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Do Welch plugs come with the rebuild kit or are they re-usable ?
Typically no, and they are NOT reusable as you most likely will need to drill a 1/8 hole in the center, thread in a sheet metal screw and pull them out with pliers.
 

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Dimples
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The kit is cheap enough but it's the cleaning that becomes an issue.
With all the environmental stuff I don't think I can get stuff to dunk and soak the parts to clean properly.
How do you figure? I’ve seen enough Canadian YouTubers doing cool things to know that’s not true.
 

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I am not so sure chasing a carb problem is the answer. A carb rebuilt "a few years ago" e.g. 3-4 should not be a problem now unless the car sits for very extended periods of time with ethanol blend fuel. The easy answer is find someone with a good running 302 to 351 and swap carbs for a good run. If the problem goes away well there's your answer.

First red flag to me is the dizzy. Sounds like you have a solid motor but for the street you really want a vacuum advance. I will totally not respond to arguments against vacuum advance, been there done that too many times. However if you have an open mind: Vacuum advance will give you throttle response when you back off and give it a little throttle to say 3/4 throttle. If you floor it, there is no vacuum so you have what you have - a distributor that is made specifically for a race car that is either WOT or off, on or off. If you want to coast or cruise at X RPM and roll the throttle a little to change lanes, vacuum advance is your friend. I ran an MSD non Vacuum advance for years that I bought brand new thinking if its good enough for racers, that's what I want - POWER!!!!!!! After reading some and learning, I put the dizzy that came with my motor that was swung for the motor (another key power source) and I could not believe the difference in driveability. Now if I punched it to the floor it was absolutely NO FASTER than the MSD but any throttle position except wide open throttle, it was a night and day improvement in drivability.

One of the most common suggestions you will read here is to get Nolan someone (someone else can chime in) to dial in a DuraSPLAT (Woodchuck please chime in) dizzy with vacuum advance specifically for your build. Put your current dizzy on Craigslist for the next powerhungry sucker and go have fun. Even if it does not turn out to fix your problem, it will be a night and day difference in around town drivability and gas mileage.

So that is my 3 cents...
 

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Discussion Starter #25
That is really good information !
The reason that I kept the non vac advance dist. is because the car is a K code and although it's not the right block I did want to retain the "original" look.
Same reason I used the hipo heads and exhaust manifolds and continue to struggle with the 4100.
I could have sold the heads, manifolds and carb and bought better performance for sure...
What I really want is great throttle response from say 0-3000 rpm and a good hole shot at a light just for fun !!
 

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I am not so sure chasing a carb problem is the answer. A carb rebuilt "a few years ago" e.g. 3-4 should not be a problem now unless the car sits for very extended periods of time with ethanol blend fuel. The easy answer is find someone with a good running 302 to 351 and swap carbs for a good run. If the problem goes away well there's your answer.

First red flag to me is the dizzy. Sounds like you have a solid motor but for the street you really want a vacuum advance. I will totally not respond to arguments against vacuum advance, been there done that too many times. However if you have an open mind: Vacuum advance will give you throttle response when you back off and give it a little throttle to say 3/4 throttle. If you floor it, there is no vacuum so you have what you have - a distributor that is made specifically for a race car that is either WOT or off, on or off. If you want to coast or cruise at X RPM and roll the throttle a little to change lanes, vacuum advance is your friend. I ran an MSD non Vacuum advance for years that I bought brand new thinking if its good enough for racers, that's what I want - POWER!!!!!!! After reading some and learning, I put the dizzy that came with my motor that was swung for the motor (another key power source) and I could not believe the difference in driveability. Now if I punched it to the floor it was absolutely NO FASTER than the MSD but any throttle position except wide open throttle, it was a night and day improvement in drivability.

One of the most common suggestions you will read here is to get Nolan someone (someone else can chime in) to dial in a DuraSPLAT (Woodchuck please chime in) dizzy with vacuum advance specifically for your build. Put your current dizzy on Craigslist for the next powerhungry sucker and go have fun. Even if it does not turn out to fix your problem, it will be a night and day difference in around town drivability and gas mileage.

So that is my 3 cents...
Well, the benefits of vacuum advance on an engine that isn't being raced have been proven, again and again. That said, my '66 with its '85 5.0HO runs a K-code dual point with no vacuum advance and performs well with good throttle response and fuel mileage which is the result of a lot of experimenting with the mechanical advance curve.

If a solid-state ignition solution is desired which, in my opinion, isn't really needed in 99-44/100% of applications but some people don't like adjusting points so no harm no foul.... get a DuraSparkII distributor, have Dan Nolan set up the advance curves and stab it in there.

