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 Post subject: Re: 232 Is back
PostPosted: Mon Oct 07, 2019 11:46 am 
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3 Deuce Webber

Joined: Sun Sep 11, 2005 6:18 am
Posts: 77
Location: Illinois
Car Model*: 69 Valiant
232, since you have the a/f meter hooked up, you should be able to tune all of your issues out. First though you need to verify your timing. The timing advance at idle only tells you a little bit. If you have 14 degrees of timing at idle, that's quite a bit. 225's were originally set up to run around 0 degrees initial timing at idle(without the vacuum line hooked up). Your distributor should have mechanical advance built in it that when combined with your initial timing should end up with around 30-34 degrees at 3000 rpm. Your timing doesn't need to advance under medium to heavy load past that rpm. You need to disconnect and plug the vacuum advance line at the carb to check this. The only purpose your vacuum advance serves is to increase fuel economy under cruise and light load conditions. The vacuum advance adds another 10-20 degrees of timing advance in these conditions. The vacuum advance cannister on the distributor has a spring in it that allows more advance with higher vacuum. How much you get and at what vacuum reading is determined by the spring tension inside that advance unit. Anyone who tells you that you will blow your engine up by not having the vacuum advance hooked up has no idea what they are talking about. If you have too much timing advance, your engine has a tendency to ping under light and heavy load as yours appears to be doing(too lean of an a/f mixture will also do this). Too much timing advance also raises your exhaust temperature and will wear out your exhaust valves and valve seats in the head prematurely. It also causes poor emissions such as oxides of nitrogen which is why all manufacturers backed off on the timing advance in the 70's. This is what lowered the power output of engines at that time. Too little timing advance causes low power but isn't as damaging(unless it's way low) because it doesn't raise the exhaust temperatures up like too much advance does. If your timing advance isn't correct it can also cause your a/f gauge to give inaccurate readings because it will allow unburned fuel to exit the engine and trick the gauge to think your running richer than you actually are.

I just put a wideband a/f gauge on my 225 and have learned a lot about what it likes and what it doesn't like. Look in the engine forum under Carter 9504 and wideband 02 sensor.

Here's what you need to check on the timing. You'll need a dial back timing light to check this or have degree marking tape or marks on your balancer. Disconnect the vacuum advance for this. Also, make sure that you checked true top dead center on your engine and verified your timing marks are correct. They are off by a couple of degrees a lot of the time.

Initial timing can start anywhere from 0 to 15 degrees advanced. Its not that important. It will idle smoother the higher it is though.

The timing should start to advance by 1000 rpm. It should continue to advance as the rpm goes up. It should be at full advance by 3000 rpm. Most performance distributors have lightweight advance springs and have full mechanical advance by 2000 rpm. If your engine doesn't have at least 25 degrees of timing advance by 2000 rpm, it will be very low on power. So somewhere between 2000 and 3000 rpm you should be at full mechanical advance between 30 and 34 degrees. If your timing advance is still climbing after 3000 rpm, your distributor is not set up properly for a performance application. If you write down your maximum mechanical advance number, then subtract your timing setting at idle, you will know how much mechanical advance your distributor provides which is usually 20-25 degrees.

Hook the vacuum advance back up to PORTED vacuum on the carburetor. If it's hooked up to manifold vacuum you'll likely have trouble setting your carb up properly. Rev the engine off idle until the vacuum advance kicks in and check to see how much advance it's giving you. It should provide another 10-20 degrees of advance. I've had a lot of trouble with these newer vacuum advance units blowing out and causing a vacuum leak so be weary of that.

Once this is set properly you can start adjusting the a/f ratio on your carburetor.

Here's what you should see for a/f ratios: You can hook the vacuum advance back up for this.

14.0-14.5:1 at idle. Set this first. If it's wrong it will affect your a/f ratio at cruise speeds.

14.0-16.0:1 at steady cruise speed which will be from 2000-3500 rpm holding the accelerator steady. The higher the a/f ratio is the better the fuel economy. The safest range is 14.0-15.0. Change your main metering jets to adjust this if it's off.

12.5-13.0:1 under load, but not enough to get into the secondaries. This is where you need your vacuum gauge. Watch your a/f ratio gauge and vacuum gauge to see where your power valve in the carb is opening. It will be around 6" of vacuum, check your carb specs to be sure. When your vacuum drops below whatever it's set at, you should see your a/f ratio drop from the 14-15:1 range to the 12-13:1 range. If it stays lean(above 14:1) you can get pinging or surging. If it goes too rich(below 12.5:1) you'll get low power or a bog.

12.5-13:.01 at wide open throttle(wot). If it's too lean you'll need to increase the secondary jet size, too rich you'll need to decrease the secondary jet size. Please note that some of the Holley carbs have fixed secondary jets so you'll need to review the spec's on yours before trying to adjust. Now, here's where your cam specs come into the equation.

