29-3-2008
René of the PMB workshop made me some nice cranking sprockets in plastic. They will allow a smoother an more silent start of the engine.
For the coming weeks, the engine will be in glass showcase at the workshop, as examinations and other higher piority stuff is taking place for the moment. (finishing the bob-car, and giving a helping hand the guys at Formula Student)
31-1-2008
As the MAP problem was resolved, still some concern arose about the still quite high MAP at idle, and the high idle speed. A design error in the volume of the plenum could have been the error, as a normal engine 'sucks' only one of the 4 strokes, and encounters thereby the resistance of the throttle, with the plenum this resistance is decreased as at the moment of the intake stroke, the engine can suck freely air form the plenum which has been filled during the last 3 strokes.
Therefore I made a direct connection between the throttle and the intake, resulting in already a much lower idle. I will have to further fine-tune to get the right numbers.
As I was intoxicating everyone in the PMB workshop while testing the engine, the workshop manager offered me the use of there 'portable' air filter system, in order to get rid of the fumes. Quite a large installation for a small engine like this one.
In order to tune the engine, I asked the Eco-Runner team to borrow there advanced computerized timing light form Snap-On, which will give the opportunity to fine tune the ignition. I will report on this later on.
25-1-2008
Although it was also an examination day, I've been spending the afternoon working on the engine. As told a few days ago, I presumed some problems with the MAP, and indeed, after I glued some parts together, in that way sealing any leaks, the MAP dropped on the cranking of the engine till 73kPa, which is clearly much better than before.
Then I started the engine, and wonderfully....She ran sooooooo smooth, almost incredible.
I've got some movies of it;
Movie 1 (high rev running engine with exhaust coming loose ..... (10mb)
Movie 2 (2 times starting engine, high rev (8mb) (Thanks to Réne, Don and Ronald for the filming)
Movie 3 (without sound, but thanks to Kevin)
Form the second movie I have a data log here; One can clearly see the first small starting sequence, and afterwards the well running of the engine, steadily increasing temperature and the steady Manifold Air Pressure
Yesterday evening I also started to contact everyone who has ever helped me, or give me advice or even just showed interest in this project, and this section is mainly for them. My appreciation goes to everyone of them, who has given me even just the smallest idea, and this page is specially for them. I would like to encourage everyone to send me comment, advice or even critics to david@dagani.be
As most of them know, I'm going to start on the six-stroke part of the project, and for the moment I've got still troubles to find an appropriate way to inject the water in the cylinder at the pressure of 80bar. A conventional diesel injector isn't an option as those are very susceptible to corrosion.....
22-1-2008
I've done some ignition adjustments today, and made a small movie about it. You can clearly hear the engine running better and better as the ignition is advanced. Also I remarked some problems with the MAP, as it isn't going below 95kpa at cranking for the moment, so there must be a leakage of 'false air' somewhere. Anyway, enjoy the small movie with the data logging appearing about a low rev (max 5400rpm) test for around 1min 20sec. Thanks goes to Don for helping me in this quite frustrating morning as electronic issues caused some delay, but here it is then;
Movie ( 8Mb)
17-12-2008
Although I wasn't reporting, the engine has been running. I moved to the 'lasserij' of the PMB-workshop, where the engine can run without intoxicating everyone in the workshop. I did some tests to check the changes on the timing-flywheel concerning the vibrations. The holes drilled, performed very well in preventing further vibration due to the missing tooth.
As told before, I had some problems with the frequent resetting of the megasquirt. Remy, which was on a visit told me to remove the ECU from the plate which encounters a lot of vibrations, and indeed, the resetting rate seriously dropped.
Then I did some tests by pushing the engine in the high rev's of which the log below is an example. One can clearly see the first run, a second start-up sequence, and a third run where the engine ran at 6072 rmp.
After this log, the engine ran a few times for 5-8 seconds on a 7000 rev limit after which I pushed it till the actual record of 8247 rpm. But this is a one time test, as the engine's max. power output should be around 5500rpm.
The cranking and acceleration forces on the timing-fly wheel put a lot of forces on the crankshaft, which resulted in serious play in the interconnecting aluminium part. I will have to change this configuration as it is vital for the well running of the engine.
A movie of the high-rev running engine will follow.
24-12-2007
The last days, the engine has been running on 4stroke mode. The new timing wheel proved to be accurate till at least 5000rpm. I've tried to do a lot of data logging, but due to troubles with my computer a lot of data went lost. All together I am quite happy to have the engine running now reliable and controllable. The engine will start now with a push on the button, and run run run.....
The coming month I will have to study but begin February I will continue to progress with the fine-tuning of the fuel algorithm and spark advance tables.
One of the coming days I will also add a small movie and interactive data log file.
Here one can see a 25sec. run of the engine. Clearly one can distinguish the engine's revs and temperature. The MAP is the pressure in the intake which stays quite high thanks to the plenum and the PW is the pulswidth; the percentage of time to complete the 4 strokes in which the ECU is giving the signal to inject fuel. The TP is the throttle body sensor which gives a quite erroneous signal and should be checked.
For a small movie of the running engine (around 15sec) click Movie (Thanks to Tim)
12-12-2007
Today the engine was again completely assembled . I've placed the new components and added another compression ring to the piston assembly (originally the engine turned only on one compression ring, but now I will try with both the rings). Also some small modifications where made on the camshafts. I also added some retaining clipses to prevent further damage to the cylinder as explained before..
A new timing was arranged on the camshafts and the new timing wheel was installed. Hopefully one of the next days I can program the ECU and fire up the engine with the new starter (Thanks to the Eco-Runner team), but for the moment, she rests in peace.
9-12-2007
The progress is major these last days compared to the past months. A new cylinder was made form cast-iron and René made the grooves in the piston for the retaining-clips I would like to add.
The mantle, which contains the new cylinder is used to test a ceramic coating. The coating consisted of a grey layer of heat insulator, and a black heat resistant paint.
Then I also finished the new 'copper coated' timing wheel and a new flywheel, this in order to have a more accurate timing sensor readout, and the flywheel gives me afterwards abilities to fine-tune the engine.
5-12-2007
I Started to get the engine apart to make the necessary modifications, and found a few more things to change. There is clearly a leakage on the top of the cylinder, which should be sealed by the Viton® O-ring donated by Eriks. Maybe I should tighten the bolds more next time. Also maybe placing a 'olieschraapveer' on the piston will decrease the amount of oil burned and leaking, but I won't do that for the moment, as to many lubrication will certainly not cause the engine to grip.
Also, thanks to René of the PMB workshop the error causing damage to the cylinder was found. Twice already I had severe scratches in the cylinder side, but now appeared that the cylinder-pin could move to much, causing it to interfere with the housing. René proposed to make some small holes into the piston in order to prevent further movement, which will be done on the lathing machine. As I'm to busy doing all kind of other things, he will do this job, which for I'm very thankful.
November 2007
I brought the engine back to the PMB workshop at the TU-Delft. I will start to work again on the engine in the next coming weeks. Tasks to do include;
- Installing the 'cooling' system
- Getting a better tach signal (without to much signal noise(I will try to use a Hall sensor this time instead of an optical sensor))
- Installing a new starter (ordered one but still needs to come in)
- Sealing the crankschaft openings in the carter.
- Tuning tuning and tuning....
- Making an new engine support as testing bench
- Making somekind of 'brake' required for high end rmp testing
April 2007
Quite a lot of problems with the starter. The starter rotor has a small sprocket, but it broke already tree times, I think I will buy a complete new unit.
After a severe despute between myself and the ecorunner-team, I decided to withdraw from the project. The six-stroke engine project will come to an momentary end.