[njsteve]

I've been doing a little bit of carb tuning the past few days. I ended up using the same recipe of jets, primary and secondary rods that I used in the 1972 T/A project. This recipe was passed along to me from other far more knowledgable members here.

The end result is the following for my original 7042273 carb: 74 jets, 44 primary rods and BE secondary rods. The 1972 7042273 carbs were way too lean from the factory and definitely need more fuel than the emissions lean factory setup, if you want them to run right. The Formula is running the stock 068 cam, a four speed, and a 3.42 rear gear which is the same driveline I had in the T/A.

I gotta tell you, the car really comes alive with this setup. When you hit the sweet spot in the power band at around 3,000 rpm, the rear tires break loose in first gear, regardless on how angrily your foot is positioned on the gas pedal. I'll post some video when I can figure out how to drive, shift and film at the same time...

[165th]

Originally Posted by njsteve

The end result is the following for my original 7042273 carb: 74 jets, 44 primary rods and BE secondary rods. The 1972 7042273 carbs were way too lean from the factory and definitely need more fuel than the emissions lean factory setup, if you want them to run right. The Formula is running the stock 068 cam, a four speed, and a 3.42 rear gear which is the same driveline I had in the T/A.

Hi Steve, thanks for the hot set up. Where did you source these parts? I'd like to give this set up a try on an upcoming dyno run I have scheduled for the WD. It would be interesting to test the stock kit of parts and then switch to this set up to compare.

[njsteve]

Do you have any local carb rebuilders in your area? Lloyd or Rocky Rotella may be able to steer you to the right source. Summit or Jegs has jets and primary rods I believe. PY has some too, but the BE or BL coded secondary rods are hard to find.

Attached are a couple articles/charts that listed the various combinations and tuning tips that I found helpful (along with a lot of advice from people here). The yellow highlighted recipes were ones that I was finagling with to see what combinations of parts I had on hand would lead to what fuel mixture. The charts had the math all predone so I didnt have to play with a calulator.

I sent the carb to Cliff's High Performance and he did an awesome job. The carb ran great when tested on the "seat of the pants dyno" in the prior mismatched cam/high compression state but once I did the engine overhaul, I noticed the carb was little lean on the top end for my post engine rebuild combination. (since we didn't know what was inside the engine at the time, he tuned it to what he thought best).

Here are the measurements for the combination of parts I had in my tool box at the time:

Jet/Rod...Cruise area...WOT area......Secondary Rod
71/43 = 2.5070..........3.4283..........CR .0550 S (72 T/A 7042273 stock configuration)
73/42 = 2.7999..........3.6545
73/43 = 2.7332..........3.6545
74/47 = 2.5659..........3.7699
74/44 = 2.7803..........3.7699..........BE .0413 S (72 T/A tuned configuration)
74/43 = 2.8486..........3.7699..........BE .0413 S (Formula tuned configuration)
72/39 = 2.8769..........3.5406..........DA .0443 M (Cliff tuned configuration)

At the moment I have the 43 primary rod in the carb and it's a touch richer than it would be with a 44 rod, since it is a new engine I dont want to lean it out too much. Once the weather clears I will play some more. But this should give you something to have some fun with on the dyno. You must post the results, of course!

[PB]

My 7042273 I just got back from cliff was set up with 72 jets, 39 primary rods, and DA secondary rods. My engine has not been apart. I haven't had it out yet to give her a good flogging, don't know when I will be able to...

[njsteve]

BTW, FormulaBruce had a good comment he sent me in a PM. You have to remember that all commercially available fuels nowadays have at least 10% ethanol in them. That means the original metering setup in the carbs are going to be very lean...by at least 10%

If I do my math correctly, the "tuned" setup listed above is around 10% richer than the stock setup.

[70RAlll]

Originally Posted by njsteve

BTW, FormulaBruce had a good comment he sent me in a PM. You have to remember that all commercially available fuels nowadays have at least 10% ethanol in them. That means the original metering setup in the carbs are going to be very lean...by at least 10%

If I do my math correctly, the "tuned" setup listed above is around 10% richer than the stock setup.

There are many stations that offer NON Ethanol fuel. There are two associations that have websites and I know one offers a Nationwide search engine for locating local non ethanol stations. I found one with in a mile of my house, use non ethanol on all my gas burning vehicles.. So ethanol really shouldn't be an issue.. Here the cost is 3 cents more per gallon.. no big deal.. Here are links:

http://pure-gas.org/index.jsp

http://www.buyrealgas.com/

Here is a list of different sites:

http://www.fueltestkit.com/find_etha..._gasoline.html

No reason to be forced to put alcohol in your gas tank..

