Lean idle. Rich cruise.
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Ironmike
Well-Known Member
Dyno'd it when built. Engine dyno. Locked.
The only curve that even was close was 10 degree bushing with two light springs. 25 initial, all in by 2500(35) It hated that the least. I tried every spring combo possible. Went all the way to 2 heavy springs. 25 degrees initial and all in (35), at 4150RPM. Also every friggin setup was rich cruising to the local "spot".
as stated earlier my carb is the XP Ultra 850.
MAB is 34. I went down to 30 and it was richer, just like I thought.
Emulsions are brass, all open. Never measured them but they appear to all be the same size. Seems ridiculous to me. Back in the day we didn't see that on the old 750 DP, or even the old Dominator 750. Which I thought were EASILY tuned.
And forTT5.9, my wideband data logger is my nephew with a cell phone.
As for checking each mod, I use a Draggy. All passes were close in temperature and RH. Really didn't need it though. 35 locked is dramatically different than all 9 curves(spring combo's) I tried.
I may be a little carb stupid, but I've been at this game a loooong time. Just trying to get it as perfect as I can. Been running around rich at cruise for a few years and just figured what the hell, it's great at Idle, great at WOT no big deal. Now.....I'm irritated as hell that I cannot get it to 100%.
Personally, I think I'm on the main jet at cruise RPM. 80's up front, 86 in the back. 2 4.5 P valves. idles 10 inches vacuum at 1150 RPM.
Look guys, I know this is rambling but I really would like to get things a bit better. I do plenty of cruising around, sometimes for nice long rides. If it was a total drag car, I would leave it alone.
Newbomb Turk
Well-Known Member
Weeeeeee. I gave myself a gold star for remembering you had your engine on the dyno.
I’m going to hold off on the timing curve a bit and talk about some of the other stuff you’ve posted.
On an 850 my starting point for a MAB is .026 and no bigger. To start. There are times to go bigger but most times .026 is the best starting point.
I get that it went richer on the smaller MAB but it only does that when it’s on the booster (pulling from the main jet). In other words, until the booster started, it SHOULD have been leaner and probably was.
That’s because the SMALLER main air bleed STARTS the mains (booster) later than a larger MAB.
So it should have been left in there (that .030 was too big too) and then it would have been leaner, longer because the smaller MAB delays the start of the main jets (and by that I mean the booster and I use jet and booster interchangeably so don’t let my double talk confuse you) and the opposite is true.
Let’s say you made a big swing the other way. Let’s say it’s lean after the T slot or better yet it’s lean transitioning from the T slot to the mains.
To clean up that lean spot in transition you can start the boosters (and by that I’m saying the main jets) sooner. That’s adding main jet fuel EARLIER in throttle opening.
So we drop in a honkingly large MAB of a staggering .048 thou!! That big mother will start the boosters way sooner than a .026 MAB because it gets main jet fuel to the engine sooner in the throttle opening.
The question is why and how does that work. Why does the MAB affect the start of the booster AND why does it affect WOT differently?
That’s because at low throttle openings (and therefore low air flow) that MAB wants to THINK or better yet wants to ACT like an emulsion bleed. Both are similar but different.
That’s because like I said that MAB acts like an emulsion bleed in that adding in atmospheric pressure through the bleed at low throttle openings makes the fuel in the main well lighter, and therefore it flows out to the booster and starts fuel flow through the boosters. That’s the BIG MAB we are talking about.
That same big air bleed, once the fuel is moving through the boosters and air flow through the carb is increasing it starts acting like an air bleed again and it then “bleeds” off booster signal and leans out the upper part of the fuel curve more than if the air bleed was smaller.
Back to the .026 MAB example, we see the opposite effect. That smaller bleed by its sizing allows LESS air to the main well (did I mention the MAB is directly linked to the main jet well?? Don’t think I did but it does and that’s important to say and remember) and therefore the the fuel is heavier (air mixed with fuel is lighter by volume than solid liquid fuel) and it takes a greater pressure differential at the booster to get the fuel moving.
When you screwed in the smaller air bleeds it would have been leaner BEFORE the booster starts and then richer at WOT because the smaller bleed doesn’t kill as much signal as a bigger MAB.
So… if you want it LEANER at low throttle openings you use a SMALLER MAB and if you want it RICHER at low throttle openings use a larger one. Then to correct WOT A/F ratio you change the main jet.
If I’m not clear the MAB controls when the booster STARTS and how much of the “signal” is bled off at WOT.
