Mangusta 8MA1010 project - running quad Weber DCNFs with a stock jackshaft

Here ya go!  Pic from "engine (Boss302) out" number 2,349......ok, number 2.... during my frame repair operation..and enginedectomy...trans had just come out. I thought I had a pic of my NOS "clock holder" somewhere....but can't find it.....yet....

Bummer that you are not allowed use of other period downdraft twin carbs.....

As for the 302 in our cars and revs......

1) the puny header size did NOT help at all.......these headers resemble old household heating system pipes repurposed as auto parts......

2) the heads are fine....right up to the fairly small exhaust ports.   A simple "gasket match" porting job brings them a bit more to life.   A full on porting job, as seen in the GT40 heads (different post somewhere on this forum....) brings them up to damned good.....no need for other heads.  Some would argue that the intake valve sizing should be increased....... likely for little gain in our butt dynos.....!!!   Intake ports are huge already.  Combustion chambers are closed style..... 68 heads are best SBF cast iron that Ford made along with HiPo289's....which still fit in our cars.   Boss 302's do NOT fit........just ask me how I know this......!!!  )))

Air injection system can stay on the car with minimal HP loss (pump drag), only physical clutter. Clean up the air...... )

What was never made for our cars, was a version with larger long tubes to emulate the look of the stock headers.   Several versions of larger tubes.....but they resemble typical 4-1 design.  Nothing wrong with that, just little resemblance to originals. IMHO.

3) The cam was pretty mild and of no assistance. Pretty much done by 5000-5500.   A HiPo 289 cam or the Ford OTC performance cam would have livened these engines up quite a bit!  Something borrowed from the GT40 or Trans-Am cars would have been nice......

Great fabrication and design.

Here's the thing though. The reversion is not caused by the carbs. It's caused by the cam timing events in a V8 with individual intake runners.

Changing to another carb other than the 48ida doesn't fix the problem. It's caused by the individual runner intake manifold.

The fires are not caused by the carbs. What happens is that the reversion pushes back the atomized fuel and that gets collected by the air cleaners.

The fuel saturates the filter elements. They get soaked with fuel.

When you go to restart the car, the ignition flame travels up the intake runner and ignites the saturated filters.

I like what you have done with the fabrication of the air cleaner but you are going to have to put the filters, not over the carbs but at the extreme end of the flexible air supply tubes and pray that the fuel plume doesn't reach that far.

You are also going to need to provide some sort of a drain in the base of the air cleaner and some sort of collection mechanism to collect the fuel in a way where it can't ignite. If you don't then you likely have created an explosive device in that air cleaner?

A Ford 302 is not a Maserati engine and has different characteristics.

As I said though, beautiful fabrication work.

I also have seen two racing Mangusta's running a 48Ida system using jack-shafts. Just not original ones and mounting brackets although still a simple system. I have no details on those though so I can't offer any help on specifics. Sorry.

Carry on!

Agree, the short individual intake runners  make the problem much more pronounced than. Interestingly although we don't have a reversion / stand off issue when we switched to the Holley we still have a breathing issue which points to headers.  Over winter our plan was/is to switch to a cam which has a bit less duration , which we see causes the problem, and a bigger lobe separation angle which should also alleviate it.  If we swap our cam and the issue is alleviated we'll report back.  May also put engine one dyno and swap out the existing headers for the 1 5/8ths we use on Mustang and see what that produces before embarking on having any made.

GT40's run "turkey trays" so at least you stop the drips getting onto exhausts - that's then theory anyway and I was told if you see flames hit the throttle and it'll suck them into the engine.... okay...

Hopefully not hijacking the thread but we got confirmation today that our car has been given an FIA Historic Passport  (with the Webers on) but not as a GT. Basically it means (unless the race organisers are "flexible" which in current climate they may be!) we have to race against Lola's, Chevrons, GT40's and 917's which is, (to put it mildly) complete BS and a kick in the teeth.  We'd hoped it would open the door to lots of races and planned on going up against E Types, Griffiths Cobra etc but no, not according to the FIA we won't.  According to them it's not a GT but a Two Seat Race Car.  Utter nonsense.

So another reason we may not race the Mangusta  but having come this far with the IDA's we are stubborn enough to try and get engine to work properly on Webers whether they are IDA's IDF's or DCNF's!!

