15 replies to this topic

[dc-65x]

Here is a new drag racer build by Rodney in his own words:

 

This drag race car is inspired by the'40 Ford that was entered in the 1962 National Drag Race Championship.  The race was featured in the November 1962 issue of Rod & Custom magazine.  The '40 Ford featured a Pittman DC9003 boat motor.  This motor filled up the Ford and the weight of the slot car is about 2 pounds according to the magazine article.

 

 

Big Al is an AMT model car kit that features a Ford Thunderbird powered by a 1,710 cubic inch Allison Airplane engine.  With the model car, the airplane engine fills up the Thunderbird.  I used the Big Al Thunderbird and filled it up with a monster KTM boat motor. 

 

 

The hefty rear motor bracket is made of brass and the chassis has brass rod main rails.  Kemtron beveled gears are used. 

 

 

K&B gasser front wheels and tires, "German rear tires" and large ball bearings are also used. 

 

 

 

You could see Mr. Driver through the back window. 

 

 

Check out the weight of this drag racer.

 

 

The model car has a clear coat of Mr. Super gloss clear UV cut over the paint and decals.

 

 

This was a fun build.

 

 

 

Big Al turned 2.38 today with 20.67 MPH with the track cleaned.  This is close to the times the boat motor cars turned in the Rod & Custom 1962 event.

 

 

 

Great build Rodney! Thanks for sharing

 

 

[Lone Wolf]

Heavy man That's a far out groovy Gasser

 

Something about the way the car sits makes it look like it want's to do a wheelie but somehow I doubt that would be possible

 

Are you basically running a 1 to 1 gear ratio? Times may improve with some fiddling in that area.

 

Overall very high on the coolness scale. I love it

[SlotStox#53]

Seriously cool Rodney

Great seeing these large motors powering the cars , fantastic chassis & build

Thanks for sharing .

[Gator Bob]

Very Cool car !

It's got the heavy duty towing package

 

Are the rears Classic tires on Buz-Co wheels?

[dc-65x]

...................Are you basically running a 1 to 1 gear ratio? Times may improve with some fiddling in that area...................

 

 

I'm thinking the thing may not have the revs. It might have peaked out at a top speed before the end of Eddie's full length strip even with 1 to 1 gearing.

 

I'll post what Rodney says about the gearing and rear wheels-tires.

[dc-65x]

Here's the scoop from Rodney:

 

Big Al is geared 1 to 1.  The '40 Ford in Rod & Custom looks like it is geared about .8 to 1.  The '40 Ford uses a slightly larger pinion gear than axle gear.  Big Al would go faster with similar gearing.  The KTM motor is a torque monster with moderate RPM as you thought Rick.  Big Al accelerates to maximum speed very quickly with all the torque that is available.

 

I think the rear wheels are Buzco.  Tires are the usual German model airplane tires cut down to size. 

[Gator Bob]

They look great with the vintage slick shoulder.

Rick, are those KTMs 1/8" shaft?  Wild looking gears.

[Lone Wolf]

If that motor has a 1/8" shaft I can send you a small set screw pinion ( probably 10 tooth ) and a small solid brass crown ( probably 30 tooth ) that should fit into those confines. Would give you a 3 to 1 ratio that may pep her up a bit. Distance from axle centerline to motor bushing will help determine what crown will fit. 

[dc-65x]

As I understand it, the motor has so much torque and so little RPM that it is reaching its maximum top speed well before the end of the strip.

 

If the gearing is changed to say, 3 to 1 it would accelerate to a slower top speed sooner but would actually take longer to travel down the scale 1/4 mile strip.

 

What the low RPM torque monster probably needs is even taller gearing to increase its top speed like the car in R&C magazine......perhaps .75 to 1 or so.

 

Anywho, here's more from Rodney:

 

I found an unopened set of gears like the ones used in Big Al.  They are Tradeship.  The KTM motor shaft is 3/16".  I reamed out one of the gears to 3/16" for the motor. 

 

 

As the '40 Ford entrant discovered, with a boat motor, it is desirable to have the drive axle spin faster than the motor.  I do not have any other gears with this large pitch so it looks like the gear ratio may have to remain at 1 to 1. 

 

Thanks for everyone's interest.

[SlotStox#53]

Wow! You learn sometime everyday

Didn't know they did 1:1 slot car gears, or such coarse pitch ! Tradeship really did some cool parts

Would larger tires help ?

[don.siegel]

Wonderful car Rick & Rodney; never noticed that about the gear ratio, but remember that 2 lb figure! 

 

I've got a DC9003 waiting for a project like this... 

 

Don 

 

PS: judging from the gears on my AC motor car, there may be some gears like that pitch in Erector sets... 

[Gator Bob]

Those look like 'off the shelf' 32 pitch 'mitered'.

Here are some in .187 bore.

 http://www.sdp-si.co...-1/81001204.pdf

 

[boxerdog]

This is a really nice car. I built a 9003 car way back when, and I love the concept. That motor is perfect!!!

[Mbloes]

Crazy retaining nuts on the rear wheels.

[dc-65x]

Yup, those are "bullet caps" or "bullet spinners".....very 60's hot rod.

[Mark Johnson]

Ya gotta make a periscope for the driver to see the tree!