Leaking front plugs are a DISASTER as engine vacuum sucks fuel directly out of the fuel bowl. Easy fix and those don't appear to be tapped for 10-32 set screws and sealed with Marine Tex. I use a 10-32 tapered tap here about 3 to 3.5 turns then test fit the 10-32 x 1/4" set screws till they lock down just below flush. IF the casting and plugs are cleaned and dry and Marine Tex used when installing them it will NEVER leak and permanent repair. Any attempts to "dab" epoxy over them is a complete waste of time. Most folks also thing that JB Weld will hold back fuel, it will not. 100 percent of the carbs I get in here with JB Weld dabbed over the plugs leaks right thru the glue even if the repair looks good. Just had one brought in here yesterday to rebuild again as it was done about a year ago and JB Weld was over the plugs. It failed a pressure test and peeled it right off with a pocket knife! I'd also mention here that the "blue" seal they used from the Marine rebuild kit purchased was all swelled up and pump stuck in the bore..........Cliff
I also saw it mentioned someplace about the intake exhaust crossovers being blocked. Another HORRIBLE idea like running a 160 degree thermostat, locking out the timing, super light weights/springs to get ALL the timing in right off idle and/or putting it a distributor w/o vacuum advance for a street driven car. Unless you live on the equator and it doesn't get much below 100 degrees outside you need a working exhaust crossover with a wet-flow intake for best efficiency. Blocking it off just prolongs the agony and the engine doesn't run up to par till the intake is fully heated soaked anyhow. Last time I looked it was 2020. One would think we would be WAY past doing all the things folks did to these engines WAY back in the 1960's and early 70's to "make more power" than only resulted in less power and heavy fuel consumption.........FWIW......
Thank you very much for pointing out the mistakes and issues. I thought it be good to minimize heat and plugged crossovers. My fault. I will contact you about ordering parts. I removed the original distributor and have no vacuum advance currently either but have been contemplating putting it back in. I really appreciate your honest assessment of making my car run great and hopefully others by learning by my mistakes. Chris
Not your fault. WAY too many opinions on these things like "block the crossovers" to make more power, etc. You LOOSE thermal efficiency with that move, choke no longer works (divorced or hot-air), and the engine doesn't run fully up to par till the intake is fully heat soaked. Combine this with not using vacuum advance and MORE timing and fuel are required everyplace, so engine efficiency is down and fuel consumption is up. Back when fuel was .29-33 cents a gallon we ALL did chit like that, along with about 20 other things that did NOT work well. But who really cared, we just wanted the "cool" Holley stickers in our windows and loved burning anyone's eyes who stood behind our cars in the High School parking lot! We didn't realize or really even care that 90 percent of the "high performance" modifications we did to our cars back then didn't make them any more powerful or quicker on the street or at the track. Jump ahead to 2020, you'd think folks would be a LOT smarter these days, but I still here the same crap all the time, 2.02's, Quadraj-junk, high volume/high pressure oil pump, 3/4 cam, double roller timing set (most are pure JUNK!), MSD, etc, etc, etc. You'd think with the Internet and all this social media out there folks would be educated a little easier on these things and make better choices for their engines. The problem as I see it is that you have to wade thru a lot of BS to get to the real deal as a high percentage of the info comes from well folks who don't really test very much (and when they do it's using a their "butt meter" or how good of a burnout they can do in a hard right hand turn leaving Dairy Queen!), others who think they know what's going on, "guru's" who may have hit a home-run a few times but struck out more times than not, and a butt-ton of "Trolls" who have good Google skills and are good at regurgitating the info of others, but they seldom if ever even have a car that moves let alone one powered by a Buick, Pontiac, Olds, or the engine family they are giving advice about!......FWIW......
There is also another variable not being discussed here. Aluminum. Aluminum conducts and dissipates heat faster than cast iron. The TA heads don't have an exhaust crossover passage that I can see, and neither do the single plane intakes, yet they warm up faster, and stay relatively cooler at the same time. I don't use a choke on my car. It really isn't that big of a deal even on the coldest winter days.
