Getting on the road is great. Problems show up, but I'm glad to hear your's solving it. I'm still working on getting to that point.

10 degrees on the standard cam makes sense. The period is short and there's little overlap on that cam so the fuel mixture in idle is good. You're probably running 800'ish idle? I have mine at 15 with the Holbay cam, which makes for a decent idle at 1100. It's huting a bit, but that's probably due to the high overlap on the cam and my cylinder head - it most likely short circuits a bit of fuel out the exhaust during idle. I have an AFR meter with a wide band oxygen sensor in the exhaust so I know the mixture is correct now.

I considered fuel injection years back. Most ECU's come with some sort of ignition controller and eliminate the distributor as they run wasted spark configurations with two coils. From an engine management perspective, that's a better system. They usually, however, depend on both a crank sensor and a cam sensor, so there's a bit of work involved and it will be completely custom. I'm not going that route, but staying with the sidedraught carbs. There's more performance to be gained by working on the airflow in the head, especially enlarging the inlet valve seat inner diameter. About the original distributors, in principle they can be tuned to do anything by replacing springs with other springs, but it requires a complete rebuild every time you want to try something different. The original Bosch has an advance curve that suits the original cam only (and vacuum takeoff from the original Solex carb). I have used it on my Holbay cam, but it will never be perfect, so I'm going to change eventually so that I can tune it to the cam and head.

/Anders

Hi Anders,

Yes, it's starting and running great now. Before that I had a few issues with the engine. After some searching it was because of a dying alternator. When I put the spare in almost everything was solved!  I had some wire connectors on the ignition coil getting loose while running the car. I change the old wire lugs with eye terminals and bolted these on the coil, problem solved.

And of course the right timing helped a lot. I found 10° advanced timing is the best. Above that doesn't work properly. I was advised 12° or more, but that's not working for this car.
For this standard engine the original ignition is fine. And I will rebuild the old alternator red so it can be used on the 2nd engine.

But most important is I can drive the car around. Because of that I found the clutch was slipping, so I replaced that. And I'm still finding little things to do.

For the spare engine injection project I think you are right to mount a 123ignition. I don't think the original will be working the best in combination with the injection and faster cam.
But first I need the injectors, all connectors, make a wiring loom and so on.

To be continued....

The objective of the cam is to time the airflow through the cylinder head by opening and closing the valves. There's a lot of theory and expeirence behind cam tuning, much more than I'm competent to explain, but I wanted to share these photos which Youri (Murena1400) has kindly shared with me and given me permission to post here as they show the channels the air is passing through when entering or exiting the cylinder.

The primary restriction on the 2.2 head is the inlet valve seat. The cross sectional area of the opening is simple to calculate by calculating the area of the circle inside the valve seat minus the valve stem circle area. The area of the valve opening is given by the lift of the valve multiplied by the valve seat circumference.

Increasing the inner diameter of the valve seat will increase both areas. Theory says that a restriction has effect on airflow when airspeeds become sonic as it's not possible to accelerate air molecules beyond the speed of sound. Remember that air flows into the head in pulses so the restriction can be said to "cap" the top of the pulses. Turbolence created by edges and the like also restrict a little, but generally turbulence in the inlet is desired as it assists mixing of air and fuel in the cylinder.

The pictures are of cut-throughs of an unmodified head.

Exhaust is even more limited as the exhaust valve (and valve seat) is significantly smaller. Exhaust restrictions affect performance far less than inlet on a normally aspirated 4 stroke engine.

Hi Henk, good to hear you finally got it reground, and also great that you have the car running again.

I notice you asked about ignition in the thread below. Have you considered converting to 123Ignition?

Classic Auto Elec in Tours, France stocks it for the Murena. It's the same distributor for all engine types, 1.6 or 2.2, you just have to choose the right distributor cap for the 2.2:

https://classicautoelec.com/en/electronic-ignition-matra/5130-6778-programmable-electronic-igniter-for-simca-1000-1200-1300.html#/180-tete_d_allumeur_a_sorties-droites/678-123_tune-non

I have run the standard 2.2 Bosch distributor on my Holbay and I've not yet converted to digital ignition advance myself, but I will since it allows tuning the ignition advance correctly to match the cam. Of course you can play with the timing springs in the distributor, but they're hard to find and even harder to replace.

123Ignition can be tuned over Bluetooth with an app on your phone.

Hi Guys,

Just wanted to let you know I finally got the regrinded camshaft back. This took months instead of weeks. As I was tired of waiting I put the other standard camshaft and head in, to get the car driving. Which it does! It passed the APK (MOT) and is working fine. There are a few minor issues which have to be taken care of, but I'm happy as it's going now.

The 2nd motor is been almost completely overhauled. The other head with the fast camshaft is mounted. I'm working on this motor so now and then. I want to try to convert this one to injection. For this I have the inlet manifold and fuelrail of a Peugeot 505 GTI turbo. The ECU and injectors are LE-Jetronic from a Peugeot 505 GTI 2.2 (non turbo), as well as the air mass meter and other parts. I hope to get this configuration working, but there is no hurry. When and if this works, this will be mounted in the Murena. if not, I've got another original inletmanifold and carburateur in stock.

Henk

 

Thanks for the information. I removed the cap and, lo and behold, it looks fine now. Thank you very much.

What an annoying problem. At least just one. Good luck getting it right!
/Anders

Andreas,

If that is definitely a Solex 34 CICF 141, then that lower photo of the new carburettor looks to have a sealing cap over the adjusting screw, which was correct to prevent tampering.  Dig out that sealing cap, and the screw should be buried down in side the flange, just like the old one, in the upper photo.

Roy

Hello all,

I recently asked Polybush U.K. to list the engine stabiliser bush kit on their website so that those in Europe (or anywhere really) could buy them directly from them.  They have kindly set up a webpage listed under Matra and there is a direct link (below) that will take you straight there, but there is a slight problem at this moment because the 49C kit also fits the front suspension of the Isuzu D-Max MkII, and the listing for the Murena simply picks up that kit and its details from the Isuzu listing!

Consequently, the photo has an arrow pointing to the front suspension and it names it the 'Front Shock Absorber Lower Bush', although the fitment diagram has it approximately in the correct relative position, and the wording above the Murena photo does also correctly state 'Stabiliser Bush For 2.2L Engine'.

https://www.polybush.co.uk/product-category/matra/murena/?v=7885444af42e

They will try to resolve the conflict but in the meantime, be assured that the 49C kit really will fit the Murena 2.2 engine stabiliser link and it is really good as I (and others here) can testify, having run them now for over a year.

So you only need one kit, which you can see is less than half what those original Metalastic bushes cost, and it is far superior and easier to fit too

Roy.

Back on the road.... but unfortunately not quite.

Today at 8am for the MOT and it went well until the emissions test. Unfortunately, the idle mixture setting is missing on the new carburettor..... As we don't have an exhaust gas tester, we agreed with the TÜV that we would just put everything together, roughly adjust the idle and do the rest on site.
But I'm still happy. The chassis, engine, brakes etc. were all classed as faultless. The TÜV manager tried everything to get the CO value below 4.5%, but we couldn't get any lower than 6.5%. Now I have to find out where the setting is on the new original carburettor. On the old carburettor it was on the driver's side towards the rear. On the new carburettor there is nothing to screw on.
Maybe you've already had this problem.

Greetings
Andreas