If I was working on your stuff before I ever touched the distributor I would correct the MAB first, make my best WAG (Wild Assed Guess) as to what main jet it will need, erring to the slightly rich side.
Then I look at the emulsion stack. Very few carbs EVER want 4 emulsion bleeds. In fact some of my tunnel ram stuff has just come emulsion bleed of .026 thou.
Saying that, I’m saying you have too much emulsion. At least DOUBLE what you should have IMO. I mean two .028’s is plenty. Having FOUR open emulsion holes is too much.
So what happens when you have all that emulsion?
You get what’s called “slugging” and you can see this in the A/F ratio. It’s unstable and looks like a saw blade.
That’s because you want to introduce small air bubbles into the main well. Remember emulsion is to get fuel flowing to the main well at the right time and as the float level drops.
The harder the booster “pulls” on the main jet the less emulsion you need. And a smaller main jet to compensate.
With too much emulsion the bubbles will grow and coalesce into a big bubble. When that happens you get a big slug of air (engine goes lean) and then you get a big slug of fuel (engine goes rich). And you get the saw blade effect on the fuel curve. It goes lean/rich, lean/rich constantly.
You can’t develop a tune up doing **** like that.
I hope this is making sense because I’ve spent a lot of time here because IMHO your carb is off far enough that it’s going to affect every other part of your tune up.
Now would be the perfect time for @Hysteric to come in and discuss why this carb work should be done BEFORE you do any timing curve set up.
It’s an about prepping the fuel BEFORE it gets to the chamber for the most complete burn you can get and how fuel size in the chamber affects tuning.
I just don’t want to type that much and he gets it. We just have different ways of getting there lol.
Ok, so I’d start with a .028 emulsion bleed in the top and third hole down, and block the second and fourth holes. You can do that with 6-32 brass set screws 1/8 inch long.
That will clean up the slugging.
Then make DOUBLE DAMN SURE the idle feed jets are in the low position. When looking at your metering blocks there shouldn’t be ANY brass above the top emulsion hole. If there is, it’s the idle feed jet and it’s to get moved to the low position.
You may have to drill and tap the lower hole to 6-32 but it’s easy. Go slow and use a lot of lube (that’s what she said) and it’s down where it should be.
Like all those open emulsion bleeds, having a fuel jet ABOVE the fuel. It just pisses off the carb at idle. That’s the kind of thing that makes people lock out timing and stuff like that.
I’m not even saying you are wrong. I’m saying what I would do long before I locked out the timing. But if your carb is as you say it is, and no o e here should doubt what you say I expect that some of your issues are carb related.
Summing it up, we fixed the emulsion, lowered the idle feed jet and trimmed the main air bleed way down. For your 850 I would START (and tune from there) with an .028 idle feed jet (restriction) and a .070 idle air bleed. We have a .026 MAB bleed installed and we have a primary main jet of .078 and a power valve channel restricter of .058 with a 6.5 power valve. A secondary jet about .084 is a nice start.
At those settings you should be on the rich side everywhere.
Now we can start looking at your timing curve. Almost forgot that your T slot restricters should be .068-072 and tune from there.
Back to your timing. I’m supposing you had every curve in by 3500 rpm or less. And locking out the timing is essentially all in on the starter.
So how can I say this is wrong the vast majority of the time? I know I can’t give a percentage because if I do some freak will say I talk in absolutes. I don’t. There are times you lock out the timing but I don’t think you are one of those cases.
I can say the curves you tried are probably wrong because all of them had the curve in before the engine reached peak torque. And that’s a bad thing as I will attempt to explain.
Hold on, **** just cropped up. I’ll finish this later.
Newbomb Turk
Well-Known Member
Ok, back to your timing. But first we need to talk about your power curve, whatever that is. I’m pretty sure you posted the numbers but even if you did post the curves I wouldn’t remember the details.
To that end, I’m not surprised it wants all that timing at low rpm. That’s because the fuel coming from the carb isn’t “prepped” correctly by the time it gets to the chamber.
You want to atomize the fuel at the booster. Vaporize it as it gets to the chamber and when it’s on the chamber.
A tightly packed chamber with with fully vaporized fuel will have the quickest, cleanest burn time. Hence, you can run less timing which reduces working losses.
When the carb isn’t doing its job for whatever reason, and especially and specifically when you are using a cold air intake (or even worse yet a tunnel ram) you don’t have the heat to help vaporize the fuel.
