Max RPM

[mpgumby]

I will keep this all in mind for a possible upgrade in the future. I would do that now, but seeing as how I've already bought one on top of the fact that my wife is about as car savvy as a fish, i'll have to wait. She freaked out after i bought the new one because the website said "it doesn't that that model". I had to explain, in great detail btw, how i know for sure it will fit (diff intake) and that it is the correct one. Trying to explain how a diff brand will fit on it might blow her mind lol

[mpgumby]

So, I hate myself sometimes. And this is one of them. Because I'm so dammed smart, and had to get the awesome deal on that Edelbrock (ebay is a terrible place sometimes :-P), I didn't get your messages about the Holley until it was too late. Now that I've looked for a 600 CFM Holley, I can see that I could have more money than switching to Geico. I think I'll keep this to myself to prevent a possible divorce/my death. Oh well, maybe I'll throw it back on ebay so some sucker (like me) can buy it for what I paid and then I'll get the right one.

[Herk]

I ran a 1406 Eddy on my Wag for years without any of the issues that so many "experts" keep parroting. Maybe I got lucky. Unless you plan on serious rock crawling in a full size station wagon I bet you'll be fine.

Holley are good carbs as well, don't get me wrong BUT I have made a few observations/learned a few lessons with them over the years:

They are, in the minds of some "easier to tune" so those who love to monkey around will find entertainment value. Keep in mind that a used Holley is more likely to have been "tuned" to the point of being seriously screwed up.

They leak. You can't do much "tuning" without removing the float bowls. Gaskets get re-used (especially the blue ones) and screws get overtightened.

Holleys are zinc, AFBs (Edelbrock or Carter) are aluminum. Zinc is heavy, aluminum makes a better heat sink. A Holley will be easier to restart on a hot day. Sadly now Holley is making more of it's carbs from aluminum.

Neither carb will make any improvement if you still have your factory single exhaust system, especially with the pellet type catalyst. Also in fairness, the Motorcraft carb is decent, and adequate for a stock engine.

For the cost of a new Holley Truck Avenger you could have fuel injection (TBI).

[mpgumby]

I'm glad you brought up the exhaust. Since I'm blessed with living on the west coast and since we don't use salt for the winter, the body is virtually rust free. But, like any vehicle almost 30 yrs old, the stock exhaust system is toast. Completely rusted and needs replaced. Even better is the fact that there are no smog laws in my area and they don't care how loud it is (to a point) as long as you aren't a jerk about it (i.e. 3 am revving on it in a residential). So I will be getting rid of that single exit exhaust and plan on going to a 2.5" dual exhaust system and have no plans to replace the cat at all. It'll be made because I can and I'm cheap like that.

However, any thoughts on mufflers, cherry bombs, glass packs, Pepsi cans, etc? While I can make it loud, I'm respectful and will not straight pipe it as a permanent solution. Open to any and all exhaust suggestions.

[Jeepguy77]

Originally Posted by mpgumby

I'm glad you brought up the exhaust. Since I'm blessed with living on the west coast and since we don't use salt for the winter, the body is virtually rust free. But, like any vehicle almost 30 yrs old, the stock exhaust system is toast. Completely rusted and needs replaced. Even better is the fact that there are no smog laws in my area and they don't care how loud it is (to a point) as long as you aren't a jerk about it (i.e. 3 am revving on it in a residential). So I will be getting rid of that single exit exhaust and plan on going to a 2.5" dual exhaust system and have no plans to replace the cat at all. It'll be made because I can and I'm cheap like that.

However, any thoughts on mufflers, cherry bombs, glass packs, Pepsi cans, etc? While I can make it loud, I'm respectful and will not straight pipe it as a permanent solution. Open to any and all exhaust suggestions.

I just realized you were from Redmond. A couple years ago I had my exhaust done at custom exhaust specialties in Bend an it was about $290 but I provided the mufflers. I used the thrush two chambers and the exhaust is 2.5" duals that dump down an outwards just behind the cab.

[Herk]

I ran dual 2.25 on my 83. Had Hedman headers and plain old super turbo mufflers (stood on edge), both pipes ran down right side. Worked well and didn't make too much of a racket. OK it was loud enough to piss off hunters for miles, but not too bad otherwise.

