Carburetor Adjusting Again

Since replacing the intake manifold, the engine has been running rather rich at up to 12:1 while just cruising around and even more rich when accelerating.  I decided I'd make a few jet adjustments today to evaluate the impact.

I checked the current jets and had 60's in the front bowl and 69's in the rear bowl.  The stock setup for a Holley 570 is 54's in the front with 65's in the rear.  This makes my configuration +6 in the front and +4 in the rear.  According to Holley, there is generally no need to increase jet sizes more than +4 over the original configuration.  

I decided to drop the fronts to 57's with 67's in the rear (+3 front/+2 rear).  After making the change, the a/f ratio was good at idle and around 14.5 or so when cruising.  Under light acceleration, it stayed roughly around 14:1 which leads me to believe the front jets are good.  However, when I accelerated hard, I noticed the engine go rich for a second and then quickly lean out and stay somewhat lean at 14:1.  

I decided to start with increasing the rear jet size again back to 69's.  After this change, the engine did not have as much of a lean spike on acceleration but was still rather lean at an average of 13.5:1.  I obviously need a bit more jetting to get the a/f ratio at the desirable 12.5:1 at full acceleration.

I did not really want to exceed the original rear jet size as I feel I would then be moving in the wrong direction.  I decided instead to increase the front jet size to 58's (+4).  After the change, under hard acceleration, the a/f ratio was near 13:1.  However, it seems that at cruise I have quite a bit of variation with the a/f at times going to 15:1.  

My current collection of jets include the following: 54, 56, 57, 58, 60, 62, 65, 67, & 69.  Seems like I would benefit from a set of 70's to run in the rear and leave the fronts alone.  

While I doubt there is much of a restriction, I wonder if I would be better off using a 670.  It is not suppose to impact my ability to have a reasonable a/f ratio.  I just wonder if jet sizes are so much large due to the flow of my engine with the new intake and heads.  If I were to switch to a Holley 670, the stock jet sizes are 65 and 69.  

I'm going to call it good enough for now.  As I drive more, I'll see what additional changes are necessary.

New Alpine CDE-172BT Stereo Install

Early in my restoration of the Mustang, I purchased an inexpensive Alpine radio on eBay.  The radio met my needs in that it had a CD player and worked as expected.  During the trip to Goodguy's last year, I noticed the CD player was not reading discs properly anymore.  I made a mental note and planned to get a new one at some point.

I purchased an Alpine CDE-172BT radio last week and installed it this morning.  The new radio is quite nice as it has bluetooth connectivity, CD player, AUX input, USB input, and high pass crossovers for the main speaker in case I elect to add a subwoofer.  The radio is no doubt more technologically advanced as it was made 16 years after the one it replaced.

In the image below, the old radio (CDM-7874) is pictured above the new (CDE-172BT).

I purchased another Alpine as I sold and installed them many years ago and was always impressed with their quality.  Additionally, I prefer a radio with a volume knob and Alpine continues to use them almost exclusively in their radios.

I spent about three hours installing the radio which is rather excessive.  I soldered all of my connections, used heat shrink, and then spent some time organizing the wiring under the dash with some zip ties.  Finally, I added a thick bracket to the back of the radio and attached it to the bottom of the dash to hold everything secure.

I do expect to add an amplifier and subwoofer later.  I actually have both available from a previous vehicle I owned.  I'd just need to take the time to make a custom enclosure for the Mustang.  I'd like to work on this in the near future to finish up the stereo install.