All that conspires to force ignition timing to compensate for poor carburation.
The goal should be (talking NA here) to speed up the burn rate as fast as you can so you can reduce timing.
If you can fire the plug at 30 degrees BTDC you will make more power than if it timed at 40 degrees BTDC as long as the burn is mostly done by 12-15 degrees ATDC.
Doing so reduces negative work on the crank.
Back to your curve.
If you look at your dyno sheets you can see where peak torque is and where peak power is.
So you have 3 points on that graph that you must account for when developing the timing curve your engine wants.
You have your minimum idle speed, peak torque and then peak power.
I’m not getting into initial now because you get that. What concerns me is what’s happening at peak torque and then what’s happening at peak power. Because the timing requirements are far different at peak torque than at peak power.
Most engines (evidently yours at this time doesn’t follow this) want LESS timing at peak torque and MORE timing at peak power.
So thinking that through when you lock out the timing you are killing one point with too much timing and the other with not enough timing.
Why is your engine different when the build is similar to many others?
Because your carb is sending a fuel/air mixture that isn’t as good as it should be. And you are correcting that with timing rather than fixing the carb and putting a curve in it.
It’s much more work to fix the carb and start over but the end result is worth it.
When you fix that carb you’ll find out it won’t want that much initial as you have when it’s locked
I’m just guessing here but from what I remember your engine will want (as a start) 20-22 degrees initial, 24-26 at peak torque and 32-34 total, depending on rpm. If you are shifting higher than I remember that total number could and probably will be higher.
And since you’ve been screwing with the timing I can assume you understand how much work it is to get a curve in the distributor.
Along those lines, with the stiffest springs you could only delay the timing to just over 4k.
That has to be at or even before your torque peak. Which means you are killing power at peak torque from too much timing and killing peak power with too little timing.
I can say that most of this could have and should have been worked out on the dyno. It’s damn hard to do in the car and even harder if you are trying to do it with a timing light rather than a test bench.
When I start out on the dyno I lock out the timing. Then I make some pulls to find the best power with the timing locked out. Then I do a series of tests where I vary the load and rpm and then vary the timing at those loads and rpm to develop the curve.
Once I get all those numbers I head over to the test bench and get to work.
I spend many hours just getting the curve in shape. It can take forever especially when peak torque is a long way from idle speed. You have to delay the start of the curve sometimes and you might need custom springs to do it.
In fact the heaviest springs that MSD and everyone else sends out aren’t strong enough for most anything.
To that end, I’m not surprised it wants all that timing at low rpm. That’s because the fuel coming from the carb isn’t “prepped” correctly by the time it gets to the chamber.
You want to atomize the fuel at the booster. Vaporize it as it gets to the chamber and when it’s on the chamber.
A tightly packed chamber with with fully vaporized fuel will have the quickest, cleanest burn time. Hence, you can run less timing which reduces working losses.
When the carb isn’t doing its job for whatever reason, and especially and specifically when you are using a cold air intake (or even worse yet a tunnel ram) you don’t have the heat to help vaporize the fuel.
All that conspires to force ignition timing to compensate for poor carburation.
The goal should be (talking NA here) to speed up the burn rate as fast as you can so you can reduce timing.
If you can fire the plug at 30 degrees BTDC you will make more power than if it timed at 40 degrees BTDC as long as the burn is mostly done by 12-15 degrees ATDC.
Doing so reduces negative work on the crank.
Back to your curve.
If you look at your dyno sheets you can see where peak torque is and where peak power is.
So you have 3 points on that graph that you must account for when developing the timing curve your engine wants.
You have your minimum idle speed, peak torque and then peak power.
I’m not getting into initial now because you get that. What concerns me is what’s happening at peak torque and then what’s happening at peak power. Because the timing requirements are far different at peak torque than at peak power.
Most engines (evidently yours at this time doesn’t follow this) want LESS timing at peak torque and MORE timing at peak power.
So thinking that through when you lock out the timing you are killing one point with too much timing and the other with not enough timing.
Why is your engine different when the build is similar to many others?
Because your carb is sending a fuel/air mixture that isn’t as good as it should be. And you are correcting that with timing rather than fixing the carb and putting a curve in it.
It’s much more work to fix the carb and start over but the end result is worth it.
When you fix that carb you’ll find out it won’t want that much initial as you have when it’s locked
I’m just guessing here but from what I remember your engine will want (as a start) 20-22 degrees initial, 24-26 at peak torque and 32-34 total, depending on rpm. If you are shifting higher than I remember that total number could and probably will be higher.
