Help with idle EGTs. Can't get 'em down...

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by Scouder, May 9, 2010.

  1. Mike Canter

    Mike Canter Top Dragster

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    Unless you have a fuel flow sensor and you are knowledgable on how many GPMs are required at stage, during first gear and the rest of the gears and at the end of the run then EGTs at certain points of the run are required to make sure all is OK and put you close to the right tuneup or on the right track. Reading the plugs and bearings ONLY tells you what happened at the end of the run from about the 1000 ft mark on on. Yes, there are factors that affect EGTs but overall they should be with certain boundaries at certain points such as idle, stage, at preset times in the run and at the end of the run to get you into the ballpark. EGTs are way too slow in changing to really use them for fine point tuning during the run. If you want to check the accuracy of the idle EGTs then use a heat gun on the exhaust pipes and correlate it to the logger temps. What is happening with Brian just needs to be figured out. There is a problem somewhere in his motor or fuel system. Just because we can't figure it out on the internet doesn't mean he should ignore it, that may cost him a lot of money when he takes it to the track. I think Brian should bring the motor up to stage RPM with the data logger on and see what the temps are then. If they stable out with an average of around the 625* then the problem is in the idle circuit/setup, if they shoot up then the problem is in the whole setup. Since this is all fairly new to Brian something that we do all the time a certain way may have been done differently by Brian.
     
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  2. Bottlefed

    Bottlefed New to Blowers

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    I have a question, if this car had port nozzles in the hat (non aerated) would this cause high cylinder temps due to poor atomization?
     
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  3. Scouder

    Scouder New Member

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    Fortunately the freeways on both sides of Wyoming are closed due to snow today, so my trip to Cheyenne is cancelled. This will give me time to get some more starts done this afternoon. Sure is going to cool the shop down when I open the doors to fire it!

    I'm gonna quit treating this thing like it's special and apply the same formula we use on all the other engines here at this altitude: Add timing, subtract fuel.

    I'll post results later today.

    -Brian
     
    #43
    Last edited: May 12, 2010
  4. Bottlefed

    Bottlefed New to Blowers

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    I have been waiting 4 days to charge my home A/C because its been too cold to get a good superheat measurement, now I know just how lucky we are to be dealing with the 50s and 60s :rolleyes:
     
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  5. Mike Canter

    Mike Canter Top Dragster

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    Bottlefed, I have a car I tune that does not have airated nozzles in the hat for a specific reason (secret). It idles and runs great.
     
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  6. SoDak

    SoDak Active Member

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    same here;)
     
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  7. Fuel Cars

    Fuel Cars AA/AM

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    Mike, do you think a leaking intake and/or using aerated nozzles at the ports could be a cause of the problems, or, would there be different symptoms?

    Thanks for all your previous replies, I'll never learn if I don't ask.
     
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  8. Mike Canter

    Mike Canter Top Dragster

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    If you put airated nozzles in the ports I understand that it will spray fuel all over the place when the ports are turned on. Never have done it but maybe someone out there will chime in and tell us what really happens. In Brian's case the port nozzles should not be tiurned on at idle.
     
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  9. jim phillips

    jim phillips ta/fc

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    i love this site i learned some thing from this thread i didnt know you guys are tough thanks good luck brian
     
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  10. secondwindracing

    secondwindracing top alcohol

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    Hey Jim, just wanted to say hello, Is it ok to give you a ring tomorrow? what is your shop # I tried a number and some phone sex operator answered:D just kiddin but I do need your shop number..Dave
     
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  11. bruce mullins

    bruce mullins Top Dragster

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    so your the one that hung up when I answered today Dave!:eek:. . .gota pay the bills somehow! :D
     
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  12. Scouder

    Scouder New Member

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    While I'm waiting for the engine to cool off again I thought I'd post an update.

    I pinned the timing at 32 and have decided to leave it there until I get some passes in the car and start getting some plug readings.

    I decided to start waaay down on the BV and bring it up in steps.

