351C where to start?

[giantpune]

Remember to put the oil slinger ring back on the crank snout, cupped side out, to assist in keeping the timing cover seal from seeping, before you put the plate back on the block.

If there's room. He put in a double row timing set. Some of those don't leave room for the oil slinger.

 

[Spike Morelli]

Absolutely true Giantpune! Sometimes, the new timing set gears are thicker. Which brings up another thing that bears checking. Because, as Giantpune has indicated, the new double row timing sets are thicker ( wider ), it's always a good idea to put a straightedge across the block where the timing cover goes to check for any interference or touching of the fuel pump eccentric to the steel cover. I've seen timing cover plates that exhibit wear marks from the eccentric. It doesn't always happen, but it costs nothing to check, and everybody owns a 12" ruler to check with for peace of mind. Multiple gaskets for spacing, or grinding the face of the eccentric will fix that.

 

[351mach1]

There was no slinger when I took it apart.

I'll check if the eccentric hits before I bolt up the new timing cover. Got the cover painted tonight and hoping to have everything buttoned back up and running tomorrow

 

[c9zx]

Remember to put the oil slinger ring back on the crank snout, cupped side out, to assist in keeping the timing cover seal from seeping, before you put the plate back on the block.

+1 on Spike's comment. I forgot it once and it caused a lot of re-work, once I stopped cussing.

 

[351mach1]

Got it all back together and running. After reading a few threads about the oil slinger I decided to roll the dice as I have the double roller set. It didn't have one when I took it apart and that last timing set has been in there for sometime with no seeping. Maybe that was a dumb call but we will see. I did however replace the cheesy oil seal that came with the speed master timing cover and put the nice Fel Pro one in there. Everything went together mostly smooth. The very last bolt on the water pump wouldn't go in so had to pull it back off to wiggle the timing cover enough to make room for the bolt to engage the threads. PITA!

I am dumb founded by the amount of jerry rigging that is going on with this car. Literally every new thing I touch was previously half assed. So the other day I notice the oil pan is dented. I almost pulled the trigger on a new oil pan as I already have it most the way off but I blasted through my budget a long time ago so decided to put it on hold. Well I go to change the oil today and the drain plug is completely stripped and held together with some chetto Autozone EZ fix plug in there. Shoulda went with my gut on that one. Its holding oil but I hate knowing that my stuff is jerry rigged. Putting oil pan on the to do list now.

Ok so I took it for a ride around town. I know I still need to dial in the timing and carb tuning but it's close and runs pretty good. I am still surprised back the lack of "pinned to your seat" feeling. What should I realistically be expecting from a stock '74 351 CJ, C6 tranny, and 3.50 rear? Should I be able to break the tires loose off the line?

 

[351mach1]

Appears that the oil pan job is going to have to move up on the priority list as the old gasket is now leaking pretty good. Doesn't look like a fun job.

I am still having some issues with backfiring and stumbling off idle. I have been tweaking the carb but just can't seem to dial it in. The issue comes mostly straight off idle. I had it pretty close at one point today but I am now back to a back fire and stumble off idle sometimes but not always. Idles very smooth and drives pretty well; just when I lay into the gas from a stop it stumbles.

I changed the fuel filter today and had some pretty dirty fuel come out. I filled the gas tank up and hoping anything in the tank is settling to the bottom.

This guy is speaking directly to me:

I most likely need to just dial in the timing and carb better.

Here are the things I can come up with that could still be causing this issue:
1. Carb isn't tuned correctly (might have to enlist a local expert to teach me the jedi ways)
-most likely the accelerator pump isn't adjusted correctly (I tried various adjustments)
-wrong accelerator pump nozzle size (I believe this carb comes with .031)
2. Dirty fuel
-New fuel filter and fresh tank of gas but maybe it gunked up the carb before I changed the filter
-clean carb?
-run this tank of fuel through and swap in another fuel filter
3. Ignition timing
-Should I be using ported or manifold vacuum for my vacuum advance?
-I have the new distrbutor that I haven't tried yet because I don't like how sloppy the rotor is. Maybe I glue it on?
-I plan to recurve the new dizzy before installing
-Need to figure out what the engine total timing and recurve should be
4. Spark plug wires too long
-I bought universal wires that also fit big blocks so they are all 6-8 inches longer than they should be
-wire routing incorrect
-I saw another thread recently that explained the 302 had a very specific way to route the plug wires to prevent cross fire. Is there a similar thing in the 351c?
5. Duraspark wiring
-I need to button up the wiring permanently with soldered connections as I still have temporary connections to just get it running
-The duraspark wiring kit I purchased has about 2-3 extra feet of wire than I need. I was thinking of trimming out the excess.

Suggestions appreciated as always! Am I missing anything glaring?

 

[Sheriff41]

What do you have the initial timing set to BTDC?

 

[351mach1]

Currently set at 10* BTDC

 

[Sheriff41]

Try bumping it up to 14, back off your idle set screw to adjust your idle speed. Many of us find 14-16° for initial timing works well. Also, I use ported vacuum for the vacuum advance.