And since you’ve been screwing with the timing I can assume you understand how much work it is to get a curve in the distributor.
Along those lines, with the stiffest springs you could only delay the timing to just over 4k.
That has to be at or even before your torque peak. Which means you are killing power at peak torque from too much timing and killing peak power with too little timing.
I can say that most of this could have and should have been worked out on the dyno. It’s damn hard to do in the car and even harder if you are trying to do it with a timing light rather than a test bench.
When I start out on the dyno I lock out the timing. Then I make some pulls to find the best power with the timing locked out. Then I do a series of tests where I vary the load and rpm and then vary the timing at those loads and rpm to develop the curve.
Once I get all those numbers I head over to the test bench and get to work.
I spend many hours just getting the curve in shape. It can take forever especially when peak torque is a long way from idle speed. You have to delay the start of the curve sometimes and you might need custom springs to do it.
In fact the heaviest springs that MSD and everyone else sends out aren’t strong enough for most anything.
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Bruce said this:
"If you want to start I would start with and old style carby and work from that. Starting at a modern complex carby with problems is difficult. Go hunt out an old prior 1972 850 and stuff that on anything you want and it goes great, so anaylze that carby. So why bother with the new stuff? I have dyno'd new ultra everything 950's 750's and they are all the same, absolute rubbish. Put the old 850 on there and 30 more HP smoother running, better emissions, cooler engine. I don't know if its like that in the USA but that's what happens to me every time here in Australia."
Start here:
Calibrations for an early list 850
PMAB .026"
SMAB .025"
PIAB .076"
SIAB .055"
P & S IJ .035"
E-bleeds 2 x .026" or .028" in each main well
Kill bleed P&S .028"
PVCR P&S .070"
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Newbomb Turk
Well-Known Member
Thanks Hysteric.
Do you by chance have the main jet sizes for an 850?
I forgot what they were from Holley.
Interestingly, Holley used a .026 main air bleed.
Nowadays you’re lucky to find a carb with an .031 main air bleed.
Newbomb Turk
Well-Known Member
Bewy, the book is wrong.
You can watch the A/F ratio on the dyno and visually SEE the boosters… wait a minute…did I write it backwards?
No, I wrote it correctly.
A bigger MAB will start the booster sooner because at low air flows the MAB acts like an emulsion bleed.
I have it correct.
That book is wrong. The author either never read the Taylor books or he read them and still got it wrong.
This is one reason guys get what you call “Holleyitus”. Big air bleeds start the booster sooner. They go rich down low and lean up top.
It’s simple to remember.
The bleed that makes the A/F ratio richer at high air flows has the opposite effect at low air flows.
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Hmm....Can't say I do.
Newbomb Turk
Well-Known Member
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Let me know and also what list no its from. Holley lists the early list carbs as 80 front and back.
Newbomb Turk
Well-Known Member
Will do. I have to call Tuner today anyway so I’ll ask him.
Much better than calling my wife and having her look for the book and never find it.
Ironmike
Well-Known Member
Phew! That's a lot to digest. But first step is to plug those emulsion bleeds mentioned and make sure idle feeds are in the lower position. Have to order some .026 Main air bleeds. So those 3 things I will try in one step. Usually don't like trying more than 1 change at a time. But it makes sense.
As far a carbs go, Id love to find a 2008 ish HP 950. Don't know why they quit making them but I've had really good results with several. Shoulda never sold the last one I had.
Drill a couple holes in the throttle plate and you're pretty much just jetting. Easy peasy. They just make **** more difficult every new "better" generation.
As far a carbs go, Id love to find a 2008 ish HP 950. Don't know why they quit making them but I've had really good results with several. Shoulda never sold the last one I had.
Drill a couple holes in the throttle plate and you're pretty much just jetting. Easy peasy. They just make **** more difficult every new "better" generation.
Newbomb Turk
Well-Known Member
Tuner says it’s 80’s square and 6.5 power valves.
I thought the 80’s were right but the power valves I couldn’t remember.
Turk,
The book is NOT wrong. Nor are the other books/people that say the same thing, including the Holley book. I do not understand why this is so hard to understand......
The air bleed bleeds off booster signal. If the AB it is increased, more signal is bled off, requiring more RPM [ to create more depression to start pulling fuel ] to start booster flow.
I seem to remember you posting info from Taylor & the info did NOT support your theory.
