Author Topic: Need help setting up a Holley on a 440  (Read 9546 times)

Offline bugsdad

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Need help setting up a Holley on a 440
« on: June 23, 2012 - 09:53:56 PM »
It sounds like I have a lean spot. Read the following to see if I'm right.

I'm close to getting a 670 Ultra Avenger Holley on my dad's street only 440. It's got a flat spot in the fuel curve. You can be going along, torquey, feels great. Put your foot in it and right as the vacuum operated secondaries engage, it struggles....be patient and hold it....feels like a rubber band getting stretched and then whoosh...you take off like a scalded dog. I'm working on the accelerator pump arm tomorrow and gonna make sure it's set for .015" clearance when at WOT.

It's got 16"hg after I adjusted the 4 corner idle. Had to adjust the rear float to get it to the center of the sight glass.

I bought a vacuum secondary spring kit, the accelerator pump cam kit, and 3 accelerator pump squirters.
Stock is a .031". I bought a .032",.035", and an .037". Just has the stock 30cc accelerator pump.
I found some amazing charts where guys have taken the different cams in the kit and charted the findings of cam affect vs. throttle position.



Has anyone graphed the engine rpm vs. throttle position? I'm just trying to take some of the guess work out of getting it set up. Its so damn close to being a good fully streetable 440.
10.5:1 pistons. Single plane manifold. Hedman hedders.
I had to set timing to about 10 deg advanced because it would backfire and detonate so bad. Vacuum advance cannot be hooked up or you can't even lightly throttle it without backfiring and pinging.




Offline Chryco Psycho

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Re: Need help setting up a Holley on a 440
« Reply #1 on: June 24, 2012 - 12:15:42 AM »
4 things come to mind ,
- you need a heavier secondary spring
- do not worry about the .015 At WOT as much as making sure there is not play a idle
- More pump volume you need a cam that moves more fuel with the accelerator pump
- the carb is too small for a 440 , 850 would be where you need to be

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Offline bugsdad

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Re: Need help setting up a Holley on a 440
« Reply #2 on: June 24, 2012 - 01:34:18 AM »
did have a 750 on it. Ran pig rich. He had 3 different shops tinker on it. It's never gonna run over 5200 rpm. For street driving holley recommended 670 based on their formula for cfm requirement. Other than the stumble it runs perfect. Ran a stiffer spring tonight. It moved the stumble. I will write down how it behaves. I will try the pump cam first tomorrow like you said and double check the initial pump shot reaction to throttle movement. The reason I think they recommend that setting for the accelerator pump is so you know for sure you are getting all the 30cc in it. I saw one holley article where they had to actually tighten it up to reduce the amount of shot available. It's amazing how versatile these are.
Here was the numbers: at 85% VE it only needed 550 cfm. And at 100% VE (which would never happen) it was 662 CFM
« Last Edit: June 24, 2012 - 01:44:19 AM by bugsdad »

Offline bugsdad

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Re: Need help setting up a Holley on a 440
« Reply #3 on: June 24, 2012 - 01:47:51 AM »
BTW thanks for the help you've given while I've been restoring this Challenger. I will put up pics when it's all done. It's amazing how much its changed and how much better it runs. We've got about $4K in the resto so far....and many hundreds of hours

Offline Cuda Cody

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Re: Need help setting up a Holley on a 440
« Reply #4 on: June 24, 2012 - 02:30:47 AM »
Sounds lean and like someone tried to big of a carb cam to solve it.  I personally like the white cam as it's super smooth to drive, but you'll need to up with the squirter to solve the lean issue.  When I've try to use a small or stock size squirter and increase the cam I get the same problems you have.  A big "jump" from the idle circuit to the driving circuit.  Kinda like you describe... a rubber band feeling or even a feeling of stabbing the throttle even though you keep your foot in one spot.  A delayed effect.  I think your engine leans out for a second when the vacuum drops and that's why you need a bigger squirter to help with that transition.  The cam profile will change how much fuel is added, but it also changes when the fuel is added.  I like smooth street driving so that's why I like the smoother carb cams like the white.  You can see how much each cam pumps...

cam color    #1      #2                             

white         17cc - 19.5cc

blue           18cc - 20cc

red            18.5cc - 20cc

orange        19cc - 24.5cc                                         

black           19cc - 18cc

green          24cc - 30cc

pink            30cc - 37.5cc (has three holes)

This is a better chart
http://www.abodyjoe.com/pictures/Misc.%20car%20info/holley%20specs/holley061.jpg


Look as the cams next to each other you'll see the biggest difference is the profiles.  White and blue pump close to the same volume, but the blue is MUCH more aggressive as to when the fuel is added making it more like a stabbed rat.  Try a few and you'll find the right combo.  Good luck.
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Offline Chryco Psycho

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Re: Need help setting up a Holley on a 440
« Reply #5 on: June 24, 2012 - 08:11:00 AM »
except that a 6 pack rated at 3" vaccum is 1350 CFM & @ 1.5 " of vacuum is 900 CFM , At wide open throttle you should have less than .5 " of vacuum so the flow of the 650 could be maybe 450 CFM , I can promise you the formula doesn't work , the factory used 750s on 440 & were found to be too small & they used an 850 on the 340/360 with the thermoquad .
 Anyway if you are happy with the way it performs & can get it tuned right it is all good .

