Reversion???
#1476095
07/29/13 05:31 PM
07/29/13 05:31 PM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
OP
master
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OP
master
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Posts: 3,695
nc
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Small block with over 500 passes, 12 to 1 414 W5- 325/240 cfm @.650, small solid roller 260/264 @.050 .685 lift 106cl on 106, max ported M1 small port, 2" spacer, race demon 1000, square jet 90s no pvs, short header 30" 1 3/4 to 1 7/8, 3.5 collector, we turn it to 7k, Intake runners has been very clean till now, starting to see signs of darkening in runners to carb base plate.... whats up with this????
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Re: Reversion???
[Re: emarine01]
#1476096
07/29/13 05:49 PM
07/29/13 05:49 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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Quote:
Small block with over 500 passes, 12 to 1 414 W5- 325/240 cfm @.650, small solid roller 260/264 @.050 .685 lift 106cl on 106, max ported M1 small port, 2" spacer, race demon 1000, square jet 90s no pvs, short header 30" 1 3/4 to 1 7/8, 3.5 collector, we turn it to 7k, Intake runners has been very clean till now, starting to see signs of darkening in runners to carb base plate.... whats up with this????
Might be getting time to do a valve job... with the
bounce the valves take it might be taking its toll
EDIT
Or the spring are going weak and bouncing even more
Last edited by MR_P_BODY; 07/29/13 05:51 PM.
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Re: Reversion???
[Re: MR_P_BODY]
#1476097
07/29/13 06:09 PM
07/29/13 06:09 PM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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Quote:
Quote:
Small block with over 500 passes, 12 to 1 414 W5- 325/240 cfm @.650, small solid roller 260/264 @.050 .685 lift 106cl on 106, max ported M1 small port, 2" spacer, race demon 1000, square jet 90s no pvs, short header 30" 1 3/4 to 1 7/8, 3.5 collector, we turn it to 7k, Intake runners has been very clean till now, starting to see signs of darkening in runners to carb base plate.... whats up with this????
Might be getting time to do a valve job... with the
bounce the valves take it might be taking its toll
EDIT
Or the spring are going weak and bouncing even more
 Reversion was always there, but worn guides added a little oil to it. How do the backs of the intake valves look?
Fastest 300
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Re: Reversion???
[Re: ek3]
#1476099
07/29/13 07:17 PM
07/29/13 07:17 PM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
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OP
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The springs are 2 years old, installed the winter before last, 245 seat 650 open, They are Comp springs for the cam , I have had the carb off several times this year for jetting & fuel issues, I think I pull the carb @ least once a month on ave & never saw the dark staining before, Is it possible that I could have overloaded the engine? I tried some very large tires last month and lost over 1000 rpm trap with poor shift recovery, max RPM went down to 6k and had some popping, could not tell if it was intake or exhaust, engine just sounded bad.
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Re: Reversion???
[Re: emarine01]
#1476100
07/29/13 07:27 PM
07/29/13 07:27 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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Quote:
The springs are 2 years old, installed the winter before last, 245 seat 650 open, They are Comp springs for the cam , I have had the carb off several times this year for jetting & fuel issues, I think I pull the carb @ least once a month on ave & never saw the dark staining before, Is it possible that I could have overloaded the engine? I tried some very large tires last month and lost over 1000 rpm trap with poor shift recovery, max RPM went down to 6k and had some popping, could not tell if it was intake or exhaust, engine just sounded bad.
JMO.. but if you have reversion in the intake thats
from a/or all intake valves being open at the wrong
time... on some engines 2 years is a long time for
valve springs... when did you test them last... I
test mine 3 to 4 times a season OR if something is
changing in performance
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Re: Reversion???
[Re: emarine01]
#1476101
07/29/13 07:47 PM
07/29/13 07:47 PM
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Joined: Aug 2003
Posts: 43,172
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,172
Bend,OR USA
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Quote:
The springs are 2 years old, installed the winter before last, 245 seat 650 open, They are Comp springs for the cam , I have had the carb off several times this year for jetting & fuel issues, I think I pull the carb @ least once a month on ave & never saw the dark staining before, Is it possible that I could have overloaded the engine? I tried some very large tires last month and lost over 1000 rpm trap with poor shift recovery, max RPM went down to 6k and had some popping, could not tell if it was intake or exhaust, engine just sounded bad.
