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Discussion Starter #1 (Edited)
I ran my 55 chevy today in the 1/4 mile and after every run my plugs were like i just put them in after every run. I jetted the carb up as high as it could go and it did not make a difference. I tried another carb no difference. So my thought was lack of fuel supply. i mounted a onboard camera on the car and it maintained 6 psi the whole run. My thought is that it has the pressure but not the volume. I took out the filter element in the inline earls micron filter i had thinking that was the culprit. (it was a filter between cell and fuel pump)it actually did pick up about 2mph faster and almost a tenth. But plugs are still ghost white. The car has a fuel cell with 8an going to the pump and out. It than goes to a holley regulator and into a dual feed. i tried a procomp black pump I had and a mallory 140 and both had the same results. also i would like to add the cell is vented with a looped 8 an line going outside the car. Is there anything I'm missing here? The cars only going 11.60's in the 1/4.
 

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r

if there is no drop in psi. i would think it is in the jetting. We normally keep our psi at 7 or 7.5. is it stumbling or acting weird at any point of the run.

you said you jetted it as high as it would go, what numbers you putting in?
 

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Discussion Starter #3
87/94 the carb brand new had 73/84 jets. i tried another holley 850 with stock jetting and it was lean as can be also. The car went the fastest with less jetting because I believe it was keeping more fuel in the bowls. When i went to the bigger jets in it the plugs looked identical as before.
 

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your probably rite about the pump not keeping up. we started running duall lines from the sump to the pump also. 2 an 8s into an10 to pump. i would get the bg220. under 250.00 . this is a buddies car. barry went with single an10 out of sump into bg220 and he has a tall deck big block running 9.60s




 

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both of those pumps will keep up with an 11 sec car no problem. did your times change any as you went up on the jetting? i would adjust the pressure up to at least 7.5 psi. i normaly run 8 psi just incase of any psi drop. also what was your timing at? it could have been to lean from timing being to high. i dont know your combo but an 850 shouldnt be to small if your running mid 11's. try an bump the FP up and double check you timing. good luck!
 

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Fuel is only one part of the equation. What do the plugs say about timing? Is there any fuel ring at the bottom of the porcelin? (you may have to cut the bottom of the plug off to see it well) Where is the timing mark on the strap?
 

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Discussion Starter #7
it went slower with bigger jets and looked just as lean. timing is at 36 total. the porcelain looked as white as it gets as far down as i could see. a tiny bit of color on the ring and the strap was colored grey all the way to the ring if that makes sense( i should have taken a pic). No matter what I did to the jets the plugs looked identical. my combo is a 454 BBC 10:1 049 heads victor jr. 850 double pumper solid isky cam 254/264 @.050. nothing crazy I'm going to start pulliong apart the fuel system tommorrow and look for any obstructions in it. The system is completely fresh so maybe somethings floating around. i bumped the pressure up and it made no difference.
 

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When were the plugs being read? Did you drive the car back to the pits then read the plugs or did you read them at the end of track after a run? If you idled the car back to the pits before you read the plugs then your reading does you know good! Where these new plugs or old plugs? All of these make a huge difference in reading a plug properly!
 

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Discussion Starter #9
new set of plugs. The first couple were at the end of the track than i noticed when i came back to the pits the plugs didn't change at all so i pulled them as soon as I got back to the pit. the plugs look great while driving all around town btw.
 

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try and find a 950 hp. maybe you know some one you can borow one from. if it gets slower as you jet it your going the wrong way. you should only add jet if its picking up ET or MPH then when you start losing power you back it down. i built a 454 simular to your set up and we are running a 850 HP carb with stock jetting right now (new motor) but the thing runs good and real crisp on throttle responce. it seems to like 32-34 total timing. if your fuel system holds 6 or 7 psi all the way down the track i think its fine. if it drops below 6 then i would be worried. or if it drops more than .5 - 1 psi from set point. -8 feed is plenty of volume also. we only run -6 to the 454 we built fed by a holley red fuel pump (with a blue spring) reg. to 7.5 psi. hope you find the problem.
 