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Offline GreenFish

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Re: Need help setting up a Holley on a 440
« Reply #6 on: June 25, 2012 - 08:39:17 AM »
Wait,...   a smaller CFM carb is going to make you run richer not leaner.  The CFM is the AIR moving through the carb not the fuel.  Not saying the smaller carb isnt the right one just that it is a misconception that a smaller carb will lean out an engine. 

Just something to think about.
70 cuda, 440, KB pistons, 10.5:1 compression, edlebrock heads,RacerBrown cam, 5-Speed Tremec, Megasquirt EFI

Offline Roppa440

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Re: Need help setting up a Holley on a 440
« Reply #7 on: June 25, 2012 - 08:58:45 AM »
First of all that carb is WAY too small. You should listen to Chryco because he is a man that knows what he is talking about.

I would be looking at the spark timing first. These days I am finding 20 degrees initial to be where a stock 440 seems most happy.

Then I would be looking at the power valve rating. If the carb has a stock 6.5" rated valve it will delay opening. I would also be looking to open the power valve feed restrictions if they are on the tight side.

As already pointed out, how thirsty an engine is has nothing to do with carb size. But not enough initial timing with modern fuel will make it smell rich for sure. The jet sizes are what makes a carb lean or rich.
Dave
1970 Challenger R/T
1997 Jeep Grand Cherokee Limited

Offline Chryco Psycho

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Re: Need help setting up a Holley on a 440
« Reply #8 on: June 25, 2012 - 09:14:11 AM »
if you pull the timing into the 16* range & leave the vacuum advance disconnected you should be OK , if you advance more than 16* at idle you will probably be over advanced at RPM as the mechanical advance adds approx 20* , so you may have to weld up the slots to limit advance as you want to have 36-38* advance total & the higher rpm is more important as the engine spend most of the time working there .

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Offline Strawdawg

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Re: Need help setting up a Holley on a 440
« Reply #9 on: June 25, 2012 - 10:08:23 AM »
Wait,...   a smaller CFM carb is going to make you run richer not leaner.  The CFM is the AIR moving through the carb not the fuel.  Not saying the smaller carb isnt the right one just that it is a misconception that a smaller carb will lean out an engine. 

Just something to think about.

Maybe not....

As Neil initially suggested, it needs a stiffer spring in the secondary.  The small carb is jerking the secondaries open quickly because the engine is begging for air.  This makes the car go lean and bog until the velocity of the air thru the secondaries increases enough to start pulling fuel out of the back side of the carb, then it jumps up and starts to run.

The cure is to put a stiffer spring into the secondaries and to increase the pump shot to fill the "hole" until the air velocity is such that it pulls fuel out of the secondaries on its own.

My experience is that a 780 vacuum secondary Holley is perfect on a tall geared low rpm 440 street engine and an 850 double pumper on something with shorter gears if striving for the best strip performance and one is willing to sacrifice a little gas mileage on the street.

Offline bugsdad

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Re: Need help setting up a Holley on a 440
« Reply #10 on: July 09, 2012 - 02:46:38 PM »
sorry guys. I shoulda given a little more history on the engine. The 440 is a 69 model. The engine had a HUGE overheating issue for the last 4 years. The first day dad drove it home from the builder, it overheated and vented fluid everywhere. Its been to many different shops. Still would bog on WOT. The 750 mechanical secondary carb was jetted and worked until it would dump black unburnt fuel and the engine would still shake, bog, and backfire through the exhaust on WOT....as well as overheat...it has overheated almost every time it was driven.

This spring myself and my brother in law decided we were sick of the beautiful car running like CRAP. The trans was a 727 that you could not feel shift and leaked everywhere along with a not so hot 5500 stall converter...yes...5500 stall as spec'd by the builder of the engine. I built a really nice non lockup 78 trans and put in a 2200 stall Hughes performance converter along with a bouchillon performance kickdown setup. At the same time I ran braided lines to its own external cooler mounted away from the radiator. Trans works AMAZING.

While doing that, the original radiator was a hemi 4 core. Unfortunately the builder had hot tanked the block for about 3 weeks....yes 3 weeks...the cooling passages had scaled and completely plugged the radiator. A shop tried to clean it for dad and blew the bottom tank out. In goes an aluminum 3 core unit from Champion along with a mopar shroud and a neat fan combo i made from the junk yard. Ford fan, chevy fan clutch and mopar water pump. Works amazing, looks stock, and pulls some serious air through the radiator. Original belts were shot. Replaced those when I did the rest.
Result was 180 deg F when cruising and will drop to 165 when driving through shade and will go back to 180/182 in stop and go traffic. Cooling issue fixed.

