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Carb. Problem
#1462361
07/03/13 05:10 PM
07/03/13 05:10 PM
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Joined: Jan 2003
Posts: 3,862
N.E. Ohio
6bblFLASH
OP
master
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OP
master
Joined: Jan 2003
Posts: 3,862
N.E. Ohio
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Had posted a while back that my HP950 would not get me the AFR I wanted no-matter what I tried. Moved the O2 location to the collectors,,,same results. To get the AFR even close I had to BLOCK the Hi-bleeds and go up 12-jets=12.4 AFR. I thought after running it last it was WAY rich,because it went quicker with less fuel,however the MPH never changed with the ET`s. So today took out more fuel and its worse and the O2 shows the numbers to go with the lack of power. With "normal" jetting it does`nt want to pull past 3,500.  Jetted super fat it runs strong up to about 5,000 and hits a wall=12.4 AFR I`ve tried larger needle/seats,larger fuel line/ electric pumps. AFR jumps to what ever its going to read as SOON as you crack the throttle, IE: from a roll/at highway speed/off the line etc... originally thought fuel volume BUT it is instant--no time for bowls to empty. Set-up like a "normal" carb yeilds an AFR of 15.1 to 1 I guess I need another carb,but regardlees WTF is going on?  Oh,and I took the plugs out of the emulsion wells and ran a drill bit thru them,same with booster passages. EVERYThing is open I`ve done ALOT of carb. stuff over the years,but I just can`t see the issue here........
Last edited by 6bblFLASH; 07/03/13 05:25 PM.
70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!
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Re: Carb. Problem
[Re: 6bblFLASH]
#1462364
07/04/13 12:11 AM
07/04/13 12:11 AM
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Joined: Jun 2012
Posts: 1,905
MYRTLE BEACH SOUTH CAROLINA
ek3
top fuel
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top fuel
Joined: Jun 2012
Posts: 1,905
MYRTLE BEACH SOUTH CAROLINA
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sorry about that... annular -dropped, thinking that rpm thing... prob. does not mean much here .I know how wild the thoughts can get when chasing the ghost.  so 12.2 is the richest yet? do you trust the readings? where would you like to be @ Wot. and what rpm? the 12.2 is an avg. of 4 cyls ?
Last edited by ek3; 07/04/13 01:16 AM.
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Re: Carb. Problem
[Re: ek3]
#1462365
07/04/13 03:56 AM
07/04/13 03:56 AM
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Joined: Jan 2003
Posts: 3,862
N.E. Ohio
6bblFLASH
OP
master
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OP
master
Joined: Jan 2003
Posts: 3,862
N.E. Ohio
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Yes 12.2 is the richest I`ve seen. Others with these blowers made best power in the 11.8 to 12.2 range. The readings were off the passenger side,and at the X-pipe. A couple odd things to go with these issues: Plugs are clean like lean,never rattles the valves even with 38* timing. It "surges" about the 1,000 ft mark when you run the 12.2 AFR . Runs smooth but slower 2-MPH with less jet AFR 13.3. 60ft loves the rich stuff of course ,but 330 times like it leaner. Best to worst MPH is 111 to 109 ,,,that includes 3-different cams and all the tuning that has`nt worked. It just goes so far and flattens out.  Now if you take it out on the highway and stay with it,it`ll run well past 6,000 in any gear. Thoughts?
70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!
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Re: Carb. Problem
[Re: 6bblFLASH]
#1462368
07/04/13 10:23 PM
07/04/13 10:23 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I think your boost reference is wrong... its lean all the time... whats your fuel pressure during a run... what ever it is I would go UP 
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Re: Carb. Problem
[Re: MR_P_BODY]
#1462369
07/04/13 11:41 PM
07/04/13 11:41 PM
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Joined: Jan 2003
Posts: 3,862
N.E. Ohio
6bblFLASH
OP
master
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OP
master
Joined: Jan 2003
Posts: 3,862
N.E. Ohio
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The boost reference is in the manifold,that part is right. Is the powervalve doing its job? That may be another issue. I need to block it and try that too. Exhaust is 1-7/8th headers/3" collectors,2-1/2" system,X-pipe,and all the way to the bumper. Its a Pypes S/S system with their mufflers. HP is really a guess the way it runs 450? I don`t know why it hits a "wall". The exhaust is a possibility,the heads --cleaned up stock castings,and also valve springs. But as I said if you stay in it it`ll rev to moon,but the good power is all done at 5,000. New cam is 110c/l 231/237@ .050which is what Compcams recommended. Only makes 3-4lbs boost now. Last cam was 114 c/l 248 @ .050 and made 5-lbs boost . I know improved air-flow will reduce boost but gain power,have`nt seen that yet...... 
70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!
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Re: Carb. Problem
[Re: MR_P_BODY]
#1462371
07/05/13 12:09 AM
07/05/13 12:09 AM
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Joined: Jan 2003
Posts: 3,862
N.E. Ohio
6bblFLASH
OP
master
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OP
master
Joined: Jan 2003
Posts: 3,862
N.E. Ohio
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No,,except for the boost readings and the cruise vacuum you would never know I opened the hood. Plugs are clean/light tan,,,definetly not rich. The more I think about what i`ve tried in 2-yrs of tinkering, i`m beginning to wonder if thats all thats in it? MPH is REALLY stubborn to change so far,ET responds fairly well. Always easier to go slower  I`m about 3-weeks from getting to run it again unlees something changes at work. So i will keep trying till it snows. Just a bit frustrated,streetcars are supposed to be easy after racing for 30-yrs  
70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!