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i agree with what you are saying above and agree. but the pro comp pumps are not the same as the holley blue or black. they are a cheaper pump and we have tried the pumps 4 different times 3 times on a 377, and once on a 406. they would not keep up. they would work fine until a full dyno pull, or a full pass. you would lean out huge up top. if he is jetting it up that high it should affect the plugs and how it runs from my experience. i dont know what the cam wants for timing or his elevation. i think it is a supply issue, but i have been wrong before many times
 

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Hey Chad,
Do you still have the filters in the carb inlets? I always toss those because it doesn't take much to clog them. I would think if it was that lean you would feel some surging or laying down on the top end.
Back when I ran nitrous, my plugs always looked brand new after a really good pass!
 

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Forget a carburetor. Talk to the company BigStuff3. They'll set you up with all your needs...
 

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Your timing mark should be somewhere near the bend in the electrode. The closer it is to the threads, the more timing it's showing & the closer to the electrode, the less timing. NGK's are one of the easiest to read. We run AC's but you can still see the mark if you look closely.

If you want to see what your pump is flowing, disconnect the outlet line from your pump and run it into a fuel jug, run it for a minute and see what it is flowing. (X60 will give you the gph)
 

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Discussion Starter #15
try and find a 950 hp. maybe you know some one you can borow one from. if it gets slower as you jet it your going the wrong way. you should only add jet if its picking up ET or MPH then when you start losing power you back it down. i built a 454 simular to your set up and we are running a 850 HP carb with stock jetting right now (new motor) but the thing runs good and real crisp on throttle responce. it seems to like 32-34 total timing. if your fuel system holds 6 or 7 psi all the way down the track i think its fine. if it drops below 6 then i would be worried. or if it drops more than .5 - 1 psi from set point. -8 feed is plenty of volume also. we only run -6 to the 454 we built fed by a holley red fuel pump (with a blue spring) reg. to 7.5 psi. hope you find the problem.
thats funny that you mentioned that because before my proform 850 I have on it now I was borrowing a 950 hp from someone. The proform is actually running a little quicker than the holley.
 

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Discussion Starter #16
Hey Chad,
Do you still have the filters in the carb inlets? I always toss those because it doesn't take much to clog them. I would think if it was that lean you would feel some surging or laying down on the top end.
Back when I ran nitrous, my plugs always looked brand new after a really good pass!

no filters in the carb inlets. no surging or laying down although up top it doesn't really climb that rpms that fast at all.
 

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Discussion Starter #17
Your timing mark should be somewhere near the bend in the electrode. The closer it is to the threads, the more timing it's showing & the closer to the electrode, the less timing. NGK's are one of the easiest to read. We run AC's but you can still see the mark if you look closely.

If you want to see what your pump is flowing, disconnect the outlet line from your pump and run it into a fuel jug, run it for a minute and see what it is flowing. (X60 will give you the gph)


OK some more information! i took apart the whole fuel system today and the lines looked clean as can be. I took the line off going into the regulator and put about 2.1 gallons into the can in 60 seconds. I than took the line coming out of the regulator and did the same it pumped out 1.6 gallons. So through the regulator Im losing about half a gallon a minute is this normal? any other things to check?
 

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Pump gas normally wont color the plug like race gas. You might get a light tan ring at the bottom of the porcelain, but you might have to cut the plug apart to see it. You need to jet the engine for the best MPH, along with watching the timing mark on the ground strap.
Yes you will lose flow thru the reg because of the pressure drop. Ever take one apart and see how small the orifice inside is?

Is that your '55 in Mikes pictures from the LA Invasion? It looks just like the one I had back in 1979.
 

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Discussion Starter #19
yes that would be my 55. that's awsome! I thought race gas wouldn't color the plugs and pump gas would color the plugs. I thought at 90 something jets i could get a little bit of color! some other information i have is that when I screwed in another pressure gauge it read 2 psi less i brought it up 2 psi to about 8 ish and the float bowl level went up from the bottom to the top on the sight glass. I could cram like 12 psi in it and it wont blubber at all. I know it's bad for the needle and seat and all that but i just wanted to see If I could get a reaction out of it to see. As i know my nova would have blubbered at around 12 psi
 

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I think it has to do with all the additives pump has has. Things like injector cleaner and ethanol etc. Fwiw, my nova ran 120 mph on motor with a regular Holley mechanical pump and a 3/8" line. Whenever I have had a fuel delivery problem, it showed on the launch or within a 100 or so feet out. I had to redo the pickup in the stock tank to move it back about 6" or so.

Here's the '55 I had in HS. I have a '55 Sedan now, not a hard top :(
 
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