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  #1  
Old 08-05-2009, 06:56 PM
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'77 308 Ignition Timing Question

Hi,

My car ('77 308, U.S. car, all stock, breaker-point ignition) has been running great for years timed at 7 deg BTDC @ 1000rpm (running R1 points only).

I recently took it for a belt service to a Ferrari mechanic with 40 years exp. here in New England. He was the one who originally set the car up 6 years ago and timed it to 7 deg BTDC.

I'm very sensitive, and noticed that when I got the car back, it sounded slightly different at idle (a little quieter, muted), but started up a little rougher (ever so slightly). The car also had a little more power in upper rpm ranges - revs a little more free.

The mechanic did not touch the carburetion, but did set the timing to 10 deg BTDC when he re-installed the distributors, explaining that this was what the Euro cars were spec'd to (I still need to check documentation to convince myself).

Anyway, is anyone running this kind of advance? Is this too advanced with the potential to cause harm? I'm thinking of re-timing the car back to where it was....

Thanks (in advance.... ; )

Anthony
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  #2  
Old 08-05-2009, 08:04 PM
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...by the way....just want to add that the distributors did not need to be set up (they were about 6k miles ago) - they were just removed from the car for the belt service (as the cam covers were removed)...thanks
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  #3  
Old 08-05-2009, 08:16 PM
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What is the timing advance at 5000 RPM?


Static advance and full advance are connected together by the centrifugal advance curve, and that could have been set up in any number of ways.

Simply advancing the base timing 3 degrees shifted the entire timing curve up by 3 degrees.

Doug

Last edited by AZDoug; 08-05-2009 at 08:19 PM.
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  #4  
Old 08-05-2009, 08:48 PM
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that's what i think was done - the base timing was advanced only, shifting the entire curve
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  #5  
Old 08-06-2009, 10:33 AM
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Quote:
Originally Posted by yank05 View Post
...I'm very sensitive, and noticed that when I got the car back, it sounded slightly different at idle (a little quieter, muted), but started up a little rougher (ever so slightly). The car also had a little more power in upper rpm ranges - revs a little more free.
Anthony
As to be expected with slightly more initial and total advance...

Quote:
Originally Posted by yank05 View Post
...The mechanic did not touch the carburetion.
Anthony
Unlikely, as with the increase in base timing, the carbs would have to be adjust to obtain the correct idle speed. (Idle speed rises as the static (base timing) is increased.


Quote:
Originally Posted by yank05 View Post
...But did set the timing to 10 deg BTDC when he re-installed the distributors, explaining that this was what the Euro cars were spec'd to (I still need to check documentation to convince myself).

Anyway, is anyone running this kind of advance? Is this too advanced with the potential to cause harm? I'm thinking of re-timing the car back to where it was....

Anthony
10 degrees initial advance is hardly "alot"...but, as already posted, what's the total maximum advance. Ferrari is quite specific in their timing procedures to set the maximum advance first, then verify that the base setting, typically at idle is correct. In that 99% of the distributors in these cars are clapped out and in dire need of rebuilds, the maximum advance setting is really all I'd be concerned with. If the two timing specs can't be acheived, or their just too far off, then a distributor rebuild is in order...

Potential to cause harm: Great question, but highly unlikely. A spark plug visual inspection will reveal detonation.

For what it's worth, a guy with 40 years experience working on your Ferrari is a great thing! (I'm just shy of 30 years of experience with these cars.) He knows that what "worked then" may not work as well, now...Remember that Ferrari speced the NGK equivalent of BP8ES plugs for these cars. Anyone who's worth their salt know that, that plug under USA driving conditions is just way too cold. Experience matters here...run your thought by your tech.

Best,
David

Last edited by fastradio; 08-06-2009 at 10:43 AM.
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  #6  
Old 08-06-2009, 12:18 PM
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Thanks! Distribs rebuilt 6 years/6k miles ago - worked perfectly - no trouble in all these years - will check at high rpm as well - just initially concerned with this timing shift by 3 deg. Spoke to mechanic today, he calmed my worries and agreed to bring it back to 7 deg if I would like him to - overall, I liked the way the car sounded and felt before the change, even given the slight increase in response in the upper registers....running BP6ES - same plugs for years - plug color always textbook "tan" for a well-tuned engine.....

Thanks Again!

Anthony
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  #7  
Old 08-06-2009, 12:40 PM
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Euro market distributors are supposed to run at 13 degrees advance at idle. The owners manual shows this to be the correct idle setting as well. The Euro 127G distributor does not advance as much as the 159 (US cars etc) because they specifically wanted the Euro cars to have a snappier off idle throttle response, which is what a 13 degree initial advance offers. Total timing on all carb 308s no matter the market is 39-41 degrees. 34 degrees advance at 5000rpm is listed as a tuning point prior to the last and most stiff advance spring kicking in. Total advance for these Marelli distributors is reached at 6k rpm. Just make for darn sure you are getting correct total advance. Personally, I marked my flywheel showing all the degrees after 34 degrees all the way to 41 degrees so I could verify I was getting correct total advance because Ferrari did not mark anything past 34! I also modified my distributor so I can run a 12-13 degree initial advance idle as these engines repond much better off idle with this arrangement. Also note that Nick's electromotive system runs a 10 degree idle, but immediately switches to 33 by 2000 or 2500 rpm!
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Old 08-06-2009, 01:01 PM
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This is great info - thank you! I have a US car - I'm a little confisued at the statement "The Euro 127G distributor does not advance as much as the 159 (US cars etc) because they specifically wanted the Euro cars to have a snappier off idle throttle response, which is what a 13 degree initial advance offers."

