New Motor on the Invader

[Mammoth]

Finally got a chance to get some work done.
Installed the disc brakes.

Also added some stronger pedals that seem to match the kart well.

The plan was not to spend a bunch on this kart because of other projects, but I like this kart. It's what I had when I was younger, so I got a few things that it needed.
Like a billet rod, thicker pushrods and an aftermarket camshaft.
I searched out a cam that was as close to the numbers as Mike Clements cams. I believe he knows his stuff.
The one I found was much cheeper. Not nearly the quality as Mikes, but the numbers almost matched.

In the past messing with briggs motors on race karts we filed on the dipper making it thinner. The more we thinned it the faster it seemed to run until it got so thin we were afraid it might break off, but it never did and it kept running great.
So on this rod I filed it a little. Here is the before and after pic.

 

[Mammoth]

Found the numbers for the camshaft. 356 grind welded lobe.

 

[Mammoth]

Forgive my absence, I've been working 90 to 110 hours a week 200 miles from home so there hasn't been much time to build.
Did get some things done in the last couple days.
Threw the counter ballance in the trash. Made a weight to fit on the crank.

[/IMG]

Welded it on the crankshaft.

[/IMG]

Now its balanced.

[/IMG]

And the flywheels are the same weight which will solve some crankshaft flex vibration problems.

[/IMG]

Cut the helical teeth off the camshaft.

[/IMG]

Fit it into a straight cut gear.

[/IMG]

[/IMG]

Made some slots so the valve timing can be adjusted.

[/IMG]

[/IMG]

 

[Hellion]

I thank you for returning to this thread as it is one of the most enjoyable stories in this dreary place. You have an enviable array of tools and know-how at your disposal... <== Green with envy.

I'm thankful for the larger pics too as they better show the quality of your machine work.

 

[bob58o]

Awesome stuff. I guess I missed this one.
Cool Exhausts. Balancing Rotating assemblies. Welding chambers. Valve jobs. P&P. Custom Compression Release. Some cool gear stuff that I have no clue about.

Durham is like the North Pole right? I right letters asking for stuff. They magically get to you. Then awesome stuff comes down my chimney?

 

[chancer]

No Bob. I think Durham is in North Carolina!

 

[Mammoth]

The gear stuff is something I'm actually pretty excited to finally get done.

In higher hp motors the helical cut gears forces the camshaft so hard to the side it can pull the case cover studs out of the block.
By putting straight cut gears in there it iliminated major drag, friction causing wear and heat which leads to a faster reving engine, higher acheavable rpm's and frees up more hp.

With the crank balanced without the counter balancer it reduced rotating mass and drag from the counter balancer ripping it's way through oil leading to an even faster reving engine, higher acheavable rpm's and frees up even more hp.

Durham California is a small almond orchard growing town in the northern part of the state far enough away from the strange people in the big citys.
It's nice here, people are friendly, no real crime and the people enjoy a slower pace lifestyle.

 

[Hellion]

...In higher hp motors the helical cut gears forces the camshaft so hard to the side it pulls the case cover studs out of the block.
By putting straight cut gears in there it iliminated major drag, friction causing wear and heat which leads to a faster reving engine, higher acheavable rpm's and frees up more hp. ...

Seeing straight cut gears in most everything else that works well, to include the almighty Briggs 5 hp, I'm puzzled a bit as to why helical cut gears were used on this particular motor of yours.

Why the added complexity (probably negligible in a factory)?

Any added benefit that you are aware of?

They are an interesting detriment to high hp engines nonetheless.

 

[Mammoth]

Still trying to make time to work on this.

Hellion, to answer your question the only benefit to helical cut gears is they run quieter.
I'm not exactly sure why they did it, but it does cost more to make.

Got the valves timed in right where I wanted by using the adjustable cam.

I'm actually very excited about this. The adjustable cam has been an idea in my head since about 2013, and I'm only just now getting around to pulling it off.

Now the valves will open and close at the optimal positions.

This engine pushed real hard before, and now with the new cam, balanced crank with no counter balancer and properly timed valves I can only imagine how hard its going to hit.

[/IMG]

 

[Mammoth]

Reconfigured the motor mount 1-3/4" below stock height to lower the center of gravity.

[/IMG]

I got an idea in my head and began wondering if it would work. After a little research I ordered some parts to build this device.

[/IMG]

[/IMG]

Can anyone guess what it is?

[/IMG]

[/IMG]

 

[Mr. Spindle]

Nitro!

 

[Mammoth]

It's not nitro

 

[Randy H]

Water/methanol injection controlled by head temperature with a knock sensor.

 

[Mammoth]

That's some good guessing, but that's not it.

OK, it's a smoke system like what you would see on an airplane at an air show.
It injects mineral oil into the hot exhaust to create smoke, and boy does it.

I test fired the engine this mouring and just tapped the button a couple times. The outcome was I couldn't see my front yard.

[/IMG]

It was hard to control the cart and take this picture at the same time. This kart has more power than most people would ever need.
It's also very loud, and I mean loud.

 

[Randy H]

Haha that's awesome. I'm going to steal that idea.

Gonna do the compression release thing too. I think. Any input on that? What CR are you running? I'm trying to go as high as 13:1 and use an electric starter. To old for bloody knuckles.

 

[Mammoth]

A compression release would take some strain off the starter motor.
I don't know if it's really needed or not in that situation.

If you are going to go that route you can find them on ebay under tp engineering compression release.

I would highly recommend it to anyone that's going to be pull starting with high compression.

 

[B.M.800]

We need a drive by smoke screening...

 

[Mammoth]

We need a drive by smoke screening...

As soon as I get a free minute I will put together some video footage.
Free time isn't something I've had much of for quite a while.

I have to fix a couple issues with it before I take it on a ride.
One is the kill switch wasn't working, and two the carb slide is sticking at about 5% throttle.

Not sure exactly why as everything looks good, and functions properly when the engine isn't running

 

[Mammoth]

Got a few minutes to warm the motor up and do a test flyby.

It was the end of the day, and the air was nice and calm when I tested the smoke system.
It worked so well the smoke cloud it let out went right to my neighbors and stayed for at least 5 minutes.

He wasn't to happy when all the smoke came in his windows. I went over there later and gave him an apology.
I can't be doing smoke shows in the front yard anymore.

At first the camera doesn't pick up the loudness of the engine, but towards the end of the video when I'm way down the block you can really hear it.

 

[Randy H]

Maybe on the 4th of July you can add some red and blue dye.

Is your crankshaft static balanced only? I like the idea of getting rid of the balance shaft. I don't plan on exceeding 6000 RPM.