Holley 4412-500 cfm air fuel testing with the Innovate LM-1

[wsa111]

I recently purchased an air fuel tester the Innovate LM-1.

This is a very necessary tuning tool. I highly recommened purchasing one.

The final testing on the 4412 is as follows:

68 main jet = 14.75 cruise air fuel ratio with good drivability.

The PVCR-power valve channel restriction under the power valve 6.5
needed a .010 piece of wire placed in each restrictor to get a 12.25 air fuel ratio, without the wire the air fuel was 11.5 way too rich for peak power & economy.
The accerator pump nozzle is .031 at the present time.

I hope this helps anyone using this carburetor. As you now are using it you are pig rich & not getting peak fuel miliage & especially full throttle power. My engine is smooth as glass & I improved my fuel miliage close to that of the 7448-350 CFM carb using a 59 main jet which gives 15.0 air fuel ratio cruising. William

 

[bdj66]

Thanks for the info maybe I will try what you said on my Holley with The Argie SP on it....I need to do something. I mean my engine runs really well right now but....man I used half a tank of gas going from Whittier to Malibu on a little cruise with the family last night. I would like a little better gas mileage. What are your spark plugs gapped at I am curious??

 

[wsa111]

BDJ, I use NGK WR51X 7510 iridium plugs gapped @ .050.

Remember I use a MSD-6AL with a Duraspark distributor.

You can rev the engine to 6000 plus with no ignition breakup. William

 

[bdj66]

What do you think will work well with the MSD 6A? I would like to think I would be able to spin 6000 RPMs with the Argie set up too...

 

[xctasy]

As you go down cubes with engines that rev out to between 5 and 6 grand, you find that the Holley is designed primarily for 351 to 400 engines, so the stock jet, power valve and power valve channel restriction (PVCR) need to be drastically reduced. Most people jet down too soon, when the best bet is to focus on the PV and PVCR.

Stock 302C or the better 5.0 2-bbl Windsors, a 73 jet is fine, 8.5 is goood, 40 thou PVCR are ideal. Good power over 200 horses with some ease.

In Ausralia, the 170 to 190 hp versions of the 202 Holden l6's and the 250 2V I6's with 4412's, headers, a small 260 to 270 degree cam, they like 69 jets, Power Valve is 6.5, the stock 40 thou PVCR can come down with a brass insert to about 21 to 24 thou. When its restricted down to a 7448 350, they go to 63's, remain with the 6.5 and use the stock PVCR.

In little sucker 130 bhp at the flywheel Pintos and Cortinas, you go to 74 jets, go down to a lower PV of 2.0, then fill the stock 40 thou PCVR with a brass inset and drill to 17 to 18 thou. When you drop down to a 7448, you use 65's, and the same PV and PVCR

The key is just as you found...jetting it down, reducing the pvcr and finding the right PV to go with that.

(For the record, I'm still a little bit sceptical about fuel pressures above 5 psi hen using mechanical pumps. I'm less worried about the needle and seat restricting but more because our Kiwi roads over here are a lot rougher than good old cement and hot mix you have back home. The Holley carb can really surge and drop a lot of fuel into the venturi under hard cornering or when the higher pressure from a mechanical pump surges. Your 7 psi electric pump won't surge as much, so you can possibly jet down a lot more.)


Nice to see a good half grand piece of kit is available now to help lock down the fuel air ratio.


I'll bet you can really sort the right pump jet, squirter and plastic cam position with that LM -1!

I've got a Bosch knock sensor we use in Falcon X-flow's down here. If you add a 20 mm steel washer, you can hook it upto No 1 front right head stud on all log head and 2v engines. It then gives a std knock signal which can be hooked into with the LM-1. Then we can see how plug burning lean we can run our I6's

Well done, Will!

 

[CZLN6]

Howdy All:

Thanks for sharing your findings William. That A/F equipment sounds good. Never too much "GOOD" information.

I did a little more assessment on my #4412 and found the PVCR to measure .0625". What was your PVCR before inserting the .010" wire"? I'm thinking mine may have been tinkered with, before I got my hands on it.

I rebuilt it with a #68 main jet, but if that is right for you at your elevation, I'm suspious that it may be too rich for 5,000 ft. I may start there, just to be on the safe side.

Adios, David

 

[wsa111]

David, the pvcr on the 4412 is .0625.

I followed your advise & went to a guitar shop with calipers, the .010 wire was on the end of the guitar string where you put it in the adjuster.

.010 in each restrictor brought the a/f right at 12.25 at full throttle.

This innovate tester is so accurate that when I put on the air filter which was about 6 months old, the a/f richened .50.

Put in a new air filter element & that brought the a/f right back to the reading obtained with no filter.

I now will focus my attention toward the 4412-500 carb with the annular discharge venturi's.

