Craig Laycocks double end piston motor.

Post here information about your own engineering projects, including but not limited to building your own car or designing a virtual car through CAD.
63l8qrrfy6
63l8qrrfy6
368
Joined: Wed Feb 17, 2016 8:36 pm

Re: Craig Laycocks double end piston motor.

Post

Around here a good design contractor working in motorsport can make around 40 GBP/hour just to churn out CAD models and drawings. Many of them can't work out a bending moment but have a sixth sense for complex composite surfacing and intricate castings, core patterns, etc. Most of the times though they tend to get the --- jobs such as bracketry, wiring harnesses and fluid hoses. Not a bad gig at all if you're into such things.

I for one think it's a real waste of talent.

Billzilla
Billzilla
11
Joined: Tue May 24, 2011 12:28 am

Re: Craig Laycocks double end piston motor.

Post

Mudflap wrote:
Mon Nov 16, 2020 4:18 am
So the question is what does this design really achieve ?
The usual result - It's different to a conventional engine.
That's about it.

User avatar
coaster
15
Joined: Sat Jun 30, 2012 4:10 am

Re: Craig Laycocks double end piston motor.

Post

His concept matured enough to cut metal, I wonder if he will make into reality?

User avatar
coaster
15
Joined: Sat Jun 30, 2012 4:10 am

Re: Craig Laycocks double end piston motor.

Post

Bump, updates?

User avatar
Stu
Moderator
Joined: Sat Nov 02, 2019 9:05 am
Location: Norfolk, UK

Re: Craig Laycocks double end piston motor.

Post

There is a guy on YouTube that has converted an A/C pump into a combustion engine.
On a slightly different note, most fluid pumps have, at one time or another, been intended to be used as combustion engines.
This particular design (as shown in the videos) has a couple of flaws that may only be a part of the modelling process (as opposed to the design). The drive gear, between the inner face of the connecting rod would need to made to very fine tolerances to avoid issues with backlash; which would not be such an issue if the engine is a two-stroke. The other would be related to the bearings, caged ball-bearings would be beneficial, but would constrain crankshaft design, plain bearings would be prone to excessive wear (due to the short stroke).
Just my two-penn’th, and not intended to be overly critical. An interesting project.
Perspective - Understanding that sometimes the truths we cling to depend greatly on our own point of view.

tok-tokkie
tok-tokkie
34
Joined: Mon Jun 08, 2009 3:21 pm
Location: Cape Town

Re: Craig Laycocks double end piston motor.

Post

In a similar vein is the Bourke engine. Long video about it but there are quite a few on YouTube


It is a 2-stroke. https://en.wikipedia.org/wiki/Bourke_engine

User avatar
Zynerji
108
Joined: Wed Jan 27, 2016 3:14 pm

Re: Craig Laycocks double end piston motor.

Post

tok-tokkie wrote:
Sun Oct 03, 2021 5:30 pm
In a similar vein is the Bourke engine. Long video about it but there are quite a few on YouTube


It is a 2-stroke. https://en.wikipedia.org/wiki/Bourke_engine
Seems like a pretty sweet setup. Maybe a huge boon for ultralights?

Greg Locock
Greg Locock
225
Joined: Fri Jun 29, 2012 11:48 pm

Re: Craig Laycocks double end piston motor.

Post

From wiki. you may recognise the writing style

The Bourke Engine has some interesting features, but the extravagant claims[14] for its performance are unlikely to be borne out by real tests[citation needed]. Many of the claims are contradictory.[15]

Seal friction from the seal between the air compressor chamber and the crankcase, against the connecting rod, will reduce the efficiency.[16]
Efficiency will be reduced due to pumping losses, as the air charge is compressed and expanded twice but energy is only extracted for power in one of the expansions per piston stroke.[17][18]
Engine weight is likely to be high because it will have to be very strongly built to cope with the high peak pressures seen as a result of the rapid high temperature combustion.[19]
Each piston pair is highly imbalanced as the two pistons move in the same direction at the same time, unlike in a boxer engine.[20] This will limit the speed range and hence the power of the engine, and increase its weight due to the strong construction necessary to react the high forces in the components.[21]
High speed two-stroke engines tend to be inefficient compared with four-strokes because some of the intake charge escapes unburnt with the exhaust.[22]
Use of excess air will reduce the torque available for a given engine size.[23]
Forcing the exhaust out rapidly through small ports will incur a further efficiency loss.[24]
Operating an internal combustion engine in detonation reduces efficiency due to heat lost from the combustion gases being scrubbed against the combustion chamber walls by the shock waves.[25]
Emissions - although some tests have shown low emissions in some circumstances, these were not necessarily at full power. As the scavenge ratio (i.e. engine torque) is increased more HC and CO will be emitted.[26]
Increased dwell time at TDC will allow more heat to be transferred to the cylinder walls, reducing the efficiency.[27]
When running in auto-ignition mode the timing of the start of the burn is controlled by the operating state of the engine, rather than directly as in a spark ignition or diesel engine. As such it may be possible to optimize it for one operating condition, but not for the wide range of torques and speeds that an engine typically sees. The result will be reduced efficiency and higher emissions.[28]
If the efficiency is high, then combustion temperatures must be high, as required by the Carnot cycle, and the air fuel mixture must be lean. High combustion temperatures and lean mixtures cause nitrogen dioxide to be formed.

User avatar
coaster
15
Joined: Sat Jun 30, 2012 4:10 am

Re: Craig Laycocks double end piston motor.

Post

The old 2 stroke was amazing before catalytic converters and lead free fuel.
Scotch yoke seems ok-ish, i would prefer a full diameter conctact with an oil film instead of single point contact, Laycocks motor observes this principal.
Ralph Sarich tried soo, soo much to bring the 2 stroke up to date in the late eighties with a direct injection 3 cylinder, it seemed like a promising future, except it was shunned by automakers, variable cam timing was doing great things to modernise the 4 stroke at that moment in time.

4 edits later with a tiny android keypad which blocks half the screen, arrrgh.

Greg Locock
Greg Locock
225
Joined: Fri Jun 29, 2012 11:48 pm

Re: Craig Laycocks double end piston motor.

Post

I drove one of the Orbital fleet. They put their engine into 200 Fiestas and then gave or leased them to various organizations. Bit noisy, loads of torque. I don't know what the result of that exercise was.