Countach Technical Thread & Questions

Anyone have cam timing specs for the QVI? The marks were lost when the cams were reground, and the only lift-based specs I have are from the old L406 engine manual.

I'm also curious about torquing the cylinder head with the factory tool. It would appear to add a little leverage, in which case I'd be applying more torque to the nuts than the wrench is indicating. Is this significant enough to require some sort of correction factor, or do the torque specs account for it?

Incidentally, the car in question is 12916, which is being resurrected after about 12 years in hiding and partial (and unnecessary) disassembly. I'll start a thread on it if anyone is interested.

Thanks!

 

Wow, another resurrection! Of course your thread is more than welcome!

 

Is there a spec for measured valve lift at TDC like there is in the old manual? My hope was to time the cams on the bench, put the engine at TDC and install the heads with everything pre-timed.

I can degree them afterwards, so the first pass doesn't have to be exact, just close enough so I don't have interference problems.

Are the degree figures at .050" lift or something else?
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I do not have the info you are looking for but if you really need it then you could calculate it. The key thing that is needed to calculate it is the lift versus cam angle. That can be measured pretty easily.

Cheers Jim

 

I have it for the 25th cars, it should be the same or very close. I'll dig it out tomorrow and post it if you like. However the factory manuals are to be taken with a grain of salt.

 

That would be extremely helpful!


Jim, I never thought about being able to calculate it, but I guess I could do it that way if I knew Lamborghini's definition of valve begins to open. It seems like .050" is common but I wouldn't want to bet on it.

 

Take them out or clean, so you can read the GKN stamp. This might not lead you to anything easy to find as usually these numbers do not work for cross-reference on the web, but fyi, on LM002 I had plain Audi 100 CV joints (in between the gearbox and transfer case) and I have a p/n for Diablo ones. It might be really easier, if you take them out and give me some size references.

 

Using 0.050 inches as an opening is more an American hot rodding thing and most likely not the correct lift to use. Since the cam specs have a duration of 300 degrees it suggests that the lift used is something close to 0.001 inches, i.e. 300 is a lot for a street driven car. There are many different standard lifts used in the industry so it is hard to tell which is correct. I do not like using the opening and closing specs for that reason. I prefer to use the opening and closing data to calculate the lobe separation angle and use that to time the cam. Lobe separation angle is independent of the lift used. The angle in this case is 105 degrees for both the intake and exhaust. Note the way I calculated the separation angle assumes the cam is symmetrical, if it is asymmetric than this calculation will not work. Fortunately it is rare to come across a asymmetric cam.

Cheers Jim

 

Degreeing at 0.050in lift is a standard made popular by Harvey Crane. It is the best way to figure out how well the cams would perform.
300 degrees sounds like "advertised" duration, someting like within 0.1 mm (0.003in) lift, i.e. barely moving the needle (of the dial indicator) off the base circle.
300 degrees ain't much for a 2V engine (advertised). It can be a good performance cam on 4V engine with medium lift, which is likely what that is. They are certainly symmetrical.

However, the QV cams use a very big valve clearance for a DOHC system which you should also count, when analyzing the cam profile: 0.35 mm for intake and 0.50 mm for exhaust. This would significantly decrease the actual cam duration. The ramps should be very long with such big clearance (especially on exhaust).

 

Does anyone know the timing specs for the 5000S? I just fixed a broken rotor and got the distributor back on.

 

So I'm still struggling with the measurements from this post:

http://www.ferrarichat.com/forum/144489598-post286.html

The front looks like it could be a good starting point. The rear right side number (13" center-to-center) for the link that goes towards the center of the car doesn't seem to fit my car by a long shot. With 13" length the car has so much positive camber it looks like a clown car...

I'll post some pictures shortly...

 

Here are the dimensions causing grief at the moment...on the rear suspension.

Also -- who would be qualified to do a proper wheel alignment on a CT?
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I would not worry to much about the lengths. I would set them all about mid way on the threads then adjust as required to get the proper geometry. Some will have to be tightened and others loosen to get the proper settings. While adjusting them you will want to make sure you have at least 1.5 times the thread diameter of thread engagement in the suspension arm.

I would look for some one who is comfortable setting up the suspension on an open wheel race car. If there is not anyone around with CT experience. The suspension designs are pretty similar.

