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| cool exhaust on one side and hot on the other https://slantsix.org/forum/viewtopic.php?t=62625 |
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| Author: | twister6 [ Fri Jul 20, 2018 5:19 pm ] |
| Post subject: | cool exhaust on one side and hot on the other |
Hey guys been awhile since I've been around. Just completed a build on my 225 with the hurricane intake 650 holley, wiseco piston and molnar rods balanced and flowed. Compression around 11/1. I have the shorty headers with dual exhaust. Exhaust on the left side sound a lot loperer with white smoke than the right side . Left side has a popping lumping sound and the left more of a even rumble. I'm running the 270/280 split pattern from erson. Holding my hands at the tailpipes the left side seems like it has some flow of cooler air at intermitting sequences, wheres the right side has a much hotter temp and a smoother sound. No X pipe just straight out. Took it on a test drive, and the more I drive it the hotter it gets, and never settles on a good running temp..if I keep going it will overheat. I just had the head reworked, all new bottom end..Any ideas what could be causing this. |
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| Author: | emsvitil [ Fri Jul 20, 2018 5:55 pm ] |
| Post subject: | Re: cool exhaust on one side and hot on the other |
Misfire. To check ignition, switch front 3 plugs and wires with rear 3 plugs and wires and see if problem changes to the other side. |
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| Author: | DusterIdiot [ Fri Jul 20, 2018 6:09 pm ] |
| Post subject: | Re: cool exhaust on one side and hot on the other |
-Did you do a hot lash on your valves to make sure that they are adjusted properly? This might be part of the problem if off/uneven on each "bank"... There are a few things that come to mind here that would be a concern... Did you do a DCR check on the cam? 11:1 SCR is kind of big for the Erson stock 111 LSA, especially if you advance it a lot and will tend to very high cylinder pressures and detonation (works great for Hyperpak at 10:1). If you are using a drool tube head, do not use the ZFR-5N spark plugs... Did you install a couple of O2 sensor bungs in each pipe near the collector? The reason I ask is that: "Left side has a popping lumping sound"- if this isn't a valve lash issue, then you are running very lean and need to check your mix... if it's lean your engine temps will be high and can be detrimental to your headgasket, exhaust valve/seats and pistons.... The O2 sensors will help you set and jet each side (if you have the carb clocked to have the bowls to the head and fender)... your setup may need to have unsquare jetting (this is especially true if you run the straight pipes as true duals and the rear collector peels off in front of the tranny cover and goes down the passenger side of the car...the extra 2 elbows will prove more resistance to flow than the straight pipe from the front collector down the driver's side. I would lock the secondaries out and work on idle/transition mix, and primary jetting since your carb is a Holley. (A street 11:1 motor will not use the secondaries until you are under heavy load or well into 4000 rpm in 3rd gear on level ground...) Your timing for break in should be limited to 30 degrees mechanical total (vaccuum adv can wait until later...but a 600 cfm+ holley on a hi-po motor won't give great mileage on the street)....if you overadvance it will not be good on things, while you work out what the engine needs and breaks in. Long Ram manifolds tend to run lean when cold and need to be richer until the manifold catches up (on my street pak the idle screws on the 390 cfm holley had to be out 1 1/2 turns... only 3/4-1 out on a 600 Holley... jetting on the 600 holley needed to be 63 primary and 68 secondary, except in the summer where I could get away with about 2 jets sizes less, unless racing). |
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| Author: | twister6 [ Fri Jul 20, 2018 8:15 pm ] |
| Post subject: | Re: cool exhaust on one side and hot on the other |
I set the lash at 20 on a warm head, I have no o2 sensors on it. Im running C12 Fuel it starts fine and it don't detonate when I turn it off. The carb is set up with the bowls facing front and back right out the box, didn't mess with the jetting yet. Timing is at 10 and 30 all in. You think clocking the carb 1/4 turn with make a difference? Maybe a hotter plug? |
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| Author: | DusterIdiot [ Fri Jul 20, 2018 9:38 pm ] |
| Post subject: | Re: cool exhaust on one side and hot on the other |
Quote: I have no o2 sensors on it. Im running C12 Fuel it starts fine and it don't detonate when I turn it off.
Ok, that's leaded so not a big deal. Run on after key turn off isn't the issue, it's knock while running a couple degrees too advanced during a run that's of interest...108 octane leaded should be no problem.Hotter plug will only work on the cold/rich side, and not on the hot side.... you might experiment with clocking the carb considering that if you have the primaries forward, 4-5-6 have an extra 4-5" of vacc pulse to draw in fuel/air...compared to 1-2-3... the O2 sensors would have quickly spotted a discrepancy between one "bank" or the other, along with a vacuum gauge which will pinpoint mix issues (and help set the proper power valve)... If you are using the ZFR plug put a set of normal electrode versions in... the extended electrode plugs work great in stock to near stock, but under high compression they will act like an extra 5 degrees of advance right out of the gate due to the position of the flame kernel compared to the standard plugs. Just as a note the only 2 slants I've seen that would use the full 650 cfm holley are still a couple points higher in compression and quite a leap in duration @ .050 than your build, so make sure to go conservative on your secondary spring until you get your carb issues figures out. What are you running for an ignition with your set up? (HEI, MSD?) |
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| Author: | twister6 [ Sat Jul 21, 2018 7:19 am ] |
| Post subject: | Re: cool exhaust on one side and hot on the other |
Im running MSD with stock dizzy..the motor don't knock or ping. Im going to mess with it some more today, do a 1/4 turn on the card and see what happens..im going put the IR thermo on the exhaust headers by the head and see if I get temp variations. Ill keep you updated. Thanks |
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