GSS mr norms car fuel problems.

[67cudaracer]

Well this is what is going on.
When the car is cold it runs great with no fuel problems.
I have a Paxton sn2000 on a 71 demon small block 365 cubic inch.
When it gets hot it wants to flood out.
I have the fuel pressure set at 8 psi and the fuel regulator is inside the Paxton box along with the carb so the regulator is pressurized along with the carb. For reference only. The other day I hit a big bump in the road and it flooded. Of course it was hot again. Went home and cked everything and fuel was coming out the front bowl vent cked it out for debris and found none in the needle and seat. No leaks after that ran it today and it happened all over again took it out cold ran fine and when it got hot it was flooding all over again. This time it started after I got on it pretty good. The boost gauge seen about 5 lbs of boost.
Should I go to a nylon needle and seat next.
The regulator seems to be doing its job so I would think the needle and seat are the problem.
Any ideas would be welcome.
THANKS

[dwc43]

Do you have a carb just for this blower? There are special carbs just for this app. An off the shelf holley wont work. Make sure to use a float with the springs on it to assist it in closing. Your also running too much fuel pressure. Drop it to 7. And old racers trick is to loop a piece of vacuum line from vent to vent and cut a V notch at the very top. Not sure if this will help you or not with all the boost pressure.

[cutting torch]

Solid floats too, so boost won't collapse them, although temp would not make much difference with collapsed floats. If your fuel is boiling, it may percolate it out the bowl vents, which I am not sure about, since a liquid's boiling point is higher under pressure. In any case it could be a cheap thing to try a higher octane fuel, it might help.

torch

[67cudaracer]

[CENTER]DWC- I talked to Holley about the carb because I wasn't sure if what I had would work. 950HP I know it's a bigger carb than needed. But they work so nicely. What they told me was to just take out the power valves and put in block offs. Being the carb is inside a box with pressure around it there really wasn't much that would need to be done to make it work other than the power valves. You might be right about having to much pressure. When traveling down the road the gauge reads any were from 9 to 10.5 pounds of pressure at about 1 to 2 pounds of boost. I'll try lowering the pressure to 7 and see what happens. Now correct me if I'm wrong isn't the pressure suppose to rise along with the boost. I'll put on a hose for the vents. I run one on my race car I don't know why I didn't put one on this car. Must of slipped my mind or something.

CUTTING TORCH- I'm presently running solid floats so I don't think that’s the problem. The first time I had and flood out on the carb it was coming out of both bowl vents. So I went ahead and replaced the needle and seats on both bowls and everything was ok for a little while and then it happened all over again but this time it was just the front bowl that was flooding out the vent tube. The octane has come to mind. I run 8.5 to one compression on 92.5 octane. Should be enough octane on such a low compression.
The one thing that has been bothering me is the regulator. When I take off the top of the regulator and turn on the fuel pump it seems to be fine but what I have noticed was that it like to bubble out extra fuel not a lot just enough to make me wonder if just maybe when it gets hot that the tolerances are going away and letting out way to much fuel.
So last night I replace it with another one that I had in the shop. I put in new diaphragm and cleaned it out thoroughly. Took it out for a drive for about and hour around town. This time everything seemed ok. It was cooler out last night so I'll try it out today in the heat and see what happens. I'm crossing my finger that everything will be fine.
I'll let ya know if everything is good.
Here is a web site that I have my car on ck it out.
Just click on the pictures to see them better.

http://groups.msn.com/BackyardMopart...gh.msnw?Page=2

"THANKS GUYS"[/CENTER

[dwc43]

9 to 10.5 psi fuel pressure is too much. All you need is 7 even at full boost. You just need enought to keep the fuel bowls full while it's running and any extra will just flood it out. You level of boost also effects how much octane you need. Even though you have low compression, you have high cylinder pressures and temps. Therefore 92.5 may not be enough octane to prevent detonation at full bost, but it might be fine at just above idle. Something that you need to look into. ANd I htink your right about the reg too. If you set it at 8 it should stay at 8, not climb to 10.5. It should stay where you set it at.

[GJS440]

Hello cudaracer: I was wondering if you could possibly list you'r engine specs. I have an original Mr. Norms supercharger setup just rebuilt from paxton. I am going to put on my 69 GTS 340 4-speed Dart. the motor is not put together yet. I have all the motor parts and would like to compare it to you'rs to make sure it will all work together. I actually bought all the motor parts before I bought the supercharger and was wondering if I need to change a thing or two before assembly. also if you could tell me how good the performance of you'r motor is with the supercharger on it, and how it pulls through the RPM range? Thanks for any info you might post......

