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I suspect this is the engine that it made 630 HP on from Harrington Race Engines:
RULE BOOK | Harringtons Machine
RULE BOOK | Harringtons Machine
BEST CARBURETOR FOR STREET OR TRACK?
- Thread starter Hysteric
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How many hours do you spend scouring the internet for examples that fit your narrative
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So is Ben Alameda......
Newbomb Turk
Well-Known Member
Never said he wasn’t. I just disagree with using a booster that eats 60 cfm. Unless the carb(s) are so grossly oversized you need to crutch them.
As you can see its a nice handy formula that brings things to where they need to be, without drilling down into mountains of data and people getting lost in the process.
Carbs installed need to be final tuned for weight of car, purpose of car, driving habbits, tire sizes and gear ratios.
Get them out of the garage and get them working.
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If your point is that a smaller a carburetor (650) is making more power than a larger carburetor (750) then shouldn't the two carburetors at least be prepared similarly and by the same builder to eliminate all the variables that could affect the power that are not cfm related? I'm not picking a side as to what size carb an engine should have. But the example you show here is possibly more about how or who prepared the carburetor than the actual size of the carburetor. In other words if I prepared a 650 carburetor and Baldwin prepared a 650 carburetor the engine is still likely to be 30 hp better with the Baldwin carburetor.
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Totally agree. Just pointing out that absolute airflow is not the limiting factor everyone here makes it out to be when making power. Just because you think you're giving an engine more airflow doesn't mean its using it.
The sharpest guys making power focus on the burn not the airflow.......That's why they can run cylinder pressures from 200 psi (Ben Alameda) to 240 psi (Bruce Robertson) in street engines on street fuels.
You always strawman that everyone is making that argument when no one really is.
You pretty much can run a 600/650 on stock to well over 400 hp what's easier than that.
9secRR
Well-Known Member
Way too much thinking and useless reading. Put on a 750 Holley and be done with it. The engine will only use what it wants to use. Simple as that.
The overthinking and research some of you guys do makes my head hurt.
The overthinking and research some of you guys do makes my head hurt.
That is what I was going to say: ^^^
Bill go start a thread in N&P if you want to talk your views on News and Politics.
There are people looking in to this thread to learn about Carburetors, some are our members but there are lots and lots of visitors that are looking in from all over that want to learn too.
Don't be tipping over the Board Game, a lot of other people want to learn.
Thank You
Bill go start a thread in N&P if you want to talk your views on News and Politics.
There are people looking in to this thread to learn about Carburetors, some are our members but there are lots and lots of visitors that are looking in from all over that want to learn too.
Don't be tipping over the Board Game, a lot of other people want to learn.
Thank You
A- MEN!
Dale Davies
Well-Known Member
A small restiction can lower pressure which tends to increase vapourization. It is like putting some water in a beaker and applying a vacuum.on it. The water will boil and vapourize at room temperature. This is the opposite of a radiator cap to pressurize the coolant to raise the boiling point.
Remember that fuel droplets do not burn. Vapourized fuel in contact with oxygen in air is what burns. The large droplets get vapourized under the high heat of combustion in time to cool the exhaust valves on the way by as unburned HC emissions.
The smaller the droplets in atomization, the more vapourization takes place going past the intake valves and during the compression stroke. This provides more vapourized fuel to react with the O2 in the cylinder to create better combustion. This better combustion is what develops more power.
Jetting rich is just to ensure there are enough tiny atomized fuel droplets to burn. If you get the atomization right a leaner jetting can be used.
Dale Davies
Well-Known Member
You can watch that illustration of the downleg and annular boosters in action on a running engine. On a dyno would be best where you can load it some. Do not just look at the fuel coming into the booster, look past and down to the throttle blades. The dial back feature will allow you to stop the air fuel as it moves along and you can basically see the atomization and vapourization taking place.
Two equivalent Holleys, one downleg and one annular or two Edelbrock 750s, one performer and one AVS2 that comes with the annular primaries. These carbs could quickly be substituted to observe.
Newbomb Turk
Well-Known Member
That’s why buying a carb based on CFM rating can send you down a rabbit hole. Carbs should be purchased based on venturi and throttle blade diameter and booster type.
Newbomb Turk
Well-Known Member
I get all that Dale. What I’m saying is you (or I or who ever) can buy boosters that increase the signal far higher than any other booster on the market with no restriction.
Thats what I’m talking about. If you can get a booster with a better signal and no restriction why wouldn’t you do that?
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Great post Dale. I might add that running richer is sometimes necessary to mask a detonation issue.
Dale I like your analogy of the water in a beaker and apply the vacuum to it and see it boil.
That makes a great visual to help the understanding of what is going on.
Thanks for posting. Sending that forward to a friend now.
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Pretty much at this point if we're choosing a Holley 4150 carburetor, buying a carb based off cfm vs venturi , throttle blade and booster type is going to lead to the same conclusion or very close
Like if you want a 1.56 venturi and a 1.75 throttle bore your going to get a 850 (advertised) cfm carburetor.
Or if you just buy an 850 carb it will net the same parts, 1.56 & 1.75
But on top of that there's other things that can increase cfm. Thinned shafts and stuff.
I'm probably not fully understanding what you mean so please explain if I'm dumb
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Newbomb Turk
Well-Known Member
That’s what it should be, but it’s not. You can buy a 950 that’s not a 950 at all. In your example above, I would consider that a true 850 size carb.
shutudown4
Well-Known Member
I’m interested in learning how to set up a 750DP like u mentioned. I have two of them just sitting around on my workbench
How limited is it based on CID?
Shutudown4
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Early list number?
Okay I see what you're saying, as the older HP 950 was a very small venturi vs what the xp is now which is a larger venturi with the same throttle bore. Gotcha... thanks
This is out of the realm a bit, talking of the fuel vapor and oxygen mix but think explains it well.
"provides more vapourized fuel to react with the O2 in the cylinder to create better combustion"
This on a much much much grander scale is how a themobaric 2 stage bomb works (like used in Nashville).
Stage 1 (explosion) expands and disperses the fuel to mix with the oxygen In the air. Now Stage 2 (explosion) acts like the Spark Plug, igniting the fuel/air oxygen mix.
This is what gives this its massive power is the proper mix of the fuel vapor with the air. Enough to take out all of the faces of the old historic buildings down a full city block.
Now imagine (on a much much smaller scale) that same proper mixed fuel vapor with oxygen in your combustion chamber creating massive maximum power for the circumstances.
Fascinating....
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"provides more vapourized fuel to react with the O2 in the cylinder to create better combustion"
This on a much much much grander scale is how a themobaric 2 stage bomb works (like used in Nashville).
Stage 1 (explosion) expands and disperses the fuel to mix with the oxygen In the air. Now Stage 2 (explosion) acts like the Spark Plug, igniting the fuel/air oxygen mix.
This is what gives this its massive power is the proper mix of the fuel vapor with the air. Enough to take out all of the faces of the old historic buildings down a full city block.
Now imagine (on a much much smaller scale) that same proper mixed fuel vapor with oxygen in your combustion chamber creating massive maximum power for the circumstances.
Fascinating....
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Dale Davies
Well-Known Member
Research what Smokey Yunick had to say with his "hot air engine".
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