Time to figure out what the motor is saying to you  It ain't happy    Let us know what you find,I would look at the valve spring pressures after checking the valve lash first   Make sure there are no broken inner or outer valve springs 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Reversion???
[Re: emarine01]
#1476106
07/30/13 11:52 PM
07/30/13 11:52 PM
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Joined: Feb 2007
Posts: 1,025
Las Vegas, NV
dodgeboy11
super stock
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super stock
Joined: Feb 2007
Posts: 1,025
Las Vegas, NV
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Quote:
I would think that the valve train would be RPM sensitive with no regard to load..... Correct me if I am wrong..... Remember I am a old Diesel guy here so these light weight go fast engines are kinda new to me 
Load will aggravate the issue because if there's no load then the mixture will light off fairly easily. If things aren't sealing properly, under load it'll show up. One reason why tuning for drivability needs to be done on a water brake type chassis dyno instead of an inertia/roller dyno. The engine thinks it's powering a vehicle that's as heavy as the roller is so it'll hide a lot of drivability issues.
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Re: Reversion???
[Re: emarine01]
#1476107
07/31/13 12:33 AM
07/31/13 12:33 AM
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Joined: Jun 2012
Posts: 1,899
MYRTLE BEACH SOUTH CAROLINA
ek3
top fuel
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top fuel
Joined: Jun 2012
Posts: 1,899
MYRTLE BEACH SOUTH CAROLINA
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Quote:
I would think that the valve train would be RPM sensitive with no regard to load..... Correct me if I am wrong..... Remember I am a old Diesel guy here so these light weight go fast engines are kinda new to me
.. remember the old radial aircraft engines? the extra load of bombs would cause a larger load on the engine and it would not lift to a hi enough altitude to avoid enemy fire! the hi compression with hi loading was blowing out the spark ! Thank you Mr. C.T. mason  for the invention / perfection of the magneto !! Dixie magneto corp.
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Re: Reversion???
[Re: ek3]
#1476108
08/01/13 02:03 PM
08/01/13 02:03 PM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
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Quote:
Quote:
I would think that the valve train would be RPM sensitive with no regard to load..... Correct me if I am wrong..... Remember I am a old Diesel guy here so these light weight go fast engines are kinda new to me
.. remember the old radial aircraft engines? the extra load of bombs would cause a larger load on the engine and it would not lift to a hi enough altitude to avoid enemy fire! the hi compression with hi loading was blowing out the spark ! Thank you Mr. C.T. mason for the invention / perfection of the magneto !! Dixie magneto corp.
I was talking about valve float/ bounce in the valve train being rpm not load related, The valve train is a mechanical spring vs weight/inertia rpm equation, Load as far as I can see has no effect on the stability and sealing ability of the valves.... Unless I am missing something?? If so please explain, The example of the airplane engine is another issue which merits discussion cause that may be part of what's going on with my reversion problem, As I mentioned earlier the engine was under a very high load due to trying to spin up 600 lbs of tire from the hit with a small block with not enough gear for the combo with the possibility of the spark dropping out due to too much gap, I have a spring tester on the way today so we will check for the weak spring / float / bounce and have looked at some jetting issues... may have gone lean after the hit... so I am still trying to hunt down the problem. On another tangent, I looked @ a sbc with a major reversion problem and it does not look the same as my engine, the chevy was burnt / carbon like looking... mine has a dark staining with a little shine to it, I thought it might be oil but its dry... it almost looks like fuel staining but I dont know if thats possible... we have been running 100LL ave gas for the last 2 outings and 110 race with lead the 5 times before? I have been increacing the load on this small block with tires all year and picking up better ets and speed till this point, The engine seemed to stay in the same rpms 6500 to 7k with all the tire combos till this last one... which I may have just gone too far... thats what I meant by overload in my posts, I have gone thru all the fuel system and basic engine checks except spring pressure to this point and cant seem to pinpoint the problem, If I change back to a smaller lighter tire the problem goes away, The only thing I could find out a spec was my coil wire It had 5 ohms instead of 80 ohms per MSD spec of 40 to 50 ohms per ft its 2ft long? If thats a problem chime in here & I will try another wire. Or any thoughts or opinions are very welcome on any topic from this post... Craig
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Re: Reversion???