 

[boilermaster]

351mach1,
Don't shorten those Duraspark wires just yet. here is my thinking.
get your recurved distributor in there , bump initial timing to 14-16 BTDC, or 2-4 degrees slower timing
from where your engine just begins to spark knock while lugging the engine.
You might find that your starter does not like this.
Pretty sure the (standard ignition) module in your pictures does NOT have crank retard feature that an OEM Motorcraft module has and will cause hot cranking issues with your starter.
Use that extra wire to move your module to the right front of the apron to give that module some unheated incoming air.
Find an OEM Motorcraft ignition module.
I know these things from experience, as I had 2 module failures using (probably) the very same module you are using.
If you can't find OEM, let me know, I have several.
Boilermaster
.

 

[Stanglover]

Boilermaster;
As I'm not at all familiar with the DuraSpark distributer, do they have the same style L slot plate under module? Or does the ignition module take care of limited crank timing advance?
This is for my own education, but may be useful to others.
I found for my own 351C M code with factory stock dist., I set the initial to 14-16 degrees and changed the limit slot to a 10L (20 degrees crank) for a total of 34-36 total with 1 factory heavy spring set just loose and 1 Mr.Gasket 925d spring and all in @ 3K rpm. I actually now have it set at 14 initial with no issues.
Is the DuraSpark set similarly?
Thanks for the education.

 

[boilermaster]

Boilermaster;
As I'm not at all familiar with the DuraSpark distributer, do they have the same style L slot plate under module? Or does the ignition module take care of limited crank timing advance?
This is for my own education, but may be useful to others.
I found for my own 351C M code with factory stock dist., I set the initial to 14-16 degrees and changed the limit slot to a 10L (20 degrees crank) for a total of 34-36 total with 1 factory heavy spring set just loose and 1 Mr.Gasket 925d spring and all in @ 3K rpm. I actually now have it set at 14 initial with no issues.
Is the DuraSpark set similarly?
Thanks for the education.

Stanglover,
Ignition crank retard is a function of the ignition module and not the stator/ pickup coil.
just as the points ignition system gives 2 ignition circuits, so does Duraspark,
wiring is via the starter relay I circuit.
In OEM Motorcraft ignition modules it offers 4degrees crank retard for easyier starting.
Cheaper aftermarket modules do not have this feature.
To prove this I switched the crank and run circuits while observing timing marks.
the module I bought from NAPA Standard ignition did not offer this feature.
burned up 2 of them using the shock tower mounting location.
Boilermaster

 

[Stanglover]

Stanglover,
Ignition crank retard is a function of the ignition module and not the stator/ pickup coil.
just as the points ignition system gives 2 ignition circuits, so does Duraspark,
wiring is via the starter relay I circuit.
In OEM Motorcraft ignition modules it offers 4degrees crank retard for easyier starting.
Cheaper aftermarket modules do not have this feature.
To prove this I switched the crank and run circuits while observing timing marks.
the module I bought from NAPA Standard ignition did not offer this feature.
burned up 2 of them using the shock tower mounting location.
Boilermaster

Very informative info. Thank you.
As my signature says "I learn something new every day"

 

[351mach1]

Happy to report that I have the stumble about 95% tuned out but I still need to dial in the carb a little bit better. I think with a little more tuning it will be nice and crisp. I ended up recurving the dizzy per @Stanglover above advice, shortening the spark plug wires, and hard wiring the DS II wires. I did not hack up the DS II harness yet as I may try to take above advice and relocate it and find a motorcraft unit.

I can now easily spin the wheels off the line. The stumble is at its worst when driving about 10 mph then trying to slam the gas. Off the line it has just a quarter second hesitation before kicking in. If I ease into it ever so slightly it doesn't happen. I think a little more tuning will have it 100%. I will update my other threads with a little bit more detail but I think as far as this thread goes, I am elated to say the problem has been solved with many thanks to everyone who replied here!!

I am still finding that the power of the car isn't quite what I was expecting. I am going to attribute that to the engine being the 74 CJ model with 260ish HP and the 3 speed auto. Looks like I'll just have to swap in that 5 speed and up the power on the engine
View attachment PXL_20241219_201621901.mp4

 

[Sheriff41]

...

I am still finding that the power of the car isn't quite what I was expecting. I am going to attribute that to the engine being the 74 CJ model with 260ish HP and the 3 speed auto. Looks like I'll just have to swap in that 5 speed and up the power on the engine
View attachment 96172

By today's standards, these old Mustangs aren't rocket ships. They make all the right sounds and fumes, and due to their outdated suspensions, are a hoot to drive. Chasing more power, speed, and handling are addicting (and expensive!). My 4X4 EcoBoost F150 can easily outpace and out brake any of these old Mustangs in their original configuration. I drive my Mustangs for fun and the smile they put on my face; my truck I drive for its function and roadworthiness.

