Holley Annular Question...?

[HamerDown]

Holley list# 9380 annular 850 DP

1) why or what are the benefits that it's a "square" jetted carb?

2) would it be of any benefit to remove the rear/secondary PV (it has two) and jet it smaller in the primary side and fatter in the secondary's ?

3) What are the benefits of this carb being "annular" vs any other 4150 ?

4) When testing w/a vacuum gauge, will the primary power valve automatically be the same as the secondary PV?

Thanks for any feedback > I called Holley and it was like talking to someone at McDonald's drive thru :roll:

[jmarksdragster]

It depends on what you want to do with it and what the specs are on what it's going on.

Assuming a street/strip or drag car, it's jetted square for even fuel distribution to all the cylinders at WOT. Even still it is not always the case as some intakes, most often dual plane intakes can have issues with even distribution and require staggering the jets or more drastic measures in some cases. Equal fuel from the primary and secondary at WOT is usually the best place to start.
And concerning equal fuel, again assuming a street/strip or drag car, there is no reason to use a secondary power valve and good reason not to. The PVCR's can come uncovered on a hard launch and make lean, even if for a moment. Also, unless you plan on cruising at 3/4 throttle it will serve no purpose, 99% of the time the secondaries are either closed or wide open. Either case needs nor PV. Jet up 6-8 to start when blocking the secondary PV, then jet up or down as needed for best MPH at the track.
Annular boosters provide the carb with a stronger and quicker responding metering signal all else being equal, but usually cut the available airflow at WOT on a 4150 carb. If you have smaller engine or run primarily on the street it is worth having, larger displacement engines or higher HP engines that keep the RPM up keeping the airspeed through the carb may pick up a little HP with a downleg booster. So it will depend on the app.
As far as the PV vacuum rating... we've determined you don't want a secondary PV most of the time, setting the PV vacuum setting is about finding the optimum point below cruise vacuum for the PV to open soon enough and not have it surge or too low allowing it to run rich too soon. You do not set the PV based on idle vacuum.

And with some of the phone tech some companies use these days you might get a better answer at McDonald's...

[HamerDown]

It depends on what you want to do with it and what the specs are on what it's going on.

Assuming a street/strip or drag car, it's jetted square for even fuel distribution to all the cylinders at WOT. Even still it is not always the case as some intakes, most often dual plane intakes can have issues with even distribution and require staggering the jets or more drastic measures in some cases. Equal fuel from the primary and secondary at WOT is usually the best place to start.
And concerning equal fuel, again assuming a street/strip or drag car, there is no reason to use a secondary power valve and good reason not to. The PVCR's can come uncovered on a hard launch and make lean, even if for a moment. Also, unless you plan on cruising at 3/4 throttle it will serve no purpose, 99% of the time the secondaries are either closed or wide open. Either case needs nor PV. Jet up 6-8 to start when blocking the secondary PV, then jet up or down as needed for best MPH at the track.
Annular boosters provide the carb with a stronger and quicker responding metering signal all else being equal, but usually cut the available airflow at WOT on a 4150 carb. If you have smaller engine or run primarily on the street it is worth having, larger displacement engines or higher HP engines that keep the RPM up keeping the airspeed through the carb may pick up a little HP with a downleg booster. So it will depend on the app.
As far as the PV vacuum rating... we've determined you don't want a secondary PV most of the time, setting the PV vacuum setting is about finding the optimum point below cruise vacuum for the PV to open soon enough and not have it surge or too low allowing it to run rich too soon. You do not set the PV based on idle vacuum.

And with some of the phone tech some companies use these days you might get a better answer at McDonald's...
Mark, what a informative reply > I thank you!
If I may give more detail about application...
This carb would be used on a 468 BBC Jet Boat
Max RPM is 5400 but I usually spend most of the time at 3000-4200.
10:1 compression
Weiand Stealth intake
Lunati Voodoo Roller Cam #60212
># Advertised Duration (Int/Exh): 282/290
# Duration @ .050 (Int/Exh): 231/239
# Gross Valve Lift (Int/Exh): .600/.600
# LSA/ICL: 110/106
# Valve Lash (Int/Exh): Hyd/Hyd
# RPM Range: 2200-5800
049 large oval heads w/larger valves ported etc.
Headers with performance baffles.