[mpgumby]

@Jeepguy77

I will only need to buy the tubing and mufflers at most. I have friends that are very good welders/mechanics (worked for Columbia Air when they were around) that have done exhausts several times so I don't plan on going to a shop. I just started looking at getting the Flowtech Redhots! because they are only 18.00 a pop. Anyone ever used them before?

[Lindel]

Originally Posted by Herk

I ran a 1406 Eddy on my Wag for years without any of the issues that so many "experts" keep parroting. Maybe I got lucky. Unless you plan on serious rock crawling in a full size station wagon I bet you'll be fine.

Holley are good carbs as well, don't get me wrong BUT I have made a few observations/learned a few lessons with them over the years:

They are, in the minds of some "easier to tune" so those who love to monkey around will find entertainment value. Keep in mind that a used Holley is more likely to have been "tuned" to the point of being seriously screwed up.

They leak. You can't do much "tuning" without removing the float bowls. Gaskets get re-used (especially the blue ones) and screws get overtightened.

Holleys are zinc, AFBs (Edelbrock or Carter) are aluminum. Zinc is heavy, aluminum makes a better heat sink. A Holley will be easier to restart on a hot day. Sadly now Holley is making more of it's carbs from aluminum.

Neither carb will make any improvement if you still have your factory single exhaust system, especially with the pellet type catalyst. Also in fairness, the Motorcraft carb is decent, and adequate for a stock engine.

For the cost of a new Holley Truck Avenger you could have fuel injection (TBI).

I don't consider myself an expert on anything. I have owned both, and the Holley was the easier of the two to "get right" for my application. I don't "tune to the point of being useless", nor do I "constantly tinker" with a carb. Once I get it where I want it, I leave it alone.

Assuming correct tune, either carb will be an improvement if the stock carb was out of tune or worn out (likely with even the newest FSJ), regardless of the exhaust. Yes, the stock Motorcraft 2100/4100 series carb is an excellent carb, has been since it's inception and in all it's varied flavors. BTW, want to guess who designed it for Ford?

[mpgumby]

Stock carb is out of the question because of the aftermarket 4 barrel intake manifold and i've already purchased the Edelbrock carb. if it doesn't seem to work out for me i'll sell it and get the Holley instead but i'm sure it'll be fine. It'll be a few months before i get home anyhow, i'm hoping my guy can get it running before then though. Then we'll really know how the engine is doing.

[abcdk5]

Hey, I've owned my 79 j10 for 25 years and I've been through one mc 2100 and four mc 4350's. As soon as I got my truck I switched it to the 4350. The first one lasted about ten years. the second about 5 years, the third one about five years with one rebuild, and the last one about five years with two rebuilds. All these 4 bbl's were brand new holley rebuilt. The last one never ran worth crap and after the final rebuild was worse than ever. So i switched to a brand new holley square bore and edelbrock intake. If you go with a 4100 or a 4350 it's gonna be rebuilt by somebody. I took everything that said motorcraft off my truck. Switched to HEI distributor also. Just my experience.

[rreed]

I've worked a bit w/ both and find the Edelbrocks much easier to get at least a basic tune but the Holleys have great potential to run better (more performance) and better mileage. Granted I've worked w/ my Edelbrock a lot more than the Holleys but I've got a second Holley on its way here to further compare against my Edelbrock (I've got some light reading on that as well).

Being that you already have the Edelbrock there are a few of us who can probably help get you in pretty good running shape. I've got a 1405 (similar to 1406, just has manual choke) adapted to the stock 4350 intake on mine and have been around it a time or two. Of course there's always somebody w/ better kung-fu.

Once we get you dialed in you're going to have a good stout running truck.

[abcdk5]

My truck is torn down right now. I'm in the process of rebuilding. Fixing to get into some body work. But I'm certainly gonna welcome some help when I get it back together. I went with the holley 4150 with my setup. I don't off road much anymore.

[FSJunkie]

I bounce around on rocky trails at 8000 feet elevation with a 2150 2bbl idleing in low range and no matter what elevation I'm at or how bumpy it gets, it idles the same. The big difference is the small damper spring on the float, without it the engine will surge on bumps and even when rocking back from coming to a clomplete stop at a traffic light.

Plus I don't know of ANY 4bbl carb that compensates for altitude automatically, and that is a huge plus for me, where a 100 mile drive south drops to 1000 feet, and a 10 mile drive west climbs to 11,000 feet. Believe me, that 2150 will rev a 360 into a terminal state without a complaint.

