Comments on: EVIC engine

By: Dave Bowes

Dave Bowes — Fri, 21 Jan 2011 04:06:40 +0000

While the current can hit 15 Amps on the exhaust valve open it only does so for a fraction of a millisecond. Average current consumption is much less and a moderate engine speeds represents only about 5% of the engine’s power output, about the same as the power required to drive the camshaft on a typical automotive engine. The newest EVIC, the 18cc Mk4 has linear Hall effect valve position sensors that help reduce the current consuption compared to the older EVIC Mk3 engine and the EVIC Mk1 & Mk2 picture here.

By: zack

zack — Fri, 03 Dec 2010 04:30:00 +0000

This sounds great, but once you read his site you see the one con that makes EVIC engines impractical. Even on this small engine, the solenoids draw about 15 amps from a 42 volt system. Imagine the power it would take to run say a 200cc engine.

By: d00m3d

d00m3d — Sun, 28 Jun 2009 15:02:12 +0000

dave, thats some awesome designing there, great job :D

By: Dave Bowes

Dave Bowes — Fri, 26 Jun 2009 23:54:29 +0000

I am the designer of the EVIC engines. They have been my hobby for nearly 10 years. I am a retired electrical engineer and I would like to make a few comments:
My solenoid failure rate has been very low, 1 in 10 years. I have had some wear problems on the solenoid shafts.
The valves on my engines are closed by valve springs. Electrical damping is used to softly land the valves on the valve seats.
The solenoid power is about 4% to 6% of the engine’s output, increasing with engine speed. The valve train on a typical car requires about 5% of the engine’s output, a racing engine can use double this amount.
It is, as some have speculated, easier to do this on a small engine than on an automotive size engine.
The F1 rules do not allow solenoid actuated valves.
BMW, Ford, Fiat and others have built prototype engines with solenoid actuated valves. Fiat has recently announced production of their Multiair system with solenoid actuated intake valves. Intake valves are far easier than exhaust valves.
I sell a plan book for the engine shown in the video. I also sell a Student Guide CD to those who want to learn about the technology.

I have used my engines to power radio controlled model boats and model airplanes. My latest 17cc single powers an 8′ wingspan Turbo beaver and puts out about 0.8 hp at 8,000 rpm.

I am pleased that you folks are enjoying what I have done.

Dave Bowes, EVIC designer.

By: bigbob

bigbob — Fri, 26 Jun 2009 04:37:28 +0000

@ roly

ah, very good point. I should have been more specific. The force required by the solenoids if implemented on a larger engine (say a modern 5.7 liter v8) would be much larger than that to regulate/allow fuel flow. The springs used to control valves exert an amazing force, especially when in high performance/horse power/rpm engines. These solenoids would be enduring tons of abuse in this application.

In addition, if a fuel delivery solenoid/injector fails there is just no fuel delivered, but if one of these fails when controlling a valve there could be catastrophic issues due to the compression present within the cylinder. Granted that there are solenoids that are designed to fail in an open or closed state, with the heat and speed they would be operating at it would still worry me.

I’m not saying that I don’t think it will ever be implemented, because I truly believe that this is an extremely viable technology. I just think that there needs to be testing done on a larger scale.

I do have a bias though :) my daily driver is a ’71 el-camino that my father and I rebuilt from the ground up. No computers in that bad boy!

really though, amazing project that I would love to give a shot trying out. How about trying to implement it on something like a lawn mower or small go-cart as a next step…

By: Enahs

Enahs — Fri, 26 Jun 2009 04:31:39 +0000

I like the idea behind all of this. But it is impractical for much heavy usage. I did notice that some kids at Bristol University converted a 50cc Honda engine to use this idea. http://home.cogeco.ca/~davebowesevic/Student%20Projects.html
But I have not found anything that tells of their success or failure.

By: sol

sol — Fri, 26 Jun 2009 00:41:45 +0000

@ac7zl

I like the piezo idea. Would there be insane problems with heat and vibration, though, or are there piezo products that are insulated well enough for those purposes?

By: Mick

Mick — Thu, 25 Jun 2009 21:37:50 +0000

sorry guys but all of you that said in F1 it was only pneumatic spring are wrong, there was a concept going with Renault (BMW and Fiat too) that did’t go on the track becos of the new rule that follow the year of development, here are some link for you that should do some research befor saying someone is wrong…Renault was suppose to race in F1 back in the days with a V12 twin charger and full camless (electro) valve control. Why they didn’t after… simple they did’t need to…

http://en.wikipedia.org/wiki/Variable_valve_actuation

http://en.wikipedia.org/wiki/Camless

By: ac7zl

ac7zl — Thu, 25 Jun 2009 20:47:00 +0000

I wonder if anyone has ever considered the use of piezoelectric materials as actuators for engine valves. Depending on the material and the actuator architecture, I would expect very fast actuation times, a decent amount of actuation power, relative indifference to high temperatures, and so forth.

By: nanomonkey

nanomonkey — Thu, 25 Jun 2009 18:20:11 +0000

Solenoids have springs and thus have a resonant frequency to which they will float also. Whats more you have the extra problems of inductive resonance and inductive impedance. Perhaps this is negligible and can be overcome by using a springless solenoid with a low enough reactance.

By: David Hagler

David Hagler — Thu, 25 Jun 2009 18:20:04 +0000

@tw – probably not much of nothing, I drove on 3 cylinders on an old honda civic for a coupla weeks when the cam started to fail. I could get up to highway speeds easily enought, 60/70 mph (not much faster)

You’d probably loose energy – obviously you’re not gaining anything by compressing air, but the friction of the piston rings on the cylinder would cause losses as well.

By: tw

tw — Thu, 25 Jun 2009 18:00:33 +0000

Can’t you skip a power cycle on a fuel injected engine by not putting in fuel? What happens if you compress and don’t inject fuel and close the valves for compress/combust phases?

Anyway, regarding the generator comment, the 12.5cc engine used probably generates less than 0.5 HP even at peak (10k rpm) whereas even with a 45% duty cycle (open slightly less than the whole intake and exhaust phases), the two draw ~265W (0.35HP).

By: F.

F. — Thu, 25 Jun 2009 16:58:06 +0000

> “can skip power cycles which are not needed”

Idling in a breakbeat rhythm. That’d be cool.

By: chris

chris — Thu, 25 Jun 2009 15:52:52 +0000

the solenoids are almost as big as the cylinder!
sure its cool, sure it runs, but I think they proved it woun’t realy work.

By: Roly

Roly — Thu, 25 Jun 2009 15:09:21 +0000

@bigbob
I would trust a typical engine over one run by a couple of solenoids any day…

…er… you mean like fuel-injected engines? :)