Soooo, with the above should I still delete the secondary power-valve and up the rear jetting...or...leave the secondary PV and keep the square jettein?
Any other advice...would be much appreciated.
Thanks Ray

[jmarksdragster]

Well considering you do have a different deal being in a boat, I would opt to plug the PV in the secondary for starters. This is to make sure you have sufficient fuel to start with when the secondaries open up. You will need to take some time to tune it, to find out what it wants for fuel. I would put a vacuum gauge on it, and if you can spring for it a wideband O2 system it would make tuning a whole lot easier. If it were me, I would disconnect and tie the secondaries closed and tune the primary to start with. You need to learn to properly read the plugs. Once you get the timing and idle set up, run it for some short WOT bursts and stop quick, shut it off and pull a couple plugs to look at. As long as plugs are OK try some extended cruising, pull plugs again. Once the plugs look good (and may take a couple sets to set it up) hook up the secondaries and run some extended higher RPM runs, check the plugs again. If it looks rich you may need the PV, and the vacuum gauge will help determine where it needs to be. I would also possibly stagger the PV vacuum #'s, higher in the front and maybe a little lower in back. Finding the load point that requires more fuel will be a little more difficult without a wideband and will require some time with it the first time out. Make sure you get it up to operating temp as well.

Here is a good place to read up on plug reading.
http://www.dragstuff.com/techarticles/reading-spark-plugs.html

[HamerDown]

Well considering you do have a different deal being in a boat, I would opt to plug the PV in the secondary for starters. This is to make sure you have sufficient fuel to start with when the secondaries open up. You will need to take some time to tune it, to find out what it wants for fuel. I would put a vacuum gauge on it, and if you can spring for it a wideband O2 system it would make tuning a whole lot easier. If it were me, I would disconnect and tie the secondaries closed and tune the primary to start with. You need to learn to properly read the plugs. Once you get the timing and idle set up, run it for some short WOT bursts and stop quick, shut it off and pull a couple plugs to look at. As long as plugs are OK try some extended cruising, pull plugs again. Once the plugs look good (and may take a couple sets to set it up) hook up the secondaries and run some extended higher RPM runs, check the plugs again. If it looks rich you may need the PV, and the vacuum gauge will help determine where it needs to be. I would also possibly stagger the PV vacuum #'s, higher in the front and maybe a little lower in back. Finding the load point that requires more fuel will be a little more difficult without a wideband and will require some time with it the first time out. Make sure you get it up to operating temp as well.

Here is a good place to read up on plug reading.
http://www.dragstuff.com/techarticles/reading-spark-plugs.html
I thank you again for the informative reply...looks like I'll have my work cut out for me getting this thing right.
I won't be able to use the wideband O2 system as my headers are water injected to keep the chrome on. Headers come up and over the rear of the boat.
I can use a vacuum gauge.
Thanks

[HamerDown]

Thinking now about blocking the secondary PV and raising the secondary jetting accordingly.
Original jetting from Holley is 78 square > but that won't apply anymore.
Any suggestions on a good Jetting starting point?

[jmarksdragster]

Start with 86 in the secondary with no PV, it may be a little rich but better than being lean. Reading plugs will be your ally in getting it right.

[HamerDown]

I finally got to try my Annular 850 DP list-9380 > the below as taken as a starting/observation reference

1)Jetted out of the box 78 square

2)Two PV's 6.5 and 1/2 idle vacuum 13"

3) floats set properly

4) set idle for max RPM with vacuum gauge = 3/4 out

5) #31 discharge nozzles P&S

6) fuel psi good = 5/7 lbs

OPERATION...
*Good idle but seems a little too choppy for 900 rpm

*Holding @ 1600 rpm engine has a faint sputter/miss

*in the 4000 rpm range engine goes flat > almost like there's a rag over the carb > then it comes to life when the PV opens.

*max RPM is now only 5K and down 2/300 rpm from my little 715-vacuum secondary carb

Vacuum Gauge Observations... vacuum seems a bit high for cam

Idle = 13"

2500 = 15"

3000 = 14"

3500 = 11"

4000 = 8"

5000 = 5" and as low as it goes

*Plugs appear to be safely on the rich side and NOT heavily rich.

*As primary throttle blades open > a steady supply of fuel from discharge nozzles > as secondaries open they also receive a steady flow of fuel = smooth transition between the two

*Looking into carb at idle nothing leaking into carb > when I blip the throttle I see fuel discharging from the annular boosters.


Your thoughts?

