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#31
07-31-2002, 03:31 PM
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Quote:
It was the ignition timing. I made sure the cam timing was correct. Couldnt degree it so I used the alignment marks on the timing chain gears. I put the distrubutor back in the "same" position as before using my calibrated eye. http://www.plauder-smilies.com/eek7.gifand it started right up. So I thought sit was right. Ran for about 20 min temp was 200. On the first cam it never hit 200.  So drove it for a while about 1 week. New bigger cam felt slower than the old one, So I tear into the carb. Wrong answer. Finally while I thought the carb was just about in I rechecked the ignition timing. 2^ ATDC  Well then, break out the timing light and set it to 34-35^ @ 3200 rpm. Car is a 70 Newport 383. 3.23 gears. It can handle more advance but didnt cause its a heavy car. And incase I couldnt get 93. I tuned it to run on 91 worste case. During this time I was rushing because it was heating up. After the igntion timng fix, had to REDO the whole carb. http://www.plauder-smilies.com/sad/bigeyecry.gif After that was about to shut it down, kept an eye on the temp and it started going down. http://www.plauder-smilies.com/rotfl.gif It was all good till I moved to AZ. Now the carb is off cause of the altitude change Cuda you going to go over altitude adjustments also?  The Carter book says 1500 foot is one step leaner, well I am at 1000 ft. I was going to use the 1500 ft but that step isnt in their carb tuning manual. OK How about a distributor curving class also????  Thanks again for all and I hope this helps some moparman318. 
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#32
07-31-2002, 03:34 PM
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cuda....
Wow....I printed the thread out and took the time and read through most of it....hehe...I still haven't read the part on tuning an Edelbrock carb! That is some very good information! No, Vic is not in the office right now. I will see if I can pass along the information on to someone else, maybe the head sales guy. I'll see if we can offer some kind of support.  Keep up the good work! Roger
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#34
07-31-2002, 09:09 PM
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cuda66273,
good stuff. Keep the tech coming. I am going to go through my 750 Speed Demon with mech secondaries on Friday using your tips from the top of the thread. I have done this already using a vacuum gage and can not get rid of a tip in stumble. Also, the carb worked fine last season. New set up listed below. I also have installed a PFM Total Control O2 sensor that I'm trying to use to help tune idle, primary and secondaries. Do you have any tips on using that in conjunction with your 4-corner idle tuning technique? Right now, I'm still getting a "lean" tip in problem even though it idles at about 12.5:1 A/F ratio on the sensor at 850 RPM. Cruise ratio is about the same. If I coast then get back into the throttle, it stumbles and goes all the way lean unless I really put my foot on it. here's the scoop on the new set up. Also note that is is a thrown together combo until I build a proper short block with the right cam land compression ater on down the road. 440 (low compression...8.5:1 or so) Indy SR heads (intake runner volume = 275, flow at 0.500" = 295.6 CFM) (exhaust runner volume = ?, flow at 0.500" = 256.7 CFM) chamber size = 78 CC, 2.195 intake valve, 1.835 exhaust Indy Dual Plane 440-2D intake Crane Powermax Hydraulic Cam p/n 684561 (this was one I had on the shelf) 0.504" intake lift, 0.528" exhaust, @ 0.050 duration intake = 232 and exhaust = 242, adv dur = 302/312, 112 deg centerline MSD 8456 Dist with 6AL Initial timing = 18, Total = 38 in by 3000 RPM Plugs are NGK BRK4E (this is a very hot plug from what I heard) Feel free to email me at onebad440@aol.com if you need more info prior to giving any feedback you can offer (I hope you can). thanks...John
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#35
08-01-2002, 07:34 AM
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The first thing I see as a tuning obstacle is the low compression Vs. the mechanical secondary's.
Slip the seconday linkage off and give it a test drive around the block, let me know if the stumble goes away. What jets are you running? What power valve? What is the vacuum reading at idle? What fuel pump system? What size fuel lines? What is the vacuum reading when you go to WOT? I'd like you to head out to the freeway and go wide open in 2 gear and give me the vacuum reading just before it shifts into high. Does it stumble when it shifts gears? Have you done a plug check yet? See my post on Edelbrock carb tuning in this post. We run the same 750 on our 318, with the original 273 "D" chamber head with 139 cc runners and 1.94/1.60 valves....and your feeding 120 more inches and double the runner volume and probably a 100 CFM more flow with the same carb.......can you see where my feeble mind is going here.... It shouldn't stumble even if the carb is too small so lets take care of that first then we'll look at the flow.
