Metering rods Jet's in spark plugs

[j par]

So I'm here in Portland at sea level and fixing to take my truck to Colorado. It has a 75 la 360 with an Edelbrock 1406. I'll shoot a picture of the jet options that I have and metering Rod options. Also want to shoot a picture of my spark plug or at least one of them. was thinking obviously I want to Jet down for economy and for the elevation. I was thinking of starting with going down to the 98 jets with the 7547 stock setup in the meteringrods? I have the 100 jet in there now in a 7342 metering rod. That really good here and a bit rich but I like the power. I want the same kind of power when I get there but again just looking to make sure my plugs are reading right and things like that it looks a little oily around the outside but the actual burn looks good.
also you can see there in the picture I do have some 92 Jets some 95 Jets and a 70-50 to set of meteringrods.

 

[yellow rose]

IDK about wide open throttle but your fuel curve looks pretty bitching to me.

As to the elevation changes going up that high...once you go over 5000 feet go up one heat range on plug, add a couple degrees of timing and lean the metering rod .005-.008 thousandths.

When you get up over 8000 feet (talking density altitude here not just elevation) all bets are off. There is less atmospheric pressure pushing on the vents so fuel flow drops on its own. Up that high, you can usually go up one more heat range on the plugs and a couple more degrees of total timing on it and it will be fine.


I've had to tune at those nose bleed, look out for low flying geese that you can grab with your bare hands DA's and altitudes. You just have to look at your plugs and remember the carb is self adjusting. As the barometer goes down, so does fuel flow with the same jets/metering rods/air bleeds and emulsion.

 

[TrailBeast]

So I'm here in Portland at sea level and fixing to take my truck to Colorado. It has a 75 la 360 with an Edelbrock 1406. I'll shoot a picture of the jet options that I have and metering Rod options. Also want to shoot a picture of my spark plug or at least one of them. was thinking obviously I want to Jet down for economy and for the elevation. I was thinking of starting with going down to the 98 jets with the 7547 stock setup in the meteringrods? I have the 100 jet in there now in a 7342 metering rod. That really good here and a bit rich but I like the power. I want the same kind of power when I get there but again just looking to make sure my plugs are reading right and things like that it looks a little oily around the outside but the actual burn looks good.
also you can see there in the picture I do have some 92 Jets some 95 Jets and a 70-50 to set of meteringrods.

No matter what you do you wont have the same power, but YR's plan looks good to me.
I live at 5,500 and run 7347 with a 96 jet and the pink springs.
The higher you go the lighter step up spring due to less air density causing lower vacuum.

 

[cannucky]

you guys are ok with that plug ? looks like it's too white with the nasty little black flecks of a plug that is too hot or running lean , coupled with a glassy black ring and oil on the bottom three threads of a plug that may be getting oiled , all the plug charts I have seen show this as outside the acceptable range on both counts.

PS shouldn't the timing band be up on the upper part of the bend ?

 

[j par]

Well turns out the plugs were kind of a joke as they we're all different colors depending on which cylinder LOL black white oily clean LOL

 

[yellow rose]

you guys are ok with that plug ? looks like it's too white with the nasty little black flecks of a plug that is too hot or running lean , coupled with a glassy black ring and oil on the bottom three threads of a plug that may be getting oiled , all the plug charts I have seen show this as outside the acceptable range on both counts.

PS shouldn't the timing band be up on the upper part of the bend ?

Not with pump gas. The timing mark on the ground wire needs around the bend for pump gas.

Most of the **** you see is detergent not detonation on the plugs.

 

[j par]

A change to the stock metering rods and jets and it runs a little bit like crap but I hope that it will get better.

 

[yellow rose]

BTW if that is a Champion plug the heat range is correct. If it's an NGK it's at least one heat range too cold. If it's an Autolite I'm not sure.

 

[cannucky]

Cool then I guess I can feed some more initial into mine then , I backed it off because the band was down there and the charts said it should be on top but it has always idled better the other way .

 

[Bulldozer]

I'm up here at 6500 feet and I use an autolite 85 in my 440, I also use two , yes , two 1406 's running 98 primary jets and 96 secondary jets both using the pink springs and identical metering rods. they are not using a progressive linkage , they are set up to run together and damn do they run good. I think you are over thinking it. most of, if not all your adjustments can be made with timing and mixture, you may want to nudge up your idle setting depending on how much timing you add.

 

[yellow rose]

I'm up here at 6500 feet and I use an autolite 85 in my 440, I also use two , yes , two 1406 's running 98 primary jets and 96 secondary jets both using the pink springs and identical metering rods. they are not using a progressive linkage , they are set up to run together and damn do they run good. I think you are over thinking it. most of, if not all your adjustments can be made with timing and mixture, you may want to nudge up your idle setting depending on how much timing you add.

Hmmmm. You say you are down the road. Sounds to YR like you are up the hill. Most everything is down the road from where you are.

 

[yellow rose]

No matter what you do you wont have the same power, but YR's plan looks good to me.
I live at 5,500 and run 7347 with a 96 jet and the pink springs.
The higher you go the lighter step up spring due to less air density causing lower vacuum.

Yep, unless you burn nitro or can jack up the boost (or change the compression ratio) all you can do is chase the power loss and keep it to minimum. You are just trying to mitigate the loss of power and not give up any more power than you have to.

 

[Wyrmrider]

What about a TQ with the altitude compensation

 

[TrailBeast]

I think you are over thinking it. most of, if not all your adjustments can be made with timing and mixture, you may want to nudge up your idle setting depending on how much timing you add.

You may very well be right.
Right, Right, You're Bloody Well Right.
You Got the Bloody Right To Say.

I frequently take my car up to around 7000 feet and the only real difference I notice is the idle smooth's out a little. (because it gets a little richer)
I keep the idle AFR around 15.5-16 average because I like the little lope of the cam at 5,500 feet.
At 7000 it runs around 13 AFR.

It's possible the step up springs may compensate a little for altitude by not raising the rods as much due to less vacuum.