(GJS440)

[cutting torch]

I didn't mention octane of the fuel for detonation or compression reasons. What I was getting at was, that in my experience, higher octane fuel seems to resist boiling better. I should have been clearer about that.

Also, on the fuel pressure, I think your pressure needs to rise with boost to maintain proper operation of the inlet circuit. If you have 7psi at idle with no boost, you should have 17psi of fuel pressure at 10psi of boost.

torch

[67cudaracer]

[CENTER]Well the regulator took care of the flooding problem.
I lower the fuel pressure and that seems to also of helped.
At idle it reads 7psi and at full boost it reads almost 13 psi and that’s at 6 lbs of boost. I had a half a tank of gas of 92.5 octane and so I added 4 gallons of 110 octane to help it out.
Now I have a different problem.
When I'm cruising a on the primary’s I have very good throttle response. Very strong and I mean it's a pulling son of a bitch. When I get into the secondary it falls flat like either fuel problem lean/fat I'm not for sure which one yet.
I jetted it down # 76 square and that seemed to get some what worse but not much it's kind of hard to describe. Then I jetted it up back were it was on the primary #78 primary and two higher #80 on the secondary. It didn't seem to get any better. My timing is set at a conservative 32 degrees total with machanical advancement only. MSD 6al.
I'm cruising from a stop I stab the gas it pulls hard in the primary’s then when I get to the secondary it seems to fall off and then it take somewhere around 60 to 100 feet before you start to feel it coming out of the stumble/lag but not totally out of the stumble just pulls better. It pulls better but it should pulls harder. I would think. This is all new to me.
I'm planning on going to the Edelbrook fuel injection soon but for now this is what I can afford. I'm about 800 shy of being able to order up the Edelbrook setup. Then I get to open up another can of worms when that gets here.
Here are my engine specs.
318 all aluminum 1994 magnum block, Indy edelbrook cylinder heads, 1.5 roller rockers, 3.79" Calais crank shaft, 6.125 eagle h-beam Chevy rods,3.91 in JE custom 8.4 to one pistons with Chevy wrist pins for weight saving, Bullet roller camshaft .591 intake and .588 exhaust. Ill have to dig up the cam card for all the correct specs. I use Cometic cylinder head gaskets custom fit to the cylinder bores 4 inch and .065 thick so in reality it should be more around 8 to 1 compression. Edelbrook air gap intake, Valve lash are set at .014 because of everything being aluminum. Timing belt drive setup from the land down under. Milodon 7 quart pan. TTI complete exhaust system 3" out the rear with X pipe and step tube header from TTI as well. 727 full manual trans brake JW valve body that came out of my race car when I went to a PG slider. Coan 9" converter set up for nitrous 3800 stall. My original plain was nitrous. It stalls out at 3800 with the super charger. Gas mileage sucks but O-well.
THANKS GUYS[/CENT

[67cudaracer]

I just would like to THANK all the people that gave me advise to help me out on my paxton set up.
THANK YOU

[dwc43]

Glad you got it working for you again. Welcome,anytime.

[cutting torch]

No problem. The bill is in the mail.

torch

[67cudaracer]

Well it happened again.
Thought I had it the problem taken care of with the regulator and today it started all over again.
I know it has to be a heat issue.
I got the edelbrock pro fuel injection in the mail last week but won't be able to install it until next month. Sent out for the EPROM and different injectors so it will be at least a week for them to get here. Got a wedding this weekend coming up and a car show up in Minneapolis the week after so I gotta get it threw till next month. Man this is really starting to aggravate me. How in the hell did they do it back in the 70s is beyond me.
Fuel injection is the way to go at this point.
Terry at Edelbrock is a big help at pointing me in the right direction for injectors and EPROM setup. Really looking forward to seing how this new set will work. I sold one of my race engines, 75 dart and some stuff at a local swap meet to buy MPI setup. Sure will be disapointing if it don't work.
But so fare from the way it looks it should.

[dwc43]

Good luck with it.

[67cudaracer]

[CENTER] Well I got a hold of the Craig at Paradise Wheels on my fuel problem.
Being I got this setup from them I thought they might have seen this problem before. They said that this was a first. I told them my problems and he told me to get the regulator out of the box were the carb was. I put it there for pressure reference. So I took it out of the box and put it down on the frame away from any heat source and it seems to have done the trick so far. We’ll see what happens in the up coming weekend.
Just thought I would let you guys know my progress.[/CENTER

[dwc43]

Glad you found a fix for that problem. Hope the efi is not a paint to install. I guess the pc set up and tunning would be the worst part.