Yup. That is what you get when ESL students write the translations. That is how Ferrari does it. Better to read the Italian version.
So, I was going through the Aldous Voice description on how to fix the timing on the 360 Modena and I realized that there is a chance I told something wrong to my mechanic... Attached below are 2 images of the Degree Wheel attached to the crankshaft.. The dark one is from Aldous Voice , the other one (with the hand showing) is from my mechanic... While explaining the procedure to my mechanic for the Exhaust Valves , I told him 9 degrees before TDC to reset dial gauges and look for 0.60mm reading on the valve closing... I missed the point that because you are looking at the engine from the opposide side (front to back, instead of back to front) , the engine is actually rotating counter-clockwise... Therefore, 9 degrees before TDC is actually 9 degrees after TDC (look at Aldous Voice) !! So I told him to do it the wrong way... I am not sure if he too my (wrong) advice, so I need to ask him to try to remember what he did... I only stayed at his shop while doing it for the right exhaust camshaft... Maybe this is where we messed up... Still I am interested to know if the 360 modena has 1 or 19 degrees overlap.. Image Unavailable, Please Login Image Unavailable, Please Login
Voicy usually does a thorough job. In this case I didn't really think his write up gave any new information that the WSM didn't. Why is your mechanic depending on you for the details of the procedure? It's like you giving your doc the how to before she operates on your kid. I'd get that thing properly done. Could have been a big blunder. Sent from my iPhone using Tapatalk
You need a new mechanic that has done valve timing on Porsche and Ferrari. Direction of observation has nothing to do with this. Overlap is 1 degree with variator disabled. Intake opens at 10 BTDC to Exhaust closes at 9 BTDC is 1 degree overlap.
Thanks for you reply !! I just found, however, the answer to my question !!! The overlap is 19 degrees (with variator disabled). I found the answer in WSM in the German/French section. See photo. I says for the "Auslass" (Exhaust valves) ---> Ende nach dem O.T. 9 degrees +-1 "Ende nach dem O.T." means in English "End after T.D.C." !!!!!!!! So, the answer is the exhaust valves close at 9 degrees ATDC !!! Overlap 10+9 = 19 degrees (variator disabled) Overlap with variator 10+9+20 = 39 degrees All agree ???? Image Unavailable, Please Login
Well THe English version you posted on post 1 says Exhaust closes 9 degrees BEFORE TDC. Not after TDC. You which one do we believe? The german one or the English one? Or the Italian one?
You have a point there !! I believe the one that makes most sense... The 360 is an evolution of the 355 engine... Instead of 3.5 it is 3.6 liter, same V8, same 5 valves per cylinder and it introduces on/off variator on the exhaust camshaft... So, how can the same engine that used to have 16 + 16 = 32 degrees Overlap (F355) now have 1 degree overlap (variator disabled) or 21 degrees overlap (variator enabled) (360 modena)?? It makes more sense to have 10 + 9 = 19 degrees Overlap (variator disabled) and 10 + 9 + 20 = 39 degrees Overlap (variator enabled) !!! The improvement in HP from 375 (F355) to 400 (360 modena) comes from small things like the variable length intake manifold, variable length exhaust and the timing of the variators... At low RPM small overlap is required so you have just 19 degrees for maximum torque... and at high RPM you get 39 degrees overlap for maximum power... Do you agree ??? (The person writing the WSM must have copy-pasted and made mistake in Italian/English)
In any case, the text of the instruction says at 9* BTDC, there is a slight opening of 0.6mm, so you may be correct in that it totally closes after that point and there is more overlap. However, if your mechanic follows the cam timing to the letter, and measure 0.6mm from 9BTDC to the flat part of the cam, then the engine should run well.
Yes, but ask yourself, does it make sense to have 1 degree overlap ?? It actually says that the specifications could be +- 1 degree. This means that you could actually have 0 degrees overlap, within the allowed tolerances !!! We all know that 0 degrees overlap would not be good for your engine... So... What do you think ?
Yes, as I posted earlier, the exhaust valve spec is just a reference. 0.6 mm open at 9 degrees BTDC. How many degrees to rotate from there of fully closed?
In theory, if we accept the German/French version (which says Exhaust Valves close at 9 degrees ATDC) and we reset dial gauge at 9 degrees BTDC , then we need to rotate at least 9+9=18 degrees for the exhaust valves to fully close and get a steady 0.60mm If we accept the Italian/English version (which says Exhaust Valves close at 9 degrees BTDC) and we reset dial gauge at 9 degrees BTDC , then as soon as we reset, the exhaust valves, in theory, are already closed.... So how do we get to measure 0.60mm ?? I have no idea !!
