Rotor position

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Rotor position

Post  460bronco on September 24th 2015, 11:19 am

Hey guys-

When the motor has #1 at TDC, where should the rotor in the distributor be pointing in relation to the #1 spark plug terminal for initial fire up after replacing a cam? (I want this thing to fire right up!)

I have a MSD 6AL programmable ignition.  The distributor is locked out and the box handles the timing curve instead of any type of mechanical advance or vacuum advance.  Right now when the max timing advance is set to 31, from idle to 1400, the initial timing is 14.  The box then ramps the timing in to full advance by 2400.

Thanks,
Jon
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Re: Rotor position

Post  gmsmkr on September 24th 2015, 11:28 am

The rotor pos does not matter just be sure the firing order is right..... I always face mine to the front carb stud on pass side for #1
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Re: Rotor position

Post  460bronco on September 24th 2015, 11:53 am

ok, I think you miss understood the question.... In relation to the spark plug terminal on the cap, what is the ideal position for the rotor?  Slightly clockwise from the #1 spark plug terminal in the cap?  Directly lined up w/ the spark plug terminal?  Half way between the #1 terminal and #8 terminal etc...???
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Re: Rotor position

Post  gmsmkr on September 24th 2015, 11:55 am

Set the rotor dead on top of #1 position on cap
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Re: Rotor position

Post  460bronco on September 24th 2015, 12:05 pm

10-4! I think I had it set w/ the rotor slightly clockwise from the #1 plug on the cap.
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Re: Rotor position

Post  gmsmkr on September 24th 2015, 12:10 pm

Ford will run 180 out also so if it does not rev like it should pull plug and get piston TDC on compression stroke..... I'm sure you already know this
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Re: Rotor position

Post  gt350hr on September 24th 2015, 12:37 pm

#1 on the cap is about 1 o'clock if the locating notch ( Ford style distributors) is facing you. If you align the rotor with the cap termenal you will "usually" be a bit retarded and will need to turn the cap a little bit "clockwise" to get some advance in it. Then use the timing light to properly set it.

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Re: Rotor position

Post  69F100 on September 24th 2015, 1:07 pm

460bronco wrote:10-4!  I think I had it set w/ the rotor slightly clockwise from the #1 plug on the cap.


It should fire right up set like this just once it fires up bring it up 2500 rpm if you braking in a new cam then set the timing with a timing light to 30-32*.
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Re: Rotor position

Post  gmsmkr on September 24th 2015, 1:12 pm

69F100 wrote:
460bronco wrote:10-4!  I think I had it set w/ the rotor slightly clockwise from the #1 plug on the cap.


It should fire right up set like this just once it fires up bring it up 2500 rpm if you braking in a new cam then set the timing with a timing light to 30-32*.

Yes it should
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Re: Rotor position

Post  butterbean on September 24th 2015, 1:51 pm

It don't matter where you put the rotor when you install the dizzy it can point in any direction, you just need to start the firing order where YOU put the rotor, #1 of course then the rest of the firing order, most people think that the rotor has to be in a certin position but it don't it can be anywhere, good luck!!!
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Re: Rotor position

Post  jasonf on September 24th 2015, 2:45 pm

Make sure you are on the power stroke and not the exhaust stroke. That will be your biggest issue. If you are close to the 1 terminal it should fire up and you will need to adjust it from there.
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Re: Rotor position

Post  supervel45 on September 24th 2015, 2:56 pm

460bronco wrote:Hey guys-

When the motor has #1 at TDC, where should the rotor in the distributor be pointing in relation to the #1 spark plug terminal for initial fire up after replacing a cam?  (I want this thing to fire right up!)

I have a MSD 6AL programmable ignition.  The distributor is locked out and the box handles the timing curve instead of any type of mechanical advance or vacuum advance.  Right now when the max timing advance is set to 31, from idle to 1400, the initial timing is 14.  The box then ramps the timing in to full advance by 2400.

Thanks,
Jon
Did you ever put a timing light on it at idle and confirm the mark with the timing pointer and balancer? If you did, and lets say it was 14 degrees BTDC, I would put the timing marker at 14BTDC on the Balancer, and stab the distributor directly in line with the #1 terminal, making sure you are on the compression stroke. That should get you close to where it was before.

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Re: Rotor position

Post  460bronco on September 24th 2015, 3:54 pm

I checked the timing pointer w/ a piston stop and my degree wheel after I installed the balancer. Balancer, timing pointer, and TDC have all been verified. I had to make an extension to space my degree wheel out because I did the cam swap w/ the motor still in the truck. (If bolted directly to the crank, the degree wheel would hit the front crossmember.)
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Re: Rotor position

Post  460bronco on September 24th 2015, 4:23 pm

This thing has been a nightmare... I guess I'll give all the back-ground now...

