The Green Hornet's Dynamark Street Machine [2017 Build-Off Entry]

The tractor i am starting with is a 1976 Dynamark 8hp 32 inch cut.
plans are:
lower it to where it will ride about 3 inches off the ground
either a peerless 700 or a 1 to 1 right angle gearbox
rear axle, mounted above the frame  on pillow blocks, chain drive
engine (possibly an opposed twin, possibly a vtwin)
brakes (hydraulic disk brakes + the kind that rub on the tires)
steering (using parts from a chinese quad. Will be using handlebars)
wiring harness (kill switch that attaches to clothes (so itll stop if i fall off) pushbutton start)
custom front axle (already built, shown in pictures)
fuel tank placement
clutch assembly + belt routing
exhaust system
tires
possibly a liquid cooling system?
clear coat, to keep the rusty look
frame reinforcements
modify fenders and footrests?

That is all I can think of off the top of my head. there is likely more that i will think of later.
Background on the mower- Picked up from a friend. Has been sitting outside for 20+ years. stock axle, engine, and transmission were all junk.

-The Green Hornet
2017 buildoff

This one should be cool! What did you mean by liquid cooling system, like an oil cooler or something?

Be sure to get your pic edited into your original post so it can be approved.

Picture is posted. Just bumping this up.

Looks cool man! I would keep the steering wheel though, instead of the handle bars.

CraftsmanQuad19 wrote:

Picture is posted. Just bumping this up.

Looks good, all set now.

MatthewD wrote:

Looks cool man! I would keep the steering wheel though, instead of the handle bars.

I think it will be easier with the thumb throttle and brake on the handlebars. It has such tiny footrests I wouldn't want anyone to get hurt because they can't find the brake

Ah right well fair enough. Just think it would look more like a tractor with a steering wheel.

CraftsmanQuad19 wrote:

MatthewD wrote:

Looks cool man! I would keep the steering wheel though, instead of the handle bars.

I think it will be easier with the thumb throttle and brake on the handlebars. It has such tiny footrests I wouldn't want anyone to get hurt because they can't find the brake

TBH from my experience with bars, I'd rather have a larger wheel. Or at least a bowtie.

We'll try the bars first and if they don't work out we could always change it. I just like having everything all contained right there. I feel like over bumps you don't have much control of a foot throttle and I just feel more comfortable with a thumb throttle. Personal preference I suppose, but to each his own.

Or twist throttle

Doug wrote:

Or twist throttle

As I took apart that moped I thought about using it, but I couldn't get it off in one piece. We have the thumb throttle though. we are putting as little money into this thing as possible. Everything we are using so far was free. Tires and rims should be the only thing we need to buy.

V twin or an opposed? any opinions on that? I have an opposed that is ready to go on, but itll take up every bit of our space in front. with a v twin i think we will have to modify the front grille to fit the cylinders, carb, and a custom air box in. I can possibly get a vtwin from a neighbor, but if that falls through or he doesnt have one, There is an FFA auction at a local high school that always has a good selection of mowers. Most have been sitting, and they usually go for more than theyre worth, but i could probably find something there.

AllisKidD21 wrote:

This one should be cool! What did you mean by liquid cooling system, like an oil cooler or something?

Yeah, i'm also curious about liquid cooling. What's the idea with that?

I'm hoping to get some copper tubing that fits snugly between the cooling fins and wrap it around the cylinder down between the fins and use a diaphragm fuel pump as a water pump and mount like a little dirt bike radiator to the shroud over the flywheel. Then the flywheel will draw cool air through the radiator and the fuel pump will pull the coolant through the system and back up to the radiator.


Does any of that make any sense?

The thing I'm worried about is if the repurposed fuel pump will be able to handle the heat. I'd like to put it right after the radiator so it is pulling cooled coolant through it rather than trying to push the hot coolant into the radiator. Do any of you have anything besides a fuel pump to suggest or do you think it'll be fine?

Could try and find a small sealed water pump and drive it by belt. Problem is I've never seen a sealed one small enough haha. Still a cool idea CQ!

I was thinking the same thing about the liquid cooling, it just seems like a lot of work, cost, and room for a radiator/pump that we dont really have.

Seems like a good idea for a cooling system, I don't know if it would keep up with the heat, but maybe. Vacuum fuel pumps like the ones used for mowers do have some good flow when not pushing any pressure. If you were interested in doing something weird and rat rodish... some really early farm tractors used an open screen as a radiator, which water would flow over, then down into a collection tank. I couldn't even find a pic on google. Or, you could use the same copper tube that was wrapped around the engine and loop it back and forth. I thought of just having a tube with holes in it across the top of the cylinder, with a collection tank under it, just having the water dump over the cylinder in the open. Maybe have an extra reservoir tank, if there is enough water in the system it will cool off enough before being recirculated. But, true it would be a lot of work just to say it had a liquid cooling system. Also copper tubing is reeealy expensive.

Yeah. we would salvage some from somewhere. this is a low cost build- unfortunately. i wish i had more money to spend on it, but my parents are pretty strict on what i do with my money, and spending 100 bucks on a lawn mower, or as they see it a death machine, is a definite no. So everything on this build we already had, or was sourced from junkyards

finding copper pipe small enough to fit between the fins is pretty small. by the time we get in a transmission, a battery, a fuel tank, and the rear axle, we arent gonna have much room for a tank. not one big enough to keep relatively cool water anyway. we could get creative though, and do a bigger collection tank back farther in the mower, with a fill spout under the seat or something. we will have to see. I like the idea of doing a dirt bike radiator above the flywheel though. would we mount it in the hood so it came up when we open the hood, or would we make a bracket and attach it to the engine?

I was thinking mount it to the shroud and cut a rectangle in the hood with a scoop on top like the General Mayhem from Roadkill

That would look cool! That'd be a nice ratty touch.

i like the idea of a scoop on the hood. i never thought of that.

Okay, time for an update, even though there isn't really much to update. Ive been ridiculously busy between marching band season kickoff, 4-H animals, end of the school year research papers, and all sorts of other things. With all the 4-H animals, im not going to have the time to pay any attention to the dynamark over the summer, and every weekend from August to september and some into october will be taken by marching band. Also, my parents do not allow me to spend money on these projects, so i kinda build them with what i have. Well i had a gokart axle, hubs, and a right angle gearbox set aside, but as with many used things, they have their flaws. I discovered hairline cracks in the axle and hubs, rendering them useless. the gearbox needs a shaft placed back in it. the only thing i can fix is the gearbox, but what good is a gearbox with no rear axle. Anyway, long story short, I am unable to build this the way i envisioned it, so i am considering turning the project over to CQ19. No final decision is made yet, but id like this project either over or out of the way before i start the sears, and id like to build the sears before summer gets into full swing so i have it on the farm this year.

I wanna see this beast come to life man!! Hahaha.

If I end up with it, it will. I know how I want it, the problem is the budget. I want a V-twin, dual side pipes, single speed, live axle, aluminum wheels, real street rod. E and I vary slightly on taste, but generally we want the same thing I think.