Thanks, Ray

PS. I can tune any Weber or Dellorto DHLA-40 and my 715 VS very well but, this Annular 850 DP will be tricky.

[jmarksdragster]

At 4000 RPM are the secondaries even open? I would still plug the secondary PV and jet up. Put an 8.5 PV in the primary, if it still appears flat try a 9.5. It needs to open when the load is high enough to warrant the extra fuel. And don't worry about any effect on idle, the idle jet is much smaller than the main jets feeding them. As far as the sputtering at 1600, have someone hold it there and cover one of the idle air bleeds, if it gets better try covering two. That would tell you the IAB/IJ sizes are too lean for the transition circuit and need to be changed to enrich the circuit. If it gets worse, then it is too rich. As far as the idle, pull the carb now that the idle speed is set and see how much of the transition slot is showing. should have roughly .020 exposed with the blade set for the correct idle speed. What kind of timing curve do you have? Insufficient initial timing will make tuning harder and will run poor, with that much cam I would expect a minimum of 20˚ initial, and maybe up to 25˚

[Scooterz]

Mark- Kuudoos to you my friend for taking the time to explain these carb questions. Each time you do, people like myself learn a lot. You have a way of explaining it that makes it understandable... I have learned a lot from you & some of the others here about carbs. I knew nothing about them 5 or 6 years ago. With guys like you (& some trial & error), I wield the small flat-blade screw driver with absolute confidence as my sword now days.

[HamerDown]

At 4000 RPM are the secondaries even open? I would still plug the secondary PV and jet up. Put an 8.5 PV in the primary, if it still appears flat try a 9.5. It needs to open when the load is high enough to warrant the extra fuel. And don't worry about any effect on idle, the idle jet is much smaller than the main jets feeding them. As far as the sputtering at 1600, have someone hold it there and cover one of the idle air bleeds, if it gets better try covering two. That would tell you the IAB/IJ sizes are too lean for the transition circuit and need to be changed to enrich the circuit. If it gets worse, then it is too rich. As far as the idle, pull the carb now that the idle speed is set and see how much of the transition slot is showing. should have roughly .020 exposed with the blade set for the correct idle speed. What kind of timing curve do you have? Insufficient initial timing will make tuning harder and will run poor, with that much cam I would expect a minimum of 20˚ initial, and maybe up to 25˚
Hi Mark, so glad you're still here...and your feedback is greatly appreciated.
Just wish I was further along with this 850 vs where I'm at > not much boating time and with the season coming to a quick end, I may only be out 2-3 times more.
At 4000 I would think I'm into the secondaries > at least some, but don't know for sure.
Question > if the carb is into the secondaries, what would be the reason to go higher w/PV on the primary side? Unless you're thinking the secondaries are still closed? My concern would be overly rich at cruising rpm's 3-4000
I can certainly block the secondary PV but let me ask you this > (if) the 6.5 isn't opening until some 4800 RPM why not just leave it and still raise the secondary jets to maybe 86?

I will pull the carb tomorrow to have a look at the transition slot.

Timing > I'm running a MSD RTR dizy > if memory serves me I'm a little conservative on total timing > 32* with 12-14 initial > all in @ 3000 rpm.
I can take it to 35* total but would need to change out the advance springs for your suggested 20* initial > just hope it doesn't bump against the starter when starting hot.
I went a little conservative on total timing for fear of detonation.
Question > conservative timing would lead to higher vacuum readings, correct?

Again, thanks for your time and feedback, Ray

[jmarksdragster]

The reason for the higher PV is to supply fuel once the load is high enough to warrant it. Of course you have to change it to see where it needs to be for your engine to get the best performance.

As far as timing, you need to look at the plugs to see what it wants for timing, being too conservative will lower vacuum and create more exhaust heat do to fuel burning outside the engine. With the timing correctly set, it will burn the air/fuel more completely and at the time needed to have the greatest cylinder pressure when the piston can do the work most efficiently, allowing for smaller throttle openings for the same power creating more vacuum. Without O2's reading the plugs are even more important as they are your biggest tuning tool. Sneak up on it a little at a time, but I would expect 36-38 to be closer to optimum for you. It's usually high efficiency heads like GM's Vortec or like my SB2's that live well at lower timing, my SB2 runs best at 29˚.