[njsteve]

Originally Posted by 70RAlll

There are many stations that offer NON Ethanol fuel. There are two associations that have websites and I know one offers a Nationwide search engine for locating local non ethanol stations. I found one with in a mile of my house, use non ethanol on all my gas burning vehicles.. So ethanol really shouldn't be an issue.. Here the cost is 3 cents more per gallon.. no big deal.. Here are links:

http://pure-gas.org/index.jsp

http://www.buyrealgas.com/

Here is a list of different sites:

http://www.fueltestkit.com/find_etha..._gasoline.html

No reason to be forced to put alcohol in your gas tank..

I couldnt find any non-ethanol stations in NJ. I think the lawyers stopped the sale of real gas here, other than aviation and race fuels.

[The Boss]

You guys suck - I drove a CRV today!

[njsteve]

Yeah, but you probably got more mpgs than all my cars put together X2!

[njsteve]

And here's the other old mopar I started up for the first time in 6 years...

http://www.yenko.net/ubbthreads/ubbt...912#Post513912

[6 Grrrs]

Steve - That Charger is a sweet ride.

I'm jealous you guys got to go for a ride. It was beautiful here Saturday. I thought about firing up my truck, but was busy all day Saturday. My GTO is in hibernation at a friend's garage up on the top rack and surrounded by Mopars. Two of the Mopars needed to move before the lift could be set down for me to get my car out.

I decided it wasn't that nice. Lots of Salt on the roads.

[charles bledsoe]

Steve-

Nice Mopars!! I have always liked the Charger, a friend of mine had one in high school. Went to the link and saw pics of your Viper, were you saying that it had not been started in 6 years? What a beautiful car!! When were you editing for Muscle Car Review? I have had a subscription to the magazine for years, it is one of my favorites.

[njsteve]

I have not taken it down off the jackstands in 6 years. I started it once last year. I am a bad car guy.

I was the tech editor and managing editor for Musclecar Review and Mopar Muscle from 1990 to 1994. I still have both the Viper and the wife from those days. (We met when I worked there). :-)

Here is the link on the haunted Charger in case you have a few minutes:

http://www.yenko.net/ubbthreads/ubbt..._of_#Post77973

[njsteve]

I was tracking down a grumbling sound in the belts and it turns out that the bearing in the idler pulley on the 80 amp alternator setup is going. The bearing is actually loose in the pulley.

Does anyone have an extra good pulley?

The 1972 pulley is different than the same set up on my 75 Firebird. The 1975 has a replaceable bearing but the 1972 is sealed in and doesn't look like there's any way to remove it.

Anyone run into this before? I replaced the bearing in the 1975 pulley and it was the same bearing as in an alternator rebuild kit. It looks like someone has had this before and I replied but didnt realize there were different pulleys at the time: http://forums.maxperformanceinc.com/...t=idler+pulley





and here is the removeable bearing in the 1975 pulley. It has a snap ring that keeps it in place. and the mounting bolt goes right through the bearing and into the bracket.

[Pepi]

Steve, I have been looking for a pulley like that also. PM sent.

[Held for Ransom]

http://www.forums.maxperformanceinc....d.php?t=668062

[njsteve]

Reviewing all the past threads on this has been a great help. Until I can send out mine to get fixed I just ordered the following from Rock Auto. Total was around $30.57 with shipping and 5% discount code.

Gates #38038 idler pulley, $17.69 This is the later style that uses the through-bolt
Four Seasons #45920, idler pulley bolt $4.06
Four Seasons #45907, idler pulley bolt spacer $5.02 (I dont know if I need it or not)

BTW, you have to search for the part numbers. They don't come up under any application for my car.

[1973Formula]

Hey Steve-

Are you sure that bearing isn't a press fit into the pulley? That knurled edge makes me think it is. It is hard to tell from the picture, but you might be able to use the threads on the bolt to fashion a puller that would allow you to remove the damaged bearing.

-Tom

[njsteve]

It is press fit but then the metal is knurled around to retain it. The bearing is actually wobbling in there and the only thing retaining it at the moment in the knurled edge. If I can't find a better one, I may send it to Pepi to see if his machinist can replace the bearing and fix the oversize.

[Held for Ransom]

Glad to help.