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Author Topic: How can you tell a real "S"?  (Read 13945 times)
macaroni
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Murena and Multipla - I like it 3 abreast!


« Reply #15 on: September 07, 2006, 09:07:18 am »

Don't say that! I feel bad enough already about selling such a good condition Activa. I hope the Murena is as enjoyable.

I got the Matra bug when I was a little kid and the local Rootes group dealer got a Bagheera in stock. I would stand for ages with my nose against the window marvelling at such an exotic machine parked beside humble Simcas.

I also loved my Mums old Simca 1100, one of the most comfortable cars I've ever been in.

I love French cars in general.
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Anders Dinsen
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« Reply #16 on: September 07, 2006, 09:44:38 am »

My wife and mother are not pleased, but who cares!! As long as me and my boys can enjoy the car, thats all that matters.
My eldest boy is very excited about Daddy buying a car with 4 exhausts!

Hahaha!! SAME HERE!!! Cheesy

My 8 yr old has the same craze about counting exhausts! And he loves my Murena, though mine only has two end pipes. I fixed the vacuum for the popup headlights yesterday, and he loved it. He thought it looked sooo cool. I also lifted him into the boot where he checked the engine Wink

Your mother and wife will learn to live with it Wink
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'82 Murena 2.2 prep 142
'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
Matra_Hans
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« Reply #17 on: September 09, 2006, 09:00:02 pm »

Hi
Attached please find from a french site the specification for a Murena S.
This will also give you an oppertunity to practice your French.
This might be a bit late but I have been busy rebuilding my fram's barn.
Hans
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macaroni
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Murena and Multipla - I like it 3 abreast!


« Reply #18 on: September 11, 2006, 11:23:55 am »

Thanks for that link Matra-Hans, can you clarify what the numbers in the "Distribution" section mean?

I am getting  hold of the specs for the Holbay cam in the car I am after, to compare with the official "S" cam.
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Will Falconer
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« Reply #19 on: September 11, 2006, 11:53:09 am »

I don't think there's much difference between a Holbay Tornado cam and an 'S"

One characteristic not mentioned is that the 'S' has a lightened flywheel, which I think makes a big improvement to the flexibility of the engine.
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macaroni
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Murena and Multipla - I like it 3 abreast!


« Reply #20 on: September 11, 2006, 01:16:12 pm »

Funny you should say that Will, as the example I drove did feel rather "heavy" to rev, if that makes sense.

Can anyone tell me what the standard rocker ratio is for this engine?

I have the specs for the Holbay cam, but they don't take into account the rocker ratio.
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macaroni
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« Reply #21 on: September 11, 2006, 03:40:17 pm »

One characteristic not mentioned is that the 'S' has a lightened flywheel, which I think makes a big improvement to the flexibility of the engine.

Actually, it does mention that, the phrase "Volant Moteur Allege" means "lightened flywheel", or so my French colleague informs me.

So, a car advertised as an "S", but with just 2 carbs and a 4 branch manifold bolted on, is a long way from being an "S".
Interesting...
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Anders Dinsen
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« Reply #22 on: September 11, 2006, 10:18:22 pm »

Can anyone tell me what the standard rocker ratio is for this engine?

It isn't going to be exact, but I've just tried measuring a loose rocker. It looks like it is something like 1.2 depending on the valve adjustment.

Quote
So, a car advertised as an "S", but with just 2 carbs and a 4 branch manifold bolted on, is a long way from being an "S".
Interesting...

Holbay cam is reported to be as good or better than the standard S cam, the large overlap means that it just continues taking revs. The lift is lower than the standard S, but the open time is greater. I have the Holbay cam in my Murena and the S-distributor with more aggressive ignition timing.

I had to remove the rocker cover on mine (don't do it if you don't have to as the gasket will *need* to replaced) and took the opportunity to take this picture of one of the inlet lobes. It does not show the 70 degrees overlap, but it's there Wink and you *can* see the oval lobe shape.

Your car will never be an original S, but it can get very close and be just as good regarding performance.

On mine the twin Solex carbs have been replaced by the standard single Solex, which i don't mind as it is plenty good enough to supply air for me.
« Last Edit: September 11, 2006, 10:28:31 pm by Anders Dinsen » Logged

'82 Murena 2.2 prep 142
'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
macaroni
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Murena and Multipla - I like it 3 abreast!


« Reply #23 on: September 12, 2006, 09:10:31 am »

OK, thanks for that. It makes sense. Nice picture too. It isn't a particularly aggressive cam lift-wise is it? Not compared to the rally cam in my 205, but it is very oval!

I have another question then - is the S distributor a completely different model or does it just have a different advance curve?