FWIW, if you really DON'T want vacuum advance you could take the DSII distributor, grind off the vacuum advance mounting ears, plug the hole with Muggyweld or JB Weld, and simply connect the "breaker plate" to the lower plate as shown in the image below. With any DSII application, pay particular attention to the reluctor phasing... you want the reluctor to trigger the pick-up coil when the distributor rotor will be closest to the spark plug tower in the cap.

760634
 

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Discussion Starter #27
OK so here's another twist to the carb story on weather to rebuild or buy new.
My carb has a stamping of C5AF-H which I have learned probably came from a 390 Galaxy.
So if this carb has the correct boosters (which I am only assuming it does) would it be "too much" carb for my engine set up and not suitable for my application or am I overthinking it ?
I don't know how big a difference there really is between same bore carbs.
Once I figure the carb situation out I will give serious thought to a vacuum advance distributor for sure !
 

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OK so here's another twist to the carb story on weather to rebuild or buy new.
My carb has a stamping of C5AF-H which I have learned probably came from a 390 Galaxy.
So if this carb has the correct boosters (which I am only assuming it does) would it be "too much" carb for my engine set up and not suitable for my application or am I overthinking it ?
I don't know how big a difference there really is between same bore carbs.
Once I figure the carb situation out I will give serious thought to a vacuum advance distributor for sure !
You're overthinking it. The booster configuration is going to determine how much air is emulsified with the fuel supplied by the main jet and how much of that mixture is drawn up and discharged through the boosters according the the vacuum signal produced. FWIW, it's not uncommon to get a reman'd 4100 sold for a 289 that will have a boosters from God knows what installed....

Like anything else, you can spend hours and hours tweaking and tuning to only get a tiny improvement. If you don't feel like messing with it and want something with easier tunability then maybe swap to the Summit M2008 series carb.... Functionally, it is very close to the 4100. The additional adjustability is much easier to deal with than messing around with solder and drill bits trying to get that precise tune.
 

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Discussion Starter #29
Here'd another question.
I also have a 1.08 carb that is in pretty good shape that I could rebuild.
Would I be better off( ie. better throttle response) with the smaller carb ? or would the 1.08 be too small based on my engine set up in post #1 ?
 

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Here'd another question.
I also have a 1.08 carb that is in pretty good shape that I could rebuild.
Would I be better off( ie. better throttle response) with the smaller carb ? or would the 1.08 be too small based on my engine set up in post #1 ?
Based on your specs posted at the beginning you might run out of air at higher rpms. A compromise, if throttle response is a potential issue, are 1.08" copper reducer sleeves that can be fitted to the 1.12's PRIMARY bores, leaving the secondaries alone.
 

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Discussion Starter #31
I have emailed Dazecars regarding the sleeves.
when you say might run out of air at high rpms, just how high are we talkin ? I'm not going to be racing at high speeds and throttle response is my main goal.
Also this 1.08 that I have is stamped C6SA with I read on another forum is not really a desirable carb because they were used on FE type engines to reduce emissions.
Is that true ?
 

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I have emailed Dazecars regarding the sleeves.
when you say might run out of air at high rpms, just how high are we talkin ? I'm not going to be racing at high speeds and throttle response is my main goal.
Also this 1.08 that I have is stamped C6SA with I read on another forum is not really a desirable carb because they were used on FE type engines to reduce emissions.
Is that true ?
Yes, the C6SA was stuck on an FE and calibrated for emissions for THAT application. Again, the boosters used may work fine with a 289..... I ran a 1.19" Autolite 4100 on a 221 so......

As far as "when" you'll run out of air.... The 1.08" carb pretty much has a maximum flow of around 465 cfm. The 1.12" carb around 550 cfm. If I was to GUESS then I'd say your 1.08 would probably be good to around 4,500 to maybe 5,000 rpm. After that expect torque and HP to drop like a stone.
 

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Discussion Starter #33
Thanks Woodchuck , I think I will go with the sleeves on my 1.12 and rebuild it.
Should I be looking at changing the booster cluster at least in the primary's when I put the sleeves in ?
And if so what should I be looking for as far as stamping ? ( I know there isn't much information on the boosters out there)
 

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This!!! Check the diaphragm. I had a similar hesitation, had checked the accelerator pump linkage, saw gas coming out of the pump nozzles, thought all was good, but the diaphragm was bad once the carb was taken apart.
With that said, Holley does have some pretty good deals on used/returned carbs that have been checked out and rebuilt on their website. Most are around $225
 
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