When you put in an aftermarket cam with high duration and lift, it doesn't make power below 3000 rpm. If you have a low numerical gear ratio in the rear axle(3.23 or lower), your engine will normally run in the 1500-3000 rpm range. With the big cam, you're not making any power below 3000 rpm. If you have an automatic, the stock torque converter is pretty much locked up at 1800 rpm. When you mash the throttle, the engine revs to 1800 rpm(max stall speed) and it feels like a dog until it gets to over 3000 rpm. By that time, you're already going well over 50 mph and it's time to let off the gas if you're on a public road. The engine feels like a dog even if the carb is tuned right. If the carb or timing is off, it gets even worse. If you have high numerical rear gears(3.55 to 4:10:1) your engine will already be running near 3000 rpm so it feels like it's got a lot more power. If you have a high stall speed converter(2500 rpm or up) when you stomp the throttle it lets the engine rev up to a higher rpm which puts the engine in it's power range so it eliminates the bog or dogginess that you would feel otherwise.

Sorry so long winded.

Hope this helps.

Joel


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 Post subject: Re: 232 Is back
PostPosted: Mon Oct 07, 2019 6:48 pm 
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Supercharged

Joined: Wed Sep 17, 2008 6:48 pm
Posts: 2740
Location: Indianapolis
Car Model*:
Joel, a lot of good information except,
It is late ignition timing that raises exhaust temperature.
And
When running a cam with a lot of overlap, adding ignition advance at idle can help to improve idle quality. With a large overlap, there is a significant amount of reversion and exhaust gases moving back into to intake charge at low engine rpm levels. That exhaust-gas mixture lights and burns slower than
a clean air - fuel mix. So addition advance at idle will get the EGR mix to burn in time.
That is why some folks run manifold vacuum instead of ported vacuum to the advance pod. It activates
ignition advance at idle. Ignition advance at idle can really help idle quality and off idle performance on engines that have larger than stock camshaft overlap.
I believe you are correct on the torque converter assessment.


Last edited by DadTruck on Mon Oct 07, 2019 7:14 pm, edited 1 time in total.

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 Post subject: Re: 232 Is back
PostPosted: Mon Oct 07, 2019 6:52 pm 
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EFI Slant 6

Joined: Thu Jun 07, 2012 4:29 pm
Posts: 300
Location: Houston
Car Model*:
Amen, DadTruck.


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 Post subject: Re: 232 Is back
PostPosted: Mon Oct 07, 2019 9:12 pm 
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SL6 Racer

Joined: Sun Nov 10, 2002 8:49 pm
Posts: 68
Location: Longview Washington
Car Model*:
Do you know what the list number of your Holley is ?


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 Post subject: Re: 232 Is back
PostPosted: Mon Oct 07, 2019 9:26 pm 
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3 Deuce Webber

Joined: Sun Sep 11, 2005 6:18 am
Posts: 77
Location: Illinois
Car Model*: 69 Valiant
Dadtruck, I don't disagree with you. The differences you mentioned are determined by the operating conditions. Too much timing advance at wide open throttle will increase exhaust temperature as well as way to little at moderate load. I should have been more specific but was trying to keep it short.
Running manifold vacuum to the distributor is just a bandaid to make it idle better. I don't like it but it will help under certain condition's. It's hard to condense all that info but I tried to give a solid plan that will get 232 on the right track without overloading with details.

Joel


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 Post subject: Re: 232 Is back
PostPosted: Tue Oct 15, 2019 6:36 pm 
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2 BBL ''SuperSix''

Joined: Tue Oct 30, 2018 7:42 am
Posts: 22
Car Model*: Valiant 100
So let's start with some information:
I am running Holley 390 CFM 4-Barrel, Model 4160. Primary jets 51, Secondaries (conversion kit from metering block to jets) 59. Pump nozzle 25, pump cam red position 1. Power valve 6.5 (stock). Timing is at 3 degrees and idles fine. Running Champion Double Platinum Spark Plug CHP 7322. I had tried to run the car on timed ported, shook like a leaf. Put it on manifold, flat even idle. On the af gauge, I sit at 12.5 fluctuating (+-.2) in park. In gear, brake on, it is at 13.2 (same flux). From 1000-2000, depending on how hard I push the throttle: light: 13-14.7 med: 14.8-15.7 heavy: 16-18 + From 2000-3000, based off of the previous scale: (l) 14.7-15.8, (m)15.7- lean out, (h)lean out. In relation to the af gauge, the vacuum gauge read out is a little confusing to me. In park, I have 19-20 vacuum. In gear, it sits at 14 +-1(wiggling furiously). Accelerating: (l)6.0, (m)4.0-5.0, (h)5.0-0.0

Now I have some questions:
On the secondaries (the stop screw), I am wondering on how to set that properly. I messed with it a while back and it feels odd. Odd by the fact that it feels late when the kick on.

On the distributor plate where it mounts to the block, is the position of the distributor that bolts on to the plate critical? With the dist. out, the plate that is on there, is there a particular position it needs to be in on the arc or is it just a mounting point?