I ran w/o a choke for a few years back when I was racing my car as many times as I could get to the track every week, and also have aluminum heads w/o a crossover option. I was OK with it, but sitting their feathering the throttle and a lot of pumping to get it to fire in sub-freezing temps is a PITA. Easier to deal with back then as I was younger and had more patience. Anyhow I put a choke back on the car around 2003 and it is now FLAWLESS on cold starts with fast idle for warm-up. It still requires 10-15 minutes warm-up time to get some heat in the intake, which is also aluminum. If I have working crossovers in the heads I'd be using them as there are no negatives anyplace on a street driven vehicle, only positives. Just for fun I decided to fire my engine two Winters ago when it went down to -26 degrees here. NOTHING else I owned started for chit that morning including my 2000 Tahoe and my 2008 Nissan Altima. I eventually got them going but battery chargers and some long cranking required. The big high compression 455 in my Ventura roared to life instantly, stalled out once, restarted fine and stayed running on the second attempt. I had to leave it on the fast-idle nearly 20 minutes before the intake had enough heat in it to make things happy at idle speed. So much for modern technology, and it shows us how good the older stuff really is........
Separate question if I may ----- Can you tell from the numbers on a Quadra jet carb how many CFM it is ?
View attachment 479309 View attachment 479309 View attachment 479309 In most cases, yes. Any Buick carburetor that came on a big block was 800 CFM STARTING in 1971. In 1970 and prior years, ALL the Q-jets on Buick engines, small and big block, were 750 CFM. The outer wall of the primary on an 800 Q-jet, which forms the last venturi is 1/8" bigger, and is jetted richer than the smaller carburetor. You can see that in the 1971 Q-jet specs, Look at the Large Venturi, 1 3/32" for the carburetors fitted to 350's, and 1 7/32" for the 455 carburetors, a difference of 4/32" or 1/8" If you look at that outer wall on an 800 Q-jet, there is a small bump because of an internal passage.
I don't see the point of starting a motor you care about at minus 26 degrees......all you are going to do is put wear on it and wash the cylinder walls down.....maybe your house was on fire Cliff....?
Going to have to throw a wet blanket on this, Cliff! Modern technology is miles ahead of the carbureted junk of 30, 40, 50 years ago for everyday driver stuff. Back in the 80’s and 90’s while working at an independent repair shop, if we got a below zero degree day, we would get a host of tow-ins for “cranks but no start”, with lots of flooded carbureted engines for many reasons. We would eat like kings for a week! Modern engines are so much better at starting in extremely cold temps that when that occurs now, we certainly don’t get many, if any tow-ins, due to no-starts. In fact, if we didn’t have a supplemental source of auto repair work at my shop in the winter, we would be staring out the windows more than I would like to on a cold, snowy day.
I have a Quad # 17057213 3316 AWP My research says it's from a 1977 Chev manual transmission. Would it be 750 CFM ?
If your Q-Jet carb came from a remanufacturer, it's likely junk by now. The reman houses take good Q-Jet cores from all different engine applications, and re-drill all of the little orifices inside to one size in order to facilitate passing emissions test results. That's all they care about. For specific engine performance, they are the worst carbs to use & are a nightmare to tune...which sounds like your current situation. If you can get a good unmolested core which is close to your base engine stock unit, that's the best bet to get optimal performance for your particular engine setup. I have about a dozen different Q-Jets from 1967-1974 around my house, all with different rods/jets/etc. which I got as unmolested cores & rebuilt myself with correct parts for my engine (ST400 drivetrain with AIR system installed).
Your 17057213 is a 1977 Chevy Truck unit. It's divorced choke and single main airbleed. Those are excellent carburetors and sort of on "oddball" carb caught up in the transition to the later SMAB design. There didn't make any divorced choke Chevy carburetors with the larger primary bores, so all are "750" cfm units. The only pre-1975 models that were larger cfm will be the 71-74 Buick 455 carburetors, 73-74 Pontiac Super Duty, and the one year only 1971 Pontiac 455 HO carburetors (plus the 7041263 400 4 speed carb). The 1971 units don't have larger primary bores but are missing the outer booster rings so they flow more than the standard "750" cfm units......
"I don't see the point of starting a motor you care about at minus 26 degrees......all you are going to do is put wear on it and wash the cylinder walls down.....maybe your house was on fire Cliff....?" Just wanted to see if it would fire up as my 2008 Nissan and 2000 Tahoe weren't doing squat. I run light oil in it so wasn't really worried about engine wear, etc. I eventually got everything started up with the help from a battery charger and space heater......