The book is NOT wrong. Nor are the other books/people that say the same thing, including the Holley book. I do not understand why this is so hard to understand......
The air bleed bleeds off booster signal. If the AB it is increased, more signal is bled off, requiring more RPM [ to create more depression to start pulling fuel ] to start booster flow.
I seem to remember you posting info from Taylor & the info did NOT support your theory.
TT5.9mag
Two atmospheres are better than one
A wonderful explanation from Tuner off of another site where the question was asked “how does bleed air effect the booster signal?”
“Gentlemen,
As always, circumstances alter cases.
For the purpose of a thought experiment look at the carburetor from the often referred to opposite point of view, the venturi doesn’t draw the fuel, the atmospheric pressure pushes it. Instead of thinking of the booster signal as drawing against a resistance or restriction of the fuel and air entering it, consider it in the sense that air pressure is pushing fuel and air through the circuits against the resistance forces of friction and gravity.
As an actual experiment to illustrate how increasing bleed air can increase the liquid fuel flow, put a straw in a longneck bottle with water in it and blow. Obviously, the air bubbles displace liquid and push the water up the neck of the bottle and out the top if you blow hard enough. The atmospheric pressure is pushing air into the bleed system and main well just like your breath is pushing air into the liquid in the bottle. Remember, atmospheric pressure is pushing both fuel and air into the main well and toward the nozzle in the venturi.
If you use a carbonated beverage the air entering the liquid causes a disturbance which causes the CO2 to flash into vapor bubbles in the liquid which further drives the liquid up the bottle neck and illustrates how the vapor pressure of the more volatile components in fuel can affect the liquid flow. Also obvious is how larger amounts of bleed air or vapor can reduce the liquid fuel delivery by occupying a corresponding larger portion of the flow path.
Obviously, the effect of increasing liquid flow is most significant in the range of very low venturi pressure difference (vacuum or signal, if you wish) from atmospheric, which is at and closely above the beginning of flow from the main in most common single 4bbl applications we deal with. A lot of venturi area, such as with multiple carbs or very large carbs on small engines, may operate in such a low pressure differential at maximum engine speed the phenomenon of bleed air increasing fuel flow can be in effect in all operating conditions. Most usually, in my experience with the common Holley-like single 4bbl applications, bleed air richens the low power range at and just above tip-in and leans the high power range closer to full throttle.
Confusion enters the conversation when the definition of operating range isn’t made clear. Sometimes, the bleed effect is considered in reference to WOT only, but from the bottom to the top of an RPM range. Other times, the bleed effect is discussed in the context of percentage of load or throttle position less than full throttle. The two different circumstances can appear to have conflicting requirements in the bleed configuration. In my view, that seems to be the result of working out the bleed arrangement using a dyno and only considering WOT in a narrow RPM range near maximum power. Obviously, the bleeds effects are significant from curb idle to WOT and maximum engine speed.
The bottom line is, you gotta dink with all the little holes until you like how it runs, no matter what size they end up. If the engine likes it, so be it.
As always, circumstances alter cases, but things are more like they are now than they ever have been.
“
“Gentlemen,
As always, circumstances alter cases.
For the purpose of a thought experiment look at the carburetor from the often referred to opposite point of view, the venturi doesn’t draw the fuel, the atmospheric pressure pushes it. Instead of thinking of the booster signal as drawing against a resistance or restriction of the fuel and air entering it, consider it in the sense that air pressure is pushing fuel and air through the circuits against the resistance forces of friction and gravity.
As an actual experiment to illustrate how increasing bleed air can increase the liquid fuel flow, put a straw in a longneck bottle with water in it and blow. Obviously, the air bubbles displace liquid and push the water up the neck of the bottle and out the top if you blow hard enough. The atmospheric pressure is pushing air into the bleed system and main well just like your breath is pushing air into the liquid in the bottle. Remember, atmospheric pressure is pushing both fuel and air into the main well and toward the nozzle in the venturi.
If you use a carbonated beverage the air entering the liquid causes a disturbance which causes the CO2 to flash into vapor bubbles in the liquid which further drives the liquid up the bottle neck and illustrates how the vapor pressure of the more volatile components in fuel can affect the liquid flow. Also obvious is how larger amounts of bleed air or vapor can reduce the liquid fuel delivery by occupying a corresponding larger portion of the flow path.