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Re: Carb. Problem
[Re: 6bblFLASH]
#1462374
07/05/13 12:53 AM
07/05/13 12:53 AM
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Joined: Jun 2012
Posts: 1,905
MYRTLE BEACH SOUTH CAROLINA
ek3
top fuel
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top fuel
Joined: Jun 2012
Posts: 1,905
MYRTLE BEACH SOUTH CAROLINA
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Quote:
No,,except for the boost readings and the cruise vacuum you would never know I opened the hood.
Plugs are clean/light tan,,,definetly not rich.
The more I think about what i`ve tried in 2-yrs of tinkering, i`m beginning to wonder if thats all thats in it?
MPH is REALLY stubborn to change so far,ET responds fairly well.
Always easier to go slower
I`m about 3-weeks from getting to run it again unlees something changes at work.
So i will keep trying till it snows.
Just a bit frustrated,streetcars are supposed to be easy after racing for 30-yrs
the intake side looks like it has the advantage for sure !!  mabe [very likely] a bottle neck in the heads . I have had better luck with no power valve in the rear and jetting the holes  gains are waiting on the exh side in my opinion  hope it works out. 
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Re: Carb. Problem
[Re: 6bblFLASH]
#1462375
07/05/13 02:11 AM
07/05/13 02:11 AM
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Joined: Aug 2003
Posts: 43,915
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,915
Bend,OR USA
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Quote:
Exhaust is 1-7/8th headers/3" collectors, 2-1/2 system, X-pipe, and allthe way to the bumper. .
Its a Pypes S/S system with their mufflers.
HP is really a guess the way it runs 450?
I don`t know why it hits a "wall".
The exhaust is a possibility,the heads --cleaned up stock castings,and also valve springs.
DING, DING, Ding chicken dinner, we have a winner Your exhaust sytem is the choke I had a 440 powered 1969 Dart that had a set of Hooker 1 7/8 primary pipes with 3.5 inch collectors feeding into a set of the old 2.5 inch in and out Turbo mufflers and then out the side in front of the rear tires ala T/A Challenger style. I ran the car three runs one night with a set of new 29.5x29x15 slicks, I let the tire pressure down from 12 lbs. to 11 lbs and then 10 lbs, the car ran 12.31 at 109.45 MPH on the first run, next run with 11 lbs it ran 12.27 at 109.53 MPH, the last run it ran 12.23 at 109.65 MPH. That was at night at LACR, it was cold and damp that Friday night. I came back the next day and removed the exhaust from the headers, it was a little warmer and a little dryer, about the same D.A. according to my weather station. The car ran 11.39 ET at 117.7 MPH with no other changes I swore it hadn't ran that fast so I made another run in the other lane and it ran 11.41 at 117.56 , it had warmed up some more so that exhaust made that much difference on that motor, it wasn't a very good motor either, your motor shuold make a lot more power at 3 lbs of boost than that one would with a single carb and no power adders Try removing the exhaust next time you take it out  Let us know how that does
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Carb. Problem
[Re: Cab_Burge]
#1462376
07/05/13 02:47 AM
07/05/13 02:47 AM
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Joined: Jan 2003
Posts: 3,862
N.E. Ohio
6bblFLASH
OP
master
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OP
master
Joined: Jan 2003
Posts: 3,862
N.E. Ohio
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Looking backwards at the results of this new cam with tighter lobe centers 110c/l versus old 114c/l and the loss in MPH the exhaust is a strong possibility.
The primary pipe is probably a bigger factor than the 2.5 exhuast pipes. There are some really fast cars with 2.5 pipes,but a large primary and larger collector than mine.
Next issue that exhaust is a 1200 dollar investment,so not so easy to just try.
Uncorking it is easy tho.
I will try it.
I need to make some collector exstensions to put on too when uncorked.
70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!
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Re: Carb. Problem
[Re: 6bblFLASH]
#1462378
07/05/13 03:18 AM
07/05/13 03:18 AM
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Joined: Jun 2012
Posts: 1,905
MYRTLE BEACH SOUTH CAROLINA
ek3
top fuel
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top fuel
Joined: Jun 2012
Posts: 1,905
MYRTLE BEACH SOUTH CAROLINA
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Quote:
Looking backwards at the results of this new cam with tighter lobe centers 110c/l versus old 114c/l and the loss in MPH the exhaust is a strong possibility.
The primary pipe is probably a bigger factor than the 2.5 exhuast pipes. There are some really fast cars with 2.5 pipes,but a large primary and larger collector than mine.--- THE EXH GAS IS 1700 DEG COMING INTO THE PRIMARY TUBE, GUESS WHAT IT IS DOWNSTREAM . HEAT = SPEED... A BIGGER COLLECTOR W/ BIGGER PIPE IS MY GUESS....-----
Next issue that exhaust is a 1200 dollar investment,so not so easy to just try.
Uncorking it is easy tho.
I will try it.
I need to make some collector exstensions to put on too when uncorked.
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Re: Carb. Problem
[Re: 6bblFLASH]
#1462380
07/05/13 08:56 AM
07/05/13 08:56 AM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Looking backwards at the results of this new cam with tighter lobe centers 110c/l versus old 114c/l and the loss in MPH the exhaust is a strong possibility.
The primary pipe is probably a bigger factor than the 2.5 exhuast pipes. There are some really fast cars with 2.5 pipes,but a large primary and larger collector than mine.
Next issue that exhaust is a 1200 dollar investment,so not so easy to just try.
Uncorking it is easy tho.
I will try it.
I need to make some collector exstensions to put on too when uncorked.
Pressurized engines dont need the collectors so forget
that part
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almost sounds like exhaust is walling up .. how much hp into what size pipes /exh system? 
