You have vacuum advance function at dizzy and it's hooked up to ported vacuum on the carb? What's you centrifugal starting rpm, finish and by how much? I find working with the 10 degree slot on the centrifugal plus a thin piece of tubing to further limit centrifugal amount with 11 degrees initial. The rest of the advance taken care of by the older style washer and plunger stop vacuum advance can. The vacuum unit is soft to where I can inhale on it and start advancing. I'm all in centrifugal at 2,550 with 37 degrees total on a 9.29 cr 414. Spring kit in the dizzy.
When set up near factory chart specs it acted like a large flat spot, all ignition when thinking carburetor was at fault.

 

Yes, vacuum advance is hooked up to ported vaccuum on passenger front side of carb. Just installed new hoses and check valve and made sure that check valve was put in correctly. The vaccum advance pot was "new" with the rebuilt dizzy. I took it out a minute ago and it looks new inside. It works when I suck on the vacuum tube. I still need to get an advance timing light. I may do that in a few minutes. I just wish I had someone around here that knows something about these old trucks so I could have them help me figure it out.

 

The balancer is accurate. I verified it while setting the valve lash when I installed the adjustable rockers...unless it moved over the last three months.

I'm going to go get an advance timing light. I'll report what I find, because I still have questions on how to recurve the dizzy advance.

 

I've got 13* at idle of 850 rpm with vacuum plugged and 27* at about 2400 rpm. I have to run an idle of 850 rpm to get curb idle in gear to be 650.

The right way to do this is to continue to speed up the engine with the vacuum disconnected and plugged until the advancing stops...correct? Or do I have enough information here to figure it out? Well, assuming that I could figure it out. From some of the posts I have read, I'm thinking that I need to recurve it to increase the advance so that I have more advance than I do now at 2400 rpm. Correct? I decided to call it quits for the night because I felt I had bothered the neighbors enough. I'll tinker with it some more tomorrow after work.

I'll throw this in there too. The parts in the centrifugal advance were stamped 18L and 13L. I seem to remember that being important from some post about recurving distributors but I can't remember why.

I also put in the 0.110" secondary jets. The lean spot is better but still there. I'll go another step richer, but I'm going to make sure the dizzy is right first.

 

Well, it runs a ton better with the weather change. I'm beginning to wonder if it was just the cold weather. I didn't have a chance to mess with it at all last night.

 

I've thought about post #19 now. 13* at idle plus 27* at 2400 is total 40* and I don't even know if that's the maximum yet. I'm over advancing...aren't I?

Wasn't there an article or thread somewhere that took you through recurving the dizzy in-depth? I looked for over three hours today and couldn't find it. It seemed like it was written by jowilker or beemer nut but I can't remember.

 

What cam is in that 360?
Are you sure your not floating on centrifugal advance at that 850 rpm idle.
That motor should be able to idle at 650 in neutral without a problem being placed into drive. What is your manifold vacuum readings at 850 and 650 in neutral? From what you posted above your total advance is too high.
Read back a few replies where I limited the centrifugal.
You can be over advanced to a point the motors bucking against itself plus making heat and detonation.
Years ago I had a 437K 360 tweaked with a 390 2 barrel premium fueled cam that kicked butt against 390 trucks without detonation problems.

 

Ok I found an article that comes setting your distributor. Type "Adjusting total distributor advance" into google and the first link that pops up should be to fordmuscle. It covers everything that you hve questions on. I hope this helps to solve some of the mysteries with your system.

 

BINGO! That was one of the tech articles I read last year that explains how to set up a dizzy. They can explain with photos better than than I can type and how i'm thinking. I still hate these new vacuum advance units, still running on the old "add washers and plunger limit" units for total control of how much and when. I have a rebuilder in Oz that can replace broken diaphragms in the older units that are fully adjustable. Thank the EPA for stopping the sale of thes units, you and your motor suffer. Think they care?

 

The cam is part of the Crane 343902 cam and lifter set. I think it's a 901 cam. Cam timing is set straight up. I thought I needed to have idle at 650 when in gear and the brake on. Isn't that right? I thought that was curb idle? I could be wrong. I've been setting idle based on when it is in gear.

FWIW, I did find another potentially huge problem a few minutes ago. I decided to replace the old voltage regulator with a new solid-state style. I followed the instructions for checking to make sure there is proper ground by testing the terminals. While doing that, I decided to check the wiring because the plug looked a little rough. Well, I found that the ground wire that is bolted to the radiator support by one of the VR bolts has all of the insulation burned off of it once it gets into the taped up section. Something has been pretty hot! I decided to pull the alternator so I could disconnect the wires on the back of it and I ended up finding something very disturbing. The black wire post (I'm assuming ground) has been burned completely through except for about a 16th on an inch of the bolt. That connection has been very hot! I've had a short or some other kind of overloading. I'm completely surprised that it still runs after seeing the condition of that wiring.

I'm going to see if I can pick up a new alternator/voltage regulator harness, because I'm sure this one is done and I'll definitely need a new alternator. I could replace some wires, but I'll never feel safe. I don't know if it's been causing some of my problems but it sure ain't right. I ordered a dizzy advance recurving kit from the local speed shop. I'll read through the article that airharley posted and determine if I still need it.

 

I was wrong. It was the battery terminal on the back of the alternator that was burned up in addition to the ground wire between the alt and the VR. Replaced the alternator, the regulator and all the wiring. Idles sooo much smoother now after I fixed those problems and made the big dizzy cap conversion with 8mm wires.

