New Edelbrock Carburator Installation Questions

[toddabney]

Well hello,

I just got a new Edelbrock "Thunder Series" 650cfm.  My 1973 brave winne has a 440-3 with Holly "double pumper" that is just not with it anymore .....so I broke down and got the Edelbrock.

Questions: The paper work that came with the carb asked:

#1  is the distributor vacuum port " timed"? (no vacuum at idle) or full vacuum advance (vacuum present at idle). does any one know?

#2  I bought a new fuel pump within the last year at NAPA.  Does anyone know what PSI that thing should push?  They say, 6.5 psi max for that carb.  As a kid I remeber using a vacum guage to test the psi of a installed fuel pump.  I just held the tester up to the fuel line from the pump with all I had and had a friend turn the engine over.  I don't remeber it being messy 'til after I released the presure from the fuel line but that was easliy cleaned-up with a rag...would that be a good way to figure  out the psi?? 

And, I have read how important the transmision linkage is.  Also, any other advice would be great.   

I tried to look up fuel pump pressure and dist vacuum port on the search link to no aval. So, thank you in advance.  This is a great well of information.

Happy trails, Todd

[ClydesdaleKevin]

If you have a mechanical fuel pump, then it will be within pressure spec...if its electric, THEN you have to make sure its not too much pressure...mechanical pumps for a 440 push out less than 6 psi...I thinks its more like 3 or 4 psi.  Someone else will have to answer your questions about the advance...I'm not familiar with the distributors on 440s. 

Kev 

[henryblair]

You need to attach the distributor advance to the full vacuum port.  Sometimes I have even disabled the vacuum advance and timed it at about 10 to 12 degrees BTDC.  The centrifugal advance is usually adequate since you rarely get over 42 - 4500 RPM.  If the fuel pump was okay with the Holley, it will be okay with the Edelbrock.  They usually put out 5 - 7 pounds of fuel pressure which is totally adequate.  The Edelbrock should be less thirsty than the Holley.

[toddabney]

Thank you...that all sounds good. I'm going to install it tomorrow. This will be fun. hmmm.... a friend once asked me how can working on a greasy old thing be fun... I told him working on a "pleasure ride" where there is no timetable on when it has to run, that is fun, no pressure other than your own. But, lets say the brakes are out on your daily driver and has to be running tomorrow morning. Well that just isn't as much fun..... I still like it though, Wrench turning, just knowing that I'm saving money doing the repairs myself instead of taking it "to the shop". So thank you again. I'll let you know how it purrs. thanks, todd

[denisondc]

   Me; I would have attached the distributor vacuum advance to the 'timed vacuum' port on the carb.  But then my Winnie has a 413, and perhaps is different.
   Its also true you can leave that line disconnected, and cap the ports off at the carb.  It will lower your mileage slightly - though I dont know much.   On a car, disconnecting that vacuum advance line can drop gas mileage by 20% to 25%, but on a motorhome I suspect it would not even be a 10% difference.
   I time my distributor with the vacuum line disconnected, and set it at 7° - 8° BTDC.  Basically you can set it earlier, as long as you dont get much 'pinging' as you drive.  When I reconnect the vacuum advance line on the idling engine - it doesnt make any difference in the engine speed; because there is no vacuum on the 'timed' port at an idle.
  I have a Holley carb, and have a fuel pressure gauge.  The engine runs exactly the same with the fuel pressure at 8 psi (which is will a new fuel filter on level ground at highway speed) or as low as 2 psi (which is with a partly clogged fuel filter, going up a long grade with the throttle open wide).  Below 2 psi it may start to misfire under heavy throttle.  At an idle the fuel pressure is usually 6-7 psi.
    I hope you know what 'pinging' sounds like.  Its one of the few sounds you can hear while on the highway that is telling you your engine is going to be destroyed if it keeps up.   It wont be very loud.  Some folks have worked to get the engine cover to absorb as much sound as possible.  I dont mind hearing the noises; valve noise, engine fan roar, because I want to know when there is an abnormal sound.   I ignored a slight 'ticking' sound for years, thinking it was just a typical dirty mopar lifter.  I found out it was a bent pushrod, after the pushrod finally broke.  I always start my Winnie with the engine cover removed, & the fire extinguisher handy.  This way I was able to hear the small 'spit' 'spit' of an exhaust manifold gasket beginning to burn out.  I also get to check for engine fires. 

[toddabney]

You know a few years ago I was driving a dodge with a slant 6. I thought it sounded great. Idle was smooth, sounded tight. A friend says "why don't you adjust the valves?" what valves? I can't hear them anymore. I kind of wondered why all engines sounded better......... so "pinging" would happen on a long hill, right. Like coke bottles banging around or is that something else. and you would stop "pinging"by adjusting the distributor, right? you know the last time I heard valve rattle or "pinging" was 30 years ago on a 1964 rambler w/straight 6.great car. Thanks for all the advice, todd