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Carter BBD and fuel line mod
https://www.slantsix.org/forum/viewtopic.php?t=19717		 Page 1 of 2
Author:  duke76 [ Fri Sep 15, 2006 6:37 pm ]
Post subject:  Carter BBD and fuel line mod
I have a question about a BBD install. I purchased a NOS BBD on ebay. I have a 71 Scamp, and have probably taken on too many different installs at once. I'm converting to HEI, from a one barrel to the 2 barrel BBD, and have switched to Dutra Duals. I'm pretty sure once I get the ground problem solved on the HEI unit it will start. But on my carb there are only two vacuum lines. One comes out the side towards the valve cover, which is obviously for the vacuum advance, and the other is a bigger outlet coming from the back right corner of the carb. On my Scamp I have the vacuum advance line, PCV line, and the fuel vent line coming from the fuel pump. Does that second outlet from the carb go to the PCV and if so what do I do with the fuel vent. Also reading past posts I have read alot about the fuel line mod. Is it really necessary on this application since my fuel line goes around the front of the engine and not over the valve cover?
Author:  Jeb [ Fri Sep 15, 2006 7:00 pm ]
Post subject: 
You want the fuel line to go over the valve cover. Going in front of it exposes it to excessive heat from the exhaust manifold, leading to vapor lock.

Yes the large port on the back is for the PCV valve. The BBD has no bowl vent nipple, just tee the purge line (goes to the fuel bowl vent) into the PCV hose.

Does your car have a charcoal EVAP canister? I think some of the early 70's models used the crankcase to store fuel tank vapors, leading to all sorts of weird driveability problems. SlantsixDan can tell you more about this subject, he is the emmisons guru.
Author:  duke76 [ Sat Sep 16, 2006 3:58 am ]
Post subject: 
No there is no evap canister. Would it be better if I added one.
Author:  70valiant [ Sat Sep 16, 2006 6:39 am ]
Post subject: 
If you don't have a Cannister you don't want to go through the trouble adding one. Just plug the line coming from the fuel pump.
I also would not waste my time routing the fuel line over the valve cover. It just adds one more thing to have to move to adjust the valves, which should be done annually at minimum. Plus if you plan on racing you probably will not pass tech if you have a good tech inspector.
Author:  duke76 [ Sat Sep 16, 2006 6:58 am ]
Post subject: 
But there shouldn't be any problem if it just tee the purge line into the PCV line right?
Author:  CStryker [ Sat Sep 16, 2006 9:00 am ]
Post subject: 
Quote:
Plus if you plan on racing you probably will not pass tech if you have a good tech inspector.
Oh really? What's required to pass tech?
Author:  70valiant [ Sat Sep 16, 2006 9:32 am ]
Post subject: 
you arent alowed more than a 6" long section of rubber fuel line. That is the rule at Englishtown.
Author:  duke76 [ Mon Sep 18, 2006 5:25 pm ]
Post subject: 
I got the car running! I can't believe it. Thanks to all of you who have helped me with my first mopar. I'm getting the exhaust on this week I hope and then I'll be able to fine tune.
Author:  75duster [ Mon Sep 18, 2006 9:01 pm ]
Post subject: 
70valient- my local track dosent allow more than 12'', however that being said you can use metal tubing instead rubber fuel line and still do the gasline mod, at least i did
Author:  70valiant [ Tue Sep 19, 2006 5:45 am ]
Post subject: 
Using metal tubing you have to remove the fuel line to set the valve lash. So to do it properly you have to take off the fuel line, remove the rocker cover, reconnect the fuel line start it set the lash, take the fuel line back off, replace the rocker cover, and put the fuel line back on. It seems like a lot of extra work for a mod that really doesn't fix anything(Ok show of hands who has actually suffered vapor lock on their slant?).
Author:  emsvitil [ Tue Sep 19, 2006 5:55 am ]
Post subject: 
Quote:
70valient- my local track dosent allow more than 12'', however that being said you can use metal tubing instead rubber fuel line and still do the gasline mod, at least i did

Usually braided stainless can be used instead of a hardline, and it gets you around the limited length of rubber line when you need some flex
Author:  64 Convert [ Tue Sep 19, 2006 8:05 am ]
Post subject: 
Quote:
(Ok show of hands who has actually suffered vapor lock on their slant?).
In our Texas heat, it happened daily when I had a 1bbl setup. When I switched to a 2bbl, the vapor lock went away, but the carb still percolates and floods after shut down.

I haven't moved the fuel line yet, but will do it this winter to see if the perc problem goes away.
Author:  70valiant [ Tue Sep 19, 2006 9:05 am ]
Post subject: 
Ok we got one, any one else have this problem?
Author:  Jeb [ Tue Sep 19, 2006 5:06 pm ]
Post subject: 
I have a horrible vapor lock problem with my Duster but it is because it the fule line was bent up by the previous owner (looked like someone lost there temper) but I straightend it out the best I could. I still vapor locks because the fuel line is about 1 inch away from the manifold at the clip on the water pump. I plan on bending a new line that is in the same location as the stock line but curves up and away from the manifold and makes a curve behind the A/C compressor.

In this picture you can see how close the fuel line runs next to the manifold.
Image
Author:  duke76 [ Thu Sep 21, 2006 3:57 pm ]
Post subject: 
Has anyone ever routed their PCV hose over to the vacuum port on the #6 intake runner? I have manual brakes and someone suggested running my PCV hose here. He said it shouldn't be a problem letting one cylinder burn everything off, but it didn't sound right to me. Or about just removing the PCV and putting in a breather cap? It is a 71 Scamp with a 198 that I'm converting to super six.
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