[HamerDown]

Carbs off > transfer slot showing appears to be a heavy .025 I took a few pics too.
Ordering a PV block-off for the secondary and a 8.5 PV for Monday.
I'll up the total advance to 35* and recheck all vacuum readings.
If you have a email address I'd like to send you a few pics.
Thanks, Ray

[HamerDown]

It's getting better > the flat spot is pretty much history.
I installed the primary 8.5 PV, jetted up to 81.
Secondary PV blocked, jetted up to 86.
Tested a nice long cruise at 3800/4000 rpm then shut down to read plugs > no fuel ring.
Then I did a few WOT passes again no fuel ring.

I'm thinking to throw more jet at it > maybe 84 primary and 90 secondaries.

Question, that slight miss at 1500 > when I placed my finger over one of the primary outside air bleeds, the stumble got much worse. What's that telling me??? Also, no brass inserts in the Primary outboard air bleeds.

Thanks for your feedback > and I also believe a 2" spacer may be in order.

Ray

[jmarksdragster]

No brass on the outside bleeds? Have a picture? The outside bleeds are for idle and transition circuits, There has to be bleeds either on top if it is a factory Holley, if there were mods to it a restriction inside in the main body or the metering block itself. When you take off the front bowl, take a picture of both the surface of the block and the main body. As far as a fuel ring, you need a good plug magnifier to see it, and doesn't show well right away. You can look at the end of the plug for fuel as well, here is a picture from another site to show you.


http://i123.photobucket.com/albums/o287/MaxRaceSoftware/Race%20Tech%20and%20Articles/Spark%20Plug%20Reading/Spark_Plug_Readings_Proper_HeatRang.jpg

[jmarksdragster]

Saw the pics you sent, if those are the primary throttle blades, crack the adjustment screws on the secondaries open a little and bring your primaries back down just a tad, try to get the t-slots more square. Readjust the mixture, it will lean the idle a little. I see the missing brass, there still needs to be restrictions in the main body in the intersecting passage to where those brass inserts are missing, or in the metering blocks. Might be threaded, making changes if needed will be a little easier, just not as easy as on top.

[HamerDown]

Saw the pics you sent, if those are the primary throttle blades, crack the adjustment screws on the secondaries open a little and bring your primaries back down just a tad, try to get the t-slots more square. Readjust the mixture, it will lean the idle a little. I see the missing brass, there still needs to be restrictions in the main body in the intersecting passage to where those brass inserts are missing, or in the metering blocks. Might be threaded, making changes if needed will be a little easier, just not as easy as on top.
Adjustment screws on the secondary's, I never noticed any??? But I'll look tomorrow.
T-slots more square as in adjust the butterflies in the shaft? The pic may not show it well but both T-slots are exposed the same.

Your thoughts on a 2" spacer and if so any recommendations for manufacture?

As usual, great info.

[HamerDown]

No brass on the outside bleeds? Have a picture? The outside bleeds are for idle and transition circuits, There has to be bleeds either on top if it is a factory Holley, if there were mods to it a restriction inside in the main body or the metering block itself. When you take off the front bowl, take a picture of both the surface of the block and the main body. As far as a fuel ring, you need a good plug magnifier to see it, and doesn't show well right away. You can look at the end of the plug for fuel as well, here is a picture from another site to show you.


http://i123.photobucket.com/albums/o287/MaxRaceSoftware/Race%20Tech%20and%20Articles/Spark%20Plug%20Reading/Spark_Plug_Readings_Proper_HeatRang.jpg
I may have a few pics of the M-Blocks and the carb body...if so I'll send them to you, If not I'll take a few.
Since I switched to 20/50 synthetic oil I noticed a slight splash of oil around the base ring > this is why I was using a magnifier to look for the fuel ring.
Checked timing > 14 initial and 35* total. I could up the total advance to lets say 38* to see if it pulls any more RPM out of the engine.
Thanks, Ray

[jmarksdragster]

On the underside of the base plate there should be flat blade set screws that affect the secondary opening amount. You can replace the screws with allen head set screws to allow adjustment from the top. T-slots square means they look like little squares at idle, as much exposed as they are wide. You can cheat the secondaries a little to allow the primaries to be closed more, the t-slot position has more of an impact on the primary side. If it reaches the point where they can't be closed enough, usually on an engine with a healthy cam, as long as timing is maximized you would need to add small holes in the butterflies to allow more air in at idle to allow the blades to be closed sufficiently at idle. Too much exposure will start drawing fuel at idle from the transition slots, and at some point will render the mixture screws useless. One thing that my help close them is initial timing, have you experimented with using more? I understand not wanting cranking issues, but if it will stand more initial it will have more idle vacuum and allow a smaller throttle opening, closing the primary blades and exposing less t-slot. Easy enough to bump up the timing to check idle to around 2000 RPM operation, once you find the most it will stand you can set the distributor curve to limit total timing to what the engine needs.