    First start. 63% leak, 1800 rpm, .005 butterflies, 32 degrees, 7500 density(really good air because it was cold outside).
    This was my biggest test. It would either prove me right or wrong as far as needing to pull fuel out for the reduced air pressure here. It proved me wrong. Egts were beautifully balanced but 730ish. Head temp, measured with a gun on a painted black spot on the back of the head went from 80 to 177 in about 1 minute (220 on the data recorder). When I pulled the fuel shut off I didn't even get a chance to let it start to lean out and kill the mag, it just died.
    Summary of start 1: Leaner than hell. You guys that said not to lean it out 1, Brian 0. Also, there is a 40-50 degree spread between the temp gun on the back of the head, and the temp probe mounted between 3 & 5. Probe is hotter. So when I was getting pissed because it was going to 220 so fast, it was really 170-180. That's a good thing.

    Second start. I cranked in 4 flats, so guessing 70% leak, 1800 rpm, .006 butterflies, 32 degrees, 7330 density(even better air, very rare).
    Egts beautifully balanced at around 640. Started with a gun temp of 110 and went to 180 in about 1.25 minutes (232 on data recorder). This time, when I shut off the fuel it idled up better so I could kill the mag.
    Summary of start 2: Still lean, but showing improvement. At least as I added fuel I was seeing the correct result. You guys that said don't lean it out 2, Brian 0.

    Third start. 4 more flats. No clue where she's sitting for leakdown, but probably in the 80's, 1740 rpm (didn't notice it was down slightly), .008 butterflies, 32 degrees, back to 7650 density.
    Egts starting to spread but down again. Started with a gun temp of 105 and went to 160 in about 1:12, 180 in 1:39, and 200 in 2:16. When the back of the head hit 160 I started a 30 second data log. The log shows 196 for head temp on the probe, so there was only a 36ish degree spread at that point. Over the next 30 seconds it only gained 14 degrees on the probe, which is a good thing. Here's the Egt trace start and finish over 30 seconds:
    1 434/365 +15
    2 512/498 -14
    3 490/468 -22
    4 315/293 -21
    5 721/770 +49
    6 652/712 +60
    7 719/753 +34
    8 701/754 +53

    Does that look like a pattern to you guys?
    Summary for start 3: Starting to spread the egts. This seems to be the pattern when I let it get rich. Also, the exhaust note started to sound a little different, and it was starting to be an eye-burner. It is interesting that I added 4 flats and the back cylinders got hotter than before, and the fronts started losing egt. Right now I'm thinking of pulling 2 flats back out of it to see if I can find a happy medium that will stabilize the fronts and bring the backs down a little.

    Whaddya think?

    -Brian
     
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  13. bruce mullins

    bruce mullins Top Dragster

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    first off quit jacking the barrel valve back and forth. if you run it with the bv lean, you can cause the blower to get hot and the rotors will actually grab the case or gear plates and tear some stuff up. the barrel valve needs to be at least 78 percent and NO LEANER!. I think you are putting way to much time into trying to get the cylinders balance at idle. another thing is how cold is the motor before each time you start it. just because the heads are cooled down, how about the oil, or the entire short block? if it sits just an hour, that's not cool enough to make a change and compare it to the first start up of the day.. if it starts and idles at 1600 to 1800 at 80 percent then relax. as I said before I have never tried to tune a motor at idle if it is idling! I understand you are nervous about this, but usually these things are tuned from staging rpm's to the finish line. I have worked with some of the smartest and biggest tuners in this game and never has one said to turn on the computer while warming it to check idle temps. If you are truly worried about the fuel system, call someone like Randy Anderson or Ralph Gorr or Bill Barrett (who I have used) and get one of them to put your fuel system on a flow bench. That would give you piece of mind if that is what your looking for.
     
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  14. jim phillips

    jim phillips ta/fc

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    hey whats up 812 228 7683 if i dont answer i will call back
     
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  15. Scouder

    Scouder New Member

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    Bruce,

    I'm done messing with it. You make the third experienced guy on this board that has said to set it at 80 and 1800 and go run it. It's also pretty much what Spud told me to do when he sent it to me, so that's what I'm gonna do. I'm not going to second guess experience.

    I'll post my track experience Saturday.

