Plugs Still look a little lean?

[TXcharger70]

I haven't had a whole lot of time to spend on the old girl since the birth of my baby boy. Last weekend I pulled these plugs from the driver side to see how she was doing. As you can see they look pretty lean. I have a holley 850dp with 84 in primary and secondarys. With 3.5 PV. I had jetted up before and thought she was fine. What do you guys think, should I go up a couple of sizes? The motor is 383 (496 stroker, performer rpm intake, stealth heads)

[A383Wing]

how many miles are on those plugs?

[TXcharger70]

About 40 to 50 I believe

[firefighter3931]

Ideally, you're looking for a nice tan/light brown coloring so based on those pics it wants more jet. I'd go up 2 sizes and see how they look. 

Ron

[TXcharger70]

That's what I was thinking. Now when I jet up do I keep the primary and secondary size identical? Since I have 84 in both. Or do I want to have always have secondary bigger than the primary? Cause before I had 82 and 84 but now they are the same

[firefighter3931]

That's what I was thinking. Now when I jet up do I keep the primary and secondary size identical? Since I have 84 in both. Or do I want to have always have secondary bigger than the primary? Cause before I had 82 and 84 but now they are the same

Usually, the primary side will be 6-8 jet sizes smaller due to the power valve enrichment. When the power valve opens it dumps the equivelant of 6-8 jet sizes larger worth of fuel. If the double pumper has power valves in both bowls then the jetting should be relatively even. If not, the secondary side should have more jet...

The fuel requirements with a 500in stroker will be quite different than the typical 440 street/strip build. 

It's best to focus on the primaries first. Once you have them dialed in you can make a WOT pass and shut down immediately to read the plugs and adjust accordingly.


Ron

[A383Wing]

40-50 miles ain't enough time to read the plugs.....I would wait for a while longer

Bryan

[heyoldguy]

Gad zooks boys. First, what list number is the carburetor?

Then, especially on unleaded fuel, you don't read the tip of the porcelain to get the fuel mixture, but down at the base of the porcelain, where it meets the metal body. Down in there you should have a light tan ring about 1/16" wide, right at the bottom. The tip of the porcelain shoud be clean and white.

[firefighter3931]

Gad zooks boys. First, what list number is the carburetor?

Then, especially on unleaded fuel, you don't read the tip of the porcelain to get the fuel mixture, but down at the base of the porcelain, where it meets the metal body. Down in there you should have a light tan ring about 1/16" wide, right at the bottom. The tip of the porcelain shoud be clean and white.

I suppose it depends on the brand of fuel but in my experience using premium 94 octane unleaded fuel the procelin will have a light tan coloring at the top of the porcelin with a 12.8-13.2 AFR as measred on my LM1 

I also like to see some tan on the ground strap as well and allways do when the jetting and heat range is dialed in. A 6 series NGK seems to work well with aluminum heads and 10.5:1 static compression from my experience. 


Ron

[TXcharger70]

Oh and yes I am using 6 series NGK plugs as Ron was recommending. Going to buy some bigger jets cause the biggest I had were 84 and see what happens.

[heyoldguy]

Gad zooks boys. First, what list number is the carburetor?

Then, especially on unleaded fuel, you don't read the tip of the porcelain to get the fuel mixture, but down at the base of the porcelain, where it meets the metal body. Down in there you should have a light tan ring about 1/16" wide, right at the bottom. The tip of the porcelain shoud be clean and white.

I suppose it depends on the brand of fuel but in my experience using premium 94 octane unleaded fuel the procelin will have a light tan coloring at the top of the porcelin with a 12.8-13.2 AFR as measred on my LM1 

I also like to see some tan on the ground strap as well and allways do when the jetting and heat range is dialed in. A 6 series NGK seems to work well with aluminum heads and 10.5:1 static compression from my experience. 


Ron

Well I can sure understand it from your standpoint. I'm out west here and 91 octane with 10% is the best I get. Yet I have found that Rocket Brand 93 octane works the same for me. We seem to run the best at 13.2-13.3 AFR. Best of all, we now have our own dyno working, so some new and more extensive experiments are now being scheduled.

[firefighter3931]

Well I can sure understand it from your standpoint. I'm out west here and 91 octane with 10% is the best I get. Yet I have found that Rocket Brand 93 octane works the same for me. We seem to run the best at 13.2-13.3 AFR. Best of all, we now have our own dyno working, so some new and more extensive experiments are now being scheduled.

No doubt.... your engines make awesome power and there's nothing like the live data on a dyno to achieve the best results. 

Oh and yes I am using 6 series NGK plugs as Ron was recommending. Going to buy some bigger jets cause the biggest I had were 84 and see what happens.

The 6 series plug is what I ran in my 446 with e-heads and mid 10's static compression....you need a bit of heat in the chamber to make it run descent on pump swill and not be cold blooded/hard to start & warm up. This is a street car afterall and not a "set to kill" tune up. 

Going off memory, mine had 84/88 with a 4.5PV using an AED 850dp carb. I would think a 496 needs more jet than mine did so you'll have to do some experimenting. 


Ron

[TXcharger70]

Thanks guys. Hopefully next weekend I can tinker with it and dail her in

[fy469rtse]

That's what I was thinking. Now when I jet up do I keep the primary and secondary size identical? Since I have 84 in both. Or do I want to have always have secondary bigger than the primary? Cause before I had 82 and 84 but now they are the same

As always an informative answer from you Ron , why are you a firefighter, you should be out solving the worlds problems , I can't wait to finally fire mine up and come to you for a consult doc when I can't seem to get it right, would like to know just one story from you when nothing went to plan, you should a thread on that just to prove your human lol  ps I like the way your one of the first with great advise and assistance

Usually, the primary side will be 6-8 jet sizes smaller due to the power valve enrichment. When the power valve opens it dumps the equivelant of 6-8 jet sizes larger worth of fuel. If the double pumper has power valves in both bowls then the jetting should be relatively even. If not, the secondary side should have more jet...

The fuel requirements with a 500in stroker will be quite different than the typical 440 street/strip build. 

It's best to focus on the primaries first. Once you have them dialed in you can make a WOT pass and shut down immediately to read the plugs and adjust accordingly.


Ron

[TXcharger70]

Speaking of have two power valves, is there any benefit of have both in place. May understanding is that it is beneficial for circle track cars. Now for a street application is there any benefit of running both?

[firefighter3931]

As always an informative answer from you Ron , why are you a firefighter, you should be out solving the worlds problems , I can't wait to finally fire mine up and come to you for a consult doc when I can't seem to get it right, would like to know just one story from you when nothing went to plan, you should a thread on that just to prove your human lol  ps I like the way your one of the first with great advise and assistance

Thanks for the compliment, and trust me there have been many times that things haven't gone smoothly ! 

I suppose when you make a lot of mistakes you manage to learn a thing or two and trust me, the learning curve has been steep.    That being said.... i try not to make the same mistake twice    Some things are obvious while others are just head scratchers so persistance is the key. For every problem, there is a solution....you just have to dig hard enough to find it ! 

I'm allways here to help so when the time comes to dial-in your beast there will be help to get things sorted out. 


Ron

[firefighter3931]

Now for a street application is there any benefit of running both?

I've never owned a Holley that had a PV on the secondary side....and had no problems associated with the lack of such  I don't see the need for the typical street/strip build. 


Ron