@v8jet posted:

Agree, the short individual intake runners  make the problem much more pronounced than. Interestingly although we don't have a reversion / stand off issue when we switched to the Holley we still have a breathing issue which points to headers.  Over winter our plan was/is to switch to a cam which has a bit less duration , which we see causes the problem, and a bigger lobe separation angle which should also alleviate it.  If we swap our cam and the issue is alleviated we'll report back.  May also put engine one dyno and swap out the existing headers for the 1 5/8ths we use on Mustang and see what that produces before embarking on having any made.

GT40's run "turkey trays" so at least you stop the drips getting onto exhausts - that's then theory anyway and I was told if you see flames hit the throttle and it'll suck them into the engine.... okay...

Hopefully not hijacking the thread but we got confirmation today that our car has been given an FIA Historic Passport  (with the Webers on) but not as a GT. Basically it means (unless the race organisers are "flexible" which in current climate they may be!) we have to race against Lola's, Chevrons, GT40's and 917's which is, (to put it mildly) complete BS and a kick in the teeth.  We'd hoped it would open the door to lots of races and planned on going up against E Types, Griffiths Cobra etc but no, not according to the FIA we won't.  According to them it's not a GT but a Two Seat Race Car.  Utter nonsense.

So another reason we may not race the Mangusta  but having come this far with the IDA's we are stubborn enough to try and get engine to work properly on Webers whether they are IDA's IDF's or DCNF's!!

The Holley runs with a common plenum intake manifold so the reversion pulses are intended to push the mixture into the next opening intake valve.

IF you want to see a light show, start the engine (with  the 48ida's and just velocity stacks) at night. It's very impressive and the kids will like it better then a fireworks display!

I recently went to a 2x4 Holley set up on a C60A trans am intake manifold. So I repainted the underside of the hood.

The flame marks from the Weber velocity stacks were still on the underside of the hood.

Yep. The GT40 "cookie trays" are there MOSTLY to direct the fuel plumes into a safe collection area.

Detomaso actually figured out that all you had to do was go to a 5" tall velocity stack and the plume would stay in the stack. Interesting that NO other teams ever noticed that before?

There were a few sets of 58ida's made for Ford and Shelby to run on the 427's. NO ONE could get them to "work" (at least to their sanctification or expectations) so the Mark II's ran a single Holley carb. That isn't a disgrace and in human terms is the simplest to make work.

Why fight it? Run the Holley and put yourself in a more competitive class. You can't compete against Lola's. The thing weighs like 1,600 pounds. Otherwise you are just being an alchemist and turning lead into gold never really worked out?

I think you're right on the money with using the Holley we're really pleased with the one we run on our race Mustang, it just performs and stays in tune.

I'll try the night time routine with a fire extinguisher on hand.

The situation with FIA and Mangusta  is just nuts, they complain like crazy about wanting variety on the grids, then allow at least 20 Cobra Daytona Coupe replicas to get certified, often with more in a single race than ever came out of Shelby and then tell me I need to race with cars like Lolas and Chevrons, even when the Mangusta doesn't fit their own definition of the class they have categorised it into.

Their loss, it won't appear on one of their grids with cars like that, would be like bringing a knife to a gunfight, plenty of other places to use it or just turn back into a road car.

But you have to admit, 4 x Weber's do look and sound VERY cool!! As Steve suggested to Nate a poly clear cover on top of the Maserati style airbus would look awesome.

I'd love yo see you race no matter how. If you go with the Holley and COBRA S2MS intake manifold, use the aftermarket Blue Thunder version.

The volume of the ports has been increased.

The 289 is being run here as a 292 and it is making 620hp at 8200rpm on a single Holley. I don't think you can get the Webers to that level now.

racing Jury is still out, still feeling FIA / regs are stacked against us so will find somewhere else to go, maybe find something with other GT's. main issue is they won't even listen or enter into a dialogue.

a 292 with 620 bhp, that is a TON of power.  We have to run iron C5AE heads, cast rockers  and Tri-Y headers with C5AE block too, please tell me that has Ali heads with roller rockers before I go into major depression ......

I understand  that the Cobra Automotive / Curt Vogt Gt350 has that kind of power but think SCCA allows much more radical mods than we can run in Uk / Europe