    -Brian
     
    #55
  16. jim phillips

    jim phillips ta/fc

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    brian stop over thinking whats going on you will be better off these guy will lead you in the right dirrection if you let them set it bv at 80% butterflies around 12tho timing 30* if you trust the 150 in the main make a short blast and look at the plugs thats safe i know i have not run in that altd but sounds lean i have run the dog shit out of these cars and i cant afford to tear up stuff your oil pressure needs to be at least 120 plus when you stage as bruce said you tune one to race not idle persay if it idle is should run everyone i know sets the bv no lower than 78% my formula is 80-84% if you set it low it will heat up way to fast not good allow plenty of time between starts so the oil pressure stays up hot oil not good i was told dont leave when i got my first hemi several years ago dont leave if you dont have 120lbs and i never have
     
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  17. Mike Canter

    Mike Canter Top Dragster

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    I agree just set it at 80%. Brian while you are setting it at 80% and you have the leakdown tester hooked up showing your 20 lbs or 80% slowly open the throttle slowly and tell us which way the needle on the leakdown tester gauge goes. Does it go towards 0 lbs (100%) or does it increase to 25 lbs, 30lbs or higher? I think this is an important check for you.
     
    #57
  18. Bottlefed

    Bottlefed New to Blowers

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    Thanks Mike.
     
    #58
  19. Scouder

    Scouder New Member

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    OK. You guys that have been telling me to set it at 80 are gonna chuckle at this. In fact, if I was younger you could call me a dumb kid that has to learn the hard way.

    I made several starts today, narrowing down the best balance of egts, with the lowest temp I could get. On my last test I felt like I was about 1/2 of a flat rich. Which is about 1%. So when I decided to just take your advice I put the gauges on it to see where I was. Yep. You guessed it. 81%! If I had just listened in the first place I would have saved myself several days, about 25 gallons of methanol, and alot of frustration and ended up in EXACTLY the same place. (By the way, Mike, I set the BV to show exactly 20 on the second gauge, and when I open the blades it drops to zero.)

    So, I will be hitting the track at 32 degrees, 80%, and 1800 rpm to start tuning.

    Thank you, Gentlemen, for your patience with a newbie, and your suggestions. I appreciate (now more that ever) the benefit of your experience and your willingness to share it. You make this forum a true treasure. Jim Phillips, Dave Lowe, thank you for your time on the phone. I wish you guys weren't half way across the country from me, I'd like to meet you in person. If you ever find yourself on I80 out here in Wyoming I'll be pissed if you don't call.

    -Brian
     
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  20. Ghost - Kevin

    Ghost - Kevin Member

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    Scouder...

    Been busy, wish I had seen this earlier.

    Like Bruce we've been running this combo for many many years and have run it hard. I've never had a computer till now on the new car. I haven't a clue what the EGT's were at idle or during the run, nor did I really ever need them. But at 250+ their hot!, that I know! :D After a few hard runs the top of the piston, the sleeve, pins, and bearings will let you know what's going on. Plugs lie!

    1. if you haven't yet, get the system on a bench and get some baseline numbers. Gorr is very familiar with these early combos and flowed mine for 13 years. Without flow #'s your progress will be slow and you will probably hurt it. Nozzel, and return area's are critical to this and any combo. Get it flowed! Call ralph or spike or anyone with expeiience with the early combo's. Don't let them flow it like it's a fat head. Not the same at all. I prefer the 16 nozzel system.

    Leak...mine has always been between 68 - 76 with a standard V-spool. depending where we were and how much first gear, what kind of track...etc....Get a good leak and remember my gauge is different than yours, and Bruces, and everyone elses....but get a good guage and use it.

    2. Timing...not real critical here. 28 - 34 anywhere in there and it will run. it does like it up there though so the 32 you have in it will be fine. But make sure your hub doesn't turn on you. Re-check your top dead center constantly!

    3. check and blow out your poppets and all fuel system stuff. Any little thing can get stuck in there and cause them to stick open when they should be closed. Get a system down where you do the same fuel system maintenence after every few runs and every race, even just warming it up and letting it sit.

    4. don't be afraid to idle it up there at 2000 or so. Get some blade in it. .010 - .012 or so. Give it some air! Especially at altitude.

    5. It likes to be hot at the line. Trust me, this combo like hot.

    6. these are all things your flow guy can get straight for you and you don't have to burn any fuel to do it.

    7. If you haven't done so turn the cam up!...Don't try to run this thing like the fat head guys..(opp's I'm one of those now! :rolleyes:) Get some cylinder pressure in it. The exhaust opening isn't that critical but the intake opening is! If it's dialed back it won't run and won't burn fuel.

    We aren't that far down the road, if you need help throw a rock and yell.....

    Kevin Hool
    "The Ghost" TAFC
     
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