Did you mean that the 127 DOES advance more than the 159, hence the 13 deg setting? Thanks!

I will check the total advance - if okay, I am now tempted to keep the 10 deg advance at idle - the car is more repsonsive - i think i'm just used to the standard 7 deg idle setting which gives me smoother start-ups and sounds "open" at idle...but where it counts, it does make a difference - better of idle response, etc....Hmmmm......
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Old 08-06-2009, 01:10 PM
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Quote:
Originally Posted by yank05 View Post
This is great info - thank you! I have a US car - I'm a little confisued at the statement "The Euro 127G distributor does not advance as much as the 159 (US cars etc) because they specifically wanted the Euro cars to have a snappier off idle throttle response, which is what a 13 degree initial advance offers."

Did you mean that the 127 DOES advance more than the 159, hence the 13 deg setting? Thanks!

I will check the total advance - if okay, I am now tempted to keep the 10 deg advance at idle - the car is more repsonsive - i think i'm just used to the standard 7 deg idle setting which gives me smoother start-ups and sounds "open" at idle...but where it counts, it does make a difference - better of idle response, etc....Hmmmm......

The 127G springs and arms do not allow the center 4 sided hub to advance as much as the 159 distributors. As in: the 159 distributor can advance from 7 degrees to 41 degrees while the 127G advances from 13 degrees to 41 degrees. The 127G brass arms inside the advance mechanism are a bit thicker than that of the 159 so they essentially have a different starting point, which when set up correctly is about 13 degrees (+ or - 2).

The Ferrari manual always notes degrees for these units in + or - 2 degrees in their advance charts. 41 is the very top of the curve and I personally do not push it past about 40.

Just out of curiosity, who is doing the work for you? I went to college in Boston and fiddled around in the area with exotics quite a bit and know many of the people in the circle out there.
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  #10  
Old 08-06-2009, 02:43 PM
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Timing how-to on early 308s

Can someone provide those of us who have not done it before, a detailed step-by-step procedure on how to set the timing on these early 1976-79 308's? With two distributors present and timing marks partially hidden, it's a bit daunting for me, but I would like to learn to do it. Like most others, I suspect, my car no longer has the microswitch which originally retarded the ignition at idle. I am reasonably sure that I'm operating on just two sets of points rather than four.
Here's hoping one of the good wrenches will volunteer.
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  #11  
Old 08-06-2009, 06:05 PM
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No one? Anyone?
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  #12  
Old 08-06-2009, 07:18 PM
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You use a white marker, or bright paint, and mark the spot on the flywheel where you want the timing to be.
you loosen the distributor bolts so you can rotate it.
You hook up a timing light trigger clamp to the number 1 spark plug wire
Fire up the engine, squeeze the trigger on the timing light, point it at the flywheel mark.
You will see the light flashes. Then you rotate the distirbutor until the mark you have made lines up with the index.
You retighten the disty bolts.

You now repeat with the front bank dizzy, with the timing trigger clamp over the number 5 wire.
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  #13  
Old 08-07-2009, 07:14 PM
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Yes, a tutorial on this topic would be a great complement to all the others on carbs, etc...!
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  #14  
Old 08-07-2009, 10:35 PM
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Quote:
Originally Posted by lvferraripilot View Post
Euro market distributors are supposed to run at 13 degrees advance at idle. The owners manual shows this to be the correct idle setting as well. The Euro 127G distributor does not advance as much as the 159 (US cars etc) because they specifically wanted the Euro cars to have a snappier off idle throttle response, which is what a 13 degree initial advance offers. Total timing on all carb 308s no matter the market is 39-41 degrees. 34 degrees advance at 5000rpm is listed as a tuning point prior to the last and most stiff advance spring kicking in. Total advance for these Marelli distributors is reached at 6k rpm. Just make for darn sure you are getting correct total advance. Personally, I marked my flywheel showing all the degrees after 34 degrees all the way to 41 degrees so I could verify I was getting correct total advance because Ferrari did not mark anything past 34! I also modified my distributor so I can run a 12-13 degree initial advance idle as these engines repond much better off idle with this arrangement. Also note that Nick's electromotive system runs a 10 degree idle, but immediately switches to 33 by 2000 or 2500 rpm!
+1 (an informative post)
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  #15  
Old 08-08-2009, 04:06 PM
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I went through it in this thread, though my car no longer has the points, there may be some useful info (the timing info comes around page 14) : 1979 308 GT4

Last edited by Beta Scorpion; 08-08-2009 at 04:11 PM.
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  #16  
Old 08-11-2009, 12:27 PM
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Thank you BetaScorpion. Very informative and I like all of the detail you've gone into. One question--what is the Crane XR 3000 box that sits under the coils with the little red light? Is this an ignition modification? Could you provide some details?
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  #17  
Old 08-13-2009, 06:20 PM
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Yes the Crane unit is the replacement for the points. I prefer originality and never had problems with points in the past, but the prior owner put the Crane units on, so I re-mounted them for somewhat of a 'stealth' appearance. The little red light makes static timing easy.
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