MatraSport Forum

Each model => Murena => Topic started by: krede on March 02, 2021, 01:32:16 pm



Title: Murena 2.2 inlet flange
Post by: krede on March 02, 2021, 01:32:16 pm
Has anybody ever made a drawing of the exact measurements of the inlet flange of a 2.2?.


Title: Re: Murena 2.2 inlet flange
Post by: roy4matra on March 04, 2021, 02:25:18 pm
Has anybody ever made a drawing of the exact measurements of the inlet flange of a 2.2?.


For the standard down-draught carb. manifold, or the twin side-draught carbs. manifold Krede?

The inlet manifold for the twin side-draught carbs. also incorporates the extension water jacket that is necessary to move the thermostat housing out of the way.  Original Matra inlet manifolds were like this and so are the ones that Ian & I have now had made and I have a few spares for sale.  The Politecnic inlet manifold did not have that extension so you had to make something yourself, and the Simon one did not incorporate it but at least he supplied a separate extension for you.  Neither of these companies have these available now and they were expensive when they were available - something like 600 Euro with taxes and delivery.  Those I have are a lot cheaper even though they do incorporate the water jacket extension.

Roy


Title: Re: Murena 2.2 inlet flange
Post by: krede on March 04, 2021, 03:31:40 pm
Its for side draughts  alright. :).
I do have a politecnic unit, and it's pretty useless, I guess it's made with motorsport in mind.
If you have a proper manifold to spare ,I'll be more than happy to buy it :). I'll send you a mail tonight when the kids are asleep .


Title: Re: Murena 2.2 inlet flange
Post by: roy4matra on March 04, 2021, 06:11:54 pm
Its for side draughts  alright. :).
I do have a politecnic unit, and it's pretty useless, I guess it's made with motorsport in mind.
If you have a proper manifold to spare ,I'll be more than happy to buy it :). I'll send you a mail tonight when the kids are asleep .

Hello Krede,

Yes, the Politecnic one does not shift the carbs. to the right, which means the left one is right up against the fuel tank with insufficient room for the intake air flow, which also should not be from the top of the engine compartment which is really hot.  It would be fine for that engine in a race car where there is plenty of room and the tank is somewhere else.

We had these made by a machining company and to keep the cost down instead of having an expensive mold made for casting them like the original, these are made by first machining two flanges, one to fit the head and one for the twin carbs. (doesn't matter whether they are Solex, Dell'Orto or Weber as they all have the same flange specification - in fact the throttle bodies for fuel injection also use that same flange so these manifold would suit those too).  These two flanges are joined by four tubes so the ducts are straight rather than curved like the original casting, but they are angled across so the left carb. is moved to the right like the original so that it misses the fuel tank and you can get a decent air box on and the leftmost intake is not compromises by being right up against the tank like some conversions we've seen.

The tubes and manifold are designed for twin 40's just like the original, not 45's as we expected more to want that size, but if there was some demand for 45's we could probably get some made with larger tubes to suit them.

The standard dipstick tube has a bracket at the top that bolts to the head, but on an "S" the dipstick tube has a modified top bracket and bolts to the manifold instead.  This manifold also has that thread to bolt the dipstick tube bracket to it, the same as the original.

Here are a couple of photos of the manifold so you can see what they are like.  I've added another photo now showing a manifold installed with an original "S" airbox so you can see how it looks.

Roy