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Holley
Edelbrock
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Holley:
Hello,
I read your article on the truck avenger and was glad to hear you have
yours running well. Mine is giving
me fits. I have a 302 with
roller cam in my bronco so I figure we are fairly close in application.
Mine is running very rich I think, at first it was barely drivable so I
called Holley and they said that there had been an engineering revision and
switched from a 6.5 power valve to a 2.5. I
did that and it helped a lot. Now I’m
trying jetting. I dropped 2 on the
primary and that seemed to help some. It
also doesn’t idle very smoothly and the idle mixture screws don’t have much
effect. Too much of the idle
transfer slot is exp
Do you happen to know which power valve you have?
Thanks for any suggestions you can offer,
When
I got my Truck Avenger and “out of boxed” it, it ran so rich I thought I was
going to see gas trickling out the exhaust pipes!
This
is the first I have heard of a revision to the pump valve. I will defiantly be
calling Holley – today. Every Holley I have ever owned was an unstable idling,
cold-blooded, rich burning, gas hog right down to the one-barrel carbs. If
Holley recommends 2 steps leaner go 3, if you removed that EGR and plugged the
holes in the heads – go one or two steps leaner.
On
the Holley’s the air mixture screws do not really affect the idle much just
the overall performance. Go 1 ¼ turns out and forget them.
I
assume you have already checked for vacuum leaks… Correct? If not, here is a
little trick to use… instead of listening to your intake manifold or doing the
extensive leak down test here is a quick tattletale start your engine use a
vacuum gauge on your intake vacuum port, (Located
underneath the left side of the front fuel bowl next to the PCV port… another
conveniently placed item) if you don’t get a rock steady reading
you have a leak somewhere. . Find
it , fix it.
As
far as the idle goes, the curb-idle screw and the choke duration are the only
“quick fixes”. The fast idle screw does not help much at all, as you
increase it generally you loose your curb idle control. The secondary idle is
your key to choke and idle mixtures, that is why they hide it so well, don’t
talk much about it and put it where you practically have to pull the carb to
adjust it. I think they are still looking out for Earl at the local garage while
targeting us of all people as buyers… I will be adding some adjustment tricks,
pictures soon for adjusting Holley's "on the block".
Anyway,
use a small ratcheting right angle screwdriver or a very small ¼ ratchet with a
bit for on engine adjustment. Chilton’s says back it off until it closes and
then open or tighten it up ¼ turn Holley’s manual says 1 full turn the
adjustment is actually somewhere in-between.
I
read your Holley vs. Edelbrock page. I was considering putting a Holley Tr. Aven.
carb in my '74 Bronco w/ a recently rebuilt 302.
Are you still using the Holley?
How does it run?
Do you do a lot of 4-wheeling?
They (Holley) talk about the angles of driving and the carb not flooding, have
you found that to be true?
What intake manifold did you use? Mine is stock.
Thanks for the info,
Yep,
still using it.
It
seems to perform well, however, if you built your 302 stock and are using a
stock intake you might want to consider a Holley 500cfm 2300 Race series Summit
Racing it will run rings around the avenger for a stock setup. I have the
marine 500cfm on my boat with a V6 and I can accelerate right along side my
friends with dual 454’s fully blown. Although they pull away above 40mph, this
still gets on their nerves.
Otherwise,
if you want to go with the Avenger put it on a Wieand Stealth intake and install
an H-pipe on your duel exhaust. Otherwise, you will be fighting the fact that
you are over-carbureted forever.
Edelbrock:
I
came across your website comparing the Edelbrock carb and Holley carb. I
have the exact Edelbrock carb that you have on a small block Chevy 283 in an El
Camino. I absolutely CAN NOT get it to accelerate properly. I’ll
hit the gas and it will be “dumb” for a second then take off fine. I
figured it was because it was running too rich. So I used the chart in the
Edelbrock manual and set it up to be number 7 which made it leaner in the cruise
mode and power mode, but it is still doggish. Sometimes if I don’t back
off when it bogs, I’ll even get a backfire L
It really baffles me since it has great response if I’m just revving the motor
and not moving, but really poor while in gear. I was just wondering if you
had encountered any similar problems or know of anything that I could try to
stop this madness.
Yes, I saw that exact problem for almost 2 years. The two solutions I found are
One – step up the idle (not what you want to hear)
Two
put a spark advance delay on the distributor vacuum line (better idea). If you
have one already, put a longer delayed one on. As far as I could tell, the delay
came from the initial air dump before the needles can react from the lack of
intake vacuum.
