Previous Thread
Next Thread
Print Thread
Page 1 of 2 1 2
Hemi running problems #2936123
06/23/21 05:56 PM
06/23/21 05:56 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
I have a 528 Iron headed 10 to 1 Hemi. Comp flat tappet hydraulic .535/.541, Mancini ready to run dizzy with a MSD blaster SS coil. Mopar performance high rise intake with a single pro systems 4150hp carb . Timing set at 32 total vacuum can capped. Car starts fine hot or cold. Runs strong but does not like low speed running. Likes to buck and surge at light to medium throttle. Vacuum is 10. Plugs are NGK R5671-9. They all seem to be firing but are black and sooty. Power valve is 6.5 with 84 mains. Trying to sort it out in a positive manner. Thanks.

Re: Hemi running problems [Re: NITROUSN] #2936161
06/23/21 08:04 PM
06/23/21 08:04 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
C
Cab_Burge Online work
I Win
Cab_Burge  Online Work
I Win
C

Joined: Aug 2003
Posts: 43,007
Bend,OR USA
Put a #7 or #6 heat range plug in it and see if that helps you or not scope twocents
Also adjust the idle fuel mixture with the motor warmed up to driving temps and adjust the idle fuel feed to get it as lean as you can and have it still idle and go from neutral into gear without stalling wrench scope twocents


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Hemi running problems [Re: Cab_Burge] #2936191
06/23/21 09:03 PM
06/23/21 09:03 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Thanks. It is a manual 5 speed transmission. Just looking at what would of been used in a stock 69 they are heat range 4. I may be way to cold. I feel I am fighting multiple issues. What do you think of the power valve with my 10 inches of vacuum?

Re: Hemi running problems [Re: NITROUSN] #2936197
06/23/21 09:12 PM
06/23/21 09:12 PM
Joined: May 2005
Posts: 1,944
Apollo, PA.
B1MAXX Offline
top fuel
B1MAXX  Offline
top fuel

Joined: May 2005
Posts: 1,944
Apollo, PA.
If you have a plug, plug the power valve see if part throttle is better. If it is then lower the power valve to keep it out at part throttle.

Last edited by B1MAXX; 06/23/21 09:13 PM.
Re: Hemi running problems [Re: B1MAXX] #2936202
06/23/21 09:16 PM
06/23/21 09:16 PM
Joined: May 2005
Posts: 1,944
Apollo, PA.
B1MAXX Offline
top fuel
B1MAXX  Offline
top fuel

Joined: May 2005
Posts: 1,944
Apollo, PA.
If its pump gas I have seen certain blends try and vapor/boil when driving causing almost flooding type conditions. Seems to happen with winter blend pump gas.

Re: Hemi running problems [Re: B1MAXX] #2936203
06/23/21 09:20 PM
06/23/21 09:20 PM
Joined: May 2005
Posts: 1,944
Apollo, PA.
B1MAXX Offline
top fuel
B1MAXX  Offline
top fuel

Joined: May 2005
Posts: 1,944
Apollo, PA.
check float level, maybe lower to delay main circuit at part throttle.

Re: Hemi running problems [Re: B1MAXX] #2936215
06/23/21 09:43 PM
06/23/21 09:43 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Originally Posted by B1MAXX
If its pump gas I have seen certain blends try and vapor/boil when driving causing almost flooding type conditions. Seems to happen with winter blend pump gas.


You could be on to something there. I was charging the a/c and going over the basic adjustments when I noticed steam like smoke coming out of the bowl vent. I thought that was very odd. It also seems the hotter it gets or the longer I run it the worse it seems. I filled this tank when I calibrated the fuel gauge end of March first week of April. I have run about half of it out. I may just drain the rest for the mower and fill with new premium.

Re: Hemi running problems [Re: B1MAXX] #2936218
06/23/21 09:44 PM
06/23/21 09:44 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Originally Posted by B1MAXX
check float level, maybe lower to delay main circuit at part throttle.


I did do that last fall when I first got it running. I can recheck to be sure.

Re: Hemi running problems [Re: B1MAXX] #2936219
06/23/21 09:45 PM
06/23/21 09:45 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Originally Posted by B1MAXX
If you have a plug, plug the power valve see if part throttle is better. If it is then lower the power valve to keep it out at part throttle.


