Will a cold air intake stop hot fuel problems in desert climate ? ? ? ? ? ? ? ?

[skip68]

I guess I have exhaust leaks on both sides for some reason.  I wonder if that's creating a ton more under hood temperatures ?  I put in a triple gauge cluster (water temp, oil pressure, volts) and ran the car in stop and go traffic yesterday and the car is running right at 192 degrees.  The hottest I've ever seen this car get is 197 for a minute and then went back down so I know my carb and timing can't be too far off because it's not running hot.    I'm going to look at the exhaust leaks in the morning when the car is cool.   I will get new gaskets and replace them and hope that helps.   Do you guys think that the exhaust leaks are causing the problem ?  The car is running great until the fuel gets hot.  It will burn rubber in first gear all the way up to 50mph now so I know I'm making headway.   

[mopar_nut_440_6]

I guess I have exhaust leaks on both sides for some reason.  I wonder if that's creating a ton more under hood temperatures ?  I put in a triple gauge cluster (water temp, oil pressure, volts) and ran the car in stop and go traffic yesterday and the car is running right at 192 degrees.  The hottest I've ever seen this car get is 197 for a minute and then went back down so I know my carb and timing can't be too far off because it's not running hot.    I'm going to look at the exhaust leaks in the morning when the car is cool.   I will get new gaskets and replace them and hope that helps.   Do you guys think that the exhaust leaks are causing the problem ?  The car is running great until the fuel gets hot.  It will burn rubber in first gear all the way up to 50mph now so I know I'm making headway.   

Does the car pull fairly well  off the line and then start to bark and puke when it is hot? If so you may be expieriencing a vapor lock issue.

[skip68]

Yes !   It runs great for the first 10-15 minutes or as long as I stay moving.  But once in stop and go traffic for 5 minutes or so it starts running ruff and if I go wide open from a stop it goes up to 2500rpm or so and then does just what you said.     bark and puke like it's missing or running out of fuel and I can smell fuel.   

[mopar_nut_440_6]

Do you run an electric fuel pump? If so I would route your fuel line away from your headers and bypass the mechanical pump and see if this resolves the issue. If it does then you can decide what changes you want to make. It definitely sounds like  a vapor lock issue where the fuel is actually vaporizing in the fuel line before it gets to the carb. Like I said previously I had the same issue and solved it by going to a 3/8 line and routing my fuel line away from the exhaust, bypassing teh mechanical pump as well as making a cool can which may or may not have helped.

It will be cheap and easy to add a chunk of rubber line to test this out. If it work then you can decide how to proceed from there.

[skip68]

Thanks, I'll give that a shot.  I have a mechanical pump.  What would be the cheapest electric pump to try this ?

[500INCHBIRD]

Why use a cheap pump that will only lead to more problem's?Edelbrock has a couple really good electric pump's.Remember cheap componets usaully never aid in fixxing a problem.

[mopar_nut_440_6]

I have heard that the Mallory's are quieter than many of the pumps out there and still work well. You will want to mount the pump as close to the tank as possible because electric pumps are designed to push fuel not pull.  Also, as low as you can get it without having it so low it gets pounded off or hit with round debris or small animals! If you install the electric pump first you may want to leave the line running through the mechanical first just to test.

[Steve P.]

Damn Skip. I cannot believe you haven't discussed this with VegasMike... You should know that we went round and round with this a few years ago and it took lotttttttts of work to figure out and fix the problems...


1) It is GD HOTTT in Vegas.
2) He had a faulty fuel pressure gauge.
3) The wood and Phenolic spacers will work the same, but I trust the phenolic spacer much more.
4) Under hood temps there ARE much hotter there than most other places in country as the ambient temps are much higher. Nothing to cool under the hood. 
That doesn't mean other places don't have hot air under their hoods. Just that you are pulling 110 degrees through your radiator. most other parts of the country are well below that. Thus trading cooler air.

After trying loads of things on Mikes Charger, in the end it was running an electric fuel pump with a bypass regulator and a (RETURN) line back to the tank. He was burning up Holley black pumps left and right until the return line.

One other thing: I don't care WHO'S gauges you bought, test the gauges properly before trusting them...

Lastly, You have to have lots of time and talent to properly tune a Demon carb.  Any carb for that matter, but more so in Demons. I would suggest you save some bucks and step into the HOLLEY or PROFORM WORLD... All carbs have their place and it seems more and more that the Holley's and Proforms just keep taking the cake....

Hope this helps buddy... The very hot days in Vegas are made for swimming. Not so much hot motors..... 

[skip68]

    Thanks Steve.   I have talked to Mike and lots of others.   BUT NOW I KNOW !!!!!!    I called Mike last night and asked what pump should I get from Summit and what about a bypass regulator and he said STOP !!!   "Don't buy anything until you look at mine.     I know for a fact now that I must run Electric fuel pump with bypass regulator and return line.      I did change my t-stat today to a 160* and now my car runs at 168* to 172* while driving.         I will be getting the proform carb when I can afford it.   I'll tell you what, that proform on Mikes is snappy as hell.               I do wonder if my gauge is off by 10 degrees.   When I had the 180* T-stat in it would run at 190*.    Now with the 160* T-stat it runs at 170*.          So, it seems my gauge reads 10 degrees more than what the T-stat is rated at.   

