The ultimate Ferrari carb airbox from a Lambo

In my continuing search to recover the documented approx 10 rwhp lost at the well known poor flowing Ferrari airbox, I think I have found a possible solution. Much as the exhaust on the flat crank V-8 takes advantage of even pulsing per bank, so might the intakes.I am going to separate the the intake tracts into two separate intake airboxes or plenums. It just so happens that a Lamborghini Jalpa airbox does just that. As a matter of observation, all Ferraris from the 348 on separate into a plenum per bank.
Have discovered something interesting about the Jalpa airbox, not sure if it means anything - it has a large volume that is offset from the centerline of the barrels. It looks like it gives the air a path around the barrels to allow the back ones to not breathe from the fronts. Alfa airboxes are similar, actually.
The Ebay Jalpa airboxes I just purchased arrived - as expected, they are 'offset' to the outside of the engine allowing a flow space to the carbs (shown). The Jalpa DCNF spacing is wider, so am quickly CAD and machining up a nice fitted aluminum adapter piece (shown). In an amazing bit of luck, a RC-5000 filter designed for a GM throttle body almost exactly matches the measurements on each airbox snout, so will go with system below for cold air induction - not perfect, but it will be cool air from the scoop and up from back around the wheel well away from the engine. It looks like the height will probably be ok.
Should have the adapter piece in a couple of weeks - will post.

I think you will have some success Russ, because Lambos have generally over history, recieved more HP from simular volumetric sizes as compared to Ferrari. And as you noticed, Ferrari has split many Intakes to increase flow and reduce stalling and resonance of intake air. And if you go back to the Big Block Mclaren days of the 60's-70's you will remember that the Stacks were staggered in hieght to keep one Cylinder from robbing the next of air.

I don't know if you're familiar with Super Trap Exhausts (you likely are but others may not be) that had Addable/Removable Plates for Differing Track Layouts & Conditions, intakes have also had many variations on Air Boxws and Stack Lenghts for the very same reasons. In the Ferrari realm one of the main reasons the "95" 355's have more HP than the 96 & laters is INTAKE FLOW (95's have Twin Inlets).

I think you'll pick up even more HP as you progress along this line.

Thanks JRV
I've been studying up on the small Lambos; I don't know if I would fit or not, but I really like what I read about the Urraco P-300.
Maybe I need to look at it more seriously - I really love mid engine 2+2's.

JRV wrote: And if you go back to the Big Block Mclaren days of the 60's-70's you will remember that the Stacks were staggered in hieght to keep one Cylinder from robbing the next of air.

I write: The staggered heights also result in a wider power band since 4 cylinders are tuned for (slightly) higher RPM power (short stacks) and the longer ones tuned to (slightly) lower RPM power.

Back to the question at hand: If r_turner could figure out a means to get only cold air to the intake (filters) this would prevent the engine from digesting warm/hot air from the engine bay. Something like an air box big enough for both intake cone filters to be enclosed (with adequate spacing around all components) would work well

Well, not all my ideas work so good.
The Lambo Jalpa airboxes fit GREAT, but the forward one is too tall and the bonnet cannot close. The metal support beam in the bonnet contacts the box and prevents from coming all the way down. Back to Ebay for the boxs probably.

Not to be dissuaded, have designed a possible solution and will go to an aircraft a&p fabricator tomorrow. Here are the issues to solve for making this worthwhile to me:
1. One plenum per bank, easily removed and giving quick access for carb tuning and work ( where you don't have to remove the whole assembly like stock)
2. More open than stock allowing more airflow between the carbs to allow cooler running temps and solve intermittant fuel system heat soak problems I've had here in Texas.
3. curved plenum top like all 348 and after dual plenumed Ferraris
4.Offset side box with flow taper to better aid even flow and enhance flow velocity to carbs and mixture stability barrell to barrell using the Jalpa offset scheme and add a front to rear taper like in older Ferraris and some others.
6. Simple
7. Use/modify existing adapter plates ($)
8. Adaptable to readily available K&N filter set up.
9. The bonnet must close

Have enclosed photo of the Jalpa airboxes installed just to show you what they looked like on a carb Ferrari engine. I think they would have worked pretty well. Also shown is a picture of the adaptor plate showing how easy it is to work on the carbs once the airboxes are quickly removed by six nuts, and my current best attempt at a solution.

