Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: Kern Dog]
#2557349
10/02/18 12:05 AM
10/02/18 12:05 AM
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Joined: Jan 2005
Posts: 4,451 Michigan
MarkZ
Worthy
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Worthy
Joined: Jan 2005
Posts: 4,451
Michigan
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I agree but how far off does it have to be to be THIS bad? A loss at high rpm would mean the cam would have to be WAAAAY advanced, right?
I had a 318 in a 74 Duster that was an absolute PIG out of the hole. It would not even peel out on gravel. It ran smooth as glass, quiet and nice. I swapped distributors, carburetors, spark boxes, I cranked the static timing to the moon...nothing made any difference worth mentioning. I pulled the timing cover to see that the cam sprocket was 2 teeth off the mark retarded ! I replaced the set since the chain had slop. Once back together, it would peel out easily on pavement and ran just as smooth as before. I was just stirring the pot. @Goody You said in your original post that the AFR goes lean the closer it gets 4k, but the fuel pressure remains steady all the way through. I'm going to say carb and not just because it's almost the only thing left at this point. lol. It really does sound like fuel starvation. If it were spark it wouldn't go lean and right up where it noses over it would get real choppy like hitting a rev limiter.
Last edited by MarkM; 10/02/18 12:13 AM.
1987 Fifth Avenue - 512/518/D60
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: MarkZ]
#2557353
10/02/18 12:11 AM
10/02/18 12:11 AM
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Joined: Nov 2004
Posts: 25,050 Texas
GoodysGotaCuda
OP
5.7L Hemi, 6spd
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OP
5.7L Hemi, 6spd
Joined: Nov 2004
Posts: 25,050
Texas
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I agree but how far off does it have to be to be THIS bad? A loss at high rpm would mean the cam would have to be WAAAAY advanced, right?
I had a 318 in a 74 Duster that was an absolute PIG out of the hole. It would not even peel out on gravel. It ran smooth as glass, quiet and nice. I swapped distributors, carburetors, spark boxes, I cranked the static timing to the moon...nothing made any difference worth mentioning. I pulled the timing cover to see that the cam sprocket was 2 teeth off the mark retarded ! I replaced the set since the chain had slop. Once back together, it would peel out easily on pavement and ran just as smooth as before. I was just stirring the pot. You said in your original post that the AFR goes lean the closer it gets 4k, but the fuel pressure remains steady all the way through. I'm going to say carb and not just because it's almost the only thing left at this point. lol. It really does sound like fuel starvation. If it were spark it wouldn't go lean and right up where it noses over it would get real choppy like hitting a rev limiter. Ignition misfires certainly cause lean AFR readings. The cylinders pump pure oxygen ["air"] across the wideband, it's an oxygen sensor, not a fuel sensor. We'll see here soon, there are only so many things that can cause it. Coil is next, it's newer, but a weak spark could be dropping out, I suppose. From there I'll rob the rebuilt 600 AFB from the Dart and stick it on there. After that, I'll find some Tannerite.
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: GoodysGotaCuda]
#2557441
10/02/18 08:43 AM
10/02/18 08:43 AM
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Joined: Aug 2007
Posts: 603 Mass
charge70
mopar
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mopar
Joined: Aug 2007
Posts: 603
Mass
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Did you happen to check float drop when you had the carb apart?
1970 Dodge Charger R/T S.E.
1969 Dodge Dart GTS 440 M-Code
1970 Dodge Charger 500 383/4-speed w/A.C.
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: charge70]
#2557447
10/02/18 09:10 AM
10/02/18 09:10 AM
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Joined: Nov 2004
Posts: 25,050 Texas
GoodysGotaCuda
OP
5.7L Hemi, 6spd
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OP
5.7L Hemi, 6spd
Joined: Nov 2004
Posts: 25,050
Texas
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Did you happen to check float drop when you had the carb apart? Yes, within the 15/16"-1" spec for edelbrock, 7/16" when shut
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: FurryStump]
#2557614
10/02/18 01:01 PM
10/02/18 01:01 PM
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Joined: Nov 2004
Posts: 25,050 Texas
GoodysGotaCuda
OP
5.7L Hemi, 6spd
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OP
5.7L Hemi, 6spd
Joined: Nov 2004
Posts: 25,050
Texas
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Fuel pressure does not mean fuel in the bowls. You could be out flowing the needle and seats add that to questionable fuel pressure and there you go. I understand. The fuel height within the carb is to spec and to the top of the baffles, validated by running the electronic fuel pump then pulling the air horn. In addition the fuel pressure was validated at 5-6psi with a mechanical gauge on the windshield while driving. I would fine it hard to imagine going from an idle directly to 4000rpm with no load could starve the carb. Perhaps a sustained 2nd/3rd gear pull, but free revving in neutral doesn’t demand much fuel.
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: GoodysGotaCuda]
#2557636
10/02/18 01:23 PM
10/02/18 01:23 PM
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Joined: Jan 2003
Posts: 14,514 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,514
So. Burlington, Vt.
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I’d be very surprised to find this was a fuel supply related problem.
I’m not 100% convinced it’s not valvetrain, but it certainly appears that area is decent, since the heads and cam have already been successfully run on another motor.
When it comes to troubleshooting electrical stuff, whenever possible I like to start out by swapping out “everything”.
For the ignition, I’d see if you could borrow an old points distributor and coil/ballast resistor, and hot wire it to the battery. If not, then I’d swap in a “known good” distributor, and hot wire in another box/coil/resistor.
I would use none of what’s on the motor now in the ignition system, including the primary wiring.