 

[351mach1]

My 4X4 EcoBoost F150 can easily outpace and out brake any of these old Mustangs in their original configuration.

I own a Transit 250 ecoboost (tall, long, and loaded to the gills) that definitely outpaces the Mach 1 but also a 09 BMW X5 I used to have. Those ecoboost engines are great! If I had unlimited time and money I think I would come up with some kind of project using the ecoboost engine as silly as that sounds. Don't get me started on current Ford customer service though. I am giving up on modern day Ford. That's another story over a few drinks.

 

[Stanglover]

@351mach1, can you remind me on what carb you have on your car?
On mine, with a Holley 670 S/A, I too had that slight stumble if and when I hit the loud pedal. The fix in my case was to swap out the "squirter" from a #31 to a #35 and now no more stumble, just a smooth hard acceleration. I do however, get some rough running until the motor is at full operating temp and usually only when the weather temps are lower. Once warmed up, it pulls like a train.

 

[351mach1]

It's a Holley 600 street warrior. I bought the cheap refurbished one for like $330 bucks straight from Holley. Figured it was a decent deal. After watching the below video I was thinking of changing the nozzle. Maybe I'll try it out. I was almost thinking of trying this out but I really doubt anything is wrong with my carb and probably just need to tune it correctly. $250: Edelbrock AVS2

https://www.holley.com/blog/post/ho...AbG5GofL3N4PJdGmCbV-9bQfVuYrlZjNjFVgOdSvuy4Dz

 

[Stanglover]

It's a Holley 600 street warrior. I bought the cheap refurbished one for like $330 bucks straight from Holley. Figured it was a decent deal. After watching the below video I was thinking of changing the nozzle. Maybe I'll try it out. I was almost thinking of trying this out but I really doubt anything is wrong with my carb and probably just need to tune it correctly. $250: Edelbrock AVS2

https://www.holley.com/blog/post/ho...AbG5GofL3N4PJdGmCbV-9bQfVuYrlZjNjFVgOdSvuy4Dz

Thanks for letting us know.
One thing; personally I don't like the 'looks' of the Edelbrock carb. It's probably a very good carb and lots like them, but they look like it is mounted sideways. It's just a weird looking carb to me. Yeah I know, I'm weird too!!
I'm not familiar with the 4160 carbs and I'm not knowledgeable either. When I got the 4150 Street Avenger, it ran very rich at idle right out of the box. I tried messing with it, but could never get rid of the horrible gas smell in the garage. I took the car to a local speed shop that has a carb guru and he sorted it out in no time. He drilled a 3/32" hole in each throttle plate, reset the transfer slot, reset the accelerator pump, set the curb idle and bingo, no more excessive gas smell. My engine vacuum was 17", but the carb didn't like an 8.5 power valve that in theory is correct at 17" vacuum. It was put back to the 6.5 pv that came with the carb. It's ran very well since with just minor tuning adjustments.
Good luck.

 

[351mach1]

I'm not familiar with the 4160 carbs and I'm not knowledgeable either. When I got the 4150 Street Avenger, it ran very rich at idle right out of the box. I tried messing with it, but could never get rid of the horrible gas smell in the garage. I took the car to a local speed shop that has a carb guru and he sorted it out in no time. He drilled a 3/32" hole in each throttle plate, reset the transfer slot, reset the accelerator pump, set the curb idle and bingo, no more excessive gas smell. My engine vacuum was 17", but the carb didn't like an 8.5 power valve that in theory is correct at 17" vacuum. It was put back to the 6.5 pv that came with the carb. It's ran very well since with just minor tuning adjustments.

Now that I am a Holley tuning "expert" after 30 minutes of youtube this morning, I think my choice of carb is just fine for my stockish motor with auto trans. 600 CFM may be a bit small if I ever go with more power but for now its fine. the 4160 doesn't have a secondary metering block which is apparently beneficial for a stock engine with auto trans. If I ever drop the 5 speed in and rebuild the motor, I can add the secondary metering block via a kit but I personally would probably just be purchasing a larger carb (likely a 700 CFM 4150). Drilling holes in the throttle plates is generally for motors with very large cams that have issues idling. Probably not my case. My carb is currently sitting at 15" of vacuum.

I have an awful smell of gasoline inside of the car while driving. I thought it was a major exhaust leak but now I am thinking I am just running ridiculously rich. I think its time I purchase a timing light with tach so I can dial in the dizzy recurve myself and then really dig into the carb tuning. I don't really like paying mechanics for things I can figure out myself so I still have a lot more patience on this before giving up. I also very much enjoy becoming more knowledgeable on what I am running. If it gets to the point where I need to mess with the power valves I may enlist an expert but I think I should be able to get it pretty darn close with normal tuning and possibly swapping out the accelerator pump nozzles.

I am still learning if I actually need a smaller nozzle or a larger nozzle. I may purchase a .025 and a .035 and see how they each affect driveability. I could also play with a different accelerator pump cam but that will probably be the last thing I try to do.

Edit: maybe also worth investing in an air/fuel ratio meter