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#36
08-01-2002, 10:37 AM
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Ok, here's what I have. Luckily, I done all but two of your questions already so I have most of the info and will get the other.
I will take the secondary linkage off tomorrow to see if it helps. I guess I'm curious why it might at tip in since the linkage is progressive and doesn't come into play until half throttle? More info: This is a street/strip car that is driven to the track and regularly cruised for fun. Also, the hardware for the car is being fortifed for a future installation of an ATI procharger once the short block and cam are done properly. Hence the heads and everything else now. Also, I forgot to say that I have the TTI 2" to 2 1/8" step headers with 3.5" collectors which were all I could find to fit the 71 Body with Indy SR's. I know that they are too big and hurt me down low. Jets: 74/83 (Holley Jets...I know, I need to go to BG and I think I need to drop the rears to within 2 of the fronts typically?) Power valve: 6.5" stock Demon Vacuum at idle in park: 9.5-10" at cruise/coast it will hit over 20" Fuel Pump: SX electric with SX filter. Mallory bypass Regulator set to 8 psi (it stays there until things heat up then it fluctuates down some) Fuel lines: 1/2" supply and return with a 3/8" oriface on the supply fitting to the regulator. WOT vacuum: 2.5-3" in 2nd gear. I think I need to measure this again though with the new intake. Stumble when shifts: Only at the track at high RPM (5700) it lays down a bit until the motor catches back up then it takes off fine. Plug check: yes, but I'm an amature and they appear lean? I ordered new cooler plugs today (BRK7E). For the NGK's 2 is the hottest and 11 is the coldest. Many have said flat out that my 750 is too small, but I still have vacuum at WOT and I'm not over 400 hp yet so I figured it was ok. I was debating ordering new acc. pumps today? Look forward to your response and I will get the rest of the info by the weekend. Hope your deal with BG picks back up. I sent the email for your support. thanks, John
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#37
08-01-2002, 11:35 AM
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"progressive and doesn't come into play until half throttle?"
So if I can presume that the stumble happens before you mash the go button then don't bother with that test. That test is to eliminate squirter problems on the secondary's. "TTI 2" to 2 1/8" step headers with 3.5" collectors" I doubt that's causing your problem... "Jets: 74/83 (Holley Jets..." I'm gonna have to make you stay after school and write "I will not put Holley Jets in my Demon" a hundred times I think we have found part of problem already, I don't believe your getting enough juice when you hit the secondary's and it's instantaniously leaning out. I run 84/86 jets in my 318 if that gives you any idea. Just for giggles I'd put a 4.5 or 5 power valve in it....if you think about it the power valve is going to dump fuel at 6.5 Inches of vac. I'll bet you drop to 6.5 by breathing on the go peddle...too much too soon...blahhhhh.....stumble and then go.... "Regulator set to 8 psi" That's a little high for my taste...I like to run them around 5.5-7 max, you could be bouncing the needle off the seat once in awhile. "WOT vacuum: 2.5-3" in 2nd gear" That is a strong indication that the carb is way to small, the WOT vacuum test should read ZERO, if your pulling vacuum then the engine is trying to outbreath the carb....sorry but the carb is definately to small you need to be looking at the 820AN with the annular boost system. "Stumble when shifts: Only at the track at high RPM (5700) it lays down a bit until the motor catches back up" Actually the carb is catching back up, at 5700 you've probably sucked the float bowls dry just from sheer demand volume and the CFM requirements of the motor have exceeded the capacity of the carb. "Plug check:" Before we spend too much time playing around with the plugs we have to get the thing jetted closer, put in the right jets those 74/83 Holley's probably flow close to 70/78 combo in a BG jet. I'm not familiar with the plugs your using, I use the 99 cent Autolite Walmart specials...always have and they've allways worked good for me even on our 360 alky sprint motors. You have to keep in mind that a plug that's too hot will burn everything off the porcelin and give you the appearance of a lean condition when in fact you could be richer than Bill Gates. When I start with a new SB Mopar or Chebby I just find a middle of the road Autolite and run it, then I just keep changing plugs to next coolest until it gets black and sooty looking and go back up one turn. Hot