I do not have a plug.

Re: Hemi running problems [Re: NITROUSN] #2936223
06/23/21 09:52 PM
06/23/21 09:52 PM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline
I Live Here
Dragula  Offline
I Live Here

Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Originally Posted by NITROUSN
I have a 528 Iron headed 10 to 1 Hemi. Comp flat tappet hydraulic .535/.541, Mancini ready to run dizzy with a MSD blaster SS coil. Mopar performance high rise intake with a single pro systems 4150hp carb . Timing set at 32 total vacuum can capped. Car starts fine hot or cold. Runs strong but does not like low speed running. Likes to buck and surge at light to medium throttle. Vacuum is 10. Plugs are NGK R5671-9. They all seem to be firing but are black and sooty. Power valve is 6.5 with 84 mains. Trying to sort it out in a positive manner. Thanks.


What size carb? Bet its a tad rich at idle and big time lean else where if not way under sized. Typically a Hemi likes a bigger carb than the book calls for. Our 474-484 Hemi's like 950 to 1050 sized 4150 carbs...Use the Proform race carb jetting. We find their calibrations to be very close for all our builds in 4150 size carbs.

I had a Prosystems 1000, and it would idle and drive around town, but if you stepped on it, it went so lean it nearly stalled. I put the same calibration in that Proform had for their carb of the same size in the Prosystems, and what a difference. I would start there...Also, I am anti power valve and always jet my stuff square.

Last edited by Dragula; 06/23/21 09:53 PM.

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Hemi running problems [Re: Dragula] #2936233
06/23/21 10:07 PM
06/23/21 10:07 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Originally Posted by Dragula
Originally Posted by NITROUSN
I have a 528 Iron headed 10 to 1 Hemi. Comp flat tappet hydraulic .535/.541, Mancini ready to run dizzy with a MSD blaster SS coil. Mopar performance high rise intake with a single pro systems 4150hp carb . Timing set at 32 total vacuum can capped. Car starts fine hot or cold. Runs strong but does not like low speed running. Likes to buck and surge at light to medium throttle. Vacuum is 10. Plugs are NGK R5671-9. They all seem to be firing but are black and sooty. Power valve is 6.5 with 84 mains. Trying to sort it out in a positive manner. Thanks.


What size carb? Bet its a tad rich at idle and big time lean else where if not way under sized. Typically a Hemi likes a bigger carb than the book calls for. Our 474-484 Hemi's like 950 to 1050 sized 4150 carbs...Use the Proform race carb jetting. We find their calibrations to be very close for all our builds in 4150 size carbs.

I had a Prosystems 1000, and it would idle and drive around town, but if you stepped on it, it went so lean it nearly stalled. I put the same calibration in that Proform had for their carb of the same size in the Prosystems, and what a difference. I would start there...Also, I am anti power valve and always jet my stuff square.


I am not 100 percent sure. Muscle Motors had it built when I made the deal. They did dyno the motor with it. I took it apart today and made notes what was in it. I might try to call Pro Systems to see if they can tell me. It is the Pro Series XE. One would assume it would be adequate. But assume usually it what bites a guy.

Re: Hemi running problems [Re: NITROUSN] #2936241
06/23/21 10:15 PM
06/23/21 10:15 PM
Joined: May 2005
Posts: 1,944
Apollo, PA.
B1MAXX Offline
top fuel
B1MAXX  Offline
top fuel

Joined: May 2005
Posts: 1,944
Apollo, PA.
Originally Posted by NITROUSN
Originally Posted by B1MAXX
If its pump gas I have seen certain blends try and vapor/boil when driving causing almost flooding type conditions. Seems to happen with winter blend pump gas.


You could be on to something there. I was charging the a/c and going over the basic adjustments when I noticed steam like smoke coming out of the bowl vent. I thought that was very odd. It also seems the hotter it gets or the longer I run it the worse it seems. I filled this tank when I calibrated the fuel gauge end of March first week of April. I have run about half of it out. I may just drain the rest for the mower and fill with new premium.


Exactly what first caught my eye on the one time I came across this also. I forget what we put in it, it was either 100 unleaded race gas or bp premium...been a while but it fixed it. It was actually causing the carb to flood, was like the needle and seat couldn't deal with the vapor.