If it is the latter, do you know what the 2 advance curves are (standard and S)? I know of a place in the UK that can alter advance curves on distributors and I could easily get the standard one modified to S spec.

I got the one on my 205 recurved and it made a decent improvement.

Your single carb is probably much more economical than the twin Solex set up too!

I pick mine up on Thursday afternoon, can't wait. Got it for £2000.
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Anders Dinsen
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« Reply #24 on: September 12, 2006, 06:17:00 pm »

OK, thanks for that. It makes sense. Nice picture too. It isn't a particularly aggressive cam lift-wise is it? Not compared to the rally cam in my 205, but it is very oval!

I know that Holbay developed a cam that is more aggressive than this - in a year or two we may see that go in a Murena in GB, it will be interesting to see how that turns out. But no, I don't think it is that "bad" Wink it's quite driveable even at low revs and it idles very well.

Quote
I have another question then - is the S distributor a completely different model or does it just have a different advance curve?

AFAIK it is only a different advance curve!

Quote
If it is the latter, do you know what the 2 advance curves are (standard and S)?

Not really, but I think we can find out.... and I'm sure that the UK Matraclub can help.

Quote
Your single carb is probably much more economical than the twin Solex set up too!

No that is the primary reason that "the experts" recommend the change, plus that the twin carbs really doesn't really give that much more power. It's also easier to maintain and adjust. So I'm quite happy with my single carb. If I'll ever change it, I will fit a fuel injection system with full ignition control too.

Quote
I pick mine up on Thursday afternoon, can't wait. Got it for £2000.

That sounds like a very good deal! Big congratulations. I'm sure you will be very happy with it! Keep it well! Cool
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'82 Murena 2.2 prep 142
'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
roy4matra
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« Reply #25 on: December 31, 2006, 05:12:42 pm »

I'm going to see a supposed Murena "S" at the weekend. It is a 1982 model, so it must an aftersales kit and it has a 4 branch manifold (with 4 output silencer!) and twin Solex carbs. Question is, is there any other way to determine if it is a genuine "S" kit with the hotter cam?

Cheers,

Antony

Although the original question was asked some time ago and no longer requires an answer for that particular purchase, the following may be useful for others in future.

To tell if a Murena is a genuine 'S' is easy - the chassis number starts VF853C432 EX 75....  Only the 'S' had the EX (1984) designation and the 75 start to the six digit number.

To tell if an earlier Murena has had a genuine Prep 142 modification, it is not that hard for anyone that knows the cars well.  It really should have the type approval sticker next to the chassis plate, but that could have been removed of course.  The obvious external sill extensions and rear wing could have been fitted to any car, and could be copies.  Or a genuine car might not have them (personal taste).  But if the engine modifications are not genuine they should be easy to spot.  A genuine Prep 142 kit used a unique inlet manifold with 15 degree incline so that the unique airbox sits above the fuel tank; it used twin Solex 40 ADDAE carbs. (the 'S' used twin Solex 40 ADDHE); it has a thermostat extension housing; a different water pipe under the inlet manifold because the original was coolant heated and the twin sidedraught carb. manifold was not; it even has a different dipstick tube.

I would suggest that if a Murena has been modified but not using the original kit, then it will most likely have twin Webers or Dell'Ortos which is the first giveaway.  In case the original Solex have been changed, does the leftmost intake sit above the fuel tank?  It will on a genuine manifold.  On a 'fake' it is unlikely to have the original airbox or air filter.  But of all the things that I doubt would be changed, would be the coolant pipe or the dipstick tube!  Those for me would be the most positive indications.

As for the camshaft...  That is always going to be difficult to prove without stripping and measuring, unless you know how a standard Murena 2.2 performs and can easily tell on road test that it is better.  And it is easy if you know how a standard 2.2 goes, to tell if the camshaft is better.

This still doesn't tell you if it is a genuine Prep 142 cam.  It could be any fast road cam - Holbay, Piper, Kent, Politecnic ...  However, the chances are if it has any of these fitted they will all be better than the standard and possibly better than the Prep 142/"S' cam too.

For anyone unfamiliar with the car, simply take a few photos of the carb./inlet/manifold/airbox areas and email me.  I should be able to tell you from those.

Roy
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Lennart Sorth
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« Reply #26 on: January 01, 2007, 03:19:25 am »

simply take a few photos of the carb./inlet/manifold/airbox areas and email me. 
Roy, you prove yourself invaluable as usual - thanks!

Happy Newyear !

/Lennart
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Lennart.Sorth@matrasport.dk
Murena 1983 1.9i silver // Alfa Romeo Giulietta 2.0d 2012 white // Smart 4two cdi 2010 blue //
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