Question on holley 4150

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skep419

skep419

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I have been reading up on wide band o2 sensors for tuning and they are saying that 13.8 is perfect for air fuel mixture. in looking at my dyno sheet it seems to be running super rich. Im wondering what everyone is running for jet sizes.
n561290572_3055481_7003.jpg

The dyno run was done with 71,s. Everybody I have talk to said mopars love fuel? am i using to big of a carb? It seems to hesitate bad off idle bursts of throttle and just recently started to pop and die.
 
Are you running a turbo or something? E85?

If not that A/F is CRAZY ridiculous rich.

All cars seem to make best power just slightly differently, but at a certain level the fuel doesn't know what brand it's in.
 
LXguy said:
Are you running a turbo or something? E85?

If not that A/F is CRAZY ridiculous rich.

All cars seem to make best power just slightly differently, but at a certain level the fuel doesn't know what brand it's in.
Click to expand...



no turbo no e85. what jets is everyone running if this is the case im gonna have to run like 60's and that seems odd?
 
sound like you might have a bad power valve...........you didnt say what pv your are running....a back fire threw the carb(pop)can blow a pv........... that looks to be way rich..........good luck
 
kennmadruga said:
sound like you might have a bad power valve...........you didnt say what pv your are running....a back fire threw the carb(pop)can blow a pv........... that looks to be way rich..........good luck
Click to expand...
stock power valve 4150 hp 750 mechanical sec. power valve front and back
 
LXguy said:
If not that A/F is CRAZY ridiculous rich.
Click to expand...

Why are you saying 13.8:1 is crazy rich?

Stoichiometric is 14.7:1 which is where you want to be or a little leaner for cruising. But max power is created with a ratio of 12.5:1 or some what leaner.

13.8:1 would be to rich for cruising and to lean for best power.
 
What size motor ,cam and etc.etc.Sounds like a PV.Drop 2 sizes in jets at a time and see what that does.
 
i'd drop to a properly setup 650 vaccum operated and a single plane. .
a 600 if you really want to tweek a carb and find best performance
 
i might of miss read your post,is 13.8 your crus AF than thats not bad....my book is old and iam not shure what pv is in a 750 hp, i would think a 6.5..would need the part number to look it up....to find the right pv for your combo...your going to have to drive around with a vacuum gauge and see what your cruz vacuum is,then get a pv slightly under that...........lets say your cruz vac is 10 to 12,then you well need to start with a 8.5 and go from there.....i hope this helps.....good luck
 
Lycandart said:
What size motor ,cam and etc.etc.Sounds like a PV.Drop 2 sizes in jets at a time and see what that does.
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360 xe284 comp cam, stock rods crank, hyper 4 valve relief hyper pistons, ported ede heads, rpm air gap, 750 dp holley hp 727 2800 stall 8 3/4 3.91

dont want vacuum anything kick in the pants secondaries
 
Well From the sound of it I think you would want to drop the PV to a 4.5 and start with 68 primary jets and a 72 secondary jetting.Stock pv in that would be a 6.5 and I think just with the cam your running you might want a little smaller one.But even at that A DP aint great with an automatic anyhow.Then you can up your jets starting with the secondarys to get it lines out.
 
i run almost the same combo........360 284 484 ,10.1 com,m1 intake ported x heads, 750 dp,but my convetor is 4200.......... that 2800 my be a bit to low.......... it would be a little easier getting off the line with a vacuum sec carb...........my carb specs are 74 frt 78 rear 6.5 pv leave at 2500, and i race at 3400 ft ...............i hope this help...good luck
 
I read a little on the holley web page they said i should check the vacuum while the vehicle is in gear at idle. its at 8
 
Where is your timing???? The hesitation might be your accelerator pump and squirter. My set up is close to yours also, little less convertor..650 DP w/proform center. I have the orange cam on the front pump with very slight play at the pump arm. 50cc pump on rear w/35 front squirter on street. At the track open the gap at the front pump,bigger/longer shot of fuel, and 38 front squirter 15-1600rpm on foot brake... jets 74f-82r. timing 18-20' idle 36*@ 2500
They recommend the pv 2 below idle vacuum...

Bob
 
BobsDart said:
Where is your timing???? The hesitation might be your accelerator pump and squirter. My set up is close to yours also, little less convertor..650 DP w/proform center. I have the orange cam on the front pump with very slight play at the pump arm. 50cc pump on rear w/35 front squirter on street. At the track open the gap at the front pump,bigger/longer shot of fuel, and 38 front squirter 15-1600rpm on foot brake... jets 74f-82r. timing 18-20' idle 36*@ 2500
They recommend the pv 2 below idle vacuum...

Bob
Click to expand...


Timing is set at 32 total(vacuum advance not hooked up) stock pump and squirters (28 front and 31 rear)
 
then 6.5 should be ok............is this combo new ...just got it runing?....just asking because the print out says may 08..myself a would check the pv and record it.....a blowen pv should cause a noteable amout rich mixture from ide to off ide.....bad cruz performance ect....you may have 3.5 whow knows .....check... good luck..........
 
my book is old and that number dose not come up sorry....try that number at holley.com it my tell you what pv you should have..........but i would still check...they been wrong with me...........good luck
 
360 xe284 comp cam, stock rods crank, hyper 4 valve relief hyper pistons, ported ede heads, rpm air gap, 750 dp holley hp 727 2800 stall 8 3/4 3.91

"dont want vacuum anything kick in the pants secondaries"

Does this mean you would not consider a vaccum carb?

http://holley.com/TechService/Instructions.asp

n561290572_4326050_2163.jpg
 
kennmadruga said:
then 6.5 should be ok............is this combo new ...just got it runing?....just asking because the print out says may 08..myself a would check the pv and record it.....a blowen pv should cause a noteable amout rich mixture from ide to off ide.....bad cruz performance ect....you may have 3.5 whow knows .....check... good luck..........
Click to expand...

The motor was on the dyno in may. The carb was brand new out of the box on the dyno. My boss would'nt let me leave to go watch the dyno runs! After i got the motor in it ran like azz (as far as idling and of idle acceleration). I've only been able to drive it about 200 miles since its been in the car and would like to work the bugs out before winter.
 
iam not shure what azz means ,if it mean bad(not good) or it mean good i would still check the pv........... also you may try more timing,says 36+ (i run 38 but dont have e heads)holley are not all ways a bolt on carb... you may have to drill holes in the prim butterflys or ajust the sec butterflys just to get a good idle...a good book would be....dave emanuels super tuning and modifying holley carbs.....hope this helps .....good luck
 
I'd buy a wideband 02 sensor.

Innovate sells a very user friendly kit, and FAST sells ones that are a little more money, but easier to use and read while driving (obviously, you need to be careful doing that).

It really helps you diagnose where your problems are.

Rich at idle? Lean/rich with the squirter?

I've always found that if you get your four corner idle squared away really well, the rest gets easier.

Steve
 
Correct me if wrong but isn't the Holley carb you have one of the new HP series? If so they are jetted real rich right out of the box so it doesn't surprise me to see the A/F ratio where it's at. A buddy of mine just put one on a 406 Chevy with aftermarket heads and a real big cam and Victor intake and it ran real rich. They come with 4.5" power valves so that's about right for you since you said yours runs 8" at idle. I'd jet it down 2 jet sizes front and back and see how it does. May even have to go down 3 sizes. The HP Holley's have 3 jet sizes larger than the regular Holley double pumpers just for reference.
 
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