Re: Hemi running problems [Re: B1MAXX] #2936246
06/23/21 10:27 PM
06/23/21 10:27 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Originally Posted by B1MAXX
Originally Posted by NITROUSN
Originally Posted by B1MAXX
If its pump gas I have seen certain blends try and vapor/boil when driving causing almost flooding type conditions. Seems to happen with winter blend pump gas.


You could be on to something there. I was charging the a/c and going over the basic adjustments when I noticed steam like smoke coming out of the bowl vent. I thought that was very odd. It also seems the hotter it gets or the longer I run it the worse it seems. I filled this tank when I calibrated the fuel gauge end of March first week of April. I have run about half of it out. I may just drain the rest for the mower and fill with new premium.


Exactly what first caught my eye on the one time I came across this also. I forget what we put in it, it was either 100 unleaded race gas or bp premium...been a while but it fixed it. It was actually causing the carb to flood, was like the needle and seat couldn't deal with the vapor.


This is BP premium.

Re: Hemi running problems [Re: NITROUSN] #2936253
06/23/21 10:36 PM
06/23/21 10:36 PM
Joined: Jan 2003
Posts: 19,304
Las Vegas
Al_Alguire Offline
I Live Here
Al_Alguire  Offline
I Live Here

Joined: Jan 2003
Posts: 19,304
Las Vegas
That plug is WAY to cold for your application. I would START there


"I am not ashamed to confess I am ignorant of what I do not know."

"It's never wrong to do the right thing"
Re: Hemi running problems [Re: NITROUSN] #2936256
06/23/21 10:55 PM
06/23/21 10:55 PM
Joined: May 2005
Posts: 1,944
Apollo, PA.
B1MAXX Offline
top fuel
B1MAXX  Offline
top fuel

Joined: May 2005
Posts: 1,944
Apollo, PA.
Originally Posted by NITROUSN
Originally Posted by B1MAXX
Originally Posted by NITROUSN
Originally Posted by B1MAXX
If its pump gas I have seen certain blends try and vapor/boil when driving causing almost flooding type conditions. Seems to happen with winter blend pump gas.


You could be on to something there. I was charging the a/c and going over the basic adjustments when I noticed steam like smoke coming out of the bowl vent. I thought that was very odd. It also seems the hotter it gets or the longer I run it the worse it seems. I filled this tank when I calibrated the fuel gauge end of March first week of April. I have run about half of it out. I may just drain the rest for the mower and fill with new premium.


Exactly what first caught my eye on the one time I came across this also. I forget what we put in it, it was either 100 unleaded race gas or bp premium...been a while but it fixed it. It was actually causing the carb to flood, was like the needle and seat couldn't deal with the vapor.


This is BP premium.

still could be winter blend...and I could be wrong on what it was, but I wasn't the only one having those problems at that time. Different blend fixed it. I didn't think it would, but someone more familiar with the problem keyed me in on it.
Fresh set of hotter plugs couldn't hurt either, but then you'll lose track of what changes did what.

Re: Hemi running problems [Re: Al_Alguire] #2936318
06/24/21 08:41 AM
06/24/21 08:41 AM
Joined: Jan 2003
Posts: 13,319
Marion, South Carolina [><]
an8sec70cuda Offline
I Live Here
an8sec70cuda  Offline
I Live Here

Joined: Jan 2003
Posts: 13,319
Marion, South Carolina [><]
Originally Posted by Al_Alguire
That plug is WAY to cold for your application. I would START there

iagree iagree Change the plugs before you do anything else.


CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
Re: Hemi running problems [Re: an8sec70cuda] #2936343
06/24/21 09:50 AM
06/24/21 09:50 AM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Thanks for all the replies. I have used and like NGK plugs. No nitrous so should I run a projected or non projected tip. A stock motor in the day ran a heat range 4. This is all street with an occasional romp on the throttle. Is heat range 4 to hot?

