'85 Mondial Cab --air injection questions

Just recently I posted info about a noise that I traced to a fractured/melted plastic T on the air injection system. I suspected the "burp valves" on the two banks had worn out after 22 years and were allowing exhaust heat to reverse flow into the air-pump delivery piping. I bought two new valves and a 3/4 inch plastic T. The only valve I was able to get to this weekend was the rear one, and upon removal and blowing through it I confirmed that it was indeed shot. So after replacing the one valve, and the T -- I fired it up. All was quiet-- the noise gone, and under cold start conditions I noticed a new sound from the air cleaner cover of pressurized air. Someone mentioned that this entire system only runs for a short period of time when the engine is cold. This I confirmed as being the case on my vehicle (at least the rushing air delivery into the air cleaner cover stopped after the engine warmed).

But-- after about a hour ride today I noticed the sound again at idle. Back in the garage with a flashlight I saw that once again -- the T had fractured -- this time on the "leg" leading to the front burp valve (Last time it was the other leg leading to the rear valve). Damn!

Of course I'm going to now remove the access cover from behind the rear seats and change out that second burp valve,and probably try and find a metal T this time-- but I'm also wondering If I may not have another problem-- say a restriction in one or more of the actual air nozzles on the exhaust manifolds.

When I had the engine running from cold-- I felt the pressure hose going to the rear air injection manifold and it seemed to be rather hard like it was under significant pressure. Has anyone seen a condition where the nozzles become clogged with carbon and end up not delivering anything (or very little) into the exhaust gas stream?

Yeah-- I know - if I was in another part of the country I'd just remove the entire blasted system and install blanking plugs on the exhaust manifolds. But I don't have that option here in Northern California, as I have to make the system fully operational.

regards,

Geoman54

 

Edwardo,

I take this as meaning that the actual air pump for injection is a electric compressor against the firewall on the drivers side? And this draws it's air from the hose plumbed into the air cleaner housing?

hmmm... that being the case, I guess it is the actual air injection manifolds that the smog station verifys are in place that constitutes that part of the visual inspection for smog equipment. After a succesful smog test I could potentially disable the electric compressor, remove the injection nozzles/manifold and fit blanking plugs for the two year period in-between smog tests.

It just seems to me that the pics I've seen on this site show the nozzles as being a major obstruction in the exhaust port. It would be interesting to know if anyone ever did a before and after dyno run to quantify the power difference.

Even though my car is a California model, I did live in Colorado up until four years ago when I acquired this car. I never registered it there, but do remember having some trepidation regarding its ability to pass the Colorado test. Did you have any hurdles to clear with your car?

regards,

Mike

 

Edwardo,

A few years before I made the trade deal with my brother-in-law that handed me the Mondial Cab, and him -- my March 832 F2 car -- he had a new twin turbo kit for the car. Then, with a momentary lapse of reason he sold it about a year before our deal. Oh well!

The only complaint I have with the stock configuration is that it needs about 50-100 more HP. How much boost were you running, and what model/make turbo's?

I do have two Faegol roots-style superchargers, and have "bench-raced" with the idea of fitting one with about 7lbs. of boost -- in the physical location now occupied by the stock intake plenum, retaining the CIS injection and moving onto a Electramotive ignition. But then ya gotta fit a more efficient exhaust from the exhaust ports down, upgrade the braking system, lower the car with new coil-overs,etc.

Put a roll-bar in it made of airfoil shaped tubing, fit a pair of the Sparco Milano tan leather seats, pull out the back ones and have the upholstery shop fabricate a nice leather deck with a couple of storage compartments in it............

Yeah -- thats the dream down the road.....for now I'm just having a blast driving it with top down and carving corners.

regards,

Mike

 

Edwardo,

I remember that grade you are talking about. That's one thing I do miss about Colorado --- all the open space in the mountains to really enjoy this type of car. The population density here in Northern California makes it a bit more of a challenge to find a place to open it up.

Thanks for the pic of your engine compartment. So-- I gather this was not a intercooled set-up (usually not required at 7 psi) --- and turbo technology was more in the infant stage back in the 80's anyway. Just look at what these kids are doing now with off the shelf stuff (my Son included who has a 425 h.p. Toyota Supra --- yikes!)

I valued the March F2 car at $35K --- with the Cosworth BDD in a box (not the original motor which was a 320 hp BMW injected 2-litre). So he gave me $5K and the Mondial in trade. He had bought a 1987 Straman TR, and the Mondial had turned into a garage queen. I'm in the process now of doing a lot of little things to make it as reliable as it should be. Having a blast.

Attached pics of my Mondial, and two of the Straman.

regards,

Mike M.
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Edwardo,

The March was constructed by the factory in England for the 1983 European Formula 2 season. It was customary that these drivers -- if talented enough and with some sponsership behind them-- would move into Formula 1 the next season. My car was re-homologated after the season ended -- sent down to Australia and fitted with a Cosworth BDA (about 100 hp down from the BMW 2 litre output of 320 hp). It weighs about 1000 lbs, and is a "ground effects" car with tunnels each sise of the main cockpit. I'll try a dig up a picture of it.

regards,
Mike