Countach QV FI Thread

It's not a question of like or dislike, it's a matter of facts.

For example, these are all the components which are different between the 2 engines and the reason why the Downdraft is @ 80 bhp more powerful.

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Key word is different. Not better. Cams to match different inductions. 0,2 Difference in compression but a lighter piston in the fi. More hp and rev gain in the weight saving than uppside in the compression difference. Ask one who knows. Similar bore and stroke head and block castings came from the same molds cars buildt side by side. All the beautiful awesome Countach.

 

Totally agree different does not mean better, indeed they are different, very different, I'm glad you're starting to grasp reality and move away from the "they are all the same" delusion you used to spout. Meanwhile just because the Downdraft has 80 bhp more horsepower does not make it a better car, but the power and performance is indeed different, that's fact not opinion.

The bottom line is the 420 bhp quoted for the USA Fuelies was an exaggeration of numbers, clearly a PR ploy necessary to protect the USA market share, not the first time Lamborghini or other manufacturers employed those tactics. The exaggeration of the factory's proclaimed horsepower numbers for the USA Fuelie as corroborated by certain ex-Lamborghini personnel is what has caused the misguided notion over the years that the cars are remotely similar in performance.

The power (bhp) numbers @ 6,750 rpms & torque (lb.ft) numbers @ 5,500 rpms paint a very clear picture that both power and torque are significantly superior throughout the measured rev range from 3,000 rpms upwards in the 6 Weber (44 DCNF) carburatori version of the L 507 V4 engine, and this is proven.

Mike Call was right about the power differences as he suggested in the "DD versus FI" thread, as was Allan Fiedler himself, as quoted years ago, bottom line, no standard Fuelie pulls anywhere near 420 on a dyno, it's more like @ 350 - 365 bhp.

Incidentally, maximum power in the Fuelie engine drops off just after 6,000 rpms, whereas the Downdraft engine gains power up to 6,750 rpms. The torque curve of the Downdraft engine not only scores higher numbers at every benchmark of engine revolution providing irrefutable proof that the Downdraft has better torque at every stage of the power band, but it's increase is more linear.
Whereas the torque curve of the Fuelie engine flattens above 4,500 rpms and then progresses to 5,500 rpms, the trajectory of the Downdraft is more linear and bell-shaped which is exactly what you want for superior performance.

Some may gloss over the matter of the differences in the engine make-up but the fact is, the engine unit used for the Downdraft contained higher-compression ratio pistons and more aggressively lobed camshafts., not only has this been photographically documented and calibrated by various specialists during rebuilds post-production, the factory’s own parts manual documents separate parts numbers for the higher-performance pistons and camshafts in the carbureted engine unit. Downdrafts camshafts are part numbers: 1220848, 1220847, 1220845, 1220846, there is a performance reason why they are different. Fuelie camshafts are part numbers: 1221851, 1221852, 1221871, 1221872, there is a performance reason why they are different. Downdraft pistons are part numbers: 001420801 producing a 9.5 : 1 compression ratio, whereas Fuelie pistons are part numbers: 001420828 producing a 9.3 : 1 compression ratio. There is a performance reason why they are different. The crankshafts of the Downdraft and the Fuelie are different also. On review of the parts manuals, it is established that the Downdraft and the Fuelie are made up of literally hundreds of different components, with resultant performance difference.

The Fuelie engine's less potent specification is all about emissions. The lower compression ratio produces lower peak cylinder pressures to reduce NOX emissions. The cams have less overlap to prevent the exhaust from over-scavenging the cylinder at the end of the exhaust stroke to reduce hydrocarbon emissions. Milder cams in general make it easier to minimize carbon monoxide and hydrocarbon emissions. Fuel injection can be manipulated more easily than carbs with a view to improving emissions. The tradeoff is that the Fuelie cars with lower compression pistons generate lower torque ratings and therefore have a lower power output. Incidentally, the factory’s tuning package for Carbureted engines allowed for a sports camshaft, bigger jets, carburetor spacers and air-flow optimization, the latter meaning that cars could be tuned to achieve 470 bhp plus. Induction for the Downdraft is vastly superior as the route the air takes from the intake trumpets of the six Weber 44DCNF carbs into the combustion chambers is a short and relatively straight column that is only @ 12 inches. This is the main reason why the throttle response of the Downdraft is superior to that of the Fuelie. With a Fuelie engine, the path the air has to take into the combustion chamber is much longer as it has to turn 180 degrees. With the Downdraft, the throttle plates are right there in the carb throats whereas the Fuelie system has two large butterflies where the flexible hoses meet the air plenum. As such, the Downdraft engine has venturi of air pulling from that air on top of the carbs in the air box as a high flow direct path into the combustion chamber.

Again, the power difference between a Downdraft and a Fuelie is not simply a mater of changing exhaust headers and dumping cats as a small group of Fuelie owners claim.

