 20, 2012, 01:42:30 pm
... OHV Briggs single and a lot of motor work. 

....what set up did you have as far as pulleys and sprockets....
 
Absolutely none that will matter to you!
your stock engine is not going to pulll any where near what Chris's do!

Are there other guys running at the track with similar set-ups that will give you any pointers?
Gearing is very track & set-up relative!

Did someone hit 48+ with a stock engine? :omg:
Title: Re: gearing for a drag mower
Post by: royalblu68f100 on April 20, 2012, 01:53:40 pm
your stock engine is not going to pulll any where near what Chris's do!

Thanks Rooster, you make me blush!!! :wub:


I would find a horizontal shaft engine and use a straight axle if all I was to do was straight line drag racing.  A CVT style clutch to a 35 or 40 chain would be FAR more reliable, versus any transaxle or transmission, even a RAGB.  Then the gearing might be there to get close to 48.  Find a used racing go kart and go from there.
Title: Re: gearing for a drag mower
Post by: TractorMan11 on April 23, 2012, 09:50:01 am
i have been persuaded to build up my motor but i have never taken one apart? what should i look for and what parts should i buy?
Title: Re: gearing for a drag mower
Post by: royalblu68f100 on April 30, 2012, 11:18:27 am
A flywheel for speed and safety, then a rod, cam, valves, port work, exhaust, and some luck if you know where to find it.
Title: Re: gearing for a drag mower
Post by: Big Mike on May 20, 2012, 09:40:34 pm
i found 2 on ebay under $180

http://www.ebay.com/itm/Bolens-1400-Eliminator-Tractor-Right-Angle-Gear-Box-/190663652415?pt=LH_DefaultDomain_0&hash=item2c6470743f

http://www.ebay.com/itm/Massey-Ferguson-19834-Right-Angle-Gear-Box-1600-Tractor-/300701558840?pt=LH_DefaultDomain_0&hash=item460335a838#ht_2396wt_775