My 427 SOHC Build..... Finally the time has come!

[My427stang]

The MSD Distributor I have (set it up before sending to Jay) has 1 light Silver spring and 1 light blue spring.  this gives us the curve in the graph below on the right side, second one down.  Looks like total timing in all at 30 degrees at 3200 RPM?  Not sure what the initial timing is.  I can just put the timing light on it at Idle and find out.  Thanks Guys.  Ill let you know.  Sad we went from possibly just tweaking the target AF ratios to this.....  LOL

First, that isn't sad, you are actually to the point where you are tuning instead of repairing!

Second, I think all in my 3200 is WAY slow, like tow truck slow.  Of course how far it goes also affecting how quick it can get there, but if you are a very low number initial 8-12, combined with a curve all in by 3200, that car is going to feel like it gained 2 cylinders around town with the proper curve, and as a second benefit, the tuning will be significantly easier.

Post what you find for initial timing, that needs to be right before you spend much time tuning the EFI.  I am excited to hear the results

[cobracammer]

Will Do.  :0)   Thanks again!

[cobracammer]

Timing at idle is 8degrees BTDC.  With the springs I have on the dizzy, do I beed to change anything or can I start the target A/F ratios?  Thanks guys

[My427stang]

So, if you are at 8 degrees, and Jay put you at 30 BTDC on the dyno, you got a little work to do, but be happy, that motor should be MUCH happier

Right now it looks like you have a 22 degree bushing in.  I'd put a black bushing in for 18, and set the initial timing to 12.  It'll run cooler, have more vacuum, and feel much healthier.  I personally would prefer to see you put 2 blue (light) springs in, but you can also just leave what you have and try it.

It'll run much better, then you can get to tuning.

[cobracammer]

Hey Ross.  I installed the black bushing initially.  So just need to tweak the timing?

[My427stang]

Well, why would it have changed? Did you have the distributor out sice the dyno run?

I was just assuming Jay set it at 30 total and you left it there

[My427stang]

I guess a better way to put it is, if you are at 8 and you have the black bushing, you are only getting 26 total, Jay says it should like 32.

I would verify both initial and total, and likely it would run better at 12-14 initial, and 30-32 total (the higher numbers just giving you a smidge more initial.

Listen for detonation though, because it's going to be a different animal if you were running it at 8 initial / 26 total

[cobracammer]

Hi Ross.  Sorry, initially jay had me put in the black stop bushing as well as swap out thesprings it came with  to the light blue and light silver springs.  Not sure on total, but initial is definately 8 degrees BTDC.  Sorry, writing from my phone as I do hurricane clean up :0)  thanks again

[My427stang]

No worries, the black bushing is 18 degrees.  So if your marks are correct, you should have initial set at 12 degrees.

If you are confident in what is in the distributor, then set initial and start with the EFI tuning, but don't start EFI tuning until you have the timing set right

The reason I mentioned the springs is that 18+12 = 30, all in by 2000 is pretty aggressive, but 30 total is NOT aggressive, so it must be a decent chamber with hemi, so I say if you know what you havem reset initial and get tuning, my guess is it is going to run WAY better with 4 more degrees from idle on up

ON EDIT:  One last thing.

- More initial = idle will go up, the IAC will step down, but it depends how much it can
- If it goes up too much and you have to close the thrttle plates, remember to reset the TPS when done
- THEN get to tuning

[cobracammer]

Thanks Ross!  Ill report back asap 

[cobracammer]

Alrighty.  Checked again, and at idle, I was sitting at 8 degrees BTDC.  Had the wife rev the engine to 3500 RPM and it came in right at 26!  I then finagled the distributor a little until I was getting 12 degrees BTDC.  Like Ross had said, I had to adjust the TPS because it uped the RPM when I advanced the timing.  Got it to idle at 1000 RPM and with initial timing sitting at 12 degrees BTDC.  Revved the engine again up to 3500 RPM, and we came in right at 30.

As a side note, smoke was gone, and in a quick spin around the block, the sputtering was gone.  Will take a longer ride this weekend now that timing is corrected. 

[My427stang]

Awesome, there is still likely power in tuning, but sounds like you are getting close!

[cobracammer]

Also wanted to throw this question out there.....  Yesterday I noticed a loud "whistling" noise that would only periodically happen.  It was hard to pinpoint, but sounded like it was coming from the water pump area.  I would go away by itself and only lasted a 10-20 seconds each time.  I thought maybe some sort of cavitation in the pump itself?  Wasn't sure so I figured I would ask  :0)

Another thought was one of the timing chain sprockets (tensioner sprocket or the fuel stand idler sprocket).  Its quite loud (not faint by any means).  Just seemed to start now that I have corrected the timing  :0)

[Heo]

Perhaps the belt slipping when the alternator cuts in

[cobracammer]

Hey Heo,
That's definitely a possibility.  I have the alternator belt tensioned pretty taught since I wasn't getting a charge (when it was too loose).  Perhaps its just gotten a little "shiny" and whistles a little.  Ill check the belt out when I get home  :0)