Need Carb Tuning Advice Again 8896 Holley 1050

I've gotten great advice so far on this carb but it is still not quite right. 8896 1050 Holley Dominator with annular boosters. Jets 86 primary, 88 secondary, Air bleeds: #53 idle, Drilled .082" intermediate, and #40 main. It used to run real rough around 2500-3000 rpm. Increasing the intermediate air bleeds helped that a lot but now it runs real rough in the burnout. I try to hold it at 5000 RPM in second gear and it almost sounds like its missing. You can here it on the bash video. It sounds like sh#t in the burnout. Going down the track it runs fine at full throttle. How can I lean it at part throttle around 5000 rpm without making it too lean upstairs? It runs exactly like it did at around 2500 before leaning the intermediate so I think it is too rich at 5000. It tends to load up coming out of the box too so I have to clear it out. Would going slightly larger on the main air bleeds delay the main circuit some without leaning it out too much up top?

Here is your dilema ... with that carb, lean it at part throttle, (which certainly can be done), and it won't be as fast at full throttle.

YOUR CHOICE...

Going smaller on high speed bleed and smaller on main jet will somewhat do what you want.

First if it is a 8896 I am pretty sure it is not suppposed to be annular boosters, standard straight is what I thought. Second, what linkage is in the carb, Progressive, Soft Progressive, or 1:1 ??

I had a similar problem with my 8896, come to find out that 40 for the main were too big. I went down to at set of 32's and it fixed the problem.
I have an extra set of 32's if you want to give it a try.
Justin

TravisRice wrote:First if it is a 8896 I am pretty sure it is not suppposed to be annular boosters, standard straight is what I thought. Second, what linkage is in the carb, Progressive, Soft Progressive, or 1:1 ??

It has annular boosters and the soft progressive linkage. I'm not sure if Holley always used annular boosters in this carb but all of the ones in recent years have them I believe.

[quote="rmcomprandy"]Here is your dilema ... with that carb, lean it at part throttle, (which certainly can be done), and it won't be as fast at full throttle.


I guess if that's true I definitely prefer fast at full throttle. I just don't like the way it sounds in the burnout and it doesn't sound good for the motor but I guess richer is better than lean. I also wonder if it really is rich in that RPM range is there a rich spot in my transition from stall at around 2500 to full throttle. I'm not sure how to determine that without just trying it. Just don't want to lean it too much. As long as I'm not hurting the engine I'm not too concerned it just sounds rough. You can hear it in a lot of the bash videos.

512Fairlane wrote:

TravisRice wrote:First if it is a 8896 I am pretty sure it is not suppposed to be annular boosters, standard straight is what I thought. Second, what linkage is in the carb, Progressive, Soft Progressive, or 1:1 ??

It has annular boosters and the soft progressive linkage. I'm not sure if Holley always used annular boosters in this carb but all of the ones in recent years have them I believe.

I fooled with a few of them before the new HP body came out. Truthfully I never had any luck with the old 8896 standard booster deal thats why I remember them so well. Just wanted to make sure it did not have a 1:1 linkage, they will act pretty stupid sometimes and get all blubbery and misfire-ish. Do as Randy mentioned and tweak there.

Travis

Some M5 , and green teeth should get you where you want to be ......... Seems to be a pretty standard answer for many-A problem.

Going smaller on high speed bleed and smaller on main jet will somewhat do what you want.[/quote]


Randy, Just so I understand this correctly, going smaller on the high speed air bleed will richen the main circuit and make it start earlier. Then am I going to go to smaller main jet to eliminate the extra fuel I am adding with the air bleed? Any suggestions on how many numbers to go with each? Thanks.

512Fairlane wrote:

TravisRice wrote:First if it is a 8896 I am pretty sure it is not suppposed to be annular boosters, standard straight is what I thought. Second, what linkage is in the carb, Progressive, Soft Progressive, or 1:1 ??

It has annular boosters and the soft progressive linkage. I'm not sure if Holley always used annular boosters in this carb but all of the ones in recent years have them I believe.

The original #8896 had straight leg boosters; (also had a restricted intermediate system). That was BEFORE they came with interchangeable air bleeds and HP metering blocks.
All #8896's with removable air bleeds were ANNULAR boosters.

512Fairlane wrote:
Going smaller on high speed bleed and smaller on main jet will somewhat do what you want.

Randy, Just so I understand this correctly, going smaller on the high speed air bleed will richen the main circuit and make it start earlier. Then am I going to go to smaller main jet to eliminate the extra fuel I am adding with the air bleed? Any suggestions on how many numbers to go with each? Thanks.
[/quote]

The air bleed will TILT the fuel curve and is NOT linear from low air flows to high air flows. The main jet will be linear.
Smaller air bleeds in the high speed will be richer everywhere but, more-so on the top. Now using a smaller main jet to get the top back where it was, will also be leaner than originally at lower air flows.

I wouldn't be afraid to open the inter. bleeds another .003"-.004" .

My 1250 Pro-Systems carb ended up being in the .090 range when it all got ironed out. The idle air bleeds were in the .063 range. that carb was fat straight from Pro-Systems. Had to go that big to make it work. It was a very responsive carb, but did not ET any fastser than the tweaked Holley 1250 that was fairly stock other than jetting .

Travis

rmcomprandy wrote:

512Fairlane wrote:

TravisRice wrote:First if it is a 8896 I am pretty sure it is not suppposed to be annular boosters, standard straight is what I thought. Second, what linkage is in the carb, Progressive, Soft Progressive, or 1:1 ??

It has annular boosters and the soft progressive linkage. I'm not sure if Holley always used annular boosters in this carb but all of the ones in recent years have them I believe.

