Dumping the FBO timing advance plate.

[TrailBeast]

As some may be aware FBO sells these mechanical total timing limiter plates.
I currently have one in my daily driver 5.9 Magnum and another car with old school welded up advance slots.

The distributor with the plate hangs up not allowing the distributor to go to the desired maximum mechanical advance.
It hangs up until the RPMs are pretty high and then suddenly dumps in the last 4 degrees.

I’m pulling the FBO plate and old school welding up the advance weight slots instead.
Yea it’s a little more work, but in the end it will work properly and be more reliable.

 

[toolmanmike]

As some may be aware FBO sells these mechanical total timing limiter plates.
I currently have one in my daily driver 5.9 Magnum and another car with old school welded up advance slots.

The distributor with the plate hangs up not allowing the distributor to go to the desired maximum mechanical advance.
It hangs up until the RPMs are pretty high and then suddenly dumps in the last 4 degrees.

I’m pulling the FBO plate and old school welding up the advance weight slots instead.
Yea it’s a little more work, but in the end it will work properly and be more reliable.

View attachment 1716400869

Are the slots not wide enough?

 

[Projectile Dart]

Can it be an issue with corrosion building between plate and weights? Maybe a thin layer of grease to help things slide around?

 

[TrailBeast]

Are the slots not wide enough?

The slots are fine, but something is hanging up so screw it.
I don’t have a problem with the distributor going in and out a few times for dialing it in.

Can it be an issue with corrosion building between plate and weights? Maybe a thin layer of grease to help things slide around?

I pull, disassemble and clean the distributor probably twice a year so I doubt it’s corrosion.
Welding up the slots will solve it once and for all.

What I see happening is when I twist the rotor it moves easily at first, then with a little more force it snaps to the full advance position.
Everything in the distributor is clean and lubricated.

 

[RustyRatRod]

As some may be aware FBO sells these mechanical total timing limiter plates.
I currently have one in my daily driver 5.9 Magnum and another car with old school welded up advance slots.

The distributor with the plate hangs up not allowing the distributor to go to the desired maximum mechanical advance.
It hangs up until the RPMs are pretty high and then suddenly dumps in the last 4 degrees.

I’m pulling the FBO plate and old school welding up the advance weight slots instead.
Yea it’s a little more work, but in the end it will work properly and be more reliable.

View attachment 1716400869

Just don't use the FBO slots for a guide, because they're wrong. He knows it and refuses to correct the issue.

 

[Syleng1]

Just don't use the FBO slots for a guide, because they're wrong. He knows it and refuses to correct the issue.

sounds like the next episode of RRR garage on Boobtube!

 

[TT5.9mag]

When I welded up the slots on my distributor I found a chart, I think here on fabo that gave a reference for slot dimensions and how much advance each provided. I’ll see if I can find it.
On mine .385 long slot gives 17 degrees of mechanical.

 

[crackedback]

This is from a magazine article a while back.
----------------------------------------
dist. degrees X 2 + initial= total


dist. degrees / slot length
6.............. .340
7............... .355
8............... .375
9............... .390
10.............. .405
11.5 ........... .420
12.............. .435
13.............. .445
14.............. .460
15.............. .475
16.............. .490
17.............. .505
18.............. .520
--------------------------------

 

[Newbomb Turk]

sounds like the next episode of RRR garage on Boobtube!

I WHOLEHEARTEDLY SECOND THAT!

 

[340sFastback]

I used a chart and welded my slots up. It just has to be close, set Total Timing, and if Initial Timing is close that should be sufficient. My Initial Timing ended up very close to where I wanted using that chart for slot hole length.

 

[mopowers]

Are the numbers on that FBO plate supposed to represent crank degrees or distributor degrees?

 

[TrailBeast]

All done and only had to pull and disassemble the distributor twice.

18 initial plus 16 mechanical and a total of 48 with ported vacuum, and all in by 2,500.

 

[stroker402]

what was hanging up ? secondary hoop spring tension in dist ?

 

[RustyRatRod]

All done and only had to pull and disassemble the distributor twice.

18 initial plus 16 mechanical and a total of 48 with ported vacuum, and all in by 2,500.

That's a lot, but if that's where it runs best, it knows what it wants.

 

[MobileCustoms]

I tried one of those FBO plates and sent it back through paypal. They are not accurate at all, as others have said. I welded mine up also.

 

[TrailBeast]

That's a lot, but if that's where it runs best, it knows what it wants.

Which one, or all in?
I ran 22 initial and grand total was 52 with vac advance for years and was getting 25mpg on the hiway.
I don’t pay much attention to fuel economy normally, but I stopped for gas on a trip at 250 miles and it took 10 gallons to fill it back up.
That’s the only reason I know.

Apparently Magnums like a lot of timing, unlike my LA.
Plugs look great as well, and been in there for 5 years.

 

[TrailBeast]

what was hanging up ? secondary hoop spring tension in dist ?

Didn’t even bother to look.
Just pulled it and took the plate out.
On reassembly it was smooth as could be.

It has the OE light spring and the Mr. Gasket super light spring (925b I think)

 

[RustyRatRod]

Which one, or all in?
I ran 22 initial and grand total was 52 with vac advance for years and was getting 25mpg on the hiway.
I don’t pay much attention to fuel economy normally, but I stopped for gas on a trip at 250 miles and it took 10 gallons to fill it back up.
That’s the only reason I know.

Apparently Magnums like a lot of timing, unlike my LA.
Plugs look great as well, and been in there for 5 years.

The 48 total. I assume that's just initial plus mechanical with no vacuum assist, right? If it likes it and doesn't spark knock, put the fire to it.

 

[TrailBeast]

The 48 total. I assume that's just initial plus mechanical with no vacuum assist, right? If it likes it and doesn't spark knock, put the fire to it.

48 vac included.
It was 52.
I leave the distributor just loose enough where I can move it.
If needed I can pull over and take a little out of it.

 

[RustyRatRod]

48 vac included.
It was 52.

Oh ok. Gotchya. I misread it then. Vacuum included, it's not uncommon to see 60 or more.

 

[TrailBeast]

Oh ok. Gotchya. I misread it then. Vacuum included, it's not uncommon to see 60 or more.

Going into summer and it has AC now.
Safe timing.

 

[RustyRatRod]

Going into summer and it has AC now.
Safe timing.

Dang right. I'd much rather be safe than sorry in that situation.

 

[crackedback]

Oh ok. Gotchya. I misread it then. Vacuum included, it's not uncommon to see 60 or more.

I was asleep and saw the vac was added

Nice job on getting the distributor set up.

 

[TrailBeast]

I was asleep and saw the vac was added

Nice job on getting the distributor set up.

Thanks.
It was time for some well deserved changes after all the years of faithful service.
All new fuel system with pump, pressure regulator, filters and 100psi EFI hose where there is rubber line, new rear shocks.
It deserved it.

 

[TT5.9mag]

how wide was the slot when you finished to get 16 mechanical?