Hope
this helps…
Hi,
I was just reading on your website about your Holley vs. Edelbrock opinion and i
have a Edelbrock performer series 600 cfm 4barrel carb on my 73 bronco. i
bought this bronco like a year and a half ago and don't know anything about
carb's. i drove as a daily driver for a year and the carb drove me nuts to
say the least. I don't know what the problem is exactly but as of now i
just replaced the fuel filter to see if that was the issue without any
luck. Anyway what it does is bogs down when light to mild gas is given to
it and sometimes gives a pop and dies and other times just shuts down. It
also occasionally does this when a lot of gas is given. You can never tell
and that isn't very comforting when pulling into traffic. It seems to run
ok when i get up to speed but if I have to stop and go again or even slow down
to a low speed to pick up again this seems to happen. Do you know if it is
running rich or lean or if this is the problem. Any help you can give me
with this would be great. I am trying to pin point this problem so i can
at least drive it for fun. Also if you think this is the problem do you
know how to tune a carb. I've been searching on the net on how to do so
but its very hard to understand and like I said I don't know anything about
carbs. I've done some work to my bronco with electrical and some
other stuff but have very limited experience with engines. Thanks for your
time.
Just
from hearing your problems below, it sounds as if maybe you have more than just
carburetion problems. To me it sounds as if you may need to look at your timing
(to far advanced possibly). If you have checked that and verified it is set at
8deg BTC (before top dead center). Then check for vacuum leaks I have found that
a $45 “Mighty Vac - Summit Racing or JC Whitney” is more than worth the
investment. Take a close look at your vacuum advance on the distributor for
leaks (usually compensated for by advancing the curb idle or timing).
All
that checked out and/or corrected, next move to the carburetor. Verify that the
distributor advance is connected to the right port. On a Ford, this is the port
on the passenger side of the carburetor.
Next,
make sure your choke (if electric) is hooked to a keyed positive power source not
the alternator as your original was. This is especially important on
the Edelbrock carburetor.
If
all of that checks out, you should be having far less problems with the “popping”
and “dieing” now. Next it’s time to address the low end bogging:
The
things that come into play here is;
1.
Carburetor
2.
Air cleaner
3.
Intake manifold
4.
Exhaust system
5.
Camshaft (I will skip this because it is beyond the home tuner
scope)
Ok,
before we go further, I will assume that you have a stock intake manifold with,
“I hope”, a duel exhaust system consisting of at least 2” ID pipes.
If
this is not the case, you will have continued problems with low end bogging
because basically, a 600cfm carburetor is over-carbureting your stock setup to
far. In fact, 600 cubic feet per minute is over-carbureting any 302 except one
built for drag racing. This does not mean through it away….
Now,
to make your Edelbrock run;
Use
as large an air cleaner as you can. I recommend a 14”x3”. Use a drop type
for clearance $14.00 Pep Boys with a 1” riser to clear your choke.
Ok
now you have covered air before it comes in and after it goes out. Next;
On
the Edelbrock one thing I noticed was the tendency for the air/fuel idle mixture
screws to vibrate out over a period of a week or two "of course at
different rates". I solved this using two plastic caps from TV coaxial
connectors. Any plastic caps that will fit tightly when pressed on will work. I
drilled small holes in the edges of the caps and wired them together so the
screws could not vibrate out. I plan to add pictures and a short “how to” on
my site soon.
Another
quick trick for the Edelbrock is to add a vacuum delay on your distributor
advance. Again, I will be adding this as tips and tricks on my site soon.
Next,
do not be afraid to lien that carb out. You are over carbureted so you need more
air and less gasoline, jet it down using the documentation that came with your
carb or download the manual from the link on my page or at www.edelbrock.com
. Go one level leaner than they recommend if you are using the stock intake. 2-3
levels leaner if you removed the EGR and air pump system and plugged the holes.
The
biggest low end improvement for your truck will come from your exhaust; lets
assume you already have long-pipe headers, duel exhaust and free flowing
mufflers like glass packs or turbo mufflers and you want a huge increase in your
low-end… install an H-pipe. It is that simple. An H-pipe is a crossover pipe
installed after the headers and before the muffler. This simple adjustment will
give you gobs of torque you will burn rubber with mudders off the line. Summit
Racing sells kits. Please note this is more than likely (Not street legal) as
with various other improvements I mentioned above.
I
hope this helps let me know how it goes…
Paint Codes:
Mike: here are some pictures of the interior paint... we are still going to bed-line the entire inside of the Bronco... the exterior paint will be done sometime around Christmas or the first part of 2005... this has definitely been a project... I had our local NAPA store mix the paint code you suggested... it turned out a straight RED... so they mixed up competition Orange and it was a nice match to what my original interior was... so this is what we went with...
Glenn, being that I'm not a NAPA fan as of recently, I'm can't
say I'm totally surprised at the paint mismatch. I recommend that people go to a
Sherwin Williams or a commercial auto body supply company to get your paint...
Did they at least give you Acrylic Enamel or at least Enamel? If they gave you
Lacquer of any kind... see if you can take it back, Lacquer is in no way as
durable as Enamel and will require a clear coat (which will change the color) in
order to even come close to the durability of Enamel.
P.S. You can do a quick color check by picking up a can of "recently
discovered (by me)" Ace Hardware "Rust Stop" Allis Chalmers
Orange, it is Enamel and almost a dead match to the original color.
Mike: Calypso Coral it is... it's a perfect match...the bed liner is going in Friday... in the same color [Calypso Coral]...