Cheers Jim

 

Hi Randomlambo, maybe this will help, I spent 3 days measuring an entire Alpine car back in 1987
the lower rear front arm rod end centre to centre 310mm
the lower rear rear arm rod end centre to centre 315mm
the upper single Arm rod end centre to centre 180mm

the 5000 owners manual says rear toe is 4-5mm, and Camber at -30'
and front suspension toe in 3mm, camber of 0 deg +-20'
front caster 5 deg

Hope this helps
GraemeS

 

Spent a little bit of time making sure the brakes on my car are correctly sorted, so a new master cylinder was fitted (still slightly long pedal travel). The net cause of the long pedal travel was however the adjustment of the pedal pushrod into the booster there being approx 3mm (this may actually increase fractionally once booster vacuum is factored in) of slack which at the pedal created about 12mm of free travel before any pressure was generated in the master cylinder.


Straight forward job to sort out as the brake pushrod is adjustable.

 

I've hit a snag in attempting to reverse engineer the valve timing. First I made some miniature degree wheels which I attached to the cam sprockets. I divided all the measurements by 2 to account for cam vs crank degrees, marked the opening/closing points, found the points where the valves begin to open, then rotated the cams back to TDC. The Destra head looks about right, or at least like what I'm used to with Alfas, with the valves on #1 closed and the cam lobes pointing away from each other. For the Sinistra head I used cylinder #7, so as a final step I backed up 30 degrees to account for 60 degrees of crank rotation before #7 reaches TDC. It looks completely different at TDC, with one cam pointing inward and one pointing more or less straight up.

Something seems amiss here. I suppose they could look different because the intake/exhaust sides are opposite on each head, but if that were the case I would think the lobes should be pointing basically towards each other.

The only other thing I could think of is that I've got my intake and exhaust cams mixed up. When the car was purchased, they were in unmarked boxes from the grinders, so I went on the assumption that the cams with taller lobes were the exhaust, because they usually are.

 

Hi guys
I haven't been on for a while as i got bored with so many people talking about values of cars and not actually about them or driving them. Well done for the new threads. They are excellent.
I lost the d shaped catch on the bottom of the engine lid for my 85 build QV. It fell off and went through rear tyre! My luck.
Anyhow, we got a new one from the factory which is L shaped but sits about 1 inch higher than the old one and the factory only list one.The engine lid now sits proud . I know we could lower the latch on the cross member, but its a difficult job.
Anyone know of the different types? Or got photos of them?

 

Was cleaning up the distributor and discovered the advance springs are two different lengths, but they both seem equally stiff and nothing looks bent or broken. I'm thinking it could be intentional: working against one spring at first would give a steep advance curve that flattens out once the second spring comes into play. Is that valid, or do I have a problem?

 

I can't speak for lambo but most springs are meant to be a different length on all the old dizzies I have worked on ,see if you can find a video of a lucus or rover dizzy rebuild on youtube on the rovers I worked on they were about 2mm different so they engaged later

 

Mikael in Finland rebuilt his. Here is a thread he posted on with a link to a photo showing all the internals of the distributor.

http://www.ferrarichat.com/forum/142795868-post14.html

Mike

 

I added some instructions for prosedure with my 512BB thread, so there you go:
http://www.ferrarichat.com/forum/boxers-tr-m/451351-my-512bb-diy-thread.html

Couple of notes:
-mark only the other weight and where it belongs, also which side they are in axle
-Open and clean (ultimately with brasd wire wheel and fine sand paper) only one side att the time.
-find VERY high temperature grease, there are even spesific products for this, use them, as mechanism spins spary bad grease all over.
-NERVER mix springs or washers in counterweights, if you do, you need distributor advance machine to fix it.

I just did this job for Urraco and found that it took me one hour to remove one counterweight, so they can be really stuck. Here you can see marks I made to help assembly and how bad they can be. (I think this mechnism worked last time in 70's)
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Got a dim battery light yesterday just like footsoldier a few years ago. It’s brighter at higher RPM.

Voltage with battery connected: 12.35 VDC
Voltage with car on: 13.9 VDC, voltage gauge is in the upper white, but the battery light is still on.

I originally thought it was the voltage regulator but with 13.9 VDC I’m not sure. The alternator was rebuilt a couple years ago with a heavy duty 14 diode bosch rectifier for 200A.

For reference the voltage regulator is a Bosch 1197311021. The new cross reference is 1197311028. 028 is listed as 65-115 Amp. Maybe I smoked it. It’s a cheap part that I can replace without removing the alternator.

Any thoughts guys?

 

Can somebody please post gearbox and differential fluids to be used on a CT?

 

Hi, From the 5000s Owners manual the diff is 11.2 pints of Agip f.1 Rotra MP/S SAE90
and Gearbox is 5.6 pints of Agip f.1 Rotra MP/S SAE90