The original #8896 had straight leg boosters; (also had a restricted intermediate system). That was BEFORE they came with interchangeable air bleeds and HP metering blocks.
All #8896's with removable air bleeds were ANNULAR boosters.

Good info. Maybe they are not so bad of a carb now with the annular boosters. The old style 8896 straight booster deal I never could get to work as good as the 9375 Annular. Even after putting screw in air bleeds in it.

Sounds like the engine may be asking for a bigger carb
Seems the engine is getting on the booster early...a good thing. The inter. thing is a crutch to fill the hole in the fuel curve between the idle and the main circuit. When the engine likes living off of the booster the inter. is not needed as much. I do agree with Randy that tuning on the hi-speed bleed is an option.....makes the booster less or more active.
It's trial and error for sure.

Thanks for the input. I'm glad you guys know what you are doing. Sounds like I need to get some more air bleeds and start playing. Lem I think it needs a bigger cam and a longer stroke too but that is going to have to wait a little while .

Be carefull what you ask for!!!
I asked Lem to convert my car over to a roller and now I have to get my license, cage certified, a physical, 5 layer jacket and pants, gloves, neck brace, and a window net!!!
He is the man. Thanks again Lem
Justin

I know. I keep saying I'd like it to go a little faster but I'm not too far from having to spend a bunch more money myself. I think 10.0's would be fine for a little while. How fast did your car go? Did you do any good at the Outlaw race?

Yeah, I am a big fan of the outlaw 10.0 racing. I made it to the final four out of 30 or so cars. I lost with a 10.06 and a 0.06 light (I lost by 0.002) I guess it wasn't meant to be, but I'll try again on Oct. 16.

http://www.racingperspectives.com/cgi-bin/store/imageFolio.cgi?action=view&link=Bret_Kepner_Photos/Domestic_Body_Styles/GIR_2010-09-18_Saturday_Outlaw_All_Stars&image=BKD10-09-18_089.jpg&img=80&tt=&tfile=tn_BKD10-09-18_089.jpg

A couple weeks earlier I was runnig high 6.20's in the 1/8 @ Coles County.

Justin

Played with air bleeds today at the NMCA race. Started by installing .086" in the intermediates from .082". I also switched to a 1" open carb spacer with a safety plate in place of my 1/2" 4 hole and installed new plugs. Car sounded a little better in the burn out but still seemed a little rough. Felt more responsive out of the hole. Ran a 10.34 at 129 with a 1.446 60 ft. Bought some .035" and .030" air bleeds for the main circuit from the Quick Fuel trailer. Had .040 's. Installed the .035" bleeds. Drove it around in the pits and if felt really fat again. Shut it off and couldn't hardly get it to restart it was flooding too bad. Stuck the .040's back in and got it to start again. Ran a 10.36 with a 1.46 60ft. Kind of think I went the wrong way on the high speed air bleeds. What do you think Randy and Lem should I go a little larger than the .040's? Or could I go a little larger on the intermediate? I know Lem you said once that around .085" was about as big as I should go.

I'm not Lem, but I would go where the engine says it needs to go. If it takes .089's and .044's and the car is faster then that is where it needs to be.
When the car slows down and starts back the other way then you need to start back the other way to. JMO.

Travis

512Fairlane wrote:Played with air bleeds today at the NMCA race. Started by installing .086" in the intermediates from .082". I also switched to a 1" open carb spacer with a safety plate in place of my 1/2" 4 hole and installed new plugs. Car sounded a little better in the burn out but still seemed a little rough. Felt more responsive out of the hole. Ran a 10.34 at 129 with a 1.446 60 ft. Bought some .035" and .030" air bleeds for the main circuit from the Quick Fuel trailer. Had .040 's. Installed the .035" bleeds. Drove it around in the pits and if felt really fat again. Shut it off and couldn't hardly get it to restart it was flooding too bad. Stuck the .040's back in and got it to start again. Ran a 10.36 with a 1.46 60ft. Kind of think I went the wrong way on the high speed air bleeds. What do you think Randy and Lem should I go a little larger than the .040's? Or could I go a little larger on the intermediate? I know Lem you said once that around .085" was about as big as I should go.

1] Work on one thing at a time.
2] You took fuel out with the larger inter. but put a heck of a lot more fuel in it with the .035" high speed. .002" h.s. is a big move....you moved .005"
3] I.M.O. put the .040" back in and open the inter. another .002"-.003".

4) Get a barrel valve...........

richter69 wrote:4) Get a barrel valve...........

Air bleeds are cheaper I just drill'em bigger.......that's free.

512Fairlane wrote:Played with air bleeds today at the NMCA race. Started by installing .086" in the intermediates from .082". I also switched to a 1" open carb spacer with a safety plate in place of my 1/2" 4 hole and installed new plugs. Car sounded a little better in the burn out but still seemed a little rough. Felt more responsive out of the hole. Ran a 10.34 at 129 with a 1.446 60 ft. Bought some .035" and .030" air bleeds for the main circuit from the Quick Fuel trailer. Had .040 's. Installed the .035" bleeds. Drove it around in the pits and if felt really fat again. Shut it off and couldn't hardly get it to restart it was flooding too bad. Stuck the .040's back in and got it to start again. Ran a 10.36 with a 1.46 60ft. Kind of think I went the wrong way on the high speed air bleeds. What do you think Randy and Lem should I go a little larger than the .040's? Or could I go a little larger on the intermediate? I know Lem you said once that around .085" was about as big as I should go.

To go smaller on the high speed bleed requires you to also go leaner on the main jets almog with it.
One works together with the other.

Changing the intermediate bleed does TWO things - it will change the mixture and ALSO vary the start-up time of that circuit somewhat.