Last year I flipped my truck at a race and thought I over-revved it in the process. After the crash, I didn't crank the engine and had it loaded on the trailer. The next day I pulled the plugs and valve covers to give everything a once over. Well, I found one exhaust valve that had excessive lash. It appeared that the keeper slid up the valve.

The truck got put on hold at this point A) because it was getting cold outside and I don't personally have a good shop to work on the vehicle in, B) My wife was pregnant and about to have our first child, and C) we moved the week after Christmas and 1 week before my son was born.

Spring rolls around and I'm ready to work on it again. The cam that was in the motor was a custom grind for some ported DOVE-C heads and a vacuum class. I now have SCJ heads and decided if the heads had to come off, that I would get a custom cam fitted for the SCJ heads.

Got a call from my head guy and he said that instead of the keeper sliding up the valve (like I thought had happened) the electronically welded hardened tip had actually popped off the valve due to valve float from a bad valve spring. All valves showed signs of valve float and after checking my springs, they had all lost a good bit of pressure.

Heads were all dressed up and good as new. I got a new custom cam just for the SCJ heads and a new set of springs spec'd just for it.

While the motor was out, I decided to pull the transmission and go through it as well.

Trans was re-installed as well as the engine for break-in of the new cam. This is where the trouble starts. I had a terrible time getting the engine started, but eventually got it started and thought everything went great. I drove the truck from the shop where the engine was re-installed (about 5 miles) before I re-installed the inner valve springs that were left out for proper break-in (I planned on doing this in the carport at my house). When I pulled in the drive-way I noticed another tic on the passenger side. I passed it off as an exhaust leak because my MAD DOG headers are a pain in the A$$ to put on. They literally take 5 hours to get on. I pulled the valve covers to replace the inner springs and decided to check all the valve lash to make sure where that tic was coming from------- I wiped a lobe on the cam-------- Evil or Very Mad Evil or Very Mad Evil or Very Mad

Luckily I had a JOMAR filter on and decided that this was all just part of it. If you change enough cams you will probably wipe a lobe. This was my first.

I didn't want to pull the engine again, so I just pulled the grill out of the truck, ordered the same cam again and re-installed it while in the truck.

This seems easy, but it has fought me the whole way. I tried to place my degree wheel to degree the cam, and it hit the front crossmember. It was a no go. No problem, I just got a piece of 5/8-18 all thread and spaced the wheel out to degree the cam. This cam degree'd in perfect w/ my timing set straight up on ZERO. That's the first time that has happened for me.

I have been slaving over this thing every night when I get off work and tried to break the new cam in last night. Tried to crank the engine 2 times w/ no luck. I felt like I was going down the same road as before. The 3rd try, it kicked back and knocked 5-6 teeth off my flex plate. Now everytime I spin it to this spot, the starter disengages, So, now the trans has to be removed to install a new flex plate.

Super Sorry for the extremely long post, but I think it gives a little insight as to why I'm being so anal about the exact position of the rotor in relation to the cap for this thing to fire as soon as I hit the key!!!!

Jon
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Re: Rotor position

Post  supervel45 on September 24th 2015, 4:47 pm

Sounds like it's time to park it and go play with the new baby and wife for a while. Anyway what I was trying to get across on the timing, is if you put a timing light on it at idle, and remember where it was on the balancer/pointer, just put it back that way. IE put the timing marker/balancer at that point and set the rotor right on the #1 position of the cap. I have done it in the past and it has come out very close to were I wanted to be. Yes rotor phasing does affect this method somewhat. If you don't remember or did not do this with a timing light then, disregard the info.

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Re: Rotor position

Post  rmk57 on September 24th 2015, 8:34 pm

I've always turned the balancer so its 12-14 BTC and then install the distributor so the rotor is exactly facing number on the cap.
Hasn't failed me yet.

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Re: Rotor position

Post  rmcomprandy on September 25th 2015, 12:14 am

460bronco wrote:ok, I think you miss understood the question.... In relation to the spark plug terminal on the cap, what is the ideal position for the rotor?  Slightly clockwise from the #1 spark plug terminal in the cap?  Directly lined up w/ the spark plug terminal?  Half way between the #1 terminal and #8 terminal etc...???

The best rotor phasing position is directly toward the post when FIRING but, being that your distributor itself does not control the advance curve and it is totally done electronically within the ignition box, that happening All the time is impossible.
At this point I would do exactly what the MSD directions tell me to do for this kind of advance curve.

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