[Steve P.]

STOP!!!  lol....   You don't HAVE to run an electric pump. You can run your stock pump with a bypass regulator and a return line. I prefer the electric mostly for security reasons. Mike can show you what I mean. The big thing about Mike's set up is where the car is driven. 2300 ft. above sea level and the heat you deal with there makes for some tough wear and tear. So in Vegas with a car that makes plenty of it's own heat,  I don't think there is much that could be considered overkill. We went round and round with Mikes Charger for a while trying to get his fuel system to work without trouble. The return line helps in keeping his fuel pump cool. He went through a bunch of pumps before I talked him into the return line....

As far as your gauge being off 10 degrees, well it could be. It could also be off 50 degrees... The ONLY way to know if a t-stat AND gauges are close to their intended settings is to properly test them. Do some homework on gauge testing and follow it step by step. The big thing people screw up on when testing is setting the gauge bulb or stat directly on the bottom of the pan. They should be hung in the water, but above the pan not touching it... Otherwise you will get a false reading there too...

You will NOT be let down at all by the Proform... more and more guys here every day will vouch for them.

[mopar_nut_440_6]

STOP!!!  lol....   You don't HAVE to run an electric pump. You can run your stock pump with a bypass regulator and a return line. I prefer the electric mostly for security reasons. Mike can show you what I mean. The big thing about Mike's set up is where the car is driven. 2300 ft. above sea level and the heat you deal with there makes for some tough wear and tear. So in Vegas with a car that makes plenty of it's own heat,  I don't think there is much that could be considered overkill. We went round and round with Mikes Charger for a while trying to get his fuel system to work without trouble. The return line helps in keeping his fuel pump cool. He went through a bunch of pumps before I talked him into the return line....

As far as your gauge being off 10 degrees, well it could be. It could also be off 50 degrees... The ONLY way to know if a t-stat AND gauges are close to their intended settings is to properly test them. Do some homework on gauge testing and follow it step by step. The big thing people screw up on when testing is setting the gauge bulb or stat directly on the bottom of the pan. They should be hung in the water, but above the pan not touching it... Otherwise you will get a false reading there too...

You will NOT be let down at all by the Proform... more and more guys here every day will vouch for them.

A return line is also a good idea for prolonging the life of a good pump. I know a Holley Blue pump, in my experience, does not have a very long life without one. Is Vegas Mike still running his mechanical pump? Has anybody built an enclosure to reduce the sound from an electric pump? I have a Holley Blue pump and they are very noisy! I am trying to build a sleeper. Does anybody have any pictures of one of these pumps installed in a way which makes them a little less easy to see? The only spot that I see them mounted is off of the RH frame rail.

Sorry to post this on this post but I think it is related information.

Cheers,

[skip68]

Mike is running an electric pump.   I was thinking the same thing about some sort of box to reduce pump noise.      

[mopar_nut_440_6]

Mike is running an electric pump.   I was thinking the same thing about some sort of box to reduce pump noise.      

Once you get everything together would you mind posting what parts and numbers you used in the setup as I will be going a similar route. Pics too!

[Steve P.]

You are correct about prolonging any pumps life with a return line. So called, "by-pass" pumps do by-pass, but they are still spinning away creating more heat and a higher amp draw. Neither of which do you want.

NOTE: While Vegasmike was having these pump problems with by-pass type electric pumps I called a few top brand manufacturers. BOTH of them told me that a by-pass regulator and return line was the only way to go. EVEN with their own by-pass pumps!!!  

You do want to match a pump to your combination.  All the pump companies will help you do that.

As far as pump noise, I think the best fix I have heard was cutting a piece of a heavy truck rubber mud flap and installing the pump hanging from it. NOT just sandwiching the rubber, but bolting the rubber to the frame and then a few inches lower bolting the pump to the rubber. You will need to run a separate ground this way.   I don't like the idea of creating a box for noise suppression. While that may work for noise, it will also create an oven effect. In essence you would insulate and keep both noise and heat created by the pump inside the box and induce the problem we are trying to fix. HEAT..   

Hope this helps...

[mopar_nut_440_6]

You are correct about prolonging any pumps life with a return line. So called, "by-pass" pumps do by-pass, but they are still spinning away creating more heat and a higher amp draw. Neither of which do you want.

NOTE: While Vegasmike was having these pump problems with by-pass type electric pumps I called a few top brand manufacturers. BOTH of them told me that a by-pass regulator and return line was the only way to go. EVEN with their own by-pass pumps!!!  

You do want to match a pump to your combination.  All the pump companies will help you do that.

As far as pump noise, I think the best fix I have heard was cutting a piece of a heavy truck rubber mud flap and installing the pump hanging from it. NOT just sandwiching the rubber, but bolting the rubber to the frame and then a few inches lower bolting the pump to the rubber. You will need to run a separate ground this way.   I don't like the idea of creating a box for noise suppression. While that may work for noise, it will also create an oven effect. In essence you would insulate and keep both noise and heat created by the pump inside the box and induce the problem we are trying to fix. HEAT..   

