My baseline A/F ratio results using a Zeitronix Zt-2
06-07-2005, 05:53 PM
#1
Melting Slicks
Thread Starter
My baseline A/F ratio results using a Zeitronix Zt-2
Check out the Zeitronix Zt-2 A/F ratio meter. http://www.zeitronix.com/Products/zt2/zt2.htm
I'm data logging with an old 100 MHz notebook computer.
(Zeitronix's tech support has been nothing short of excellent. Always a prompt reply to email.)
Today I took baseline A/F readings prior to making any changes.
The first thing I plan to do is install a new ignition system, recheck the A/F readings, then make changes to my Edelbrock Q-Jet carburetor, #1904, as needed. (…when time permits).
The tachometer values are erratic, thus useless. I contacted Zeitronix for tech support and they suggested trying to ground at various places. None of them worked. They said that only one other older car like mine has had this problem. I'm hopeful that it will work fine once I install my new ignition system.
Crane HI-6 Performance CD Ignition
http://www.cranecams.com/?show=brows...mber=6000-6440
Crane Street/Race Distributor
http://www.cranecams.com/?show=promo...cf52dfc1c4c283
Here's some screen shots of my baseline results:
IDLE
CRUISE
WOT
The Zt-2 has a lot of INPUT/OUTPUT capabilities. I would like to add a MAP sensor for additional data.
Lambda > .43 to 0.64 Wideband
AFR > 21.0 to 9.5 Wideband
Vacuum > 5.5 inHg or 650 mmHg
Boost > 35.3 PSI or 2.4 BAR
EGT > 392 F-2200 F or 200 C - 1200 C
Analog Wideband Output > 0 - 5V
Throttle Position > 0 -100 %
RPM > 0 - 10,000
User Input > 0 - 5V
I'm data logging with an old 100 MHz notebook computer.
(Zeitronix's tech support has been nothing short of excellent. Always a prompt reply to email.)
Today I took baseline A/F readings prior to making any changes.
The first thing I plan to do is install a new ignition system, recheck the A/F readings, then make changes to my Edelbrock Q-Jet carburetor, #1904, as needed. (…when time permits).
The tachometer values are erratic, thus useless. I contacted Zeitronix for tech support and they suggested trying to ground at various places. None of them worked. They said that only one other older car like mine has had this problem. I'm hopeful that it will work fine once I install my new ignition system.
Crane HI-6 Performance CD Ignition
http://www.cranecams.com/?show=brows...mber=6000-6440
Crane Street/Race Distributor
http://www.cranecams.com/?show=promo...cf52dfc1c4c283
Here's some screen shots of my baseline results:
IDLE
CRUISE
WOT
The Zt-2 has a lot of INPUT/OUTPUT capabilities. I would like to add a MAP sensor for additional data.
Lambda > .43 to 0.64 Wideband
AFR > 21.0 to 9.5 Wideband
Vacuum > 5.5 inHg or 650 mmHg
Boost > 35.3 PSI or 2.4 BAR
EGT > 392 F-2200 F or 200 C - 1200 C
Analog Wideband Output > 0 - 5V
Throttle Position > 0 -100 %
RPM > 0 - 10,000
User Input > 0 - 5V
06-07-2005, 10:39 PM
#2
Race Director
Cool deal. Curious about the 16:1 cruise AFR. Sounds really lean to me. What rpm was that and what spec cam are you running? I'm running port EFI on the 454 and can't go that lean without picking up a lean miss. But I only have 3.08's so my cruise rpm is low. 75 mph is 2000 rpm.
As for the tach input, try hooking it up on the tach-side of the filter.
As for the tach input, try hooking it up on the tach-side of the filter.
06-07-2005, 10:52 PM
#3
Melting Slicks
Keep us posted. This is something I plan to do myself someday (If I ever get done fixing all the the other stuff that is continually going wrong. This week it was the temp gauge quit and RF caliper leaking.) 
06-07-2005, 11:16 PM
#5
Melting Slicks
Thread Starter
zwede, I agree, the 16:1 cruise AFR is too lean and that was today while the ambient temperature was ~90*. I can only assume that this lean condition gets worse during the winter due to the cold/dense air!? I'd prefer it to be ~15 - 15.5:1.
I have not detected a lean miss but that doesn't mean it isn't happening.
I would like for my WOT AFR to be between 12.5:1 and 13.0:1
Regarding the tach, I've tried before and after the tach filter. No luck either way.
My RPM at 70 mph cruise is ~2200-2300 (3.73 w/700R4). I haven't checked my gas mileage in a good while due to a broken speedo. It's repaired now so I'll check it the next time I take it on a road trip. Previous mileage checks always yeilded high 16's to low 17's.
My cam is a Comp Cams 12-212-2
I have not detected a lean miss but that doesn't mean it isn't happening.
I would like for my WOT AFR to be between 12.5:1 and 13.0:1
Regarding the tach, I've tried before and after the tach filter. No luck either way.
