Help ID my carb - Feedback or Non-Feedback?

[Gary Lewis]

The HEI's had problems early on, but they corrected them pretty quickly.  One problem was that the rotors and distributor caps weren't up to handling that much energy.  I've see rotors with the tips burned off and distributor caps with holes burned in them.  The power in that ignition system is fierce.

But, with that power came a requirement for power.  By that I mean the wiring providing power to them had to be large.  And that wasn't always the case out of the factory.  IIRC, Bill has a story about just that problem.

So, if you are going to run an HEI you need at least a #12 wire to it and maybe even a #10.  And that needs to be controlled by a relay.  But not everyone does that, so some get poor results from the HEI distributors.

[86 1/2 Brutus]

Thanks for that Gary.  

[85lebaront2]

The story I have on HEI systems concerns the secondary wiring. Due to the high output of the HEI coil and it's location in the cap I have definitely seen some interesting failures the hole burned right through the center of the rotor was always interesting, I have also seen where the coil contact for the rotor wasn't properly installed (spring had come off) so the coil self destructed. Bad plug wires, weak insulation just gives a misfire, high resistance from a bad section in the carbon coated string will cause the voltage at the coil to find a way out, usually either through the rotor or by destroying the coil.

Here is a thought for someone contemplating doing an HEI conversion. On the Ford V8 engines it is very difficult to get much if any clearance for that huge GM distributor. Let me move away from US stuff, Lucas (English purveyor of electrics) had a system called OPUS, for Oscillating Pick Up System where a three sided transformer frame (quite small) was used with a plastic drum containing steel pins 4, 6 or 8 as needed that when the pin was aligned with the open side of the transformer it would produce a voltage spike which was used to fire a transistor ignition. It, like many Lucas products was at best so-so, and frequently failed. In 1980, Lucas released their Constant Energy Ignition as a refit for the MG and Jaguar models the used the OPUS systems. It consisted of a new distributor, an aluminum box with two plug in connectors, two longer coil mounting bolts and instructions for installation. The box had two through holes that matched the existing spacing of the coil mounting bolts. The procedure was to remove the OPUS distributor and replace it with the new one, move the plug wires to the new cap. Remove the coil, discard the ballast resistor and reinstall the coil with the longer bolts through the bracket. The two lead pickup wire from the distributor plugged into the box and a second two wire harness plugged into the other point on the box and connected to the + and - on the existing electronic ignition coil.

Now the reason I went through this explanation, the new distributor had in it what looked for all the world like a Chrysler electronic ignition pickup and it was gapped like one with a brass feeler gauge. In the nice aluminum box was a GM 4 pin HEI module that used the Chrysler pickup to trigger it and fired a normal Lucas electronic ignition coil. I would venture the opinion that a DS-I or DS-II distributor will fire a GM HEI module and most likely a DS-II or TFI coil. If you were to take a non-Motorcraft DS box and gut it keeping the grommets and plugs for connecting to the GM HEI module then install a suitable heat sink and the module. Lucas did not use the #12 or #10 wire, just the normal wiring which leads me to believe it is the HEI coil that is the power hog not the actual module. This way to the average person the truck (or car) will look completely stock.

[ArdWrknTrk]

Pretty obvious it's the gm coil and not the module.
The module is not consuming much current, but it is sinking the coil, so it should have a substantial heatsink itself.

I'm of the opinion that a gutted DSII shell or a remote TFI mount is up to the task, if proper paste is used.
Back in the day this was 'Arctic Silver' but I don't know what's best on the market now.

[86 1/2 Brutus]

Jim from what i understand what Gary said, he dosen't have the computer so the tfi is out the window, but i stil say i'd do a dsII.  my thing is with no computer how is the yfa acting?  I know tht yfa well, and while you can do course adjustments, the computer fine tunes everything, i think that would be an issue, but i do believe he said something about going to a 2150 carb  which i actually  thought about doing on Brutus but after changing the manifold this weekend.   H E double Hockey Sticks NO.

[ArdWrknTrk]

I only mentioned the TFI remote as a heatsink for a GM module.

You know what that finned chunk of aluminum looks like.

Yes, while Dave says some people get away with a YFA and no computer, we've had discussion about the Chinese YF clones recently.
I think that if you purchase the proper configuration clone (@ well under $100) you can have a fine running 300 with no conflicts and plenty of adjustment.

[ArdWrknTrk]

And,I'm not discounting DSII. I run the stock setup myself.

My post was more a reply to Bill's post about the Lucas ignition, and how it did not need a large power wire or heatsink, because it didn't use the GM coil.

But, I'm known to throw something in from left field, so put me in my place if you think it was non-sequitur

[86 1/2 Brutus]

Jim, now why would i do that :-)  i kind of came in the middle of it all myself

[ArdWrknTrk]

  Because I'm often told to shut up and go sit in the corner???

I really do have a unique perspective on the world because of my 'condition'.
I can interject something that only makes sense to me, and other atypicals.

But that vantage means that (sometimes) I notice the incongruity that everyone else in the room looks right past.
So it does have value, even if it is odd.

