Hoots One Device

[PJGD]

Take a look at this: https://hoots.de/en/specs/

Starting at €1,000, this device is somewhat expensive and thus not for everyone, however for some classic car owners it will be extremely helpful. Essentially, it is a computerized data acquisition device which is mounted on the car somewhere (probably under/behind the dashboard), and connected to a few sensors which then continuously records critical data from whatever feature you are interested in. This data is then available to you via a Bluetooth connection to your smart phone where it is displayed in the units of your choice either in real-time on "virtual" gauges, or plotted over time, say across a typical journey.

Typical parameters of interest are likely to be those that, if something goes wrong, could result in engine failure such as oil pressure, coolant temperature, coolant level, etc. Thus Hoots have available various sensors including a lambda [mixture strength] sensor and GPS location that can be tailored to and applied to your specific car to relieve you of worry. All in all, it sounds like a very useful bit of kit particularly for high value cars, or cars that are driven extensively or in competitive events.

In theory, it should be possible to build up a similar capability for perhaps a lot less money by basing it on a Raspberry Pi or Arduino base, but for most of us that would require getting a coding-adept son or daughter interested enough in working on such a project. . .

[Keith Clements]

I have often wanted to fit a cylinder pressure sensor to my Jowett as this is one of the best ways of getting peak performance , dealing with different fuels and detecting issues. Look at this site after looking at his page to see all the other sensors available.
https://autoditex.com/page/cylinder-pre ... -64-1.html

Many years ago I did use my oscilliscope to look at the spark waveform which is quite a good indication of engine health. This was similar to the 1960 Crypton engine diagnostic systems.

[PJGD]

Keith,
I have a research grade piezo cylinder pressure sensor that is potentially available if you want to launch into that sort of project. If you are interested, let me know and I will provide details of the sensor and outline what would be involved.

[Keith Clements]

Thanks Philip,
Along with the many other things I HAVE to do such a project is unlikely to start. I used to tweak the advance right up and could probably have done with it and a knock sensor. The problem is I would need to find a suitable control circuit to plug into my programmable ignition system fitted to the Jup. Although fitted I am not using it having reverted to the points system before doing the long trip to Switzerland! I do not trust Jowetts and electronics.

[PJGD]

Keith;
My initial thoughts are that this sort of project would probably be beyond the resources of any one person and thus it would need to be a team effort if it were to happen at all. As it happens, Andy Jackson has asked what would be involved, so over the next week or so I will prepare a document with what I think it would take. . .

[Mike Allfrey]

Hello Philip and Keith,

All very interesting.

My son has created a distributor-less ignition system for his BMC Mini. I think he based it on a Ford Mondeo ignition module with suitable programming for the Mini's requirements. The arrival of twins has put a temporary halt to the Mini restoration project, so I don't know how the engine is performing, but I do know he can alter the timing, advance curve and (I think) the engine's low idle speed.

My Jupiter has been running very well using a Honda Civic distributor (as rare as hen's teeth now!) and its control module. The only concerns I have experienced were with Chinese-made ignition coils (2 off) leaking their cooling oil when mounted in the horizontal position. My Lucas Sports Coil never did that. I now have a Bosch coil, made in Brazil, and mounted vertically. That does not look right but it works well. The distributor was set up to match the Lucas DM2 for Jowett advance curve by a local ignition systems specialist. In fact, when I had a pair of Solex carburettors installed, the low idle could be reduced to an even beat at 450 rpm. I cannot match that with the Zeniths back in place. The rev counter is electronic, so should be reasonably accurate.

All the best,

Mike A.

[PJGD]

Earlier in this thread, Keith pointed out the value of recording cylinder pressure, if it could be done. I noted that I have most of the equipment to do this but to actually make it happen would require a lot of effort that might require a joint effort from interested parties.

In the attached document with its supporting files, I have outlined what is required and how to go about it. At this time, I am not planning to make a move on this but am just putting it out there to see if there is any interest within the club to pursue such a project; if there is, then I would support it.

Cylinder Pressure Sensing Project.pdf

Combustion in IC Engines.pdf

PCB 112b05 Pressure Sensor.pdf

[Keith Clements]

Read and partially understood!

Whilst it would be nice to know if my engine was as efficient as it could be across all possible speeds and loads, I think there are too many factors that would affect any findings from one particular engine that would be general enough for us all to use. We are about to be subjected to E10 petrol with E5 becoming increasingly difficult to obtain. Even my 20 year old Aston will allegedy not like the stuff, so what affect will it have on my 70 year old Jowetts? Possibly none, as the Jowetts are not so highly tuned.

