Topic: First time builder Murray Wide Body

[matt68396]

My name is Matt, I live right outside of Winston Salem, NC.  This my first time building a racing mower.  I'm building it to race locally but, I would it to be legal to race it in uslmra if I get the chance.  It will be built for a 14 vanguard twin but, when I first hit the track I'll probably run the 14.5 ohv that came on it.  If I run in the us I'll prob use the 14.5 to run G/P.  To my understanding the the chassis rules are the same for all prepared classes, just the motor rules are different and if its legal for the us its legal for the arma.  The only sure plans I have for the vanguard is a tear down, billet flywheel and governor removal.  I'll cross that bridge after the chassis is done.  Anyways enough of that I'll get on with it.

Here's the victim a 1999 widebody



Drilling pilot hole for the valve stem in a super nice EC wheel.   The hole is close to the center incase I run tubes later on.  Don't want too but would like to have th option.  Final hole size 15/32



Running 8x8 EC wheels with 16x7.50 in the rear and 6x8.25 with 13x6.50 in the front.  Tires are deestone turf saver knockoffs.  I'll be running mostly on hard packed karts tracks so I'll try these and can upgrade tires if need be.  Front tire mounted up.



No tear down pics so, frame rails blasted and ready for some work.

[Jeff McKelroy]

Welcome to Heymow Matt, and Good Luck!

Remember, the only dumb questions are the ones you don't ask.

[Tazz914]

Nice build, im from hamlet, nc. Hopefully we might see you at our local track some time

[matt68396]

Thanks fellas.  Yeah it will probably take a while to get it finished but, I'll definatly be when it's done.


Well here's my idea for reinforcing the frame.  There were a couple spots on the bottom that wanted to fill in.





I cut 34 of these out of 1/8x1 flat stock.



I welded them down the whole inside of the frame on 45 degree angles.  It ended up adding a tick over 3 pounds to each rail.

[matt68396]

I bought a complete racing kart a while back for $500.  Previous owner seemed to be good about bearing maintence, all are super smooth and roll for a while.  Spindle heims are tight but tie rod heims have a little play.   May use them for clutch linkage.  Here parts I'm keeping that I might use in the build.



The axle and front wheels also came from the kart.  I think I have the motor, clutch, and pit buggy sold for $350.  So i may be able to get all my money back off the parts I don't need.

Here's my balancing act so I can get a measurment on how wide the front axle needs to be.



I cut the camber plates of the kart frame and tacked them on my axle.  I flushed the plates to the back of the tubing so I could weld it directly to the frame and maintain the correct wheel base.  Tubing is 1x2 11 ga.



The spindle (not a typo...) has 10 degrees of kingpin inclination built in.  So the plates go on at 10 degrees.  The right side was off by only a half degree so a very slight tap to left one made it match.  The right could have been corrected but I would have had to grind the axle beam.  Everything looked to good to worry about that.  Spindles are what set the kpi anyway.







Hard to see in the pic but I had it run the top heim out to get the camber set on the right side (left in the pic).
So I scratched my head double checked.  Pulled the wheels checked spindles directly. Scratched my head.  Pulled spindles and rechecked the axle beam.



Turns out the right side spindle was built with 5 degrees of kpi.  So...



I had to cut it, clean it, and reweld it.

Set everything up on the table to axle position measurements.  Frame is 4 1/8 off the table and I have 3 pounds of air in the tires.  I will be able to adjust the front and rear up or down 3/8's of an inch.  Total of 3/4's adjustment.



I drilled the bottom hole for the bearing cassette on one frame rail.



Then I clamped the two together to drill the other.



Now here's a question would this be legal in the uslmra?  It says primary mounting point not sole mount point.  Not trying to cause a ruckus or anything.  I know welding flanges to the frame is legal.  I do plan on bracing the top but everything will be based off the factory frame.

[Tazz914]

Im no tech guy but everything seem legal so far

[Burwell555]

I see nothing wrong with that...

[Huffy044]

National points race in Shelby Sept 30, come say hi.

[Rooster]

To my understanding the the chassis rules are the same for all prepared classes, just the motor rules are different

Not eggzactly, but close for IMOW, GP, SP,CP & BP, there are wheel base differences and other small things you have to watch for!

and if its legal for the us its legal for the arma. 

NO!
There is one difference that has caused a few some problems, the seat Location.
US requires the seat to be on the top of the fender, ARMA requires it to be above the top of rear tires.
It is possible to mount the seat in such a way it is on top of the fender, but below the top of the tires.
It is an easy fix, simply requires a seat spacer

Now here's a question would this be legal in the uslmra?  It says primary mounting point not sole mount point.  Not trying to cause a ruckus or anything.  I know welding flanges to the frame is legal.  I do plan on bracing the top but everything will be based off the factory frame.

Not Sure what your asking here?
That is a legal mounting for your axle however.

H) FRAME: Discrete strengthening is allowed. Front and rear axles must use
original frame as primary mounting point.

[matt68396]

Yeah I was planning on checking that out.

I should have worded that differently, I seen that about the wheel base and I think wheel sizes.

I am debating on my fender.  Local rules let you fabricate them and drop the seat pan a maximum of two inches below the tops of the tires.  I'm thinking about getting another fender and building two sets.  One for local and one that would work for us and arma.  and yes I was talking about the way the axle is mounted to the frame.

Thanks for the help!

[Rooster]

Good looking build you got going there!

[matt68396]

Thanks

Here is about 30 minutes measuring leveling and squaring.



This a shot of how straight the rails are after welding a the plates on the inside.  



I cut hitch off the back plate and got it put in place.  You can see the where I had to cut the plates on the inside for axle clearance.  If I would have planned better I would have started with the first one on the opposite angle.  Then I have only had to notch the frame.



Capped the cut ends.

[flatlander]

Depends on what class your going to run watch that gear hub for your rear axle the cart ones are lighter and i broke it with big power.Bought a EC hub and never had a problem again.

[matt68396]

Good point, if there's a chance it would break on the sprocket side I'm definitely not going put my brake rotor on it.  I'll use it for mock up and order a couple hd one's when the time comes.

[LC]

What was the stock wheel base of that mower?

Did it change?