 

I guess what you are trying to say is ,carbs are better than fuel injection? Probably why every sports car manufacturer,at the time vhere using fi. They where all wrong. We been down this road before lets move on. I will promote the fi and the Countach as a whole. And you can promote whatever your little hart desires. Enough said. One big happy family.

 

Thank you very much. I will only be doing the rear taillights for now. I will do the side marker lights when I decide to repaint it someday. Also thank you for the measurements for the emblem placing.

 

Yes I was also going to install the down draft valance. Emilio actually sent me some pictures of the one he has. Once my car goes to paint/body guy I will grab one and get it installed. The side marker lights might have to wait for now untill I do a full repaint. My car had the euro front bumper already installed. The original owner did tell me years ago he had the motor out and apart. It had some exhaust valves that’s burned out. Supposedly there was a run of some bad valves from the factory? He did say he increased the compression but not sure of any more details. He did say the motor was apart. The car had 3200 original km’s on it and I put over 6000kms since 2008. The car and engine is actually very easy to work on and do much of the service. It’s as easy as my 60’s musclecars. I love it! One thing I have been searching for is the camshaft specs for the intake and exhaust camshafts for both the fuelie qv and the downdraft qv. Like valve timing, duration, lift ,LSA ,ICL ect

 

No I am saying they are they are different, the key word you stated above, but I am also saying the engine unit itself is different, so in total they produce different driving experiences and performance outcomes, meanwhile enjoy your Countach.

With a skilled coach-builder or body shop you don't have to repaint the whole car at all to do the side-markers.

 

I will see if my paint/body guy can look at it and do it. If he can I will definitely do it

 

Problem is,our cars are old. And mine is red,wich is not an easy color to blend or match, but i will admit i will give it second glance. Would love to loose the big markers. Will have my innhouse painter look inn to it. On that note. What is a good source for the small markers?thanks

 

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Gentlemen, you can do it easily, blending isn’t rocket science, a competent shop does it all the time, and can create a match so it's indiscernible to the average eye in daylight. All the shop has to do is mix a color that is a blendable match with the base coat and apply the clear coat to match the rest of the car.

IMO it's the next most significant item after bumpers that makes all the difference in the Euro conversion, and to the extent that it is not done, the conversion is half-done.

Remember, there are few cars that lend themselves to blending as much as the Countach does, with all its sharp seam lines & angles, it's perfect for blending, and the net result should reveal no cut-off lines at all as each quarter panel will be sectioned work bordered by the aforementioned sharp seam lines.

I would save painting the whole car for a time when it actually needs a mini or major restoration.

You can source the small Carello fender turn-signal lights on EBay or Emilio of course.

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The challenge is the vertical blend mid fender,unless you paint the whole fender, front and back. LSS,working on it , report coming

 

To do it right you paint each of the 4 fenders in the vertical plane, you don't want to blend mid-fender, blending at the seams should be simple for a skilled coach-builder.

 

I do understand ,it is the easiest way,but also means you are painting the complete fender, with the exeption of the up facing surface. At that point poss better to just mask of the complete fender to the next body panel,this is why I have not already done this. Anyway ,will look inn to it, also have a poss total resto in mind, will weigh my options,but thanks a bunch for your advice and suggestions.

 

Since I have an aftermarket exhaust installed with a cat delete and not using the o2 sensor. Would it be possible to install the down draft camshafts? Is there that much of a difference in the cam profiles that it is worth using? I know it is the whole package that makes it work properly (carb’s and intake manifolds) but would it would with a fi system? Does anyone on here run the down draft camshafts in their fi motors?

 

I believe the fuel distributor on the FI car uses a flapper valve in the intake to measure the airflow rate. FI systems that use this type of metering are sensitive to cams with large overlaps. The distributor has a hard time metering the correct fuel rate to go with the airflow when the metering plate is jumping up and down due to the pulses from the overlap. The exhaust system is not a big factor in whether a big cam will work with the FI system. An alternate approach would be to keep the cams and install larger valves. This will effectively do the same thing as bigger cams without the low end losses of a cam with a lot of overlap.

Cheers Jim

 

Thank you for the observation, but that was a set of Diablo SE30 grilles I created, across the Atlantic, from just photographs. These are my Countach front grilles: K9

 

Should Countach front markers have chrome surrounds as in the top picture Joe or do some have the black surround shown in the lower picture?

K9

 

The ones with the chrome are the correct ones, the ones with the black rubber are the cheap Alfa units which are NOT correct!

 

Kinda what I was getting at and why I asked the question. I was surprised to see the wrong ones posted. K9

 

Guys, both can be correct that's why I posted both.

The ones with the chrome bezels are for all the early Countachs through 88.5, but a few late 88.5s and some 25ths intermittently got the black plastic bezels, witness the 25th at the Lamborghini Museo for example.

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I guess they were rather no more able to source the correct ones!

http://www.lambocars.com/images/countach/1/xxl/25th26.html

http://www.lambocars.com/images/countach/1/xxl/25th58.html

 

Of topic ,but my Countach got its daily driver mid engine stablemate.
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