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 Post subject: Re: 232 Is back
PostPosted: Tue Oct 15, 2019 7:10 pm 
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Supercharged

Joined: Wed Sep 17, 2008 6:48 pm
Posts: 2740
Location: Indianapolis
Car Model*:
Quote:
Timing is at 3 degrees and idles fine


when you say timing is at 3 degrees and it idles fine,,
are you checking the timing with the hose attached to the distributor advance can and the manifold?
If so the vacuum advance is activated and you should be seeing 20 + degrees of advance.
The 20 degrees would be your initial advance of 5 to 10 degrees plus the vacuum advance of 10 to 15 degrees.
If you are only seeing 3, either the advance can is not working or your initial timing is set way retarded.

To find out where your timing is, disconnect the vacuum hose at the distributor and plug it, use a pencil or golf T.
Start the motor and check the timing. Record what the ignition timing is. I would be looking for 5 to 10 degrees.
Reattach the vacuum hose and with manifold vacuum, at idle you should see the initial timing + the vacuum advance.
Subtract what you have as timing with the vacuum can attached from the initial timing obtained and that is the addition advance that the vacuum advance is adding. 20 to 30 degrees ( initial + vacuum) degrees of timing at idle could be fine. You will need to determine what runs best, I do subscribe to the theory that says for a slant,, 30 to 35 degrees total, ( initial + vacuum + mechanical) is a good target.

Concerning the distributor position, it will 'clock' anywhere, but if it is too far out of position radially, the vacuum can will bump the
block and limit the initial timing setting. I set the can so it is about 4 or 5 o'clock.


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 Post subject: Re: 232 Is back
PostPosted: Tue Oct 15, 2019 7:47 pm 
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2 BBL ''SuperSix''

Joined: Tue Oct 30, 2018 7:42 am
Posts: 22
Car Model*: Valiant 100
I had done it in the fashion that you have mentioned. That is where I got the 3 degrees from. However, I have not "seen" whether or not it is at 20 +. The can is pointing about the same as well.


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 Post subject: Re: 232 Is back
PostPosted: Tue Oct 15, 2019 8:30 pm 
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Board Sponsor
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Joined: Tue Oct 29, 2002 8:27 pm
Posts: 9570
Location: Salem, OR
Car Model*:
Quote:
I am running Holley 390 CFM 4-Barrel, Model 4160. Primary jets 51, Secondaries (conversion kit from metering block to jets) 59. Pump nozzle 25, pump cam red position 1. Power valve 6.5 (stock).


Jeez that's all out of whack for that kind of build....

I'd bench it here:

Primaries #52 Jets
Secondaries #54 jets
Pump Nozzle (aka Shooter) #28
Acc Cam = Red is too short and stops giving a shot too soon when the plates are open... go to Orange #1
Power Valve on a slant six should be an 8.5...
Secondary Spring = Purple

Looks like you need to determine your timing curve and make sure that the static timing is set accordingly...

When you say 3 degrees at idle... are you saying that it is 3 marks BTDC on the timing tab from 0/TDC... or
does your dial back timing light adjusted to 3 and the timing mark is on 0? (Just making sure everyone is
referencing the same marks...)


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 Post subject: Re: 232 Is back
PostPosted: Tue Oct 15, 2019 8:38 pm 
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2 BBL ''SuperSix''

Joined: Tue Oct 30, 2018 7:42 am
Posts: 22
Car Model*: Valiant 100
When I had the capped the distributor and shot the timing, it was set for 3 degrees advanced (3 marks BTDC)

Well that's comforting :lol: Fortunately, I have most of those parts, except the spring.


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 Post subject: Re: 232 Is back
PostPosted: Wed Oct 16, 2019 6:07 am 
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Board Sponsor
User avatar

Joined: Tue Oct 29, 2002 8:27 pm
Posts: 9570
Location: Salem, OR
Car Model*:
Quote:
3 marks BTDC


Typically on the timing tab each mark is 2 degrees and depending on year the marks end on 10-12 deg...(more if it's the 1979+ tab)

So if you are 3 marks on the tab, you are actually 6 degrees advanced...


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 Post subject: Re: 232 Is back
PostPosted: Wed Oct 16, 2019 3:54 pm 
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2 BBL ''SuperSix''

Joined: Tue Oct 30, 2018 7:42 am
Posts: 22
Car Model*: Valiant 100
Correct. I was using the timing light and marks to make sure that read the same. I said that it is 3 marks BTDC, but saying it was 3 marks (which makes 6) is not true. It’s at 1 1/2 “marks.” Thanks for looking out though.


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 Post subject: Re: 232 Is back
PostPosted: Thu Oct 17, 2019 12:19 pm 
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Supercharged
User avatar

Joined: Sat Feb 16, 2008 1:25 pm
Posts: 5394
Location: Downeast Maine
Car Model*:
Holley float level adjustment:

https://www.google.com/search?client=fi ... aJ2K2wCw26

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