Re: eddy carb ?'s
[Re: moparmandc]
#223204
02/13/09 04:42 PM
02/13/09 04:42 PM
|
Joined: Jul 2006
Posts: 4,179
California
mickm
master
|
master
Joined: Jul 2006
Posts: 4,179
California
|
it is trial and error, unless you can get an a/f ratio monitor. that will tell you exactly where you are. short of that, you just need to put something else in and try it out.
the metering rods are in 2 steps, cruise and power, so you need to know where you are rich. that is really important for finding the right rod. if you are only rich on cruise, and you end up leaning out power as well, that doesn't do any good.
keep in mind that 1 metering rod step is approximately equal to 2/3 of a jet size. that changes with the size of the metering rods, but it is a good rule of thumb. so the 650 thunder comes with a .068 X .047 metering rod, stock out of the box. .068 is cruise, and .047 is power. if you just needed to lean out the cruise, you could go for something like a .068 X .042. that would leave your power as it is, and lean your cruise out by almost 1 jet size.
it is a lot of trial and error, and i can tell you from experience that a few hundred $$ for a few hours on a dyno with an a/f monitor can save your hours upon hours of trial and error.
the other thing is that unless you have a local source for them, or get it right in one or two tries, buying metering rods pair by pair and paying for shipping each time really adds up. look at what you have in there now, and look at what is in the kit they sell.
note that if you are really rich for some reason, it may make sense to go down a jet size, and then play with metering rods.
good luck with it!
|
|
|
Re: eddy carb ?'s
[Re: moparmandc]
#223205
02/13/09 05:25 PM
02/13/09 05:25 PM
|
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
|
Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
|
Quote:
sound's like a good place to start. just adjust till i have the best vacuum reading? not real sure about off idle but seems real boggy and not to good throttle response at times. i did put a overhaul kit in it about 2 years a go for the same reason but did not help much. other that that it is the same as it came out of the box.
It will never be a holley.
|
|
|
Re: eddy carb ?'s
[Re: Mr.Yuck]
#223207
02/13/09 06:16 PM
02/13/09 06:16 PM
|
Joined: Oct 2004
Posts: 214
moparmandc
OP
enthusiast
|
OP
enthusiast
Joined: Oct 2004
Posts: 214
|
Quote:
Quote:
sound's like a good place to start. just adjust till i have the best vacuum reading? not real sure about off idle but seems real boggy and not to good throttle response at times. i did put a overhaul kit in it about 2 years a go for the same reason but did not help much. other that that it is the same as it came out of the box.
It will never be a holley.
sounds like i should just break down and buy a holley they seem easier to work on. do any of you have an opinion on a good street carb
|
|
|
Re: eddy carb ?'s
[Re: Mr.Yuck]
#223208
02/13/09 06:52 PM
02/13/09 06:52 PM
|
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
|
Quote:
Quote:
sound's like a good place to start. just adjust till i have the best vacuum reading? not real sure about off idle but seems real boggy and not to good throttle response at times. i did put a overhaul kit in it about 2 years a go for the same reason but did not help much. other that that it is the same as it came out of the box.
It will never be a holley.
what took you so long ...
|
|
|
Re: eddy carb ?'s
[Re: moparmandc]
#223209
02/13/09 06:53 PM
02/13/09 06:53 PM
|
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
|
Quote:
Quote:
Quote:
sound's like a good place to start. just adjust till i have the best vacuum reading? not real sure about off idle but seems real boggy and not to good throttle response at times. i did put a overhaul kit in it about 2 years a go for the same reason but did not help much. other that that it is the same as it came out of the box.
It will never be a holley.
sounds like i should just break down and buy a holley they seem easier to work on. do any of you have an opinion on a good street carb
No , you'd still be on here asking what adjustments to make because it not calibrated to YOUR engine out of the box .
|
|
|
Re: eddy carb ?'s
[Re: S/SSJOHN]
#223211
02/13/09 10:44 PM
02/13/09 10:44 PM
|
Joined: Jul 2006
Posts: 4,179
California
mickm
master
|
master
Joined: Jul 2006
Posts: 4,179
California
|
Quote:
MickM, I believe you've got that backasswards, If you got a 68 cruise and a 47 power side , you would have to go to a 70 needle for the cruise with a 47 power, if you wanted to lean out the cruise! By the same token if you wanted to fatten up the cruise you would go to a 66 step ,and to fatten up the power side you would go to a 46 or lower #. You can only go a certain no of changes before you change jets, and go bigger in rods again! Have fun, John Lang (HEMIHEAD) 
yeah, you are right. i always do that, and then have to think it through again. going bigger on the jet makes it richer, going bigger on the rod makes it leaner, (as long as you only change one at a time). i always confuse the two.
thanks for pointing that out, would have been a bummer if he followed my advice, then he never would have got the damn thing tuned 
|
|
|
Re: eddy carb ?'s
[Re: moparmandc]
#223212
02/13/09 11:02 PM
02/13/09 11:02 PM
|
Joined: May 2005
Posts: 211
ILL
Greentween
enthusiast
|
enthusiast
Joined: May 2005
Posts: 211
ILL
|
Quote:
yea but it is slightly easier to have a box full of jets and try them. they are much easier to change than taking half the carb apart to change a metering rod. I think that i will use the 02 sensor in the header trick and see exactly where im at or just find an easier to work on holley. i just thought that some one might have close to the same set up i have and could give me an idea before i start to beat my head on the wall.
To the Holley lovers: Changing the needles allows you to alter the A/F curve for both the power circuit and cruise. How EXACTLY can you do that with your average Holley? NOT POSSIBLE. The power valve circuit cannot be tuned for A/F ratio - only when it opens.
Once you put in an O2 sensor you will find out.
|
|
|
Re: eddy carb ?'s
[Re: Greentween]
#223214
02/14/09 01:24 AM
02/14/09 01:24 AM
|
Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar
master
|
master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
|
Quote:
Quote:
yea but it is slightly easier to have a box full of jets and try them. they are much easier to change than taking half the carb apart to change a metering rod. I think that i will use the 02 sensor in the header trick and see exactly where im at or just find an easier to work on holley. i just thought that some one might have close to the same set up i have and could give me an idea before i start to beat my head on the wall.
To the Holley lovers: Changing the needles allows you to alter the A/F curve for both the power circuit and cruise. How EXACTLY can you do that with your average Holley? NOT POSSIBLE. The power valve circuit cannot be tuned for A/F ratio - only when it opens.
Once you put in an O2 sensor you will find out.
It is possable to tune the PV on the Holley, just need to re-size the restriction in the metering block or use a metering block with screw-in restrictions.
If you live in the Denver area and need tuning help let me know, I have a fairly large selection of rods and jets you could try.
|
|
|
Re: eddy carb ?'s
[Re: moparmandc]
#223215
02/14/09 08:18 AM
02/14/09 08:18 AM
|
Joined: Nov 2006
Posts: 319
Northern Va
Mopar73340
enthusiast
|
enthusiast
Joined: Nov 2006
Posts: 319
Northern Va
|
Quote:
yea but it is slightly easier to have a box full of jets and try them. they are much easier to change than taking half the carb apart to change a metering rod.
You only have to take the top of the carb apart to change jets, two screws and the rods can be changed. Also there is no fuel spillage all over the engine. Try that with a Holley.
|
|
|
|
|