[Re: emarine01]
#1476109
08/01/13 02:11 PM
08/01/13 02:11 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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Different fuels do have a dye in them and that might be what your seeing... does the color correspond with the fuel your using
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Re: Reversion???
[Re: emarine01]
#1476110
08/01/13 02:32 PM
08/01/13 02:32 PM
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Joined: Aug 2003
Posts: 43,172
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,172
Bend,OR USA
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I had a issue in nuetral with a set of older MSD spiral core wires, they ohm tested well but ran like crap on a new motor, wouldn't idle and a bunch of other symptoms. I had ran those wires on my Duster and replaced them with a new set before selling the car last year, I had a older MSD 7C box on the car, the new car has a MSD 7AL2 box, it is different internally than the older box is so  I replaced them with a new set of spiral core Taylors I had in stock and all was good, remember the coil wire fires on every RPM, not every eigth RPM like the spark plug wires carry Ohms is one consideration on determing the abiltity of a conductor to carry a load, conductance, MHO, is another factor as well as impedance That little tiny stainless steel wire wound around the graphite coated nylon main conductor can be misleading on testing 
Last edited by Cab_Burge; 08/01/13 02:40 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Reversion???
[Re: Cab_Burge]
#1476113
08/01/13 03:54 PM
08/01/13 03:54 PM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
OP
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OP
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Joined: Jan 2007
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Quote:
I had a issue in nuetral with a set of older MSD spiral core wires, they ohm tested well but ran like crap on a new motor, wouldn't idle and a bunch of other symptoms. I had ran those wires on my Duster and replaced them with a new set before selling the car last year, I had a older MSD 7C box on the car, the new car has a MSD 7AL2 box, it is different internally than the older box is so I replaced them with a new set of spiral core Taylors I had in stock and all was good, remember the coil wire fires on every RPM, not every eigth RPM like the spark plug wires carry Ohms is one consideration on determing the abiltity of a conductor to carry a load, conductance, MHO, is another factor as well as impedance That little tiny stainless steel wire wound around the graphite coated nylon main conductor can be misleading on testing
We ditched the MSDs for blue streak 10mm spiral wound last year, they run @ 15 ohms per foot and checked good, the coil wire is a msd that tested low ohms, I also ran ngk 8s non resistor plugs for the first time but have changed back to autolites 3911, Well the springs are pretty close to spec its a little funky getting the pull right on this tester but it looks like 225 lbs is the lightest spring maybe 230.. it depends on which way you hold the handle on the tester & hold your breath, the open pressure is harder to do, this handle could be a little longer for us old guys  but its close to 650 lbs with a little shake I pulled the carb and ran a leak down with out the gauge just 135 lb air pressure checkin the intakes and there was no leakage past the seats.... One more piece of info, we sometimes have to use the engine to help stop the truck... major decell from 7k with two feet standing on the brake  ... so intake vac may be very high @ that point.... I know its not real good for con rods but its better than wrecking the truck or killing someone, thats one of the main reasons for the super light piston and alu rods.
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Re: Reversion???
[Re: oldtimer5151]
#1476114
08/01/13 04:03 PM
08/01/13 04:03 PM
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Joined: Jan 2007
Posts: 3,695
nc
emarine01
OP
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Quote:
I have the same stain in mine. The intake and exhaust valves being open at the same time causes this. This exhaust gas stain is in a place that robs horsepower. I use a anti-reversion plate beneath my carb. and seems to help. The collector length has to be just right to time the returning pulse wave and sonic wave to keep from pushing the residual exhaust gas to the intake. I also need some tips on how to stop this. 
Thats what my friend the cam man thought, He thought it was the overlap vs my short header causing the problem, we are cut on a 106 lsa & installed on 106 maybe more retard due to chain stretch The large load from the big tires dropped us down in rpms where we usually don't spend any time causing the stain
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