'68 Charger R/T 440 carburetor question

[MW 413]

My Max Wedge(dual 750CFM AFS carbs) and my AAR(center Holley 350CFM carb) both do it after setting a week or so. Totally normal. I just crank it about 2 to 3 short 4 to 5 revolutions and wait about 3 to 4 seconds in between cranks to let the mechanical fuel pump get the gas into the carb bowls. Pump it several times and starts right up after that.

 

[Mick56]

After your car has been sitting, and you take the air filter off, is the choke plate completely closed? If not, it needs to be adjusted so that it is.

 

[RJRENTON]

My Max Wedge(dual 750CFM AFS carbs) and my AAR(center Holley 350CFM carb) both do it after setting a week or so. Totally normal. I just crank it about 2 to 3 short 4 to 5 revolutions and wait about 3 to 4 seconds in between cranks to let the mechanical fuel pump get the gas into the carb bowls. Pump it several times and starts right up after that.

IMO...
My RS23VOA***** GTX (an origional six barrel car) exhibits the same issues. After sitting several days, it is hard to start....yes the choke system is adjusted and is functioning correctly. I attribute the issues to the percentage of Ethanol in the fuel....as ethanol has a higher RVP (Reid Vapor Pressure) index value which is a measure of the volitility of the fuel. The higher the RVP, the easier the fuel volitizes (evaporates), thanks to the alcohol content. In addition, Ethanol (and the other blended components of the mix) has half the heating value of gasoline (energy) requiring a richer fuel mixture to develop the same horsepower level. The fix....not sure there is a simple solution....ethanol blended fuels are a fact of life.....I guess all we can do is suffer in silence....unless we switch to a fuel injection system, which is more tolerant of the fuel being used..... which is not appealing to me because I want to maintain correct appearance and origionality. Just my opinion of course.
BOB RENTON

 

[Jerry Hall]

IMO...
My RS23VOA***** GTX (an origional six barrel car) exhibits the same issues. After sitting several days, it is hard to start....yes the choke system is adjusted and is functioning correctly. I attribute the issues to the percentage of Ethanol in the fuel....as ethanol has a higher RVP (Reid Vapor Pressure) index value which is a measure of the volitility of the fuel. The higher the RVP, the easier the fuel volitizes (evaporates), thanks to the alcohol content. In addition, Ethanol (and the other blended components of the mix) has half the heating value of gasoline (energy) requiring a richer fuel mixture to develop the same horsepower level. The fix....not sure there is a simple solution....ethanol blended fuels are a fact of life.....I guess all we can do is suffer in silence....unless we switch to a fuel injection system, which is more tolerant of the fuel being used..... which is not appealing to me because I want to maintain correct appearance and origionality. Just my opinion of course.
BOB RENTON

Bob;
Your input is very true, but the fact remains that these cars were made to be driven on a daily basis. I run a 50/50 mix of 100 octane LL and 90 octane no ethanol in all my old engines. They exhibit the same problem after sitting for 3-7 days. A couple have electric fuel pumps and this lessens the problem because of immediate fuel pressure.

 

[RJRENTON]

Bob;
Your input is very true, but the fact remains that these cars were made to be driven on a daily basis. I run a 50/50 mix of 100 octane LL and 90 octane no ethanol in all my old engines. They exhibit the same problem after sitting for 3-7 days. A couple have electric fuel pumps and this lessens the problem because of immediate fuel pressure.

Jerry,
The mistake I made, years ago, when I rebuilt the engine in the GTX, I used TRW 11.0:1 pistons.....but better quality fuels were available. Today, when I have a few extra $$$ in my pocket, I'll buy a few jugs of SUNOCO RACING fuel. I use the leaded standard grade @ 110 octane (R+M /2 method), blended with 93 octane pump gas, Shell seems to work best for me, with 2-3 gallon of the Sunoco fuel...which the GTX tolerates OK, with about 35° total advance @ 2800 RPM, no vacuum advance. Since the car is only a "cruise car" used only occasionally, the cost is "bearable"....just don't tell the wife.
FYI.... link to the Sunoco website so you can compare the different grades and perhaps locate a dealer in your area. BTW.....not cheap but you can do a little negotiating...... www.sunocoracefuels.com/fuels
Just my opinion of course.
BOB RENTON

 

[Jerry Hall]

Jerry,
The mistake I made, years ago, when I rebuilt the engine in the GTX, I used TRW 11.0:1 pistons.....but better quality fuels were available. Today, when I have a few extra $$$ in my pocket, I'll buy a few jugs of SUNOCO RACING fuel. I use the leaded standard grade @ 110 octane (R+M /2 method), blended with 93 octane pump gas, Shell seems to work best for me, with 2-3 gallon of the Sunoco fuel...which the GTX tolerates OK, with about 35° total advance @ 2800 RPM, no vacuum advance. Since the car is only a "cruise car" used only occasionally, the cost is "bearable"....just don't tell the wife.
FYI.... link to the Sunoco website so you can compare the different grades and perhaps locate a dealer in your area. BTW.....not cheap but you can do a little negotiating...... www.sunocoracefuels.com/fuels
Just my opinion of course.
BOB RENTON

So you get the Standard Leaded. I looked through a lot of the mixtures and that would suit me fine if I could get it here. I will see if they have any distributors close by and the cost. The last 100 LL I got was $5.45 a gallon. Then I have to add 4 oz. per 5 gallons Marvel Mystery Oil to take the dryness out of that AV gas. Over 10 years with no problems. I have 110 & 112 unleaded racing fuel available at the drag strip, but costs $50 a 5 gallon can. I do use it in the Hemi Dart without mixing.