Obviously, the effect of increasing liquid flow is most significant in the range of very low venturi pressure difference (vacuum or signal, if you wish) from atmospheric, which is at and closely above the beginning of flow from the main in most common single 4bbl applications we deal with. A lot of venturi area, such as with multiple carbs or very large carbs on small engines, may operate in such a low pressure differential at maximum engine speed the phenomenon of bleed air increasing fuel flow can be in effect in all operating conditions. Most usually, in my experience with the common Holley-like single 4bbl applications, bleed air richens the low power range at and just above tip-in and leans the high power range closer to full throttle.
Confusion enters the conversation when the definition of operating range isn’t made clear. Sometimes, the bleed effect is considered in reference to WOT only, but from the bottom to the top of an RPM range. Other times, the bleed effect is discussed in the context of percentage of load or throttle position less than full throttle. The two different circumstances can appear to have conflicting requirements in the bleed configuration. In my view, that seems to be the result of working out the bleed arrangement using a dyno and only considering WOT in a narrow RPM range near maximum power. Obviously, the bleeds effects are significant from curb idle to WOT and maximum engine speed.
The bottom line is, you gotta dink with all the little holes until you like how it runs, no matter what size they end up. If the engine likes it, so be it.
As always, circumstances alter cases, but things are more like they are now than they ever have been.
Newbomb Turk
Well-Known Member
Actually the Taylor book says exactly what I’m saying, what I’ve seen because it’s easy to test for and it’s what every carb guy I listen to know.
I can’t quote the Taylor book exactly because I’m not at home but he says that at low air flow, before flow to the nozzle (or booster) starts the main air bleed acts like an emulsion
I may have a picture of the page in his book on this phone but it may have been on my iPad.
I’ll look in a minute.
Ironmike
Well-Known Member
I was wrong! Digging in again today I realize I mis spoke. Their are FIVE emulsion bleeds on each side of my blocks. 2nd from the top is a blank, all others are .028.
Idles are on top and .035.
FYI: you cannot use standard brass set screws in these blocks. They will screw all the way into the well. The damn factory bleeds have a little head on them. Picture a tiny miniature main jet. Stuck buying them from Holley. No clue which ones to block off now. What the hell were they thinking?
Idles are on top and .035.
FYI: you cannot use standard brass set screws in these blocks. They will screw all the way into the well. The damn factory bleeds have a little head on them. Picture a tiny miniature main jet. Stuck buying them from Holley. No clue which ones to block off now. What the hell were they thinking?
Newbomb Turk
Well-Known Member
Save your money and buy your brass from McMaster-Carr. Just regular 6-32 set screws.
You’ll go BROKE buying headed brass.
I install the set screws until they are flush and send them.
Open the top hole and the fourth hole from the top to start.
It’s insane running all that emulsion.
Edit: you can lower the IFR. That helps with idle a bunch.
Also, a .035 is pretty big. You may end up in the .076-.078 idle air bleed range.
That’s not always a bad thing unless you run out of idle circuit and T slot before it gets on the booster.
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TT5.9mag
Two atmospheres are better than one
Use the brass that’s there. Solder the hole closed and drill it to whatever size you want.
mderoy340
Well-Known Member
You can solder some of those .028 shut. A tiny bit of flux cleaner and you will have no problem soldering shut from the bottom.
Ironmike
Well-Known Member
Yeah I thought about that. But why in the crap did they put so many bleeds there i the first place? I can't imagine any benefit with 8 friggin holes on each block. I'm wondering if this is a WOT thing.......totally baffles me.
Newbomb Turk
Well-Known Member
Because there are times when you may want to clean up the fuel curve a bit and moving an emulsion bleed can make a world of difference.
I had to use one of my tunnel ram carbs on the dyno for a friend and it made the most power with only one bleed open.
Moving that one bleed up and down will affect different parts of the fuel curve.
Ironmike
Well-Known Member
Well I'm going to block #2,3 and 5. See what the hell happens soon! I'll pivot to Holley tech now......... I called today and played dumb. They have no clue why or how many emulsion bleeds are there. Dude says "you're mistaken sir, there's only 1 at the top of the block and 1 at the very bottom." "they help control VAPOR LOCK" Honest to God. ..........Dude sounded about 13 years old and suggested just moving on to Sniper FI.
What a world
What a world
Newbomb Turk
Well-Known Member
That is exactly why I don’t buy anything with the Holley name on it. Ever.
I can buy at least as good a carb and I can argue a better carb from ATM for less money.
I don’t buy Holley. This just reinforces that.
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