[86 1/2 Brutus]

Jim, if you only knew how many times i've been told the same  thing, LOL.  It was leaded gas i tell you.    teehee

[Minkheel]

Jim —
Could you expand on this point RE YFA “I think that if you purchase the proper configuration clone (@ well under $100) you can have a fine running 300 with no conflicts and plenty of adjustment.”

Given that my best move appears to be replacing my carb with a non-feedback carb and going to an DS-II or HEI ignition, what else should I do to get the best possible set up?  

YFA refers to the choke on the carb, yes?  

[ArdWrknTrk]

The (A) at the end means it has a feedback solenoid and different metering.
If you're getting away from having a computer you want a YF.

I am not any kind of 300 expert, but I will say some have straight thermal chokes, some have electric assist, some have electric only.

And we have linkage differences for automatic transmission kick down.
Heatshields in different locations.
Provisions for all kind of stuff, like how the fuel line enters.

You just need to take stock of how your current carb is configured and get one that matches (or, at least doesn't conflict!)
Like if the new one had the fuel line coming from a direction that is obstructed on your truck.

You've got to remember YF's came on dozens of different vehicles over the years.
Which one of those a particular clone is based on I just can't say.

I am not a 300 expert...

[Minkheel]

It doesn’t  look like you can get a remanufactured YF only carb. Isn’t the A just a matter of electric choke (YFA) vs manual chock (YF)?

On Wed, Aug 19, 2020 at 7:34 AM ArdWrknTrk [via Bullnose Enthusiasts] <[hidden email]> wrote:

The (A) at the end means it has a feedback solenoid.


If you're getting away from having a computer you need a YF.



I am not any kind of 300 expert, but I will say some have straight thermal chokes, some have electric assist, some have electric only.



And we have linkage differences for automatic transmission kick down.


Heatshields in different locations.


Provisions for all kind of stuff, like how the fuel line enters.



You just need to take stock of how your current carb is configured and get one that matches (or, at least doesn't conflict!)


Like if the new one had the fuel line coming from a direction that is obstructed on your truck.



You've get t to remember YF's came on dozens of different vehicles over the years.


Which one of those a particular clone is based on I just can't say.



I am not a 300 expert...

 Jim,


Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with an Edelbrock 1826 and Performer intake.


Too much other stuff to mention.

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NAML

[Gary Lewis]

David/1986F150Six put a 1970's YF on his truck and it worked extremely well.  Maybe he'll come along to tell us what the carb was off of, but I'll go see if I can find it....  

[Minkheel]

One can get a reman carb with a hot air choke for a 1975 F150 L6.  

https://www.summitracing.com/parts/urm-7-7523

On Wed, Aug 19, 2020 at 8:11 AM Gary Lewis [via Bullnose Enthusiasts] <[hidden email]> wrote:

David/1986F150Six put a 1970's YF on his truck and it worked extremely well.  Maybe he'll come along to tell us what the carb was off of, but I'll go see if I can find it....  

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches




Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow


Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker in front & 10.25 Spicer/Trutrac in back, & EEC-V MAF/SEFI

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NAML

[Gary Lewis]

Here's a hit:

<quote author="1986F150Six">

Ford F834 wrote

On the advice of the straight six guru Frenchtown Flyer he bought a Carter YF carburetor for a 1970 F350. That age and GVWR meant that it was calibrated for a NON- EGR application. If you have deleted your smog pump this is the carb to order.
/quote>

Carter YF 4901 S

[Minkheel]

That leads to this reman ...

https://www.summitracing.com/parts/urm-7-7330

On Wed, Aug 19, 2020 at 8:18 AM Gary Lewis [via Bullnose Enthusiasts] <[hidden email]> wrote:

Here's a hit:



<quote author="1986F150Six">

Ford F834 wrote

On the advice of the straight six guru Frenchtown Flyer he bought a Carter YF carburetor for a 1970 F350. That age and GVWR meant that it was calibrated for a NON- EGR application. If you have deleted your smog pump this is the carb to order.


/quote>



Carter YF 4901 S

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches




Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow


Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker in front & 10.25 Spicer/Trutrac in back, & EEC-V MAF/SEFI

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NAML

[85lebaront2]

From what I remember when they first came out YFA was an updated model with a much shorter throttle body than the 50s and 60s YF models. Y seems to be Carter's designation for the basic design, there are YH versions (side draft) a YS version for the Military M151 family (no mechanical pump or metering rod control). The YFA carbs all have a metering rod adjustment that is only supposed to be done with a proper exhaust gas analyzer on a dynamometer. I am sure that the better rebuilders have a flow bench to do this calibration.

[85lebaront2]

Jim, the issue with using the remote mount TFI heat sink, it is designed for a straight module with all the connections on one end. This brings up another point, there are two different types of TFI modules that have entirely different characteristics. The gray modules (distributor or remote mount) are referred to as "push start" and have a cranking signal like the DS-II modules. These "push" the dwell duration for a hotter spark when cranking. The black TFI modules are called "CCD" for Computer Controlled Dwell and the EEC controls the dwell time to get a hotter spark when needed.

[Minkheel]

Ok, so the carb for a 1970 F-350 (or any other 1970 with the 300 L6) is this one ...

https://www.summitracing.com/parts/urm-7-7330/year/1970/make/ford/model/f-350/submodel/base