All that being said........ disconnecting the tac is too easy to not try that first.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: B3422W5]
#2557678
10/02/18 02:36 PM
10/02/18 02:36 PM
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Joined: Aug 2006
Posts: 2,537 God's Country Maryland
GODSCOUNTRY340
master
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master
Joined: Aug 2006
Posts: 2,537
God's Country Maryland
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It takes 30 seconds to unhook the tach from the negative side of the coil, I've seen a bad tach cause your problem.
I love the smell of Deer guts in the morning, it smells like... VICTORY!
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: GODSCOUNTRY340]
#2557733
10/02/18 04:09 PM
10/02/18 04:09 PM
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Joined: Sep 2011
Posts: 1,487 STL
cdstl
pro stock
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pro stock
Joined: Sep 2011
Posts: 1,487
STL
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It takes 30 seconds to unhook the tach from the negative side of the coil, I've seen a bad tach cause your problem. What he said
1972 Cuda 340 4 speed, 2001 Ram CTD 4x4 6 speed, 1970 Duster 408 4 speed, 1996 Ram 5.9 2x4 auto, 1965 Coronet 500
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: GoodysGotaCuda]
#2557928
10/02/18 08:36 PM
10/02/18 08:36 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
master
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master
Joined: Sep 2014
Posts: 4,457
Washington
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So I’m guessing you didn’t degree the cam in. Nope. There's no reason why it shouldn't run fine installed dot-dot with two different timing gear sets. So you'll have no idea where the cam timing and evidently you don't care. Try and not be offended when I say that you shouldn't assemble engines. For you, or anyone else. Until you learn how to degree a cam, and WHY you do it, every single time. I can give you reasons why dot to dot is a bad way to do it, but you wouldn't care. There is no reason EVER to skip the simple process of degreeing a cam. EVER.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: madscientist]
#2557933
10/02/18 08:47 PM
10/02/18 08:47 PM
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Joined: Nov 2004
Posts: 25,050 Texas
GoodysGotaCuda
OP
5.7L Hemi, 6spd
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OP
5.7L Hemi, 6spd
Joined: Nov 2004
Posts: 25,050
Texas
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So I’m guessing you didn’t degree the cam in. Nope. There's no reason why it shouldn't run fine installed dot-dot with two different timing gear sets. So you'll have no idea where the cam timing and evidently you don't care. Try and not be offended when I say that you shouldn't assemble engines. For you, or anyone else. Until you learn how to degree a cam, and WHY you do it, every single time. I can give you reasons why dot to dot is a bad way to do it, but you wouldn't care. There is no reason EVER to skip the simple process of degreeing a cam. EVER. Thanks for the feedback.
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: madscientist]
#2557940
10/02/18 09:06 PM
10/02/18 09:06 PM
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Joined: Dec 2009
Posts: 20,668 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,668
in a cattle trailer down by th...
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So I’m guessing you didn’t degree the cam in. Nope. There's no reason why it shouldn't run fine installed dot-dot with two different timing gear sets. So you'll have no idea where the cam timing and evidently you don't care. Try and not be offended when I say that you shouldn't assemble engines. For you, or anyone else. Until you learn how to degree a cam, and WHY you do it, every single time. I can give you reasons why dot to dot is a bad way to do it, but you wouldn't care. There is no reason EVER to skip the simple process of degreeing a cam. EVER. There actually are good reasons to not degree a cam every single time, but you wouldn't care so why bother. Let us know when the coil or distributor fix your problem.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: Guitar Jones]
#2558007
10/02/18 11:02 PM
10/02/18 11:02 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
master
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master
Joined: Sep 2014
Posts: 4,457
Washington
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So I’m guessing you didn’t degree the cam in. Nope. There's no reason why it shouldn't run fine installed dot-dot with two different timing gear sets. So you'll have no idea where the cam timing and evidently you don't care. Try and not be offended when I say that you shouldn't assemble engines. For you, or anyone else. Until you learn how to degree a cam, and WHY you do it, every single time. I can give you reasons why dot to dot is a bad way to do it, but you wouldn't care. There is no reason EVER to skip the simple process of degreeing a cam. EVER. There actually are good reasons to not degree a cam every single time, but you wouldn't care so why bother. Let us know when the coil or distributor fix your problem. Yeah, don't degree the cam if it's the same cam and the same timing set. That's about it. Other than that, degree the cam. Takes less than 20 minutes. I've seen name brand [censored] that when used together were 8 degrees off. And that was good, quality parts. They just had tolerance stack up. Again, you degree the cam every time. Unless it's the same parts. It's not that hard.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: madscientist]
#2558035
10/02/18 11:49 PM
10/02/18 11:49 PM
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Joined: Feb 2005
Posts: 20,201 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,201
PA.
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I think you are wasting your breath. You can only help those that want to do things the right way.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: pittsburghracer]
#2558057
10/03/18 12:52 AM
10/03/18 12:52 AM
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Joined: Dec 2009
Posts: 20,668 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,668
in a cattle trailer down by th...
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Right! The factory is degreeing every single engine that comes down the line. Moving the cam 2 degrees changes its peak power band about 50 rpms. So moving it 8 degrees changes it about 200 rpms. You figure 8 degrees advanced or retarded that is a spread of about 400 rpm. Ooh, I can feel the difference already.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: LA 360 - Hits a wall at 4,000rpm - *not cam timing*
[Re: Guitar Jones]
#2558066
10/03/18 01:33 AM
10/03/18 01:33 AM
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Joined: Feb 2005
Posts: 20,201 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,201
PA.
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Wow. I guess I give some guys more credit than they deserve.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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