Re: Hemi running problems [Re: NITROUSN] #2936373
06/24/21 11:15 AM
06/24/21 11:15 AM
Joined: Jun 2014
Posts: 3,105
Md.
C
carnut68 Online content
master
carnut68  Online Content
master
C

Joined: Jun 2014
Posts: 3,105
Md.
Originally Posted by NITROUSN
Originally Posted by Dragula
Originally Posted by NITROUSN
I have a 528 Iron headed 10 to 1 Hemi. Comp flat tappet hydraulic .535/.541, Mancini ready to run dizzy with a MSD blaster SS coil. Mopar performance high rise intake with a single pro systems 4150hp carb . Timing set at 32 total vacuum can capped. Car starts fine hot or cold. Runs strong but does not like low speed running. Likes to buck and surge at light to medium throttle. Vacuum is 10. Plugs are NGK R5671-9. They all seem to be firing but are black and sooty. Power valve is 6.5 with 84 mains. Trying to sort it out in a positive manner. Thanks.


What size carb? Bet its a tad rich at idle and big time lean else where if not way under sized. Typically a Hemi likes a bigger carb than the book calls for. Our 474-484 Hemi's like 950 to 1050 sized 4150 carbs...Use the Proform race carb jetting. We find their calibrations to be very close for all our builds in 4150 size carbs.

I had a Prosystems 1000, and it would idle and drive around town, but if you stepped on it, it went so lean it nearly stalled. I put the same calibration in that Proform had for their carb of the same size in the Prosystems, and what a difference. I would start there...Also, I am anti power valve and always jet my stuff square.


I am not 100 percent sure. Muscle Motors had it built when I made the deal. They did dyno the motor with it. I took it apart today and made notes what was in it. I might try to call Pro Systems to see if they can tell me. It is the Pro Series XE. One would assume it would be adequate. But assume usually it what bites a guy.
I bought a Pro Systems [4150] carb and it wouldn't idle at all out of the box took a lot of tuning. WOT was good.


America First!
Re: Hemi running problems [Re: carnut68] #2936388
06/24/21 12:16 PM
06/24/21 12:16 PM
Joined: Jan 2003
Posts: 2,289
NE Ohio
DoubleD Offline
top fuel
DoubleD  Offline
top fuel

Joined: Jan 2003
Posts: 2,289
NE Ohio
By chance did you re-curve your distributer - sounds like you may need some more initial timing on it - that ready to run dizzy has a big curve that usually needs tightened up a little

Re: Hemi running problems [Re: carnut68] #2936402
06/24/21 01:13 PM
06/24/21 01:13 PM
Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
N
NITROUSN Offline OP
I Live Here
NITROUSN  Offline OP
I Live Here
N

Joined: Jan 2003
Posts: 18,389
UPPER MICHIGAN, MARQUETTE COUN...
Originally Posted by carnut68
Originally Posted by NITROUSN
Originally Posted by Dragula
Originally Posted by NITROUSN
I have a 528 Iron headed 10 to 1 Hemi. Comp flat tappet hydraulic .535/.541, Mancini ready to run dizzy with a MSD blaster SS coil. Mopar performance high rise intake with a single pro systems 4150hp carb . Timing set at 32 total vacuum can capped. Car starts fine hot or cold. Runs strong but does not like low speed running. Likes to buck and surge at light to medium throttle. Vacuum is 10. Plugs are NGK R5671-9. They all seem to be firing but are black and sooty. Power valve is 6.5 with 84 mains. Trying to sort it out in a positive manner. Thanks.


What size carb? Bet its a tad rich at idle and big time lean else where if not way under sized. Typically a Hemi likes a bigger carb than the book calls for. Our 474-484 Hemi's like 950 to 1050 sized 4150 carbs...Use the Proform race carb jetting. We find their calibrations to be very close for all our builds in 4150 size carbs.

I had a Prosystems 1000, and it would idle and drive around town, but if you stepped on it, it went so lean it nearly stalled. I put the same calibration in that Proform had for their carb of the same size in the Prosystems, and what a difference. I would start there...Also, I am anti power valve and always jet my stuff square.


I am not 100 percent sure. Muscle Motors had it built when I made the deal. They did dyno the motor with it. I took it apart today and made notes what was in it. I might try to call Pro Systems to see if they can tell me. It is the Pro Series XE. One would assume it would be adequate. But assume usually it what bites a guy.
I bought a Pro Systems [4150] carb and it wouldn't idle at all out of the box took a lot of tuning. WOT was good.


What did you do to make it work. Mine idles and wide open is fine. Just low speed surge and jerk along with hesitation at light throttle tip in.

Page 1 of 2 1 2






Powered by UBB.threads™ PHP Forum Software 7.7.1