plugs scare me, way too much tip temp for the kind of driving we do....I'll address this more in my Mission Ignition article that's on the word pad as we speak. "I was debating ordering new acc. pumps today?" I think that you should hold off a bit on new pumps....your problem is deeper than a set of bigger pumps, they may just multiply your problems, let's try some of the other stuff first. If you can't find a set of 84/86 86/88 BG jets (this hurts) pick up a set 90/92 Holley jets and we'll throw them away after we see if it improves performance and get you some BG's coming. So...in conclusion...although we have determined that the carb is probably too small we should be able to get it to perform correctly off the idle circuits and through the primary/secondary transition...otherwise a 440 two barerel engine would never run.... So here's your Work Order for today: 1. Jets 2. Power valve 3. Fuel pressure 4. Plugs 5. 4 corner tuning 6. In my opinion, I feel that your initial timing is a little high...if were mine and it's not, I'd like to see the intial at no more than 10 but that really depends on who set it up and where it starts to wind up the springs. Cheap and easy, we'll go from there. "Hope your deal with BG picks back up" Thanks, me, you and thousands of others I saw the copy....thanks, your too kind. Don
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#39
08-01-2002, 12:20 PM
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Ok, I think I have my work cut out for me but I'm up for the task.
I'm going to print the latest post and get to work on it Friday afternoon. I think I might have misled you a bit. Here is another brief run down of the conditions just so you'll have it. These conditions should tie to what I tried to describe earlier, but here is more detail. Idle in park...smooth as can be considering the cam. Runs about 12.5 on the richness sensor. Also, I haven't measured EGT's to see if I am really on the 1:1 scale for the O2 sensor. Just barely open the throttle (blip it to 1500 RPM from 850) and it stumbles bad and goes past 16:1 on the O2 sensor. Give it a good solid hit up to mid throttle without opening the secondaries and the lean and stumble go away instantly and I go back to 12.5:1. This is the same scenario even if I'm under load like leaving a traffic light and you just barely give it gas to roll foward. If you blip the throttle then hit it past tip in, it's fine. Mash the gas hard from a light and it just barely stumbles then catches and accelerates fine. Hit it even harder and the secondaries open and the O2 sensor barely moves if at all and there is a smooth transition when the secondaries open. No stumbling and no leaning out. Launch off the transbrake/2-step at 3200 and it lays down, but I cant see if it is lean or rich. Need to watch that one time rather than just trying to cut a good light. After about 0.2 seconds it catches up and takes off fine through all gears until I shift and it lays down but is still rich then catches back up and takes off again. Your theory on draining the bowls sounds good. I have jet extensions but I dont have the notched float yet. I first though my new valves were floating like a rev limiter (2-step has a 6400 high end chip). Hope that helps some more. Thanks again for your help. I'm sure there are tons of other people that might benefit from these tuning tips on this post. John
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#41
08-01-2002, 12:32 PM
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"Just barely open the throttle (blip it to 1500 RPM from 850) and it
stumbles bad and goes past 16:1 on the O2 sensor." I think you'll find when you get the 4 corners all set right that should cure alot of this problem. I'll bet your way to rich on the idle cicuit, and you probably have the idle adjustment speed screws turn way to far up to compensate, so as soon as you whack the throttle hard you jump over to the to the primary main feed cicuits and it get the correct mixture. Your accelerator pumps activate in the range your taking about and with the combo of the puumps and a poor adjustment on the air bleeds you flooding the engine with too much fuel and not enough air mostly not enough air, I'm sure that BB can handle the fuel OK....I drilled a 1/16th hole in both of the primary butterflys before I really new what I was doing and although it won't hurt it any it did help with a similar problem to yours. It just allowed more air past the butterfly's to lean the intial tap on the throttle. Let's see how it is after you make the changes...
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#42
08-01-2002, 02:33 PM
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Ok everybody take notes here....