The few racing Jowett owners may well be interested in tackling this research project. Richard Gane and Jullian Crossley have already done quite a lot of research and development over the last 5 years, but their engines are not representative of the 'standard' Jowett engine.

Having subjected my Jupiter (and Subaru) to a couple of dyno tests I realise how difficult it is to maintain comparable test runs. The operators and the software that they use can make adjustments for humidity and temperature and many other factors such as power train loss but you can easily reach the wrong conclusion after any change and the subsequent test run.

A grand presentation by Philip but subjecting a precious Jowett engine to the modifications and stress is something I would have done 20 years ago, but unfortunately not now. Yes it would be nice to have an on board computer that would tell me if any cylinder in the engine was not running optimally. My highly tuned Subaru did that and put the engine into safe mode if a blip occured. The Audi I had would tune itself until it just started to knock so you could put almost any juice in it. My Skoda computer controls everything including the gearbox, supercharger and turbocharger so even your right foot is not really thinking and your left foot is redundant.

[Forumadmin]

The spark plug is the obvious place to take a pressure reading but not a very friendly environment for a sensor. However, could a small hole be drilled without affecting the insulation and from this feed off to the piezo device? There would be a change to the compression ratio slightly. I have run a colourtune spark plug many times to see what is going on so a modified plug seems feasible.

[PJGD]

Keith: Indeed, spark plug sensors are a "thing" as a Google search will show; both sensors integrated with the spark plug and also load cell washers under the plug which record the reduction in clamp load as cylinder pressure increases.

However, finding a sensor that is integrated with a Champion L10 pug or similar might be hard, but if someone had something like that it could be worth a try.

[Forumadmin]

Will the measuring affect the measurement? Looks like they are about £250+

003-269e-3.0.pdf

I am still pondering if just looking at the High Tension waveform effectively tells you what is happening. Taking a feed off to a scope is easy.

fuel-4-1031600.jpg

The secondary ignition waveform is not just about the coil, it is about the resistance of the air and fuel mixture inside the combustion chamber. When you are looking at a secondary ignition waveform, you need to be looking at the spikes and the hash in between. The first spike is where the coil discharges and the spark starts to jump from one electrode to the other. These spikes change depending on the resistance between the electrodes and the cylinder.

Now, imagine the air and fuel inside the combustion chamber as ohm resistors between the spark plug electrodes. If you increase the distance between the electrodes, you are increasing the amount of air between the electrodes and the value of the resistor between them. As cylinder pressure increases and fuel mixture changes, the amount of energy required to fire the plugs also increases. The resistance also changes because the amount of fuel changes the resistance.

Less fuel means higher resistance between the two electrodes of the spark plug. In the waveform, you can see this as the spikes change in height. Also, the burn line might be higher and shorter. But, the sign that there is a lean cylinder is the spike on the other side of the burn line. In some cases where the fuel injector is making the cylinder run lean, the two peaks might be the same height when the throttle is snapped or the engine is put under load. This is the leftover energy in the coil.

If the mixture is too rich, the resistance of the air and fuel mixture is lower than normal. This will result in normal burn time with no spike at the end.

https://www.autosuccessonline.com/scopi ... ave-forms/

https://www.youtube.com/watch?v=SUShO72Grq8

[PJGD]

That is good information that will likely encourage me to build up a distributor test rig and take a look at some of these aspects.

Nevertheless, the Combustion in IC Engines file that I posted earlier shows that there is a significant delay of many crank degrees between passage of the spark and build up of peak combustion pressure which is not seen from the HT waveform. The critical parameters as far as engine performance goes is the overall burn duration, and the location of the cylinder pressure peak relative to TDC which can only be seen from the pressure trace.

If the overall burn duration (largely controlled by turbulence in the chamber) is too long then fuel consumption suffers. If the pressure peak is to soon or too late (in the range 10° to 15° after TDC would be about right) then power and fuel consumption suffers.

[Keith Clements]

There is lots of good stuff on using a laptop for diagnosis
This video is good.
https://www.google.com/url?sa=t&source= ... bV3EYIWT_k

Still trying to find one that shows tuning rather than faults.
An upward slope of the spark section indicates a weak mixture whereas a downward slope indicates a rich one.
Can this be used to get the best performance and set up the carburetor jets?
I have a 1970's gas analyser which I stick up the exhaust pipe but this is crude and takes a long time to get a reading and is an average of all cylinders.
The 1970's Colourtune spark plug is more accurate but not easy to use.

All fairly complex when trying to get four, not very well balanced cylinders, to be efficient between 600 and 6000 rpm.