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Anonymous
Guest
Clifford's adapter for the on bbl for the 200 inline, is it worth it to get it cuz isn't the hole the same size so you still have the same air flowing in?
bigcatchdaniel555
Well-known member
The motor onlt takes what it needs from that hole the standard 1bbl is undersized it doesnt allow the motor to breathe very well its another limitation to the turd head. When you add a 2bbl even though your putting more stuff in the hole the motor is using more fuel because it is no longer limited i'm trying to explain this the best I can so if someone can crutique me go ahead. PLain and simple the motor can use a bigger card the hole has the capability to flow mor cfm than the 1bbl does.
The carb hole is still going to be your choke point, no matter what you mount on it.
However, many have found that the popular 2bbls offer increased performance in the way of better fuel atomization and economy over the 1bbl, not in pure flow capability.
Also, the stock 1bbl you have on there now has a smaller venturi than the hole in the head, so is more of a restriction than the carb holes is itself.
So no, bolting a 1150 dominator onto an adaptor onto the 1.75" hole isnt going to get you more flow - but using a 2bbl that is just a "better" carb will increase your performance as well as a slight increase in flow due to the carb hole being the restriction as opposed to the 1bbl venturi.
Make sense?
However, many have found that the popular 2bbls offer increased performance in the way of better fuel atomization and economy over the 1bbl, not in pure flow capability.
Also, the stock 1bbl you have on there now has a smaller venturi than the hole in the head, so is more of a restriction than the carb holes is itself.
So no, bolting a 1150 dominator onto an adaptor onto the 1.75" hole isnt going to get you more flow - but using a 2bbl that is just a "better" carb will increase your performance as well as a slight increase in flow due to the carb hole being the restriction as opposed to the 1bbl venturi.
Make sense?
An engine system, from air-intake to the exhaust tip is simply an HVAC ducting system with a few complications and the engine being the prime mover. Like any HVAC ducting system, losses in the system are additive: the shocklosses at the snorkel of the air intake canister, the air filter, carburetor, log-manifold intake, log manifold, engine, exhaust manifold, muffler, exhaust tubing etc. Each of these components has a friction/shock loss associated with it measured in inches mercury or water; since a two barrel carburetor has a higher flow rating at 3"mercury than the stock 1-barrel it poses less of a restriction and makes the system more efficient. Yes, the single hole inlet on the manifold poses a restriction, but the overall losses in the system as a whole are reduced and there will be a power gain.
Believe it or not, in HVAC systems, shock losses associated with sudden restrictions or sharp entrances can be greatly reduced by simply flaring the inlets and outlets - this is why you see gradual reductions/expansions on inlets/outlets of large fans: it saves a huge amount of energy since there is less turbulence and therefore less loss since the air isn't fighting itself to get in. The same goes for your engine: if you flare the snorkel inlet on the stock filter canister, you will gain power. Likely one of the cheapest power improvements you'll ever make on any engine.
Believe it or not, in HVAC systems, shock losses associated with sudden restrictions or sharp entrances can be greatly reduced by simply flaring the inlets and outlets - this is why you see gradual reductions/expansions on inlets/outlets of large fans: it saves a huge amount of energy since there is less turbulence and therefore less loss since the air isn't fighting itself to get in. The same goes for your engine: if you flare the snorkel inlet on the stock filter canister, you will gain power. Likely one of the cheapest power improvements you'll ever make on any engine.
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Anonymous
Guest
how about the hood clearance ???
bigcatchdaniel555
Well-known member
Hood clearance is better on some models than others. What car do you have?
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Anonymous
Guest
i have a 67 mustang with the 200
bigcatchdaniel555
Well-known member
I just used a 1 bbl chrome one NPD and cut out the hole to fit my 2300 never touches the hood.
My plan is to purchase the air plenum for the holley-weber, purchase some 4" ducting and fittings at the home despot and duct cold air into the plenum. It won't look very good, but there'll be plenty of room to put nice smooth bends and gradual intakes in the system without worrying about hood clearance. It'll solve quite a few problems: intake losses, denser/cooler air and a cooler engine. Most expensive thing would be the plenum ($100 at Pierce Manifolds) and an aftermarket inline filter.
