Setting Timing

[Bernica]

Originally Posted by patrickt

If I wanted it to come in later I would just use a stiffer spring combination, but I think you'll find having it all come in before 3000 RPM to be quite rewarding.

Patrick is right. All in around 2,500. Same as what Mr Kirkham said earlier. These are light cars...they go and don't need what a big Galaxie might need. IMHO...

[Large Arbor]

10-4, that is what it is doing now as its all in at 3,000. My problem is I do not know initial crankshaft degrees. Should I experiment with bushing sizes? The MSD sheet shows the following:

[Bernica]

You should definitely find your TDC and get a timing tape to use to establish your timing marks as mentioned above. Also, just taking a shot here..but ask your engine builder if he indexed the cam.
My 2 c...not worth much.

[Large Arbor]

I can see the timing marks on the balancer. I have a mark at 0 and 38 or 35 and I can see them well.

Phil

[patrickt]

Tell you what, try setting your distributor to exactly what I run. Same springs, same silver bushing, and set your timing to 35 degrees at 3000 RPM. That will set your initial timing to ten degrees. That will give us a nice starting point.

[DanEC]

I will digress from Patrick a little - if this engine has a healthy cam and the distributor doesn't have vacuum advance, I would run the blue or purple bushing. I would try to run around 15 to 16 degrees of initial advance. I had Tim O'Connor set up my 427 dual point distributor and I it has 22 crank degrees of centrifugal advance and then I run 16 degrees initial (but I have low compression steel heads) for a total of 38. This will give you a stronger idle, help keep the engine a little cooler in traffic and make starts a little less of an issue.

[patrickt]

For historical purposes only, but as an insight in to the issue of timing on 427/428 engines, here are the specs from the original Ford Service Manual. Note the reference to adding an additional five degrees of advance.

[PeteF]

Large Arbor, I found some spare circlips in an old Holley rebuild kit, new in bag. I'll mail them to you if you give me an address.

[Large Arbor]

Thanks Pete, I did however drop $5 on some assorted sizes and I think one will work. If they don't I will PM you my address!

Phil

[Large Arbor]

Ok, I have tried various bushings and it seems to be best with the Blue one. I can set it for 35 degrees, but when de-accelerating it does not seem to want to return to an idle with the blue bushing. It seems like the black bushing gave the best idle but with it I could not get to 35 degrees. It's kind of difficult doing this with one person. I have help coming tomorrow.

The Blue bushing and stiffer springs (silver) seems to give me the most advance movement.
I will try to get closer tomorrow. Any thoughts you folks have are greatly appreciated.

Phil

[DanEC]

Phil - why can you not get to 35 degrees? You just need to turn the distributor a little more to enter a little more initial advance in. 21 deg centrifugal (blue bushing) with 14 degrees of initial timing will give you 35 degrees. So I'm having trouble understanding your comment?

On the idle, the only way the distributor can cause a hanging throttle (provided it's not rusted or gunked up), is if the springs are so light, they won't pull the weights back to center until the engine speed falls to a point below where your idle speed is. Now, I've never had a MSD distributor so I'm assuming it doesn't have some other component or goofy thing that could cause that. If the advance springs are too light to pull the weights in at idle then you will need to go to the next heavier spring or see if there is someway to modify the light springs to shorten them and pull the weights back in a little more positively.

I've seen people disagree with this, but I insist on using an advance spring that is strong enough to keep the weights pulled in solidly at idle. I don't want the springs so weak that the weights are slipping in and out because that is jumping your timing around and making the idle speed inconsistent and unstable. I use the weakest spring that will still keep the weights pulled in solid at idle. You can test for this by watching your timing mark at idle - if it is jumping around a little, kill the engine and remove the cap and put rubber bands around the weights to keep them closed. Then check the timing again and if the timing mark is steady - you know the springs are too light to keep the advance weights closed at idle.

A Cobra is light and with a big engine, everyone wants to use light springs and a fast advance curve because you can. But, you may need to slow it down just a little to keep a solid idle. Also, if you have a lot of horsepower and torque, a little slower advance curve just might help a little to keep from completely blowing the tires at lower speed when accelerating. Just my opinion.

[Large Arbor]

Thanks Dan, I can rotate the distributor and get to 35. The stiffer springs seemed to help. I may try a stiffer carb spring as well. Will let everyone know how I come out tomorrow.

Phil

[Large Arbor]

Dan,

You hit the nail on the head. I went to the heavy duty springs and it is real close. Better than it has been at 15 degrees at idle and moving to 35 about 3,000. I will try to dial in from here tomorrow.. Thanks again.

Phil

[Large Arbor]

Well what started as fine tuning turned into the following. Not sure what caused this except that I must not have had the pushrod in the rocker completely. I will have to watch very closely when I put it back together.

Phil

[patrickt]

Originally Posted by Large Arbor

Well what started as fine tuning turned into the following. Not sure what caused this except that I must not have had the pushrod in the rocker completely. I will have to watch very closely when I put it back together.

Phil

I don't understand. I thought you were just tweaking your timing a little bit? How did you do that?

[Bernica]

I'm with Patrick. How the f*** did you do that?

[Large Arbor]

Scratching my head here as well.. The car had ran likely 3-5 hours before this occurred. Been to 3-4,000 rpm and still no issues. Timing was perfect today for about 5 minutes at 35-38 degrees coming in at 3,000 rpm and holding. Went for a ride around the block, and a ticking sound was bothering me. I decided to pull the valve cover and reset the rockers to see if the noise would go away. I then discovered the pushrod. Lifter looked fine. Looked like the pushrod jumped out of the lifter by the little mark on the intake. Lifter looked fine. Pic below of the little mark on the intake...

[patrickt]

Refresh my memory -- solid or hydraulic?

[Bernica]

Well as far as I know, there are only two places that can do that. At the cam or at the rocker/valve assembly.

[Large Arbor]

Hydraulic lifters. Stock rocker shaft and rockers. No adjustment for valve lash.

Phil