Ever wonder what it would be like to rev a Visible V8 engine to 7,000 RPM?

Well now you can stop wondering.

http://youtu.be/kx_j1ixjxac

That sound! Out of a Plastic Engine!

I built one of these when I was a kid... Sure didn't run like that. And sure didn't run for long after I hooked a couple (maybe 3 or 4?) of batteries together to make it run faster.

I hadn't ever wondered that.
But am glad that someone else did!

Looks like it has a bit of a blow-by problem with all that oil in the exhaust.

Ok, so a plastic engine block probably isn't too good for ring seal.

Dang. I'm surprised it didn't blow. I'm thinking plastic connecting rods aren't rated for 7k.

They make a rotary engine model also you know....

My mind is blown to find out how much of the noise a typical internal combustion engine makes is completely unrelated to the actual combustion. Amazing

Test #135? Really? Life is so boring he did 135 tests on a plastic engine?

I haven't done that many tests on a real engine.

Toyman01 wrote: Test #135? Really? Life is so boring he did 135 tests on a plastic engine? I haven't done that many tests on a real engine.

I'm going to say Retired.

We need to figure out how to harness that guy's powers for good. His original goal was to get it up to 500 rpm, but due to "mission creep" he ended up going past 7k.

He needs to step away from the plastic engine and see if he can raise the redline of an actual car engine.

tuna55 wrote: My mind is blown to find out how much of the noise a typical internal combustion engine makes is completely unrelated to the actual combustion. Amazing

But it sounded good.

souless po

I'm torn.....It's cool that he got it to spin way past a reasonable speed... but a catastrophic failure would also have been cool to see.

I have a half built Visible Rotary in my basement and a Smithsonian Motorworks four cylinder that's still in the box. I'm planning to build the four with my six year old this winter.

tuna55 wrote: My mind is blown to find out how much of the noise a typical internal combustion engine makes is completely unrelated to the actual combustion. Amazing

Intakes are a lot louder than many people think. Same goes for the valvetrain, hence hydraulic lifters being most commonly found in pushrod applications, eliminates the chatter of all the parts between the camshaft and valve stem slamming together every time a lifter hits an opening ramp. Then there's piston slap, and gear and chain noise, and the fan if equipped.

I built that 4-cylinder one with my nephew one Christmas...

In reply to Kenny_McCormic:

I've got a 1950's British motorcycle in my fleet and I've always been surprised at how much noise the valvetrain makes.

I've had it apart, adjusted, tightened, modified, etc with no improvement. Only thing I hadn't done was split the case to look at the cams.

Other guys with the same bikes assured me that the noise was normal and their bikes were the same.

One day I got a look at a set of stock cams for this engine and holy crap... They don't set the valve down, they just plain drop it! There is almost no ramp on the closing side of the cam.

No wonder it makes noise.

Shawn

In reply to Trans_Maro:

I figured out that an old Honda engine is supposed to sound like a sewing machine.

In reply to Woody:

How soon till it poops out the apex seals?

Yeah, way back when I learned that if an OHC bike engine did NOT make valve train noise investigate IMMEDIATELY. Pushrod engines, typically the valve lash opens as the valvetrain wears. OHC, the wear is not as prevalent because there's fewer parts. What happens is the valve seats wear, this causes the valve to 'grow' out of the head. Since the lash is usually around .004-.006 it doesn't take much to close it, thus making the noise go away. But the quiet valves fry!

There's a lot of engineering that goes into getting rid of intake 'honk'. Somewhere or other I recall that is about 25% of the noise from the average engine, so when you see all that stupid plumbing stuck to the airbox that's what the engineers were trying to accomplish. It also explains those weird long tubes and stuff that seem to do nothing, they are resonance chambers.

Appleseed, he's gotta add boost to do that.

tuna55 wrote: My mind is blown to find out how much of the noise a typical internal combustion engine makes is completely unrelated to the actual combustion. Amazing

A lot of the cool noises we hear are intake drone, which is a good chunk of why Diesels can be so loud. The rest is combustion (not exhaust) noise ringing through the block, which is why inlines tend to be a lot louder than V engines - on a V engine half the noise disappears into the valley.

And then there's timing chain noise, which was the bane of Quad 4s and a good chunk of the reason why VW is burying the chains in the back of the engine so the noise disappears into the bellhousing...

Kenny_McCormic wrote:

tuna55 wrote: My mind is blown to find out how much of the noise a typical internal combustion engine makes is completely unrelated to the actual combustion. Amazing

Intakes are a lot louder than many people think.

I had a completely stock '80 RX-7. The Silent Sports Car. I probably made the car twice as loud by putting a modified carb with no choke horn on it. Removing the choke plate let a LOT more intake noise out of the carb! Sounded like the guys who put Webers on their engines, not tinny but kind of a high-pitched throatiness.

This is why, when I put the poorman's ITBs on my engine, I spent probably the first three months deliberately whacking the throttle open at low RPM so I could hear the intake bwuuuuuuuuuuugh. Reminded me a lot of the original Getaway in Stockholm when he was putzing the 911 around in that town square area. This is WHY I want to put twin Webers on my GTI.

Where can I get one like that?

I don't need one that revs to 7K, but I would like one that runs (circulates oil, has timing adjustment, etc.)

The only ones I am familiar with have a hand crank and rev to about 3rpms.

Any one know a better one?

I want one to teach my kids.