MercuryMarc
Well-known member
I have a 2 barrel on my 63 Comet with a 250. I have less than 1 inch clearance from the carb (measured a the highest point of the choke plate with the choke 100% open and vertical) and the hood. I have fabricated an air cleaner to be only 1/2" higher then the top of the choke plate, and drops 1.5 inches. A small wingnut on top that is 1/4Â inch gives me and entire 1/4 inch of room!!!
5200 on the Stovebolt Adapter, mounted float forward
View of the air cleaner base plate
2' x 1/16" alum stock bent, dremeled, and tapped to fit the wingnut
View of the air cleaner minus the top
Entire Air Cleaner Unit
See more pics at:
5200 HW Carb Setup
Good Luck!
5200 on the Stovebolt Adapter, mounted float forward
View of the air cleaner base plate
2' x 1/16" alum stock bent, dremeled, and tapped to fit the wingnut
View of the air cleaner minus the top
Entire Air Cleaner Unit
See more pics at:
5200 HW Carb Setup
Good Luck!
Hey MercuryMarc, how did determine how much to enlarge the carb body bores of your 5200? (Check Marc's link 5200 HW Carb setup in the post).
Do you notice a big difference in performance over stock?
I have the same carb on my 1976 BMW 2002, and may give it a try.
Does anyone have any thoughts about enlarging the carb body on a Holley single barrel 1946, in a 80 Mustang automatic?
Any thoughts on how much it could be enlarged?
Would it have a negative effect on engine vacuum?
Thanks.
Max.
Do you notice a big difference in performance over stock?
I have the same carb on my 1976 BMW 2002, and may give it a try.
Does anyone have any thoughts about enlarging the carb body on a Holley single barrel 1946, in a 80 Mustang automatic?
Any thoughts on how much it could be enlarged?
Would it have a negative effect on engine vacuum?
Thanks.
Max.
I'll butt in here.
It was Marc's insight from a known problem he found. He noticed that even when jetted better, his little Pinto 140 cubic inch carb on his 250 six felt like it had even less power than his stock 1-bbl Holley when extended.
I quickly remembered from David Vizards work that with the Holley Weber 5200 carb on even a 121 cube Pinto engine, it could benefit from 31 and 32 mm venturi size, up from the stock 26 and 27 mm respectively. Stock, the carb was limited to about 100 hp or so. When upsized internally, the 31/32 combo was good for 130 hp or so. There is enough meat in thecasting to go up to that level.
Australian 200 and 250's had 120 to 130 hp net. They used a Weber 34 mm carb with two 30 mm venturi's.
Mathematically, there is a critical point when carb venturi area is too small in relation to the cubic inches of the engine. At this point, the air speed at wide open throttle goes up too much, and the engine feels like a vacuum cleaner with a blockage. Engine dyno operators tend to find that over 265 feet per second at wide open throttle, the result is a loss of performance and power.
General mathematic rule is take the total cubic inches of the engine, and then divide that number by the total venturi area in inches with all throttle wide open. A stock 5200 Weber is about 1.71 sq inches, and on a 250, it has got over 145 cubes of engine for every square inch of venturi, and the air speed gets very high when the throttle is opened above 3000 rpm on these engines.
From observation from the Ford, GM and Chrysler six cylinder kingdom, if the cube to venturi figure is greater than 125, then the carb most certainly can be reamed out and you'll get an improvement in peak power. Depending on the casting quality, most Holley carb bodies can take a 62.5 thou ream out, or up to 125 thou if you repair any porous areas with Deveon/JB weld. On little pip squeek engines like 67 cube Healy Sprites and even 121 cub Pinto's, just opening up the venturis can make a 25% increase in power if other mods are done in unison.
For the 5200 Holley Weber, the limit of the increase is that the throttle size should never be more than 1.0625 times the venturi diameter, and best results occur when the stock throttle size is 1.125 times the venturi diameter.
It was Marc's insight from a known problem he found. He noticed that even when jetted better, his little Pinto 140 cubic inch carb on his 250 six felt like it had even less power than his stock 1-bbl Holley when extended.
