Base Line Help

I have a a 526 hemi with a 206D and am experiencing something that I was told should not happen with my settings. I am getting cylinder temps in the 200's at stage and the hottest during an 1/8th mile pass of 850 and that was just one cylinder, the others were as low as 450. Here is the base line that I was given and it is exactley what I have.
Hat Nozzles are 2 x .080 and 2 x .060 on 30 lb check for a total hat area of .0157. My dribblers and ports are all in between .048 and .050 for a total are of .0155 dribbler and .0155 port areas. My total area is .0467. I have one servo bypass in low gear only of .060 and the pump is a 17.4 gallon pump. I am using a 100 main bypass and am spinning the blower 96%. I have since changed the .060 in low gear to a .080 and added a full time pump loop with an .080 in it as well and am having the same problems. My pump is flowing what it should be at the RPMs I checked it at. I have tried everything I know to do, this is my first time running a screw charger and am beginning to think that my total area must be too great. I have also spun the blower up to 120 over and only minimul change. This thing is a turd. Any ideas?

 

Here is the psi tune upright from the book they send with the injecror and blower @ 92 over (leagel nhra)
d p
.047/#1/.048 Hat 2@.80 in airated nozzeles
.050/#3/.047
.050/#5/.046 Hat 2@.80 in 30psi check nozzles hat area .0201
.050/#7/.051

.050/#2/.046
.050/#4/.049
.050/#6/.062
.050/#8/.049
drib.area 155 in
port area157 in


What i think is going on here is the motor is SO lean that you dont have enough fuel to make any heat, this is just a starting point, you may have to richen up the port nozzles, rember a screw blower likes a lot of fuel it is basicly the opaset of a roots,also did you buy or modafy your barrel valve to acomadate the screw blower? if not you can buy one from PSI, or buy drazzys book from psi and it will tell you what you have to do, good luck

 

Guys;
Here is what I'm thinking;
I don’t think it is “so lean it’s not making heat”. To sustain the combustion process you need a relatively close air to fuel ratio. If as you say it is lean, then the temps would be on the hotter side of the equation. It’s the same as when we pull the fuel shutoff after a warm-up, the motor leans out, revs up then shuts off. There would have to be some indication of being too lean, such as cooked oil, popping cracking of bolts, blued headers, something that would point you in the right direction. For him to make runs with the blower at 96% and then 125% over without any noticeable temp changes or performance gains, something has to be very wrong. His fuel system sounds like it should be “Close”. I agree it must be an extremely weak ignition or a very retarded mag or camshaft timing. For him to be able to make repeated runs past half track and not blow the burst panels out, I don’t see it being too lean. We also run a dual nozzle setup and I think he just said it wrong about the hat nozzles after a 30# check, it wouldn’t last multiple runs setup like that.

Gerry Woz

 

The 30lb. check is a little spring and ball that go`s in the nozzel holder, i know what hes talking about, going from 92% to 125% would make it even leaner, proving my point. Its called being on the wrong side of the fuel curve/Or the mag or coil is bad like Will said. Peace! any how let use know what you found to be wrong! Oh, one more thing when you get the right barrel valve leak it to 75/80%

 

The barell valve has been altered per PSI's diagram and is at 76%. The 30lb nozzles on the hat were via them but I see what you are saying, at what pressure should I reduce that to? Also the car is obviously rich, it looks ok on the stands but after a burn out and stage it seems to get richer and begin misting fuel from the zoomies. It alomost seems as if the fuel going into the cylinders is not misting, more like pouring in and not allowing it to burn efficently. The oil is another indication of how rich it is. I have had 2 cams in the car, one was in at 38degrees and I just recieved my cam back from being repaired and it is in at 36 degrees, it is a 296/500 crane. I took it off the crank trigger, changed the mag and cap set up, wires check ok in ohms, different msd box, new rev chip and took it off of the retard, still have the same problems. It acts as if it is retarded but I have checked and changed everything I know to check or change. It is a Veney motor and I run it at 29 degrees timing. The application is pro mod. The baseline I am using is the same one posted above out of the PSI book. I also changed the barell valve. Could there be something wrong with this blower that would make it do this, I have eliminated most every other possible problem. I'm about ready to pour the next jug of alcohol on the roof and setting it all on fire LOL.

 

Don't know anything about PSI superchargers but I had a friend who put the rotors in backwards on an 8.71. It acted the same way as what your describing. Hope this might help. Jon

 

wow

am confused !!! check the quill shaft lolololo

 

If you have a racepac in the car check the fuel flow graft aganist the rpm graft, if it`s below the rpm its lean if its above the rpm its rich, theroedacly if it follows the rpm on the same plane its just right, i like to keep it just a smig above the rpm ,just because im cheap and don`t like to blow shit up!Buy the way did you buy that blower new or used????

 

Bought the blower used, but from someone I know, the blower lifted on the last pass it made prior to me getting it. It was running consistently prior to that. The fuel flow follows the graph. Boost is down some but I assume it is would be in a situation like this, only about 39 lbs or so at 96%

 

check your mesages

 

I just learned that my plate was supposed to be modified for port nozzles which it is not, the coil is new as well as the msd and I only too the crank trigger away as a process of elimination. When the plate arrives I will start over I guess but on the jacks and not the track. I will post after trying it out. The heads are grounded on one strap connected to both heads and then to the chassis where they have always been. What can go wrong with a screw charger? I know things break but what should I look for?

 

It sound like you need more air in the injector. 12/14 thousandth of clearance in the butterfly. Cantrell racing product. Kevin. specializing in screw blower upgrade.

 

Blwnaway, Well I bet your head is spinning now, You got about 15 different things to check, You can rest asured that your problum will be some thing stupid, Start from scrach check all your fuel system ,make sure every thing is clean inside the lines, nozzels are not cloged, All the poppets are going in the right direction, The plate your refuring to is that the one that comes with the blower? If it is do not mess with it just make sure the o ring is in place on both sides, Check your cam timming, And recheck your top dead center mark.

 

PSI Blower

Have you checked the fuel pressure. According to my calculations, you are putting 15 GPM to the motor, which is good for aprox 2500 HP, with 2.5 GPM returning to the tank. With the Total area at .0545 which includes the return pill, my calulations show about 70 PSI at 17.4 GPM which would be at aprox. 7000 R'sPM, or 35 PSI at 3500 R'sPM, etc. I think you mentioned that you thought the fuel may not be atomizing properly. Good Luck!!!!!!!!!!!!

 

The black book from PSI is not always correct. It is information that came from other racers....some good and some Bad! The pump loop should not be the same as the main jet. You are way too rich. The black book tells you to set the butterflies at .002/.003 - this is wrong! The motor is loading up with fuel. The longer it runs, the worse it gets. Kevin, Cantrell Racing Products PS. Specializing in upgrading the screw blower. 602-918-4945