Hope this helps...

Will the factory return line work for this or will the diameter be too small. I normally work on modified vehicles where looks do not matter but this time I want my car stock appearing.

[Steve P.]

In my opinion the stock return lines are better than NO return lines. It's all about easing the work of the pump and keeping the fuel from sitting near a heat source for any length of time.

In every kind of pumping situation I can think of, the return line is larger then the pressure line. A/C, power steering, fuel transfer systems, (I have worked alllllot with them), hydraulics, steam, you name it. The high pressure side is figured by the need, (pressure and volume). The return and or bleed of systems are always larger.

Berry Grant's site shows typical fuel systems that they recommend. Typical racing systems are from the tank to the pump= 1/2" line. Pump to the regulator = 3/8 line. Return from the regulator back to the tank is 1/2" line. Regulator to bowls= 3/8 line. I think this is up to 7 or 800 HP. This is overkill for a daily driver with 3-400HP, but it damn sure WON'T hurt.... 

[skip68]

Thanks Steve.  I'll go bug Mike tonight and check out his set up.   

[Steve P.]

No tools around Mike's Charger, Chuck.... 

[skip68]

Yes sir. 

[mopar_nut_440_6]

No tools around Mike's Charger, Chuck.... 

Is there a link to his Charger?

[skip68]

I'll ask him tonight to post a few pics of the areas you need to see.   

[hemirr]

Skip68 -  I also have a 68 charger coming out of a 7 year rotisserie resto.  440 motor mild cam with 1/2 wood spacer and Holley carb.  I have an over sized Alu radiator with a 7 bladed fan with shroud.  Here in S. Florida this year its been 95-98 degrees every day with about 85-90% humidity.  While at speed temps run around 170.  10 minutes in traffic it starts to run real hot, motor pings like crazy.  I am currently experimenting with different octane gas mixtures to calm down the knock (along with timing changes)  One thing is what carb are you running?  I originally had an Edelbrock and it ran like crap in the heat.  Their float bowls are on the side, right over the heat crossover.  Switched to a Holley and that side of things are fixed.  The drivability is like night and day, just knocks when hot.  I run a stock mechanical pump with no issues.

[Steve P.]

Skip68 -  I also have a 68 charger coming out of a 7 year rotisserie resto.  440 motor mild cam with 1/2 wood spacer and Holley carb.  I have an over sized Alu radiator with a 7 bladed fan with shroud.  Here in S. Florida this year its been 95-98 degrees every day with about 85-90% humidity.  While at speed temps run around 170.  10 minutes in traffic it starts to run real hot, motor pings like crazy.  I am currently experimenting with different octane gas mixtures to calm down the knock (along with timing changes)  One thing is what carb are you running?  I originally had an Edelbrock and it ran like crap in the heat.  Their float bowls are on the side, right over the heat crossover.  Switched to a Holley and that side of things are fixed.  The drivability is like night and day, just knocks when hot.  I run a stock mechanical pump with no issues.

New Port Richey, Fl. here.  Are you using a shroud?  Also what t-stat is in it?

Something I was reading a few weeks ago was a guy in the same boat as many of us. Trying everything he could think of. I answered him with a few things and got him to send me a few pics. Once seeing his set up, (aftermarket monster aluminum rad), I told him I thought the rad sat too low. His upper hose was higher than the top of the rad. tank. He said he has tried everything else under the sun and would try raising it. I got an email from him saying he raised it just over 3 inches and it runs under 200* in traffic and sitting at lights.  All fixed...

I have seen this on a few cars before. Your rad. will seek it's own fluid level. If it is mounted too low if will have a large amount of air in the top of the rad. once the engine comes to temp.  Simple rule is to keep the rad at least as high as the OEM rad. was. The cap/fill should be higher than your t-stat.

[mauve66]

when i was re-searching mine i noticed that the 440-hemi motors had a 3/8 feed line and a 5/16 return line plumbed as a set for the car so i just got the b-body setup for a hemi and just clipped them into the same place as the old lines.  I had to drill out the pass through at the torsion bar support (i think that was were it was at) to get both lines through it.  i used some JB Weld to insert a metal tube into the tank for the return line to connect to.

[hemirr]

I am running a shroud.   The radiator is a Griffin muscle car series that is 1 1/2 times thicker than the stock unit but yet runs hotter ?  It is mounted perfectly centered so the cooling fins fill the support opening with no overlap.  As  a matter of fact it it can not go any higher as the cap will hit the hood and the rad cap is higher than t-stat. The top hose is a little higher that the tank as it is setup for AC and needs the belt clearance.  I can cut it down to lower it a bit but when the AC go's on this fall it will may have to be raised for clearance.  I have tried a a 160, a 180 and 195 degree t-stat with same results.  So for the best combo believe it or not is not t-stat.  I know all about the reason this isn't supposed to work but by far it is the best results to date.  The one thing I did notice is that it looks as the water pump pulley is a a little smaller diameter than a friend of mine with same car and no cooling issues. If so the water pump maybe underdriven a bit witch would make a difference at slower speeds.  Maybe, its a thought.