I quickly remembered from David Vizards work that with the Holley Weber 5200 carb on even a 121 cube Pinto engine, it could benefit from 31 and 32 mm venturi size, up from the stock 26 and 27 mm respectively. Stock, the carb was limited to about 100 hp or so. When upsized internally, the 31/32 combo was good for 130 hp or so. There is enough meat in thecasting to go up to that level.
Australian 200 and 250's had 120 to 130 hp net. They used a Weber 34 mm carb with two 30 mm venturi's.
Mathematically, there is a critical point when carb venturi area is too small in relation to the cubic inches of the engine. At this point, the air speed at wide open throttle goes up too much, and the engine feels like a vacuum cleaner with a blockage. Engine dyno operators tend to find that over 265 feet per second at wide open throttle, the result is a loss of performance and power.
General mathematic rule is take the total cubic inches of the engine, and then divide that number by the total venturi area in inches with all throttle wide open. A stock 5200 Weber is about 1.71 sq inches, and on a 250, it has got over 145 cubes of engine for every square inch of venturi, and the air speed gets very high when the throttle is opened above 3000 rpm on these engines.
From observation from the Ford, GM and Chrysler six cylinder kingdom, if the cube to venturi figure is greater than 125, then the carb most certainly can be reamed out and you'll get an improvement in peak power. Depending on the casting quality, most Holley carb bodies can take a 62.5 thou ream out, or up to 125 thou if you repair any porous areas with Deveon/JB weld. On little pip squeek engines like 67 cube Healy Sprites and even 121 cub Pinto's, just opening up the venturis can make a 25% increase in power if other mods are done in unison.
For the 5200 Holley Weber, the limit of the increase is that the throttle size should never be more than 1.0625 times the venturi diameter, and best results occur when the stock throttle size is 1.125 times the venturi diameter.
MercuryMarc
Well-known member
I enlarged the venturis from the standard 26/27 mm to 30/32 mm. I had a lot of great suggestions from Execute and Addo....
It idles and runs at low speeds the same as stock but when the 2nd throttle plate opens up, WOW- it really is powerful.
See the thread and posts at:
http://fordsix.com/forum/viewtopic.php?t=36108&highlight=5200
Good luck!
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Anonymous
Guest
does anyone sell thoughs after market air tubes that will fit on the bbl hole and alow me to use that tiangle air cleaners for cold air
Thanks for the advice Xecute, and Marc, and the excellent link.
Back to the Holley 1946 on my 1980 Mustang. It has been a reliable, trouble free carb so far but I am contemplating changing to a 2 barrel.
However enlarging a one barrel sounds easier then switching carbs.
I just don' t want to mess it up for minimal gains in performance.
I have never had the carb off the car and will try to measure the venturi diameter once the weather warms up, then see if, and how much, it can be bored out.
Does anyone have a late model 1946 Holley "laying around" that they could measure the venturi diameter on?
I understand that there is no way to change the jets to enrich the fuel mixture on the 1946, is this a factor that could result in an excessively lean mixture?
Can you expect similar benefits (although maybe not the same level of horsepower increase) from enlarging a one barrel as you would from enlarging a 2 barrel?
Max.
Back to the Holley 1946 on my 1980 Mustang. It has been a reliable, trouble free carb so far but I am contemplating changing to a 2 barrel.
However enlarging a one barrel sounds easier then switching carbs.
I just don' t want to mess it up for minimal gains in performance.
I have never had the carb off the car and will try to measure the venturi diameter once the weather warms up, then see if, and how much, it can be bored out.
Does anyone have a late model 1946 Holley "laying around" that they could measure the venturi diameter on?
I understand that there is no way to change the jets to enrich the fuel mixture on the 1946, is this a factor that could result in an excessively lean mixture?
Can you expect similar benefits (although maybe not the same level of horsepower increase) from enlarging a one barrel as you would from enlarging a 2 barrel?
Max.
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Anonymous
Guest
with the linkage on the carb would be set up diff right, and what about that warming plate would that all change?? would it come off or would you have to adapted to it, (i dont want to buy the 600$$ setup from cliffored) so what would go on with that?