"Car has slown down recently as the day progresses" Let's assume that the fuel quanbtity never changes with atmospheric conditions, which is kinda true....If you watch your fuel pressure gauge, you do have one mounted where you can see it while driving right? You'll notice that your fuel pressure varies with air desity...but that's a whole new post. Let's stay with assuption here... So if the fuel quantity is identical and variable is air density and quality then as the oxygen content of the air decreases due to humidity or lower barometric pressures what happens to your air fuel mixture....it get richer right...less air more fuel..makes it richer. So with that formula in hand as the day goes on and air quality goes down and your car goes faster whats happening in your tune up? Your lean! Your car should slow down as the day goes on, remember we're bracket racing here and predictability without detonation is the key to winning...this fact is so predictable you can dial the car from a barometer and Relative humity gauge...try it, write down the barometer reading and the relative humidity (Our track prints it right on the time slip) In the case of Onebad440 his problem is probably just not enough fuel and air, so as the air quality decreases it just makes the whole package worse. So print out this section: Air Bad...car goes slower...rich Air Bad...car goes faster...lean So if your out to set a national record or running an index class like Super Pro you'll need to start changing jets to keep the car on the index or take a little out of the delay box. See David Nickens needs me, he just doesn't know it yet...LOL...I've been watching his cars and their numbers and I can see whats happening. They won at Woodburn Yesterday...temp was 74, barometer at 31.00 and relative humidity was about 55%...perfect conditions for the base tune up line....and they smoked them! Seattle, cold 60, wet 90% humidity and a about a 29.2 barometer..out in the second round (I think) I'll bet the RacePak showed the car fattened up at the top end, no oxygen in the air. It's called missing the tune-up
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#46
08-09-2002, 05:57 PM
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Hey Don I got my 650 and I was wondering if I can use the throttle adapter off of my old Edelbrock or if I have to get a new one?
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#48
08-22-2002, 01:26 PM
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Cuda66,
What procedure would you recommend for tuning a dual quad set-up of 4 corner idle Holleys/Demons (progressive primary/secondaries)? What about progressive throttle linkage use on a tunnel ram? I have heard mixed advise.
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#49
08-22-2002, 03:33 PM
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I've only set up one tunnel ram in my life and it was on a stock 350 in a 74 Camero....My favorite, I fought it for 3 weeks before I could get it run half decent. They were Eddy 600's on it and they were WAY Too Much carb...But I did eventually get it to run...and run is an overstatement.
I'll talk to Jerry and consult my library for some tips and proceedures. Give me a couple of days...If I forget..email me at cuda66273@hotmail.com and remind me, Ive got about 8 projects going right now.
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#50
08-27-2002, 10:19 AM
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4 cornering a 1050 Dominator(Cuda 66273)
Cuda66273: Have you dealt with tuning a 1050 Dominator carb? Is it 4 cornered in the same way that a 4150 model is done? I've got a Gary Williams special on my 400 ci small block. It seems ro work good but I want to get the most out of it. The car currently 60 fts at 1.57 on the motor. I hope it does a bit better when I retune the carb. Your professional opinion is greatly appreciated.
I also wanted to comment on all the technical help the you've offered to me and all on this board which I'm sure have learned as I have from all your posts. Keep those pro tips coming!!!! Thanks, Wedgehead
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#51
08-27-2002, 11:38 AM
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Thanks Wedgie
Wow, 1050 Dominator on a 400 SB....I have no idea where to even start. The huge venturi holes in that carb are taking away all your velocity, I believe and correct me if I'm wrong but that carb is reccommended for 450+ CID in 650+HP high RPM applications. Without knowing all the details and just judging from your impressive 60' times I believe stongly your motor needs a 750 Mighty Demon at best. Your probably making 550 HP at the crank??? What fuel pump are you using? You need a minimum of a BG 280 pump to be safe, the Mighty Demon wet flows at around 900-920 and still maintains the velocity needed to charge the cylinder. I'll bet you will knock off .15-.2 off your ET by going to a smaller carb with the same wet flow. I believe I read somewhere the WET flow numbers on a 1050 Dominator one time and they actually flow at about 980 at best. When you say "On the Motor" are you running giggle juice on this car? If so I have some tech tips for you....