I speculate the valve actually may be seated at 9 degrees, and we are dealing with the clearance ramp for the last 9 degrees ( 0.6mm). Sent from my iPhone using Tapatalk
Doesn't matter. It's just a reference for zeroing the dial gage. When you rotate the engine forward the dial gage should show 0.6 mm+/- when you reach the base circle. If you get more or less, timing is off. If you start at the wrong angle the exhaust timing will be off by +/- 18 degrees. Now, looking at the Aldous Voice picture, they are using 9 BTDC as the crank rotates clockwise.
You are absolutely right !! If I were to have made a mistake of 18 degrees, wouldn't there be a CEL ?? I remember reading that for the exhaust cam it is possible to read from the ECU the position of the exhaust only camshaft relative to the crankshaft... something with "bits" ... is it true? (I think I should start a vote : who thinks the overlap on the 360 modena is A) 1 degree (variator disable) / 21 degrees (enabled) OR B) 19 degrees (variator disabled) / 39 degrees (enabled)
Camshaft timing, always an interesting subject. I'll try to chip in. The answer is A: 1 degree (variator disable) / 21 degrees (enabled). Valve overlap on F131: With the variator enabled, exhaust scavenging is increased to maximize volumetric efficiency: At high RPM, exhaust will be retarded. Valve will close later so the escaping exhaust gas stack will help the inlet gas flow. The WSM data is correct. IN: 10 < TDC /50>BDC EX: 76<BDC / 9<TDC Exhaust variator enabled: EX 56<BDC / 11>TDC. Interestingly, 360 CS has same cam timings as the standard Modena. Please note that the actual seat contact of the closing exhaust valve will be around 10 degr after TDC. Cam timing data as provided in the WSM does not mean anything as long as one does not know how the valve timings are measured. Based on my measurements, Ferrari describes valve movement (open and close) at 0.50 mm valve lift. The 0.50 mm is used because the cam is ramping up against the lifter and it can take 15-20 crankshaft degrees before a valve actually makes/leaves contact with the seat. Several manufacturers are using this 0.5 mm standard (eg Alfa Romeo). In US I believe camshaft builders are using 0.25 inch. (0.63mm).
Thanks for the write-up and the explanation !! I followed your advice and looked at the 360 CS Workshop Manual. Guess what ? You are right, overlap is indeed only 1 degree (variators disabled) / 21 degrees (enabled) Now all I got to do is figure out what I did wrong !! Image Unavailable, Please Login
Does anybody know if it is possible to check electronically the position of the exhaust camshaft from the ECU (OBD) ? I remember reading somewhere that the exhaust camshaft are monitored from the ECU because they have variators and their opening position can be expressed in bits (i remember something like 657 being the factory spec). Is it possible and if yes what equipment do you need to read this ?
There is a video showing a SD2 displaying this number. I'm just trying to figure out if the Leonardo can do it was well.
I got the Leo to show the number this evening... they call it "Camshaft and engine fase angle" . So that then begs the questions..... Q1. How do these units relate to angle Q2. What does "Camshaft Cross Factor" mean ? is it overlap and if so what units is it in ?
In the video I posted above it shows for the RIGHT ECU "Angolo Fasatura Ca" 656 (very close to 657 which I read somewhere is the factory standard) 1) How do see the left side ? It must be in the menu correct ? 2) can you see the same info with an OBD reader ? if yes, which one do you recommend ? Thanks
PS/. I translated "Angolo Fasatura CA" and it means "Firing angle approx" which is not related to the opening of the exhaust valves !!! It is just when the firing occurs ... correct ??
I have not seen these numbers viewable on any (cheap) ODB software. On a LEO, you first select which engine ECU you wish to talk to. Right or Left. So you can only interact with one at a time. I guess the SD2 is the same. It gets worse. The Functional Test items are on one page, and the parameter monitoring are on the other page. And you can not jump between the two of them whilst monitoring any parameters. Which means the function to test Variator activation can not be done whilst you actually watch the important numbers. Now how stupid was that of them.
Do you have any idea what this number 656 means ?? (Angolo Fasatura CA) Is it measured in degrees ? Is it position of exhaust camshaft opening or spark plug firing timing ?