Anyways...

So does anybody have a good source for a mechanical advance recurve kit with lower numbered weights, or would I be better served to just install the thin tubing over the little arm? My thought is that if it is in the 13L weight slot, then I have 26 degrees of mechanical advance. If I limit it with the small piece of tubing and I reduce it by 5 degrees (theoretical number) then I would also be increasing the initial advance by the same 5 degrees because the little piece of tubing would not allow the mechanical advance to come back out completely. So would I need to change the initial advance any?

 

Well, I'll keep posting for posterity's sake.

I installed a #8 size rubber bolt cap on the arm in the distributor and now it's not advancing enough. I went looking for an advance recurve kit and it doesn't seem like any one sells them anymore. The only kit I could find was for a GM HEI. I think I'm going to pull the dizzy this afternoon and switch it over to the 18L slot with the piece of tubing on it. I think that might get me close. It already runs a ton better. It doesn't seem like it is laboring just to hold highway speed but it's still not quite there.

Hey Beemer, how are you using washers and plungers on the vacuum advance? If I understand the vacuum advance correctly, a longer plunger decreases the max amount of vacuum advance and increasing spring pressure makes it less sensitive to vacuum. Or are the effects the same: less vacuum advance?

I did have an interesting comment from an engine builder at a local speed shop. He said throw the vacuum advance in the trash, run as high initial as I can (about 20*) and put in as little mechanical advance as possible (like 10* or 15*). Does vacuum advance affect mileage or just emissions? I figured that it affected both. He said that I wouldn't notice a mileage drop. Oh and he's not a chebby guy. I was talking to him while he was assembling an old FE.

 

First thing I would do is trash the advice from your local speed shop engine builder, just because he has his hand on a FE doesn't mean he knows FE's.
A person like him can work on a Packard motor that was around before he was born and only know basics like this part goes up and down.
Unless it's a hot street or drag motor you can run without vacuum advance, on the street you need it to run properly plus fuel mileage.
Go to the larger slot with a thicker sleeve over the arm.
Too much initial, centrifugal and vacuum will cause the motor to
buck and surge, this you'll feel best around 2,400 rpm's in 1st gear in a
stick box vehicle.
Combined inital and centrifugal gets me 37 total then I set the vacuum total
to just below surging them set when vacuum pulls in preventing detonation problems.
With my combination with a stick box I had light random detectable detonation from 500 to 5,000 rpm's in 4th gear, the advamce was even thru the whole rpm range.
Years ago whith the fully adjustable vacuum units the phenolic plunger stops
came in different lengths due to year and application besides different thick and thin washers to increase the spring pressure.
This sure is handy with a collection of old vacuum unit parts to tune with.
You change cams, intake, compression, altitude you'll run it, loads pulled, gearing, air and water temps plus changing from stick to auto all effect the vacuum unit setting not alone inital, when and how much total centrifugal.
It took me weeks of road time driving before I arrived at the best it can be.
By the way are you driving with a vacuum gauge on the seat with vacuum pump to change the vacuum signal while driving taking notes what happens to give you directions to how to tune?
If it were easy anyone could do it.
I can get 15 mpg with 414, C-6, 3.5 gears and 33.5" tires provided driven
a steady 62-63 mph. Before with 360 13.4 best from a starting point of 11.2.
Stay away from that speed shop idiot unless fuel mileage isn't a concern.

 

Oh, I knew better than to listen to the speed shop guy. I just thought I would put it out there to see how you guys felt about it. I have a feeling that they only rebuild hot street motors and drag motors from some of the things I was talking to them about. They seemed to take the easy way out on a lot of stuff. I want my truck running right.

I've hooked up a vacuum gauge and stuck it under the windshield wiper facing the cab, but I haven't tried it with a vacuum pump. I'll go pick one up today and try that out.

I'll also take another look at my total initial and centrifugal. My thought is that if I subtract my total with the sleeve in from my total without it, I can find out how much I am reducing it by adding the sleeve. It should be pretty simple to find out where I would be if I switched the arm over from the 13L slot to the 18L slot. I'm pretty much maxed out on sleeve thickness because I'm very close to rubbing on the distributor body. I might also try to see if I can find some thinner sleeve.

 

I checked my total advance and it is at 35* at about 2600 rpm with 17* intial with vacuum advance plugged. That seems like just a bit too much initial to me, but it has no problem at all with starting when hot so I'll leave it where it is. I'm getting that while using the tubing over the reluctor arm and the arm in the 13L slot. Simple calculations tell me that I am getting 18* mechanical advance (35* total minus 17* initial) so the tubing must be reducing mechanical advance by a total of 8* (26* expected minus 18* actual). My thought is that if I move the arm over to the 18L slot, then I'll end up with 28* of mechanical (36* expected minus 8* reduction). If I run 17* of initial that puts me at 45* total. I could run less initial, but I thought I want to run as much as possible until it kicks back against the starter and as long as I don't get any pinging.

According to the A/F gauge it is running pretty rich so I think any drivability problems I still have can be attributed to bogging now. I still haven't checked the vacuum advance with a vacuum pump but I'm going to lean the carb down and see what happens. If it runs better, great, if it starts to ping, I'll go back to ignition.

Am I thinking along the right lines here?

I appreciate everybody's patience. Until a few weeks ago, I didn't even understand the reason for looking at total advance. Now, thanks to you guys, I'm able to make a few highly respected mechanics' eyes glaze over when I get into what I've done. I know I have a long way to go, but you guys have gotten me very far. Thanks!!