My RPM at 70 mph cruise is ~2200-2300 (3.73 w/700R4). I haven't checked my gas mileage in a good while due to a broken speedo. It's repaired now so I'll check it the next time I take it on a road trip. Previous mileage checks always yeilded high 16's to low 17's.
My cam is a Comp Cams 12-212-2
Last edited by MIKER; 06-07-2005 at 11:55 PM. Reason: edit to repair image
06-07-2005, 11:23 PM
#6
Melting Slicks
Thread Starter
Originally Posted by Mike Mercury
I like all the inputs you have access to.
How do you feel about your 13.3 WOT reading ?
How do you feel about your 13.3 WOT reading ?
I'm all ears when it comes to suggested AFR values.
I've got some general ideas as to what they should be from internet research but I'd like more information.
06-11-2005, 08:58 AM
#7
Melting Slicks
Thread Starter
I checked the AFR again this morning while the ambient air temperature was 73*F.
The only other change was a new set of spark plugs.
17:1 during light throttle CRUISE. (16.1 @ 90*F).
From ~14.x:1 to ~15.x:1 during WOT. (13.3 @ 90*F).
It must be REALLy lean at 50*F and below!
The only other change was a new set of spark plugs.
17:1 during light throttle CRUISE. (16.1 @ 90*F).
From ~14.x:1 to ~15.x:1 during WOT. (13.3 @ 90*F).
It must be REALLy lean at 50*F and below!
06-11-2005, 10:16 AM
#8
Race Director
Time to rejet the carb. 
What did the old plugs look like? With that kind of mixture they should have been pretty much bright white. Look closely at the center porcelin with a magnifying glass. If you see small aluminum specks on it you're pinging. The specks are pieces of your pistons...
What did the old plugs look like? With that kind of mixture they should have been pretty much bright white. Look closely at the center porcelin with a magnifying glass. If you see small aluminum specks on it you're pinging. The specks are pieces of your pistons...
Last edited by zwede; 06-11-2005 at 10:51 AM.
06-11-2005, 12:15 PM
#10
Safety Car
Originally Posted by MIKER
From ~14.x:1 to ~15.x:1 during WOT.
Brett
06-11-2005, 09:06 PM
#11
Race Director
I thinlk I got my LM-1 working, no tach yet just the A/F reading over time. I had to run a separate and run all wires so they aren't near anything esle. This thing is way to sensitive, I am not imprssed for the money I spent on it. I still get huge spikes but it has a smoothing feature that gets most of them.
It looks like I am going lean to on WOT, my idle and cruise seem OK in the the 12 to 13 range.
WOT starts at the beginning of the graph and goes to 3.48.5
So if it is OK at idle and cruise then maybe it is the secondary jets I should be playing with ?
Don't mean to steal your post Miker just a little excited I got this thing working I think
It looks like I am going lean to on WOT, my idle and cruise seem OK in the the 12 to 13 range.
WOT starts at the beginning of the graph and goes to 3.48.5
So if it is OK at idle and cruise then maybe it is the secondary jets I should be playing with ?
Don't mean to steal your post Miker just a little excited I got this thing working I think
Last edited by MotorHead; 06-11-2005 at 09:19 PM.
06-11-2005, 09:21 PM
#12
Le Mans Master
Member Since: Oct 2002
Location: Las Vegas - Just stop perpetuating myths please.
Posts: 7,098
Received 373 Likes
on
356 Posts
Multi-spark ign?
Nice pix of the data - Zeitronix is gonna but a lot of dyno's out a business.
U didn't list what u use right now for ign so i checked in ur profile too but without finding anything. So just a heads up if ur using a MSD multi-spark or similar the coil pos + will see additional sparks when triggered. MSD has a connector for the tach that i would suggest u use if installed. BTW that new Crane ign box doesn't show a tach connection.
I really like that Crane dist and u should have fun tuning with that instead of the old springs and weights. Something else u maybe interested in is a MSD knock indicator - $150. Sensor just replaces the block coolant drain plug - easy to install. With that u can safely dial in max advance as pre-detonation occurs long before u or i would be able to hear it.
Well sounds like u'll soon have a super tuned '80. cardo0
U didn't list what u use right now for ign so i checked in ur profile too but without finding anything. So just a heads up if ur using a MSD multi-spark or similar the coil pos + will see additional sparks when triggered. MSD has a connector for the tach that i would suggest u use if installed. BTW that new Crane ign box doesn't show a tach connection.
I really like that Crane dist and u should have fun tuning with that instead of the old springs and weights. Something else u maybe interested in is a MSD knock indicator - $150. Sensor just replaces the block coolant drain plug - easy to install. With that u can safely dial in max advance as pre-detonation occurs long before u or i would be able to hear it.
Well sounds like u'll soon have a super tuned '80.
cardo0
06-11-2005, 11:09 PM
#13
Race Director
Motorhead: That some pretty serious leaning out you have there. Before touching the carb make sure your fuel system is adequate. You might be running out of gas at higher rpm.