 

[RJRENTON]

So you get the Standard Leaded. I looked through a lot of the mixtures and that would suit me fine if I could get it here. I will see if they have any distributors close by and the cost. The last 100 LL I got was $5.45 a gallon. Then I have to add 4 oz. per 5 gallons Marvel Mystery Oil to take the dryness out of that AV gas. Over 10 years with no problems. I have 110 & 112 unleaded racing fuel available at the drag strip, but costs $50 a 5 gallon can. I do use it in the Hemi Dart without mixing.

Jerry,
Yes....this is works for me. I'm sure there are other fuels that I could use....just st a higher cost.
I used to live in Pennsylvania and there was a few stations where I could get either 115 octane leaded or 110 octane unleaded fuel. The only issue was it was labeled "for off road use only"....you could NOT pump it directly in the car....you had to pump it into containers.....and drive off the premises....and then pour it in the car....what this accomplished is a mystery...typical of Pennsylvania legislation....a real PITA. I could buy either 110 unleaded or 115 octane leaded for approximately $ 7.85 / gallon....I always opted for the leaded fuel.
BTW....does adding Marvel Mystery Oil to your fuel mix cause any detonation problems because it has a lower flash point? Most, if not all oils, have a lower flash point than gasoline. Does it contribute to cylinder carbon formation? ....just asking...
BOB RENTON

 

[Jerry Hall]

Jerry,
Yes....this is works for me. I'm sure there are other fuels that I could use....just st a higher cost.
I used to live in Pennsylvania and there was a few stations where I could get either 115 octane leaded or 110 octane unleaded fuel. The only issue was it was labeled "for off road use only"....you could NOT pump it directly in the car....you had to pump it into containers.....and drive off the premises....and then pour it in the car....what this accomplished is a mystery...typical of Pennsylvania legislation....a real PITA. I could buy either 110 unleaded or 115 octane leaded for approximately $ 7.85 / gallon....I always opted for the leaded fuel.
BTW....does adding Marvel Mystery Oil to your fuel mix cause any detonation problems because it has a lower flash point? Most, if not all oils, have a lower flash point than gasoline. Does it contribute to cylinder carbon formation? ....just asking...
BOB RENTON

A couple of years ago all stations in Alabama quit selling 93 octane no ethanol fuel which I had most of my cars tuned to run good on. After that I had detonation problems on most everything except the Hemi Dart which always got race fuel. The first alternative I had was mixing a local stations 108 octane racing fuel with the 89 octane no ethanol fuel available. When the 108 fuel went to $9.99 a gallon I looked for an alternative and was told by several drag racers that our local airport would let us fill containers there. I don't know what the actual octane rating ends up with my mixture but I have no detonation issues. All my old engines are built to stock specifications other than some cam changes, so compression is between 10:1 & 10.25:1. So the Marvel Mystery Oil must not be pulling the octane down much. What I do know is that the change from straight 93 octane no ethanol to the mixture I now use really woke everything up noticeably.

 

[RJRENTON]

A couple of years ago all stations in Alabama quit selling 93 octane no ethanol fuel which I had most of my cars tuned to run good on. After that I had detonation problems on most everything except the Hemi Dart which always got race fuel. The first alternative I had was mixing a local stations 108 octane racing fuel with the 89 octane no ethanol fuel available. When the 108 fuel went to $9.99 a gallon I looked for an alternative and was told by several drag racers that our local airport would let us fill containers there. I don't know what the actual octane rating ends up with my mixture but I have no detonation issues. All my old engines are built to stock specifications other than some cam changes, so compression is between 10:1 & 10.25:1. So the Marvel Mystery Oil must not be pulling the octane down much. What I do know is that the change from straight 93 octane no ethanol to the mixture I now use really woke everything up noticeably.

Jerry,
Thanks for the insight....come spring, I'll try blending some MMO. Since I live in corn country, NOT getting ethanol is not an alternative....i'll try the airport to see if I can buy some av-gas. The one commercial carrier uses a Cessna plane with a piston engine but I'm sure its low lead fuel...not sure of the octane or cost or if they'll even sell it to me.
Thanks again.
BOB RENTON

 

[Richard Cranium]

I put a marine squeeze primer ball before the fuel pump on my cars. Just pop the the hood, reach down a squeeze it 8-10 times and the bowls are full again.