Initial testing I went down to a .025 accerator pump discharge nozzle, 67 main jet. But because the annular nozzle has such a stronger signal I am going to have to enlarge the high speed air bleed & put a .030 wire in the PVCR. The throttle response was instant much like the 7448-350 but with a lot more torque.

I'll keep everyone informed at a later date. William

 

[wsa111]

Guy's, just got back from an extensive road test with the 4412-500 CFM.

Using the Innovate LM-1. I improved on off the line acceration by changing to a .028 accerator pump discharge nozzle. Leaning by using the smaller nozzle made the initial lunge stumble free.

Just use this as a guide line, cause every engine depending on size, camshaft, head work & exhaust might vary.

But this proves that just bolting the carb on with the stock 73 jets & a unrestricted PVCR you are pig rich & wasting fuel & not getting top performance.

You fellows using an adapter to the single hole intake might require a different combination & owners with an argie or aussie head the same applies. William

 

[mcmillal]

William,

Is it possible for you to get to a 1/4 mile track? I would really like to see how well your car is running from a performance point of view. If a track is not handy how about at least using a G-Tech?

..........Cheers, Alex

 

[wsa111]

Alex, I made only one 0-60 using a digital watch stopwatch & it was a 8.73 seconds. Remember my vehicle has a 2.83 differential, C-4 trans with a stock converter so its not quick out of the hole.

I was looking at your times and at 660 feet, which is a 1/8 mile around 11 seconds @ 60 mph. so maybe my times are ok. William

 

[mcmillal]

Sorry William, that's still seat of the pants 0-60, assuming your speedo is spot on, and a hand held stopwatch. Actually, my best 1/8 mile was 10.8sec @ 62.6mph which should extrapilate to sub 10sec 0-60.

At least you're giving at least a ballpark number. Much appreciated.

..................Alex M.

 

[wsa111]

Alex, all the local strips are closed to march. At that time I will get some times.

You might try my mods to your carb & let us know your results. At least you have a base line to work from. My throttle response is a lot crisper & the fuel miliage improved greatly. The color of my tail pipe now has the light gray look, just like when I used the 350 carb.
Regards William

 

[mcmillal]

Hi William,

Much like yourself and coming from the Great White North, I will have to wait until the spring also. I am very curious to test your findings.

...........Cheers, Alex

 

[Anonymous]

Great write-up.
Its neat to see someone do the experimenting that you have.

 

[xctasy]

I think you may have done this already, but there were no details from your former posts


Rather than having to peg back the power valve channel restrictions, you may like to tray this:-

Use the restrictive 4150/4160 series 25BP-475A-12power valve! It is unable to flow more than the 60 thou PVCR's so it becomes a bottle neck. It party opens at 12.5" Hg, then fully opens at 5.5 "Hg.

The item was a heavy RV item which allows a real lean main jet, but still flows rich enough under load. It was never designed as a high performance power valve, but on our little sixes, say 125 to 200 hp, it would gives a lot of acceleration without cuaing problems like it does on the hotter V8's. In a situation where the power valve channels are too big, this more restrictive power valve will allow you to run a set of even leaner main jets without any full throttle lean out.

Hope this helps.

 

[Anonymous]

Use the 25BP-475A-12power valve!

It really amazes me with the different kinds of information you come up with.

 

[ranchwagonray]

good to see someone else messin with the innovate lm-1. i picked one up about a month ago, in anticipation of tuning my 3x1 setup, still messing around with a single carb for now, but the lm-1 is an excellent tuning tool to have! it erases any guessing about what your engine is doing as you make changes to the jetting. i'm running holley 1 bbls, which are a bit of a pain to tune compared to the 2 or 4 bbl carbs, no different power valves that i know of, if there are, you'd have to buy an entire carb kit to get em, not a lot you can do to the accelerator pump, and even if there was, it requires quite a bit of carb disassembly.

it's really amazing what you can learn from using the lm-1, first thing i noticed, was how much difference running an air filter makes, it didn't just run lean without a filter, the mixture fluctuated all over the place, no wonder it snapped and popped at idle before! having this tool gives you the courage you need to start messing with the air bleeds and stuff without guessing at what you are doing.

 

[Anonymous]

Having this tool gives you the courage you need to start messing with the air bleeds and stuff without guessing at what you are doing.

Bingo!

 

[addo]

Everyone who has got serious "gear lust" from this thread put up your hand. It's the most solid, thorough example I've seen of somebody applying intelligence and ideal tools to a difficult task - finetuning Holleys. Nothing more to say, than how impressed I am.

 

[Anonymous]

Everyone who has got serious "gear lust" from this thread put up your hand. It's the most solid, thorough example I've seen of somebody applying intelligence and ideal tools to a difficult task - finetuning Holleys. Nothing more to say, than how impressed I am.

Of course!! Well, at least inquiring minds want to know......

It is too bad that a wideband is such an expensive (relatively) tool, it would be nice if others had the chance to play with one as well. You can pick up a lot of power AND fuel mileage when the tune is done right.