tuna55
SuperDork
2/27/12 11:59 a.m.
This is for the LTD, it has a 460 high compression, aluminum dual plane intake and stock exhaust and cam, it's got an edelbrock performer carb on it now.
Idles OK, but throttle response is soggy and occasionally backfires through the carb on the transition to WOT from idle in park. We have the following:
dwell is set too low (working on it)
timing is set by ear at idle
idle mixtures screws are untouched from previous installation
calibrated in terms of jets and rods by the edelbrock tech guy.
I am thinking idle mixture screws and dwell in combo - what say you?
timing, idle mixture, and pump shot. probably step up springs, too.
http://gasalley.thetumbleweeds.net/tech_archive/general/edelbrock_tuning.htm
read, do, report back.
you cant tune a carb over the phone, or in park. follow the directions in the link. thats what ive done for every eddy equipped car ive built, and have always succeeded well.
michael
why are you running a points distributor when it's so easy to put in a factory ford electronic ignition?
and why are you setting the timing by ear? get a timing light on that thing and dial in about 10 degrees btdc with the vacuum advance unhooked.
set the idle mixture screws to about 1.5-2 turns out as a starting point. if you don't have it, download the tuning manual for the carb from the Edelbrock website.
tuna55
SuperDork
2/27/12 2:52 p.m.
novaderrik wrote:
why are you running a points distributor when it's so easy to put in a factory ford electronic ignition?
and why are you setting the timing by ear? get a timing light on that thing and dial in about 10 degrees btdc with the vacuum advance unhooked.
set the idle mixture screws to about 1.5-2 turns out as a starting point. if you don't have it, download the tuning manual for the carb from the Edelbrock website.
Points because we have it, we are out of time, and because points have never failed me, ever.
Timing because nobody has a light, we are out of time and money. It works pretty well, honestly.
Thanks for the screw adjustment starting point
Where is your pump shot at? And which Performer is it? Out of the box the 1411/750 could use a little bigger squirter.
tuna55
SuperDork
2/27/12 3:38 p.m.
Rob_Mopar wrote:
Where is your pump shot at? And which Performer is it? Out of the box the 1411/750 could use a little bigger squirter.
Dunno, but it's stock - we have the 1406 crappy one, but we've retuned it with jets and rods, but not pump.
You'd surprised how "off" timing by ear can be...
Just get a light on it!
Racing engine timed by ear? You really want to risk burning an exhaust valve in this thing? Timing lights are cheap and shouldn't impact your budget for this utterly goofy racing series...
90% of carb problems are ignition issues.
get them sorted out first before you work on the carb.
+1 on the electronic ignition.
+100 on getting a timing light
tuna55 wrote:
Rob_Mopar wrote:
Where is your pump shot at? And which Performer is it? Out of the box the 1411/750 could use a little bigger squirter.
Dunno, but it's stock - we have the 1406 crappy one, but we've retuned it with jets and rods, but not pump.
The 1406 isn't a bad carb. Might be a bit small for a 460 though. Go ahead and use a piece of coat hanger to hold the secondary air door open now. There's no way a 460 will bog when the secondaries open up on a 600 CFM Performer.
After the ignition timing is known value, take a look at the pump shot linkage. Try it in the middle first, then the lower position to see how it reacts. The nozzles are still going to be on the small side. You can get a set of 3 from Ed or you can use some numbered drill bits in a pin vice to open 'em up.
