Carb swappin

[machoneman]

Here's a great post with pics of a Ford carb spacer and how this one (and others) can trip up the unsuspecting. The base on the carb's bottom doesn't line up with some intakes leading to a massive vacuum leak...which may not be hard to find, but also a small leak, harder to detect.   

http://www.network54.com/Forum/119417/message/1229625787/FYI-Ford+Carb+spacers+%26amp%3B+narrow+pad+intakes

We had that hissing on an Olds Engine in a Chevy work truck(ex diesel thats why the Olds Engine).
After the boss swaped carb to a Holly like that. It was a chanel in the baseplate that
reached just outside the sealing area of the intake.
It was in the front of the carb as i remember it
I found it when a rag i had on the intake got sucked in there and the sound changed

[Drew Pojedinec]

well, have an edelbrock performer rpm, then a gasket and a 3/4 inch spacer, then a gasket and ford/holley 1/4inch thick insulator/gasket.
Spraying water on that doesn't make a change....
I just had shop visitors so I can get back to messing with it now

[Drew Pojedinec]

Took carb off, test fit everything on the bench, no overhanging problems (ie, the gaskets and all I'm using aren't the problem as far as I can tell).  Also siliconed the one carb stud into the manifold (performer rpm has one stud that is threaded into an intake runner).  Regreased and installed everything, got everything leak free.  Ran around town for a bit and some on the highway, more responsive in most light throttle applications.

Whistling persists tho is pretty minor, still have 22inches of vac, so....  It increases very slightly if I open the throttle a little and totally goes away if the throttle is opened more so I'm going to chalk this up to my overly sensitive hearing (the neighbor can't really hear it) and the air moving over the primary butterflies.  If I was getting 18inches or something of vacuum I'd be concerned, but I don't see how I can be getting 22inches with a leak.

Water temps are the same as before, and IR heat gun on each header doesn't show any tube being a ton hotter than the others so I'm gonna ride with it like this and call it good.
As an experiment I might try opening/closing the secondaries and adjusting the primaries to see if the pitch of whistling changes.  Getting more confident about the 70 mile trip thursday at 2:30am  

[Heo]

That Olds 350 probably had a quadrajet intake with some
spacer of unknown origin when i Think about it.
Anyway it was a small leak made a hissing sound and
he could not get the idle down low enough
Then we found the leak and the carb worked fine for a while,
And the fuel consumption got alot better than the worn out quadrajet
But it started to leak fuel and he take it apart and made things
worse the more he worked on it ::)but as i said his favourite
tool was the sledge hammer
And he used it to remove most of the carb from the intake

[66FAIRLANE]

  The carb itself is also made from not so tuff stuff.... 4 screws were stripped out and needed to be addressed.

Newer Holleys seem to be made from butter!

[Drew Pojedinec]

Well, despite the teething problems, I drove to the airport this morning, truck ran great.  I will not drive back and refuel until I go home in a month, but looking at the crappy gas gauge, it appears I used less fuel.

Question to the masses:
Wideband, whats the preference, Innovate LC1 or AEM Uego?
I don't really need datalogging, this would be more something I could use just to fine tune carburetors.  I'm leaning toward the AEM.

[jayb]

I like these:

http://www.summitracing.com/parts/ngk-91101/overview/

[KMcCullah]

I installed the LC1 on my truck 2 years ago and it works good. And since the collectors on my headers were rusted so thin, I used a clamp on o2 sensor bung.

http://www.summitracing.com/parts/avm-30-2355-300

The LC1 has a control that's separate from the gauge that I mounted under the truck. I like the unit in the link that jay posted because it appears to be a all-in-one deal.

[Drew Pojedinec]

Well, Thursday I got up at 6pm and worked until 5am when I drove from a shipyard to Norfolk airport....
7am flight to atlanta, 9:50am flight to valdosta, landed got the old Truck fired up, drove the 70 miles home, fueled up, sat down for 20 minutes.  Probably got home around 1pm.
The wife and her sister rented a house on the beach, they were all "Very tired" so I loaded the Explorer and I drove them 3 hours to the beach.  Got there around 5pm.  Beach lifestyle rejuvenated me and so I spent until Friday midnight drinking beer and walking in the sand....  finally sat down this morning to post another report.

Truck started easier with this style carb than with a traditional holley. 
Truck still feels more responsive off idle and smoother at cruise.

Fueled up and got 12.6mpg, an improvement from the 11.4mpg with the QF 735cfm.  I honestly expected more, but it seems a good start.
I only have a few days off, going back to work next Sunday for another 35 days!!!
I intend to do another 140 mile run to and from the airport so I can average the two, I never trust one record as it could be a fluke a lil one way or the other.
After I do this run I'll install an LC1 and try to fine tune the holley and QF and do the runs again with both of them.  I'll post again in another 1.5 months

[Ford428CJ]

Glad you picked up the carb Drew! Like I said, if you dont like it... I'll buy it from you! To fix your crack... This is what I would use!

US Forge  p/n 02532 Scroll to the near bottom of the link~

http://us-forge.com/Products/Welding/Electrodes.htm

[Ford428CJ]

  The carb itself is also made from not so tuff stuff.... 4 screws were stripped out and needed to be addressed.

Newer Holleys seem to be made from butter!

 Not the shoe box carbs.... But the Holleys are made out of Pot Aluminum. They melt at 650 degrees or so..... I have brazed them before but not easy thing to do.... New or old.... Doesnt really matter

[Drew Pojedinec]

Right on Wes.
I was *going* to use muggy weld, but due to the hurry I was in to get it installed and fired up before I left, I used JB weld.
If I decide to keep it long term after this little experiment I will certainly grind off the epoxy and braze it for a more permanent repair.

At the moment I'm not blown away with the economy improvements.... I'll do another run, then try getting the LC1 hooked up and figure out what I can do to get the QF 735 and also the Holley dialed in as perfectly as I can.

I figure it'll be another 6 months before all the info is collected and I have a full idea of what I can do.... tho at the moment I'm thinking with the adjustability of the QF it might still come out on top.  Ideally getting a Vac secondary QF with annular boosters in the 650cfm range would probably net the best results.  Guess we'll see.