I've never dealt with Edelbrock 4bbls, nor do I ever want to.

I've rebuilt a couple Morotcraft 4350's, and they don't impress me. The mechanical secondaires only open when the pedal is nearly to the floor.

I just rebuilt my first Holley 4bbl a week ago and I liked the overall design, with the exception of the non-annular boosters (less low RPM response and economy), idle mixture screws not at the venturi (poor idle mixture atomization), and lots gaskets below the fuel level (prone to leaks). I did like the vacuum secondaries.

From what I could figure out just from messing with the carb on the bench, the secondaries only come open during periods of high manifold vacuum, and never open more than the primaries. At light throttle cruise, the secondaries will be open the same as the primaries, allowing the driver to let off the pedal. The only issue I see with that is low air velocity through the boosters, affecting fuel shear. When the throttle is opened for passing, the secondaries will close to increase the vacuum signal to the primaries, resulting in greater response. As the engine revs up and the primaries run out of flow, the secondaries will begin to open. As they open, manifold vauum will drop, closing them. In this way, the engine manifold vauum will regulate the carburetor airflow capabilities to maintain a certain level of manifold vacuum and performance. By contrast, to maintain the same level of performance on a 2bbl carbureted or a mechanical secondary 4bbl carbureted engine, the driver would have to open the throttle more and more as the engine reved higher and higher. Not to mention the driver would also have to change throttle opening as engine loads changed, from gear changes for example. The Holley mechanical secondaries do that job automatically and will regulate their airflow.

For that reason, I call a vacuum secondary carb "Airflow compensating" because they regulate their airflow capabilities bases on primary throttle opening, engine RPM, and engine load. They also compensate their airflow based on engine size and type. It's a very cool thing!! If only the vacuum secondary holley 4bbls were also altitutude compensating like a 2150, and had annular boosters. If such a carb is ever made, then I am totally sold on it.

If the carb is properly tuned, the driver should not be able to tell when the secondaries are opened or closed, or by how much. It should be seamless. I've never driven a mechanical secondary carburetor, but I can image that when the pedal is nearly floored and the secondaries begin to open, that a massive rush of power comes in to play.

I'm sure mechanical secondary carbs have advantages and disadvantages compared to a vacuum secondary, but vacuum secondaries are a whole lot more fascinating!!!!!!!

[Ristow]

Originally Posted by FSJunkie

From what I could figure out just from messing with the carb on the bench, the secondaries only come open during periods of high manifold vacuum,

it is not manifold vacuum at all. the secondaries open according to AIRFLOW thru the primary circuit.typically will be LOW manifold vacuum scenarios. it ensures good fuel shear by optimizing airflow through the primaries BEFORE the secondaries can open. unlike rochester,carter or motorcrafts that open the lower butterflies mechanically,and expose the air door regardless of airflow.


you used the term fuel shear. you've been paying attention.

If only the vacuum secondary holley 4bbls had annular boosters. If such a carb is ever made, then I am totally sold on it.

well,ok you weren't paying attention the whole time......but i won't make you wear the edelbrock hat of shame just yet.

http://www.ifsja.org/forums/vb/showthread.php?t=100852

http://www.ifsja.org/forums/vb/showthread.php?t=112934

[FSJunkie]

Originally Posted by Ristow

you used the term fuel shear. you've been paying attention.





well,ok you weren't paying attention the whole time......but i won't make you wear the edelbrock hat of shame just yet.

http://www.ifsja.org/forums/vb/showthread.php?t=100852

http://www.ifsja.org/forums/vb/showthread.php?t=112934

I try. Like I said, that's just what I concluded after rebuilding the carb for an afternoon. In any case, it's still a really cool thing.

[Ristow]

At light throttle cruise, the secondaries will be open the same as the primaries, allowing the driver to let off the pedal. The only issue I see with that is low air velocity through the boosters, affecting fuel shear. When the throttle is opened for passing, the secondaries will close to increase the vacuum signal to the primaries, resulting in greater response

furthermore. the secondaries will not (should not) be open during light cruise. they would open when the throttle was opened to pass,after air velocity in the primary venturi was strong enough to generate the vacuum signal need at the secondary pot to open the secondaries.