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HI
yeah that is way to high and is going to cause the dieseling . fast idle when cold should be about 1200. but warmed up curb idle should be 650 manual and 750 automatic transmission. You can't adjust the mixture screw's at that RPM (1000) thats out of the idle circuit.

good luck take care be safe
tim
 

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Your distributor needs to be properly sorted out.

Spun up on a machine and recurved to the application.

OEM and remanned distributors have curves that are all over the place AND
are two stage. One lite spring and one heavy to delay the last bit of mechanical advance until 4000+ rpm.





Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
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My dizzy is not locked out as total timing does change to 28*/30* at 3900 and somewhere past 40 at 5k
Whoa, that thing is way out of the ball park, and you are risking your engine's health.

+1 to Mad Porter. Your application requires a custom timing curve, and you will not see any satisfaction nor solution to your problems until you do that. Do that.

It sounds like your distributor needs some minor mods to get about 12° mechanical advance, and springs selected to provide that advance from about 1000 to about 2800 rpm to get all 12°. Once you have that, pre-set the distributor to 16° BTC before start-up*. Vacuum disconnected and running, verify total of 28° BTC at >3000 rpm, and adjust if necessary. Idle-down when warm and tune your idle mixture evenly for the most vacuum you can get, at 800 or less. Juggle the mix and the rpm as you tune. Test drive. If OK, connect the vacuum advance and test again.

Report idle rpm, idle vacuum, and test-drive results.

* DuraSpark: To pre-set timing, set crankshaft by hand to the desired base timing, on compression stroke of cylinder #1. Mark the distributor body under the cap #1 terminal position. Remove cap. Insert distributor with rotor facing the cap #1 terminal position. Twist distributor body if necessary until the sensor face bar aligns with the nearest shaft reluctor bar, verifying the rotor is still closest to cap #1 terminal position. The rotor should be slightly clockwise of the mark. Snug the distributor clamp. With care, timing should be close, but verify with a timing light when running.
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Discussion Starter · #27 ·
Your distributor needs to be properly sorted out.

Spun up on a machine and recurved to the application.

OEM and remanned distributors have curves that are all over the place AND
are two stage. One lite spring and one heavy to delay the last bit of mechanical advance until 4000+ rpm.





Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
I followed that guide to take the distributor apart, and found out that the slot it's using is a 13ll. I bushed the pin so it shouldn't advance quite so far anymore, but now it has zero spark when cranking. Any idea what I did wrong?
 

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I followed that guide to take the distributor apart, and found out that the slot it's using is a 13ll. I bushed the pin so it shouldn't advance quite so far anymore, but now it has zero spark when cranking. Any idea what I did wrong?
No clue, but likely incorrect reassembly or connections. Perhaps look at the photos and compare to spot issues.
I'll need msd because the stock distributor doesn't clear the intake without a heck of a lot of grinding.
If it's cap clearance, just use the old points-style and original DS small cap and rotor. The big caps and funnel-shaped adapter were used for later high-energy DS-I, then cross-fit to the older DS-II in order to extend maintenance intervals and simplify supply chain, as everything would be high-energy and big cap in the future. 1977 was the last year you could have received either a small cap or big cap and adapter on DS-II.
 

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Discussion Starter · #30 ·
Late update because second shift:

The no-spark condition was because the ground for the pickup coil wasnt clean enough. With a new ignition module, adjusted valves, modified advance curve, better tuned carb, and clean plugs, it pulls just about perfect until 5k with vac advance disconnected. When vac advance is connected it still starts having issues around 3800, but I can drive with it unhooked for now. It misses here and there but I think that's just because the plugs have been rather epically fouled several times.

Vacuum bounces between 7" and 10" at idle, which is 800 rpm. It was a lot more bouncy before, so that's improved somewhat. I can't adjust the carb anymore or check the timing because everyone's asleep, but I'll try to work that in tomorrow.

Edit: spelling
 

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Oh. Huh. I assumed total included vacuum advance.
It reaaally liked 17 initial at 800rpm, but as soon as I connect the vac advance it jumps to 36 degrees and nothing except lowering the idle will adjust that. The more I retard the distributor the higher it'll rev before it starts acting up...is it just advancing too much??
I'll check to see if it's locked out or not.
If your timing jumps to 36 degrees at idle, you are using intake vacuum for the advance. You need to be using ported vacuum, in that the amount of vacuum increases with rpm.
 

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Ported vacuum by design is 0 at idle. As the throttle is cracked open to about 10 to 20% load it is exactly the same as manifold vacuum.





Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
 

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Discussion Starter · #33 ·
If your timing jumps to 36 degrees at idle, you are using intake vacuum for the advance. You need to be using ported vacuum, in that the amount of vacuum increases with rpm.
It was jumping when I connected it because my idle was set way too high. I just have it disconnected for now because as soon as it kicks in no matter rpm that is it starts knocking.
 

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It was jumping when I connected it because my idle was set way too high. I just have it disconnected for now because as soon as it kicks in no matter rpm that is it starts knocking.

Vacuum advance is adjustable and need to be quantified and pulled back to about 10 / 12 *@ 15" vacuum.

SR 71 heads have a VERY efficient combustion chamber. 28* TOTAL timing is all that is typically needed.







Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
 

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Discussion Starter · #35 ·
Vacuum advance is adjustable and need to be quantified and pulled back to about 10 / 12 *@ 15" vacuum.

SR 71 heads have a VERY efficient combustion chamber. 28* TOTAL timing is all that is typically needed.







Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
I've tried adjusting it, it doesn't seem to help. It's six turns out and no improvement. I'll keep trying though, you seem like you might know a thing or two😂
I think it's at 28/29* right now but can't remember for sure. Definitely runs a lot better though!!
 

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I've tried adjusting it, it doesn't seem to help. It's six turns out and no improvement. I'll keep trying though, you seem like you might know a thing or two😂
I think it's at 28/29* right now but can't remember for sure. Definitely runs a lot better though!!

Maybe a thing or two...

CCW to remove and CW to add advance.
If the adjustment is damaged then you have to replace the cannister or dizzy...







Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
 
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