Had tons of exhaust leaks at the header where it meets the head....had a local place, kamer and kamer, machine the headers so the flange was flat and installed a copper gasket on both sides....leaks fixed...noticed something and will explain it later.

Wires and plugs. Oh God. Bird nest. I built wire separators and got 8.5 mm custom wire set and took out the iridium plugs and replaced them with champion plugs gapped at .035"....he had wires wrapped around shock towers and everything. Coil wire had infinity resistance when I ohm'd them. Got all of that fixed. Stock ecu had melted and ran down fire wall and had been replaced with an orange unit 2 years ago by a shop.

Distributer was replaced by original engine builder that hot tanked the crap out of everything. Never worked with vacuum connected and was advanced all the way around to where I had to lay on the ground with a timing light to find the mark. I have it set about 10 deg advanced now at idle. Runs sooooo much better. Still cannot hook up vacuum to distributer or it back fires through exhaust under any light throttle.

It has a single plane M1 manifold. Again. Bad idea for the street. I know it shoulda had a dual plane on it. It's what is on there though and I'm trying to make it work as best I can.

Ok. Did everything. Got it running really decent. Down to the carb. Talked with Holley about 2 hours. They swear for 5200 rpm on a 440, that carb is more than enough. Anyway, the same issue is present with the 670 as it was with the 750. Under WOT it bogs, sounds like the engine is trying to shut down, shakes and coughs. Only now it isnt dumping enough black gas out to repel mosquitos for 2 square miles.

I'm wondering now if the valves or springs were damaged with all the engine overheating. I mean constant overheating. I mean, get out with the engine running at idle to open the garage door and start spewing antifreeze overheating...which is now taken care of but the heads have already been exposed to this torture. I'm gonna do the paper test for a burnt exhaust valve today when I go to dad's.

I'm worried that either the iginition (accel aftermarket coil, stock orange ecu, still has ballast resistor, and after market proform distributer) has something wrong with it making it break up under load, or the heads/cam has something wrong with it. Remember, this engine has NEVER run right. It is now running the best it has since built.

Again the symptom is a bog under heavy acceleration or when climbing a hill with steady throttle and the trans downshifts, putting load on the engine. The engine will bog, shake, and act like its cutting out..lift off the throttle..ease back into it...then the car will eventually get past this weird spot and really take off...but not under load. only on level ground will it take off after the bog senario.

I can tell you that the vacuum gauge will fluctuate 2" at idle unless I get the idle speed up to steady it. I have not done a compression test yet. I hate that this has happened with an engine with less then 3k miles on it after a shoddy build. I appreciate any help and hope this kinda gives light on what I'm dealing with.

Offline Strawdawg

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Re: Need help setting up a Holley on a 440
« Reply #11 on: July 09, 2012 - 03:06:01 PM »
Well, I would vehemently disagree with the Holley guy based on way too many years of experience, but....

A vacuum secondary carb is designed to cover up user error as I stated above as it should limit air flow until the engine needs it as I stated above.

I would suggest two things.

First, tie off, or disconnect the secondaries to see if the problem goes away at wide open throttle with them not functioning.

Second, I would check the balancer mark for proper top dead center to insure the balancer is the correct one, and the ring has not slipped around

Offline bugsdad

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Re: Need help setting up a Holley on a 440
« Reply #12 on: July 09, 2012 - 03:09:54 PM »
Almost forgot. The exhaust manifold gasket reference above. I suspect all the leak in the exhaust where it met the head was from all the backfiring through the exhaust. Chunks of the original fiber gasket and carbon down the head were everywhere.
Anyway. On the number 1 cylinder exhaust at the bottom of the head is an area where it is dished. Like someone had stuck it with a hammer. None of the other cylinders had this. I found a pic dad took of the engine on the stand after it was built and it didn't have this. This is what makes me wonder if there is head damage if the exhaust port has this kind of appearance. Anyone ever seen this before? I think I have a pic I took with my cell phone somewhere. It looks just like someone took a hammer and just gave it a whack right at the bottom of the exhaust port.

Offline bugsdad

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Re: Need help setting up a Holley on a 440
« Reply #13 on: July 09, 2012 - 03:11:48 PM »
I will try that but it did this with a mechanical secondary 750 as well as this one. Again, they rejetted the 750 until it dumped raw fuel and it made no difference. It makes me think I'm chasing the wrong thing.

Offline bugsdad

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Re: Need help setting up a Holley on a 440
« Reply #14 on: July 09, 2012 - 04:46:31 PM »
Ok. Did a green cam in the #1 hole (holley reccomendation). Also went with a .035" shooter from the stock .031". Gonna do a stiffer spring from the holley kit tonite and see how it behaves. I'm gonna do the stiffest spring in the kit and then tie it off completely if that doesn't make a difference. Power valve rating is tough to figure. Holley has two recommendations. One is that is it 2" lower than idle vacuum and the other is HALF of idle vacuum. Don't understand why they would say two different things but it would make sense that a 6.5 valve would be way too low for 16" of manifold vacuum.