The Cars are the Stars Contest.

NEW222 wrote:A question regarding roddies build...... Since he is using a 'traction tire', does it matter where that tire/ engine is placed? Inside or outside, as a reedie can run either direction. Just kinda thinking like a control line plane here, and mI mind is wondering.

I thought about that beforehand. I wanted a rear-wheel/direct-drive arrangement for simplicity. I figured that the drive-wheel should be inboard for a roundy-round tether-circuit. It seemed to me that an outboard traction-wheel might crab the chassis inward. Maybe that would be favorable?? IDK. I just hope that I can get the car to move on its own.. without the engine stalling. Direct-drive; even with a mild reed-valve engine is going to be comparable to launching in "high-gear".. especially with a 1.500" X 1/2" slick..

I suppose that I could "treat" different tires*.. to alter their traction-properties if needed; for varying degrees of "slip". The 1.437" X .500" drive-wheel uses stretch-fit (quick-change) 1/2" width "slices" of 26" bicycle-tire "inner-tube" (Butyl-rubber) turned "smooth-side out" for a tire.

I made a few spares..





Redneck? yes....

I need to devise a fender of sorts.. to help keep the grit; kicked-up by the drive-wheel, from finding its way into the exhaust-ports of the engine-cylinder.



On the list of "support-equipment" will be my "cordless leaf-blower" to help minimize sand/grit on the chosen tether-circuit.

I boxed-off a section where the wedge-tank will locate.. using 1/8" balsa sq. stk. and glued-in a piece of inner-tube rubber for cushioning. I used a sm. sq. rasp to cut notches into the top and bottom of the body for a rubber-band style mounting. The area around the notches was then treated with thin CA for added strength.




The tank sits low.. but the "feed-tube" is just slightly higher than the engines NVA. If I oriented the tank any lower; the bottom-vent would be scraping the pavement. I think it will be fine though.

944_Jim wrote:Lemme see if my math is right at Too late:30 at night.

1.5"x3.14=4.71" circumference.
4.71"x15000rpm=70,650 inches per minute.
70,650/12=5887.5 feet per minute.
5887.5/5280=about 1.1 miles per.minute, or roughly 66 mph!

How much will it weigh? I hope it is going on steel line.

Geezus.. it's "too late 30: tonight" for me to understand that math Jim.. But I like the estimated speed; providing I can get the power to the pavement.

OVERLORD wrote:Hey, Roddie, you are well under way. Wouldn't it be better to mount your engine upright. The exhaust port woud be higher fro the round and cooling will improve. It might also be easier to fix a small fender as you suggested.

I would consider to add weight to the rear part to give more grip. Your driving wheel and tyre seem to be very hard. Ony the bike inner tyre gives some softness. I can imagine your wheel spinning round at full revs with the car standing still. What's the width of the wheel? Is that 1/2"? and diameter without tyre 35mm?

I purposely oriented the engine horizontally with cylinder-forward, to lower the center of gravity.. and to maximize the exposed surface-area of the heat-sink to be facing into the wind-stream. I also wanted unrestricted rear-access to the needle.. and for the fuel-line to also be positioned horizontally; facing forward for a short 180 degree bend back to the wedge-tank's feed on the outboard side of the body.

The drive-wheel/tire set-up will be a "test" for sure. There's no other way to prove it.. other than to try running it with a "bare-bones" chassis. That's what I'm shooting for. More weight may be needed.. but that should be easy to accomplish. I will make provisions for adding weight. It's something that I can do.. in small increments with what I have in mind. Thanks for the suggestion!

Cribbs74 wrote:Looks good Roddie!

Thank You Ron. This is turning-out to be a fun build. I honestly wasn't sure if I was ready to take-on another project.. but I love a challenge. I like the feeling of wanting to work "steadily" on a model. It doesn't always happen that way. This is a bit different; being a car. I've never had a petrol-powered model-car.. and this is my chance to actually design/build one.

It's a lot easier to set-up a "tether-car" circuit.. than it is to fly a model airplane.

Last night I made some "mods" to the car. I have a "to-do" list.. and took care of one of those items.. plus a few other things that needed some attention.

The "non-powered" 1/8" dia. music-wire outboard axle slides-into the back of the engine-mount. I designed it that way so that the outboard-axle would be on-center with the engine's crankshaft/inboard drive-wheel. There was a "through-hole" that needed a plug installed to prevent the outboard-axle from sliding in "too far".. which could block the reed-valve engines' air-intake. That was a simple matter.. by inserting (w/CA glue..) a 1/8" hardwood dowel into the hole slightly.. and cutting it off "flush".




Then I beefed-up the fuel-tank area.. and cut two different types of material to cushion the tank.







Then I bored a series of holes for the addition of "weight" (if needed..) A while back; I bought some round "Pine-Car" weights that can be inserted into the holes and glued-in,






I still need to "rig" the chassis for a tether.

How about a fourth category.  A real car carrying a Cox car with an engine and body that won't start or run.

After a frustrating day of trying to get two Cox Mercedes engines and three Enya engines to run I gave up. Walked over to my rebuilt MG and hit the starter, started even before I released the key.  This with a constant depression carburetor and a three week lay-up.  No choke.

Brits rule.





I would post my MG build log but it would run several pages.  You know me and pictures.

Entered and immediately withdrawn for obvious reasons.  

Maybe with enough time and patience I will get that POE (piece of excellence) Cox Mercedes together enough to run on June first, but I doubt it.

Marleysky wrote:......and we have a WHINER ! !  OR IS THAT WINER?  Bob, you crack me up! Love the CL MG.

I literally laughed-out-loud.. Yes Robert.. British Leland rules! Do you remember the "Tom Connelly" dealership on US Rt. 1 in Norwood, MA? They were a N.E. US British-Leland dealer/service location. I worked there in the early/mid 1980's.. but it was a GM "Pontiac" dealer at that time. Tom Connolly was a decent man to work for. In those years that I worked for him; he had also bought a small Saab dealership in Medfield, MA ("Hillcrest Saab") and moved it to Norwood. "Tony Camara" was service manager of the Tom Connolly dealerships.. while I was employed there. Tony was my boss.. and a very well-liked/respected man.

Good one Bob , if Mark was there he could bee the driver , thats a real Bunitch that the Mers. didnt go , i was looking forward to the run . I guess you didnt test the engine before installing ?

I don't remember the Tom Connelly dealership roddie, but I did buy my wife's 1969 Mustang at Garten Ford in Fall River. I still have the original bill of sale but the Mustang is long gone.

Wouldn't need a driver Eric, just lock the steering wheel and let it chug around a circle at idle about 750 rpm and you know these old tractor engines have a bunch of low end torque. Oh, oh Ron's going to catch me on this one as it has the 1500 CC engine not the MG four bangers of the twenties.

I could get that Mercedes to run in less than a minute if I just installed one of my known good Cox runners. But that's to easy.

Thanks guys for sharing my joke.

Bob

One more comment and I will let this thing go.

Just for grins I let this MG idle around a circle with the steering wheel locked at about 7/8ths, but with me at the wheel.  After just three loops I was really dizzy and quit.  

No way I'm ever riding a Merry-go-round again.

Bob