Thats just it though man, it isn't falling flat on its face or anything. It pulls hard and then just signs off. There is no distinct bog, sputtering, or end point. It just seems to run out of steam fairly quickly.

I mechanized the secondaries today, that sure seemed to help the acceleration but not the top end. How do you holley guys have your ignition hooked up? I still have mine @ stock with both trailing and leading advancedments hooked up.

 

What port is your engine, what exhaust, what rpm is it falling off at? it's a 12a right?

 

I have an idea, but I need a pic of your setup first!

 

Had the same issue before, pretty well fell off on power at 6000rpm completely...

 

What part do you need pics of? It is a stockport, I'm running a RB header with no cats or presilencer into an RB muffler. There is no paticular RPM where it runs out of power, it just doesn't pull hard in the upper RPM range (4000-7000).

I opened up my primaries, they are 50s. I also got a look at my plug, I think it looks too lean, but I'm not quite sure. Looking for some expert advice here

Sorry for the blurry pic, cell phone.

 

Bump.

Anyone? Note the whiteish colour around the edge.

 

do you have bigger jets? put somthing bigger in and give it a run.

 

I wanna see the air cleaner

 

too me look definatly leaner than what you want it for power .. should be a tad darker on the plugs to work better ... just my 2 cents .

 

still waiting

 

Yea, generally:

white/lighter color on the plug = lean mixture
black/darker color on the plug = rich mixture

Plugs should have a 'Mocha' brown color to them when A/F ratios are where they should be..



Oh, and I have an Autometer narrowband if it would help you. U can have it for the shipping costs... PM me

 

Hey I just tried a 390 holley on a channeled manifold with an adaptor plate the other day. Power falls off at around 6000 as well. Runs really well at medium RPM and is no slouch down low. Kinda interesting.

 

So you guys think that my plugs are too light too? Yeah, I think I need to go richer on the secondaries.

BTW-heres your pic man. I don't know what you can tell from this but have at it. Its just a standard RB cleaner with an oiled foam insert.

 

Take it for a spins with no air cleaner at all, bet your top end will be better.......don't leave it liek that, just do the test.

 

Eh, I tried it. It was maybe a bit better but nothing considereable.

 

what 84 stock is trying to get is that normally the foam filter aren't that great. Pretty restrictive, but on the other hands clean pretty good. You can only go one way or another (cleaner, or more flow).

But ya first thing I would do is try to richen it up. By the looks of the plugs you're sitting at high 14:1 to maybe even low 15:1 AFR ... you should bring it down to about 13:1

 

Richen it a whack load, like 6 jet sizes and test it with and without the airfilter. Replace the powervalve, determine the right one for your car. Also, add a 1" open spacer under the carb. jet sizes make a notable difference for me. A restrictive air filter will drop my car on it's nose at 6000.

 

Your setup should be good for about 130-140whp. But it'll fall flat just past 6000 rpm, and fall completely off at 6600. it is clearly running too lean by those plugs richen her up then set the timming to 20*BDTC fully advanced.
http://www.yawpower.com/pultime.html

 

disassemble the secondary and note what metering plate is installed for reference.
it needs to be replaced in order to richen the WOT fuel mixture.
replace the air filter with a k/n/generic high flow one.
spark plugs should be med brown in color for safe A/F ratio (old skool tunning).

 

you can buy an aftermarket secondary metering with jetting. Before you do that, just bump the primaries a bunch for you full throttle test. You really need a wideband for proper tuning.

 

Alright, heres what I'm thinking-I think I need bigger secondary jets, but because that costs a fair chunk of change, I'm going to go with bigger primaries to see if that makes a difference. If I go with bigger primaries and it helps, then thats a pretty good bet that I need bigger secondaries, and then I'd go back to the stock primaries.

So with that said, what should I try in the primaries? I was thinking 54s or so, there are 50s in there right now.

 

56 or 58 just for the test

 

Alright, update.

I put some 56ers in the primaries. Big bump in power. It doesn't stall out when I get on it, and the high end pulls alot harder. Although after 20 miles of highway+20 miles of aggressive backroads, I'm getting 13mpg where as 16 before the swap.

This tells me my motor was definately begging for more fuel. I don't think that the 56s in the primaries is the final solution, so where should I go from here?

 

get a qft secondary metering plate so you can just change secondary jetting. http://www.quickfueltechnology.com/home_2.htm

 

Sorry for the bumpage, but I have the cash to get an adjustable metering plate now, what jets should I be looking at for primary and secondaries? I'm at about 1200ft. above sealevel. I was thinking I'd go back to my 50s in the primaries, but I was wondering I could go leaner without popping, to get better gas mileage? And for my secondaries I'd like to bump them up rich so I can get this power.

FWIW, I think I could go richer than my 56s in the primaries and get more power, but they get me 8mpg, so I need to overcompensate and make the secondaries rich.