As far as spacers, they are usually a bandaid for some other issue. Intake plenum size too small or large, too much reversion from the cam or intake runner length incorrect. With that said, a lot of engines can improve from a spacer of some sort, unfortunately it a trial and error thing. If you have none to borrow and want to purchase something, I would suggest something like the anti-reversionary spacer below sold by Reher-Morrison. If it wants any at all it will probably gain with that one, and less likely to lose any. Available for 4150 or 4500 carbs. And if it does help, remember you are affecting the signal at the carb and may need a jet change.

http://www.rehermorrison.com/images/components/InductionAntiReversionPlateDemo.jpg

[HamerDown]

Mark, thanks for clearing the confusion with this annular 850 and the many questions I have asked > and you have been more than gracious to answer ;)
*I located the secondary adjustment screw however, I may not need to touch it.
*I now understand the "squaring of the T-slots"
*"spacers" I understand the bandaid comment > my way of thinking > being I'm using a dual plane intake for lower RPM throttle response and drive-ability 'maybe' a spacer will trick my Wieand Stealth to act more like a Team-G and add a little more RPM to WOT...no?
*or, would a Edelbrock Victor be a better direction?

Update from Thursday...
*the 1600 rpm miss is history as I simply turned out the idle mixture screws as you suggested.
*while out on the water, I rotated/advanced the distributor about the size of a pencil line.
*the results from the above were >>> I was able to back down idle RPM thus close the butterflies even more.
*the engine picked up 200 RPM up top > I'll need to put a dial-back light on it to see where total timing's at. It was 35* total, all in @ 3000 rpm.
*even with increases jetting > the plugs appear very white and again, not seeing any fuel ring way down low in the plug > I may cut one open to have a better look.
*I'll email you a few pics of the primary M-block and corresponding carb body surface.

*** I feel it's coming together quite well in small steps (like you said)...I would like to set total timing for the max RPM but > be cautious to make sure I'm not on the cusp of detonation.

[jmarksdragster]

Sounds like you are real close, takes a little time but feels much better when you can make it better yourself. I don't have a definitive answer on a BBC intake, although have always found the Edelbrock intakes to be the best on my SBC's. You can try an open spacer to give the intake a common plenum. A dual plane makes the engine think you have a smaller carb, thus the increased throttle response at lower RPM's. You have to decide where you will spend the most time, anything over around 4000 will give way to a single plane as long as the carb is not too large and you are OK there. The positive of a single plane is that fuel distribution is much better, dual planes tend to have rich and lean sides. With no other knowledge if you decide to change my choice would probably be the Victor Jr. Smaller runners and plenum to keep the velocity up.

[jmarksdragster]

Got the picts of the carb, interesting about the IAB's missing in the front. Do you see any restrictions farther in the hole or in the intersecting passage? And can you measure the idle feed restrictions in the metering blocks? Did you get the carb new or used? An open bleed would need a lot of idle feed restriction and limit the time the transition circuit was active. You might get it to work, just might make tuning it a bit harder.

[HamerDown]

Got the picts of the carb, interesting about the IAB's missing in the front. Do you see any restrictions farther in the hole or in the intersecting passage? And can you measure the idle feed restrictions in the metering blocks? Did you get the carb new or used? An open bleed would need a lot of idle feed restriction and limit the time the transition circuit was active. You might get it to work, just might make tuning it a bit harder.
I can use a drill set to determine sizes, I 'think' the outboard ones have a reduced step down inside > but isn't that std for a brass insert to sit on?
"intersecting passage" I'll have to put it under my ole Science class microscope for that one. lol


I'll pull the carb again > it should have sippers vs bolts for as many times I've been in it LOL

Purchased the carb back in 98 from a friend that used it on his Hot Rod strip car > the inside was a mess until I went through it. It sat clean and bagged for a loooong time.
Dellorto DHLA 40's I know like the back of my hand, Hollies well, I know where the idle mixture screws are and know how to rebuild them.

Thanks again, Ray

[HamerDown]

More testing Friday, Saturday and Sunday > it's getting better and better :wink: