Living Throttleless

[jesse.rizzo]

Just the other day I came up with an idea for a throttleless gas engine. It would have to have electronically controlled valves. The ecu would automatically cut fuel and hold open the valves for a split second really fast. So for example it would provide fuel for one revolution, and then cut it for 3 revolutions, and the engine would be producing 25% power. But it would be fast enough that the driver would never notice. The only question is if the slight amount of engine braking would be too much.

Anyway, congrats on the fairly out there mod. Interested to see how it works out.

[roflwaffle]

That's certainly an interesting idea jesse. The only things I wonder about are emissions and harmonics/surging.

[cfg83]

roflwaffle -

Originally Posted by roflwaffle

That's certainly an interesting idea jesse. The only things I wonder about are emissions and harmonics/surging.

Yeah, that would be my "long run" concern, but for the purposes of experiment and "proving the mod", I have no problem with it. It's way too cool not to try it.

CarloSW2

[Christ]

Originally Posted by cfg83

roflwaffle -



Yeah, that would be my "long run" concern, but for the purposes of experiment and "proving the mod", I have no problem with it. It's way too cool not to try it.

CarloSW2

But first, someone has to perfect a solenoid-drive valve train. Another ECU cell with full data to control each valve individually, at precise timing, then a crossover map to connect the basic valve control map with the input and output devices, to precisely control the valves' speed, lift, and duration as necessary for a wide range of load variables.

Yep, have fun with that.

Personally, I was going to try this with a crank trigger on a 4 stroke 1cylinder engine, but I still haven't found all the parts to be able to do it. (Solenoids that can handle the heat and response time, primarily.)

I might try it as "proof of concept" one day, with door lock solenoids or something, and just see how fast it will allow the engine to go before the solenoids can't keep up.

[theunchosen]

Cylinder 3 went hot and bored a hideous hole right through the piston and slagged the rod.

Happened unbelievably fast. Injector 3 went belly up(dirt or particulate matter from the line itself) and by the time the pressure built up enough to pin open the valve to feed through the backup unit Piston 3 was toast. So In a matter of just about 2 minutes Michelle chewed up her own heart.

Will rebuild engine with aluminum pistons w/ heat syncs. Should drop a large boost in cooling.

Backed out of my spot turned pulled out of driveway got to the top of the hill(400 yards steep incline) started applying lean and diagnostic started spitting all kinds of errors. Shut it down and watched it smoke.

I think the problem was the pump was pumping up hill(its located inside the resevoir in the trunk so its 10 feet away and now on a steep incline) and it lost alot of pressure having to pump and the dirt got lodged under the low pressure(would normally be difficult at 30 PSI, all injectors were bench tested and new none had problems and the old resevoir had more junk floating in it than this one and it had no problems). So I think a Much more powerful pump for the resevoir, piston heat syncs and the other remaining bits and pieces I didn't have time for today.

[Christ]

Originally Posted by theunchosen

Cylinder 3 went hot and bored a hideous hole right through the piston and slagged the rod.

Happened unbelievably fast. Injector 3 went belly up(dirt or particulate matter from the line itself) and by the time the pressure built up enough to pin open the valve to feed through the backup unit Piston 3 was toast. So In a matter of just about 2 minutes Michelle chewed up her own heart.

Will rebuild engine with aluminum pistons w/ heat syncs. Should drop a large boost in cooling.

Backed out of my spot turned pulled out of driveway got to the top of the hill(400 yards steep incline) started applying lean and diagnostic started spitting all kinds of errors. Shut it down and watched it smoke.

I think the problem was the pump was pumping up hill(its located inside the resevoir in the trunk so its 10 feet away and now on a steep incline) and it lost alot of pressure having to pump and the dirt got lodged under the low pressure(would normally be difficult at 30 PSI, all injectors were bench tested and new none had problems and the old resevoir had more junk floating in it than this one and it had no problems). So I think a Much more powerful pump for the resevoir, piston heat syncs and the other remaining bits and pieces I didn't have time for today.

Are you capable of rebuilding with a compression high enough to allow for compression ignition? If you could, that would allow you to rid yourself of the spark plug altogether, and put a water injector right in that spot, which could spray directly on the piston, if things got too hot (like in a loop with EGT sensor... EGT's get too hot, injectors spray a mist on the pistons on the compression strokes or something)

If you need a set of D-series pistons, I have some PG6B's still on the rods that I'd part with for the cost of shipping to keep this project going! (They're 86-87 D16A1 (1st gen 'Teg) pistons.)

[Frank Lee]

"Will rebuild engine with aluminum pistons w/ heat syncs. Should drop a large boost in cooling."

What?

[theunchosen]

Frank you caught that. . .Yeah I'm planning on attaching some very small strips(fins) to the back of the second set of pistons. Not a huge number but a few. We'll see if it helps pull heat out of the cylinder itself and dump it in the crank case(coolant lines run through here as well as oil thats being cooled in a full size radiator). It won't stop melt downs like yesterdays but it might give me an invaluable extra one minute, long enough that I might notice the diagnostics pitching problems and shut it down. I was thinking of putting them on either side of the rod because there shouldn't be anything moving in that area and its attached to the heated body(piston). Understandably its not going to be much hotter than the crank case, unless it, this is hypothetical I don't have any data that indicates this is something that will work or has been done or should work this way, . . .So unless I lose an injector I don't think the pistons going to get hot enough to heat sync(unless the internal reservoir combined with the larger pump cools the crank but is not enough to cool the areas around the cylinders).

Christ, Ideally I would have the injectors in the cylinder. Its crowded and. . . I don't know if its possible. The octane from combustion event to event is probably different because the fuel is not truly homogeneous. Diesel has such a high octane rating. . .whats actually igniting is the air itself(I'm not familiar with diesels so please correct me if wrong) not the diesel. Air itself will ignite on its own once you get a little bit above 500 C pretty reliably, combined with hot cylinder walls and pistons the air will ignite under the temperature(caused by the pressure).

I appreciate the offer for the piston and rods but I'm going to go ahead and bump them to stronger components and aluminum everywhere I can get it. The future of the project is to get this going reliably and then boost it to try and jump on AFRs up in the 60s and I would prefer to only rebuild the engine once(now with ally stronger rods, instead of replacing cylinder 3 now and then coming back in a few months and replacing all of them with better rods and pistons.)

I put my FG/CF layup for the custom on hold. If that engine is going to do this I want it to have every advantage from the get go, whether thats enormous amounts of air venting or what, I plan on building that one to spec for the ultimate performance situation for lean burn.

In the meantime I'm putting everything on hold for the rest of the week. A little tired from engine work lol, and I'll pull Michelle's engine next weekend and start over. Totally open for speculation on how to make it work better or more reliably. Might be till next weekend before I post again ^_^

[greasemonkee]

I haven't read all the details, but have you considered inert exhaust gas dilution? If an egr system were to be used, but with an added egr intercooler to keep cylinder charge temps down (for detonation purposes) during compression. You would be able to displace some of that oxygen instead of using something (water) with such a high specific heat to cool with. Just an idea off the top of my head.

[roflwaffle]

Originally Posted by theunchosen

Frank you caught that. . .Yeah I'm planning on attaching some very small strips(fins) to the back of the second set of pistons. Not a huge number but a few. We'll see if it helps pull heat out of the cylinder itself and dump it in the crank case(coolant lines run through here as well as oil thats being cooled in a full size radiator).

Why not put in oil squirters? OEM, proven, reliable, etc..