Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Internal Combustion Engine

ciechanow.ski

Post reply on HN
Print view View original

231–240 of 415 posts

Re: Internal Combustion Engine

#231

Post by zeusk »

tmh88j wrote: post #129
zeusk wrote: post #117

Earlier quoted context omitted.

They're meant to be dual duty. There aren't any road car engines I'm aware of that use individual throttle bodies or 12+ compression without direct injection.

The S54 engine which came before the S65/85, was also high revving, had 11.5:1 compression ratio and didn't have any of the rod bearing issues. The 20v Toyota 4AGE also had them too with a high compression ratio.

S54 most definitely had rod bearing issues.

4AGE is 4cyl 11:1 compression producing 155hp with 7200rpm redline.

S85 is 10cyl 12:1 compression producing 500hp with 8250rpm redline.

Re: Internal Combustion Engine

#232

Post by jonplackett »

qwertox wrote: post #164

One of those web pages which deserves an award. Some place in some kind of Internet Hall of Fame, an historical archive which shows the only best highlights of what websites were actually capable of presenting. Milestones of web development. This page summarizes pretty good what web technology is capable of, when in the hands of a real professional. --- Ok, I just realized this is from Bartosz Ciechanowski, and this…

Love how it's written

> While reliable and easy to direct, a cannon ball won’t be very effective at pushing the crank

Re: Internal Combustion Engine

#233

Post by blamazon »

therein wrote: post #208

I have always wondered, if it would be possible to make a small enough internal combustion engine so that you could just have it laying around in an apartment, sitting a few feet away from you, powering your appliances or charging a 12V or 24V battery. Dispensing the exhaust through a long tube. If all goes well, complete combustion of propane should yield CO2 instead of CO anyway. An additional enclosure shouldn't b…

In japan some rural households use propane solid oxide fuel cells in this manner. Instead of combusting the fuel, which is loud, it’s pushed through a piece of exotic ceramic which causes a chemical reaction that splits the fuel into hydrogen gas and water vapor—the resulting free electrons are used for electricity, the hydrogen gas is used as a home/water heater and to keep the ceramic fuel cell at its reaction temperature, and the water vapor is simply vented.

Re: Internal Combustion Engine

#235

Post by Alupis »

elihu wrote: post #228
Alupis wrote: post #194

Earlier quoted context omitted.

Just talking about the RX-8 brings back great memories - what a strange, yet beautiful car! The cat blower, and the subtle whining sound it made when you started up cold was one of the ways every RX-8 owner was hazed into the fold... after calling the dealer or posting on a forum and finding out it's entirely normal! Other oddities included how it deliberately burned oil (scaring new owners into thinking they had a s…

I'm hoping LiquidPiston's rotary engine design pans out: https://news.ycombinator.com/item?id=25450477 In theory, it should fix some of the maintenance issues (apex seals are attached to a stationary part of the engine where they can be more easily lubricated) and fuel efficiency / emissions issues (combustion chamber is closer to spherical). I like the idea of the Mazda rotary engine, but I'm not really surprised th…

Wow, that LiquidPiston rotary looks very interesting! I hadn't seen that before - I too hope it pans out.

> I'm not really surprised they stopped making them, due to fuel economy...

Eh, nobody bought that car for the fuel economy!

The car sold itself... just one test drive and you had to have it. I've owned and driven muscle and other sports cars, and still nothing compares to the RX-8 - it's just such a unique experience.

Not sure how you're doing the conversion, but if you're keeping the carbon fiber driveshaft (vs. a motor on each wheel I suppose), there will be nothing keeping it from screaming off the line with an electric motor under the hood (traditionally the wankel wasn't good off the line with low RPM's, power band kicking in around 6500 if I recall - could make for a great "sleeper"). Although I'm unsure if the driveshaft would stand up to the torque a motor would output, since the wankel wasn't particularly torquey.

If you're not already, keep a blog and pictures of the conversion - that would make for an interesting read!

Re: Internal Combustion Engine

#236

Post by londons_explore »

cesarb wrote: post #199
londons_explore wrote: post #45

Earlier quoted context omitted.

> Additional cost for regen brakes of course. Regen braking has no physical cost associated - it's pure software/firmware. The exact same hardware that is used to power the car forwards can be used for regen braking. It can be as simple as a single negative sign in the code to cause the phase to be 180 degrees out, current to flow backwards, torque to go the other way, and the battery to be charged instead of dischar…

> One day regen braking will take over hydraulic brakes, and another big cost/complexity of a car will be eliminated. I have read somewhere that the regenerative braking is much less effective when the car is going really slow, so you still need the hydraulic brakes to come to a complete stop.

True, but you can also use a tiny bit of battery power to do "reverse acceleration" to do the final stopping.

It is true that electric braking would continuously use a small amount of power to stay stopped on a slope. That wouldn't be an issue for a few hours, but you couldn't park on a hill for months without ending up with a flat battery, and then eventually the car rolling away.

Small locking pins are the answer to this, rather like the "park" on automatic gearboxes. They are very cheap, since they don't need to do any actual stopping, but merely keeping something stopped.

Re: Internal Combustion Engine

#237

Post by Grazester »

specialp wrote: post #205
Grazester wrote: post #113

Earlier quoted context omitted.

I have a buddy that is adamant about not flushing transmissions if you dont have a issue because he think its guaranteed to have an issue after, from his experience. lol

I'd concur with that. Note this was one of the notorious to fail JATCO nissan/mitsubishi transmissions. Blowing fluid through with pressure makes no sense. Sediment sitting in pans does not affect operation until it is agitated into suspension

The Nissan automatics and especially manuals(cd009) are fairly strong. It's their CVT that's the issues. I don't know why Nissan insist on using them with their V6's.

Re: Internal Combustion Engine

#238

Post by blamazon »

CRConrad wrote: post #210
TheSpiceIsLife wrote: post #204

Earlier quoted context omitted.

The engine in one of the vehicles I own has timing gears rather than a chain or belt. Another option, different trade-offs.

Much more common with pushrod engines, where the camshaft is situated close to the crankshaft; less so with overhead camshafts. Though I think some very high-revving sports and competition engines have gears driving overhead cams; IIRC the McLaren TAG F1 turbo V6 (by Porsche) back in the 1980s was one example.

The engine used in the Ferrari Enzo and Maserati MC12 is a notable example:

https://36.media.tumblr.com/8a928fcccf1b41e82be0273ccbe2005a...

Re: Internal Combustion Engine

#239

Post by cratermoon »

When I was a boy, my dad decided that our '66 Mustang with a straight 4-cylinder engine needed new piston rings. I helped a bit but mostly watched as he tore down the engine to the barest elements, only the engine mounts keeping the block held up in the compartment. The crankshaft, connecting rods, tappers valves, piston heads, piston rods, all laid out neatly on the garage floor along with all the nuts, bolts, washers, seals, gaskets, belts, and everything else you see in this video.

Although I really appreciate the reliability, efficiency, and durability that modern engine design has brought, a part of me is sad that modern cars are all about chips and software, and the average guy in his garage or under a shadetree can no longer break one down to the bare bones of electromechanical parts and put it back together better than it was.

Re: Internal Combustion Engine

#240

Post by B1FF_PSUVM »

Hat off, deep bow. Haven't seen such clarity of exposition in decades, if ever.

Pity it's about technology on the way out, but hey, "perfection is achieved on the edge of collapse".

P.S. Learned a few things, and I'm even more amazed that all this actually works and gets things moving at over 100 mph ... looks like a very clever Rube Goldberg joke.

Post reply on HN