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#52
08-27-2002, 09:05 PM
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Demon carb or 1050 Dominator
Cuda66273, i am running giggle juice on this thing. And I also have a Demon 750. I purchased it from Summit and it came set up as a 775 cfm. I called Barry Grant and ordered everything I needed to upgrade the carb to a 975 cfm. They sent the air bleeds, venturis, and base plate. I asked Gary Williams about both carbs and of course he wanted me to use the larger carb. I use the BG280 fuel pump. I'm all ears for the tech tips that you may have and any other info you can offer. Thanks in advance, Wedgehead
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#53
08-28-2002, 07:50 AM
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Most places you take a Demon and Holley to will always opt for the Holley just because of familiarity and not performance.
This is the way I would set it up: 1. Send the carb to BG and have it wet flowed, email me direct and I'll set that up for you. 2. You need 2 fuel pumps, one dedicated to just the Nitrous. 3. A fuel return line from the Nitrous side to the tank and it should be a -03 and no more than a -04, the fuel return should go into the top of the tank. 4. A minimum of a 1/2 inch or -08 tank vent with a filter to keep the dust out. 5. The size of the carb should fit the engine, the nitrous runs on the fuel enrichment solinoid. 6. If you running this on the street you should have a voltage reduction circuit on that pump it is NOT designed for continuous use. 7. Both pumps will rrequire a -10 feed from the tank to the filter, -10 to the pump, -08 to the pressure regulators, and -06 to each end of the carb and on the nitrous side I wouldn't be afraid of a -08 feed to the solinoid. Bigger is better so if you've got more that's a good thing, less and you need to make some changes, Nitrous needs fuel...Lots of fuel.
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#54
08-31-2002, 06:20 AM
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Sorry for another Holley question But... I'm running a Holley 3310-2, 750-780cfm dual feed on my built up 400 BB truck. Four corner idle adjusts apply the same? Came off a 440 boat w/6hrs run time, till motor blew years ago.
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#56
10-24-2002, 09:21 PM
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Nitrous Fuel Plumbing
Cuda, I've read several of your posts - good job - interesting. Just above I believe you said in your <#2 point "you need 2 fuel pumps, one dedicated to just the Nitrous.">
This would likely be true, though the second pump would only need to be powered up when the nitrous system is readied for action. At his HP level, 2-pumps are likely needed - unless he was running something like a BG-400 or similar flowing pump from another manufacturer. <3. A fuel return line from the Nitrous side to the tank and it should be a -03 and no more than a -04, the fuel return should go into the top of the tank.> Now, is this 3 AN or 4 AN line coming from the pump regulator itself or actually acting as a 'bleeder line' from the fuel solenoid on the nitrous system??? If it's coming from the fuel solenoid (acting as a bleeder line) directly at the solenoid inlet, it would need to be 'jetted down' even if flowing through a small 3 AN line - otherwise it will return too much flow 'past the solenoid' and create too much turbulence. For that reason, most nitrous Pro Mods run a #16 Holley jet on all bleeder valves to both control the flow & turbulence. <5. The size of the carb should fit the engine, the nitrous runs on the fuel enrichment solinoid.> Yes but, and there are always a 1,000 'buts' with nitrous - if he's running the system HARD, unless he's running something like a fogger sytem where he can individually 'jet' or tune each individual cylinder, stagger jetting 'individual corners' of a carb can often help cure some of those 'bottle induced' ills. <6. If you running this on the street you should have a voltage reduction circuit on that pump it is NOT designed for continuous use.> Not kicking BG stuff here, but two old Holley Blue Pumps hooked in tandem, can work pretty good too & can often run/last a long time.
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#57
10-25-2002, 09:09 AM
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I agree with everything stated and this is an excellent addition to the post..I should have gone more into the nitrous return system.
I'm glad you chimed in to clearify the nitrous side as I don't like the juice and we very seldom get to work on a Big Power Nitrous car I tend to skip over the finer details of the giggle juice. ProMod car huh....my BB Big Brother runs a ProMod in Canada
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#58
11-16-2002, 01:34 AM
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cuda: this may be slighly vague and while i haven't read the ENTIRE post, i'm fairly certain i want to go with a 4 corner carb. What would you suggest atop an m1 feeding a 408 stroker with a wild cam of roughly .546" lift @ 298 duration? Thanks for your EXCELLENT advice. You are truly one of the small group of people that keep me comping back daily to check posts. Thanks again.
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#59
11-24-2002, 05:11 PM
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Cuda66273 could you ckeck out denom vs preditor post and give me a recomendation,Thanxs
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