06-12-2005, 12:39 AM
#14
Melting Slicks
Thread Starter
Motorhead I'm glad you got your LM-1 working!
I'm more than happy to have you post your AFR information in this thread. We're both in the learning curve with these things.
cardo0, I'm currently using an old HEI ignition that has been in my car for at least the 11 or so years I've owned it. I suspect it is the original other than a SVE QuickCurve Kit and the usual consumable parts.
My new Crane ignition box does have a tach output wire. We'll see how well it works. The knock sensor would also be a nice feature to have.
zwede, I think that I can almost see some specks on spark plug #8. I'll post some pictures.
Brettmc, it's too late for the warnings about WOT. I've been running this engine on the lean side for 4 years now. :o
I'm more than happy to have you post your AFR information in this thread. We're both in the learning curve with these things.
cardo0, I'm currently using an old HEI ignition that has been in my car for at least the 11 or so years I've owned it. I suspect it is the original other than a SVE QuickCurve Kit and the usual consumable parts.
My new Crane ignition box does have a tach output wire. We'll see how well it works. The knock sensor would also be a nice feature to have.
zwede, I think that I can almost see some specks on spark plug #8. I'll post some pictures.
Brettmc, it's too late for the warnings about WOT. I've been running this engine on the lean side for 4 years now. :o
06-12-2005, 09:42 AM
#15
Melting Slicks
Thread Starter
Here are pictures of the spark plugs that I recently removed.
They have been in my engine since it was built, (4 years.)
When judging the color of these plugs keep in mind that the last time they saw action was to idle the engine for 10 minutes. I was warming the engine up to operating temperature prior to performing a cranking compression test.
The compression test turned out well. All cylinders were within 5% of each other and >200 psi.
The spark plug from cylinder #8 does appear to have a few specs of aluminum on it. I didn't have much luck with getting the specs to show up in this picture.
They have been in my engine since it was built, (4 years.)
When judging the color of these plugs keep in mind that the last time they saw action was to idle the engine for 10 minutes. I was warming the engine up to operating temperature prior to performing a cranking compression test.
The compression test turned out well. All cylinders were within 5% of each other and >200 psi.
The spark plug from cylinder #8 does appear to have a few specs of aluminum on it. I didn't have much luck with getting the specs to show up in this picture.
06-12-2005, 10:14 AM
#16
Race Director
Good news is there are no signs of electrode melting so it hasn't run terrible hot. The electrodes are a little rounded so I'd recommend a new set of plugs. Heatrange looks perfect so stick with the same type of plugs. Also no signs of burning oil.
Once you jet the carb up to get WOT around 12.5-13.0 and cruise in the 14.5-15 range you will be amazed at how much more power the engine makes.
Once you jet the carb up to get WOT around 12.5-13.0 and cruise in the 14.5-15 range you will be amazed at how much more power the engine makes.
06-12-2005, 10:48 AM
#17
Melting Slicks
Thread Starter
Originally Posted by zwede
...I'd recommend a new set of plugs. Heatrange looks perfect so stick with the same type of plugs...
Judging by the difference in electrodes, the Autolite's appear to be a hotter plug. What symptoms should I look for to determine whether or not they are too hot of a plug?
06-12-2005, 11:52 AM
#19
Race Director
Originally Posted by MIKER
I installed new spark plugs following the compression test. The plugs pictured are "AC Delco FRILS". I replaced them with "Autolite 3924." The Autolite 3924's were one of the plugs recommended by the manufacturer of my cylinder heads, (Trick Flow.)
Judging by the difference in electrodes, the Autolite's appear to be a hotter plug. What symptoms should I look for to determine whether or not they are too hot of a plug?
Judging by the difference in electrodes, the Autolite's appear to be a hotter plug. What symptoms should I look for to determine whether or not they are too hot of a plug?
If the heatrange is too hot you get the same appearance as a lean condition. Very white center electrode, blued ground electrode and specks of aluminum. In extreme cases you can see melted electrodes and cracked center electrode porcelin but it has to be real bad before that happens.
06-12-2005, 01:32 PM
#20
Melting Slicks
Thread Starter
Trick Flow recommends the following plugs for my heads, Autolite 3924, NGK FR5, and Champion RC9YC.
Prior to placing the engine in my car, nobody in town had any of the three plugs recommended by Trick Flow. The guy at NAPA pulled up the AC Delco FRLIS plugs and said "these'll werk!", so I took'em
Regarding heat range, I thought that the electrode protruded out of the porcelin more on hotter plugs and less on colder plugs. Is this a misconception?
Prior to placing the engine in my car, nobody in town had any of the three plugs recommended by Trick Flow. The guy at NAPA pulled up the AC Delco FRLIS plugs and said "these'll werk!", so I took'em
Regarding heat range, I thought that the electrode protruded out of the porcelin more on hotter plugs and less on colder plugs. Is this a misconception?