Five Cylinder Radial With Ohc

[BRIAN]

The next project is beginning to take shape after doodling for hours on paper and computer I have come up with this offering.

Five cylinders-- 25mm bore X 28mm stroke. with overhead camshafts.

Capable of being made on a 7X12 and a small mill.

It's next winters project and possibly another two winters after that so It will be a long haul.


Watch this Space.

Brian.

 

[Franko]

My hat's off to you Brian. That looks very ambitious.

I will be watching.

 

[bpratl]

Great project, looks very challenging and sure it will be rewarding when completed.
Looking forward in following this project. Thanks. Bob

 

[BRIAN]

Two more drawings showing the cam drive gears and belts, a cover will be fitted over the inner belt pulley's to take the two oil pumps on cylinders three and four. the ignition system will be split between camshafts two and five a magnetic trigger on one and distributor on the other.
Next job will be to draw the crank and accessory shaft.

Slowly Slowly. Brian.

 

[T Bredehoft]

I was surprised to learn that the early (maybe the first versions) had a stationary crank and backplate and the whole cylinder arrangement revolved. The backplate served the purpose of operating the valves, too. The prop was fastened to the cylinder body and turned with it. I can't imagine the bearings they had....

You've got a great design there, but keeping timing with belts is going to be a problem. Maybe you can use geared timing belts.

 

[BRIAN]

Thanks for your concern, the belts I have specified for this engine are 2.03mm pitch 6mm wide M X L timing belts so this problem will not arise.

I will have to put a tensioning pulley on the outside of belt, but as I have not made up my mind if the engine is going to be clock or anticlock rotation, I do not know what side it is going to go because it is best put in the slack side of the belt.
Brian.

 

[BRIAN]

Over the past 3 months the engine has evolved . changes to case diameter --stroke --barrel--material & design--cylinder head. Just to name a few.




However today we cut the first material to make the jig for the crank case, in the design all the parts of the case have the same register diameter allowing me to us a single jig that can be fitted on both the rotary table and the lathe face plate, keeping set up time to a minimum.



The 100mm blanks only just fit in the self catering 4 jaw PHEW!!
machining starts today.





Brian.

 

[BRIAN]

The first part of the jig is made , this 90mm od ring has two jobs it is the Go-- No go ring for all the female locations on the crank case and the jig.

also it coverts the female jig into a male .



Brian.

 

[JPigg55]

Your design looks a lot like the Cyclone Power engine except it being a 6 vs 5 cylinder, http://www.cyclonepower.com/technical_information.html.
I was talking to a guy on another thread who'd talked to the inventor and he had this info:

"More than you ever wanted to know about the Cyclone valve control system:
The Cyclone automotive system uses a single needle valve in the cylinder head operated by a rocker arm/push rod/cam assembly. Since it is a radial piston design, then all 6 valves are actuated by a single central cam. The cam is forced up automatically with increasing speed using a small hydraulic actuator - the purpose is to advance valve timing with 3-D cam shape and the cam lobe is shortened some to lessen the cutoff range possible. The actual cutoff of the valves is controlled by the operator with a single mechanical rod. The 6 push rods extend from the valve rocker arms at the cylinder heads to the cam through a ring that surrounds the cam. The ring is rotated with the valve control rod (i.e. the throttle control). In the neutral position the ring positions the 6 push rods against the center of 6 small central rocker arms (note that the central cam actuates the push rods via these 6 small rocker arms). In this position the valve push rods are not moved just like a child sitting in the center of a see saw does not move up and down. Now, rotate the ring and the ends of the push rods move along the lengths of the small rocker arms to reciprocate back and forth with an amplitude that changes with the control rod position - and with a frequency a function of cam timing. So, one can just bump the valves open to let in a tiny charge of steam, or one can force the ring over completely and allow the cam to open the valves for a long period and let in a lot more steam for more torque. Also, the cam allows up to 33" cutoff with zero advance while the engine is at rest to allow for starting the engine from rest (direct drive - no clutch or transmission), and the engine reverses by rotating the ring 30 degrees to change valve timing. ----- Actual compression ratio is approaching 30:1. Also relevant is the geometry of the spider bearing. The pistons do not take a sinusoidal path. Rather, the piston dwells near top dead center for a longer period because the connecting rod at the bearing literally pivots at the top and bottom of the strokes. This buys time for pressurizing the cylinder and provides higher mean effective pressure and expansion for higher efficiency. There is also the reheat tube - most of the compression volume is the reheat tube placed in the furnace next to the injector where temperature is maximum. The reheat allows peak steam temperatures to exceed 1400F despite the steam in the primary heat exchanger maintained at 1150-1200F, and the length of the tube is tuned to optimize heat transfer during operation by setting up a standing wave at higher engine speeds corresponding to highway driving where optimal efficiency is more important. However, the efficiency does not vary significantly over the power range partly due to the physics of the uniflow expander and the heat regeneration of the system - city mileage will be better than highway for these reasons along with the lack of idling of the engine. NOTE: There is additional compression volume added at low engine speeds, and a small valve shuts as the engine speed increases beyond about 600 rpm - this reduces compression at low engine speeds to avoid rough running. Engine efficiency is lower at these very low engine speeds, but this corresponds to a vehicle speed under 15 mph where high efficiency is not so important."

Not sure if any of the info will help you, but thought I'd put it out.

 

[BRIAN]

Thanks for the info JP very interesting, nice to know what others are doing.
brian.