I apologize that the engine is so dirty - I've been driving it a lot in the rain this fall/winter and need to do a spring cleaning. It really does clean up nicely I promise.

All ideas and comments welcome. Hope this is interesting for the 3 guys left following this.

best

Russ

Here are the roughed out dual plenum intakes; The snouts will be refined but I must say the aluminum welding on the box is aircraft quality.
I've also removed the side vent and am working on an appropriate duct.
Note the space now between the carbs for cooling air flow. The Plenum tops can quickly come off to allow easy DIY tweaking.
It looks like the new ones will fit much better than the Jalpa boxes (for sale, by the way)
I was going to paint them black or red, but I may just leave them aluminum...
I have no idea if this will affect the sound.

Hi Russ,
Did you get any where with this? I have my airbox off at the moment!

Off topic, would the colours your engine is painted be standard? My GT4 has gloss black cam covers - yours look so much neater!

Interestingly and purely by coincidence I knocked up a similar shaped airbox for my last car which ran twin side draft webers 40 DCOEs, Although it was aonly a 1300 Triumph it still produced 135 bhp which was quite impressive (the airbox was not the only mod)! If you can squeeze 135 out of a Triumph Spitfire lump, is it possible to get 290+ out of the Ferrari V8?

On the triumph, the setup was as follows:

Stage 3 Engine Ground, Stroked, Indexed, Tuftride Lead/Copper Bearings 010/010 - Bored, Rodded, Acid dipped. Whole rotating assembly balanced, including pistons and conrods the Flywheel was Lightened and balanced, AE Hepolite +030 Pistons Kent TH3 Camshaft with duplex timing set.
Manifold Triumph Tune 4-2-1 exhaust manifold
Cylinder -ead Triumph Tune Stage 3 unleaded cylinder head the Rocker gear Triumph Tune Roller Rocker assembly and lightened hollow pushrods with Twin Weber 40 DCOE carbs and Piranha Electronic Ignition

The engine was built by Williams racing for me and was truley awesome HOWEVER.. Surely most of this would be standard (not withstanding the differences between the two motors) on the Ferrari V8 taking into concideration its pedigree? (http://home.btconnect.com/ntruman/Spitfire/index.htm)


regards
Nick

Nick
Thanks for the email - am waiting to pick up the final plenums this week. In addition, I am also picking up a modified side scoop with a new aluminum duct to direct air at the air filters and around the carbs to keep them cool. I hope to have everything installed this next week. The original factory engine finish was aluminum; these colors are as close as I could find to the factory when they powdercoat the cam covers.

It is interesting to look at the restriction of the original intake scoop duct. After a lot of **highly scientific** (using a floor fan) and different duct ideas, I settled on strong and simple. I may not be the absolute best, but it is quite simple and should lower engine bay temps as well.

Your engine looks fantastic - very well done. Anyone that puts out over 100 hp per liter, well, that is impressive.

Should have photos in a week or two I hope.

Very Impressive HP output on the Brit. Especially considering the small valve sizes. Good going!
Russ, are you going to powdercoat the new housing? Perhaps a thermal coat? Might be a couple of ponies to be found there. I have been doing thermal coating on motors in the past, and note the ffactory did coatings on the F-40 intake.. Food for thought.

Kermit - Actually, the powdercoating does sound like a good Idea - I will look into it tomorrow when the plenums are supposedly finished.

Part of this whole installation by neccesity is a new airscoop. The old Mondial sidescoop had been trimmed to accept a rubber duct to attach to a stock 308 airbox. Well, upon disassembly of the starboard side scoop, it has a smaller intake opening and is more complicated than you may think. The intake scoop opening itself is only about 1/3 of the total scoop area or less, about 4" x 3", with other air being ferreted off to cool in front of the front cylinder head and around the vapor recovery cannister. The big discovery for me was that the airscoop has a built in resonance chamber at the bottom of the airflow tract vented by two holes.

I removed the air induction piece and the rear vapor recovery scoop and replaced with an aluminum duct that points towards the two K&N filters for the plenums. It is simple, robust, well ventilated the filters once the car is moving and also blows cool air on the carbs in the engine V. I may be overselling the carb cooling thing I realize, but my gut reaction is that it will help on hot Texas days.

Will post some plenum photos tomorrow.