FrontEngineDragsters.Org Forum
Technical => Spud Miller's Cave => Topic started by: GlennLever on August 06, 2017, 03:34:53 PM
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I have two topics I wish to talk about.
1) I only have hat nozzles, cylinders 2 and 7 run hotter then the rest and would like to cool them down, how can I accomplish this?
2) I have been working on tuning so that I run it out without lifting. This past race my first time trail was too slow (8.08) the second was to fast (7.96) the third was too slow (8.05) and my first round of elimination was to fast (7.89 yep, way to fast). I have been tuning using my main jet and pulley adjustments. I need to add to the mix, timing. It would be really nice to have a pointer at the base of the distributor (something I can make up), and a disk on the base of the distributor (it could be split to get it on) marked with "degree" markings so that timing changes could be made without pulling a timing light out. These markings would not necessarily have to correspond to degrees of advance and retarding. They could be used as quick reference and over time I would know what each mark meant in regards to how many degrees in timing they referenced.
Does anyone know of someone that makes such a "degree gauge" for the base of the distributor? I would like it to sit on the top of the base, not on the side.
Thanks Glenn
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Glenn, I can't remember who made it, but back when I was running the funnycar I had a Mallory super mag that had something like what your wanting. It had a strip with degrees marked on it that was on the magneto, and a pointer that attached to the base. Wish I could be more help, but the memory isn't as sharp as it once was
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Blower rotor throws fuel forward, so staggering nozzles to put more fuel thru onto those is not likely to change. Port nozzles in the manifold could even the temps but cause other issues that slow the car and harder to tune. It sounds more like a manifold issue. Maybe an alu dam down the middle so the fuel puddle will distribute evenly instead of favoring #1.
Mag lll come with a timing venier and pointer, you would have to find a machine shop with a horizontal devideing head to scribe witness lines on the base in the area that you can use a pointer
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Look up Moroso 26100 Distributor Timing Indicator
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I'm baaaaack! Did you miss me? (no need to answer that :) Thanks to all the knowledge here, you guys do fine without me.
Took a week long road trip vacation last week with the family to the Grand Canyon through San Fran, Vegas, Reno, etc. Train rides, mule rides, casino arcades, a swimming pool at every motel...lots for an 8 and 11 year old kid to flip out over. 3000 miles of driving...good to be home.
I don't remember what mag you run Glenn, but Super-Mag bases come with provisions for a pointer and our factory label has graduations on it just for this purpose.
If you're using a Vertex, there is a special clamp-on degree ring available (we don't stock it but can get you one if you like). You'd have to make your own fixed pointer for it. It clamps to the mag body and sticks out horizontally, so space could be a problem using it with a blower.
There are also degree tapes out there...the Pro-Mag and Super-mag are pretty much the same body diameter, so the MSD Pro-Mag tape will work on either. The Vertex is a smaller diameter however, so the degree marks will be off (still a good reference though).
I'll fire up the CAD tool and report back with the distance per degree needed for both styles of mag. Do-it-yourselfers can make their own that way. I've had my laser engraver lady make me custom crank ring tapes on "brushed aluminum" label material before. Works great! Back a little later...
Depending on your blower exit style, staggering hat nozzles can sometimes help...sometimes not. If you are OPEN bottom (not delta or delta-retro), then I would make the nozzles over #2 and #7 larger...they will see the benefit. If you have a front discharge, delta-type exit, then port nozzles really are the only way to do it. If #2 and #7 are the only issues, you could just use a port nozzle for each of those two. There are several tricky ways to do that easily.
Spud
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Ok, here's the degree tape/marker info.
At the diameter of the magneto body, this distance equals 1 degree (at the mag):
Vertex (3.530" dia): .0308"
Super-Mag (4.060" dia): .0354"
Pro-Mag (4.000" dia): .0349"
So...reference marks on the mag body at the distance above would indicate 1 degree of MAGNETO movement or TWO degrees of crankshaft movement.
Spud
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On the big engine (you have the fuel system now) it will be a mag, on the current engine I have a distributor.
I found this
(http://static.speedwaymotors.com/RS/SR/Product/54526100_L.jpg)
and ordered it.
Not much room for port nozzles and the new engine is maybe three races away. I may have to live with the in balance to the new engine. Heat is all the way around the base of the plug but not into the threads at all. Others show no heat at all.
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so is your issue strickly by plug reading or to you have EGT probes in the headers and what are those temps???
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so is your issue strickly by plug reading or to you have EGT probes in the headers and what are those temps???
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Glenns problem is one cylinder...and I'm not sure which one.....is running hotter than the rest. That is verified by that plug showing heat all around the shell. The rest are plenty safe. Even the hot cylinder is safe...It is just that that cylinder dictates the whole tune up.
If he was going to continue running this engine next year I would have him install one small nozzle in the cylinder.
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How about a nozzle right above that cylinder in the Blower case just below the rotors?
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If the blower is fully open on bottom, and the other cyls on that bank are way safe heat wise. Then check to be sure the nozzle bodies are aimed straight down into the blower. If this is the case then a valid test could be done by twisting all nozzle bodies on one side to aim toward the week cyl. , maybe start at around 20*. There is a variation on this that I have also use in the past with success and that is to progressively twist the nozzle bodies toward offending cyl. For example on the right bank to get more fuel to #2 , twist #4 nozzle 30* toward #2 , then #6 nozzle 20* snf #8 turn it 15* . Nice thing about this is there is no change in nozzle area to compensate for , no purchasing nozzle jets you don't have or modifying any hard parts. Can be done at the track for back to back testing. I have done this to numerous cars with success. The last one Greg Means, I made the suggestion , he tried it , it worked. The nozzle holders don' have to face down, it is not a rule written in stone. I have even seen some pilgrims try aiming them at the top of the hat in order to alter the destination of the fuel.
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If the blower is fully open on bottom, and the other cyls on that bank are way safe heat wise. Then check to be sure the nozzle bodies are aimed straight down into the blower. If this is the case then a valid test could be done by twisting all nozzle bodies on one side to aim toward the week cyl. , maybe start at around 20*. There is a variation on this that I have also use in the past with success and that is to progressively twist the nozzle bodies toward offending cyl. For example on the right bank to get more fuel to #2 , twist #4 nozzle 30* toward #2 , then #6 nozzle 20* snf #8 turn it 15* . Nice thing about this is there is no change in nozzle area to compensate for , no purchasing nozzle jets you don't have or modifying any hard parts. Can be done at the track for back to back testing. I have done this to numerous cars with success. The last one Greg Means, I made the suggestion , he tried it , it worked. The nozzle holders don' have to face down, it is not a rule written in stone. I have even seen some pilgrims try aiming them at the top of the hat in order to alter the destination of the fuel.
They are all currently facing directly down. Over the winter I pulled them all and used an ultrasonic cleaner to clean them.
I will try your suggestion on tilting the injectors.
The front opening is fully open, the rear is a delta
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Just like people they are all a little different. Most of the ones I have had this work on were conventional standard open top and bottom . Tried it on a delta bottom blower with minimal success . Ended up adding extra nozzles. Only way to know is to experiment.
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Just like people they are all a little different. Most of the ones I have had this work on were conventional standard open top and bottom . Tried it on a delta bottom blower with minimal success . Ended up adding extra nozzles. Only way to know is to experiment.
The fron is open, it is the rear that is a delta. I will try this.
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All this go fast wizz bang trickery stuff, YOU DONT NEED IT!!!! it complicates everything, standard opening on the bottom, nozzles in the hat gets you 7's and 200mph, I have proof!!! No EGT's, just 2 threads of heat on all 8 spark plugs
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Didn't you ask me if I had EGTs?
I did not believe what they were telling me so I looked at the plugs.
The bottom of the plugs in 2 and 7 show heat all the way around on the base, but not into the threads.
The rest of the plugs look brand new and show no heat at all.
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Ken Veney told me the story about his old Ford Cleveland powered Top Alcohol Dragster. He ran it with all hat nozzels but it always had one relatively lean cylinder that limited the tune up. He decided to run one fuel line to the port on the lean cylinder and went testing. It looked weird but it worked like xxxx. The car went undefeated for a whole season. I believe he ended up running seven other port nozzels that were blanks to keep everyone guessing.
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We will try to angle the hat nozzles this next race to see what we can see, do not want to change to ,much, still number one after four races, two to go
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Just a follow up. we did tip the nozzles as suggested, and that helped a lot!
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Just a follow up. we did tip the nozzles as suggested, and that helped a lot!
Helps on my combo too Glenn.