I have a '72 442 with a 455 engine, NOM. It has a cast iron intake. I had the quadrajet rebuilt but have been unable to get it running right. I took it to a local tune shop and he told me until I get all of the vacuum leaks fixed he couldn't tune it any better. The secondaries are not kicking in. He said the intake manifold leaks just about everywhere and will need removed and new gaskets installed. My question, if I were to put on an aluminum intake which one should I use. I want to use all of the stock connections and carburetor and I would like to add an OAI hood at some point so it will need to be at stock height and dimensions. What intake are you guys using for this? I have added an electric choke and I am still using the old distributor with points. I do want the car to look stock and am not concerned with speed, just want it to run good, run cool, and be dependable. I guess I can always bead blast the iron one and paint it. Could it be warped from heat, thus the leaks? Thanks for any help or suggestions!

PS. EGR, exhaust gas reduction. I don't think my '72 has it but...?

 

Is this an actual U code W29 car? If it's original I'd just replace the turkey tray seals and call it good.
BTW, EGR is exhaust gas recirculation and no the 72 Olds didn't have it.

 

Is it time for this discussion again?

Sorry, but this comes up almost weekly. If you are talking about the secondary air valves on top of the carb, they open in response to load. You will NOT see them open much (or at all) if you are simply revving the engine in PARK. The secondary throttle blades are on the bottom of the carb and are mechanically actuated. The air valves open in response to mass air flow, not throttle position.

As for vacuum leaks, you are correct. Until you find and fix any leaks, you are wasting your time with other adjustments. Do this first.

 

To answer some of your questions:

The Edelbrock Performer 455 aluminum intake manifold would work with all of the factory components and has provisions for the vacuum ports you need. It will likely be too tall for use with an OAI hood and air cleaner assembly, though, as it is significantly taller than the factory manifold.

I would recommend you clean up and reuse the present manifold, especially if you are "not concerned with speed."

It is highly unlikely that a factory iron intake manifold is warped.

 

No Allan it is not an original U code car. Sorry Joe to be redundant. I guess I didn't look hard enough to find a search window for my issue. The car's secondaries do not kick in when I floor the car while driving, sounds like it is attributed to the vac leaks. Kenneth, you answered my concerns about the aluminum intake and warpage on my iron one, thank you. I will just clean mine up and re-use it and save $. It is original to the engine, serif type F block, and has Ga heads along with W and Z exhaust manifolds.

 

How do you know this? Seat of the pants? Sound? Neither is particularly scientific. Is this a Qjet or some other carb? The secondary throttle plates on a Qjet are mechanically actuated and open when you press the throttle, period. If they really are not opening, someone has messed with the linkage on the carb. Vacuum has nothing to do with it. If the air valves are not adjusted properly, this can also cause a problem, but again that is not related to vacuum.

A vacuum leak can certainly make the car run poorly, but that has nothing to do with the secondaries opening or not. As I said above, find and fix the vacuum leak before trying to diagnose any other problems or you'll be wasting time and money.

 

It is the original re-built Quadrajet. Thanks for the reply. I guess seat of the pants and sound. I remember on my '73 Cutlass, '72 Chevy Cheyenne, and many Corvettes, the noticeable wha whaaa of the secondaries kicking in. I had a friend, may he RIP,that used to turn the breather lid over on his 4-door Caprice with a 396 4bbl just to hear the sound of the secondaries kicking in. I'll fix the leaks and take it back to the tuner to adjust the carb.

 

The original Qjet has a lockout that prevents the secondary air valves from opening before the choke is fully open. If this is not adjusted properly, it will prevent the air valves from opening. If the problem persists after the leaks are fixed, check this.

 

I had a smoke test done on mine and found most of the leaks were on the carb. Just curious, What test did he do to determine the intake was leaking everywhere? P.S. I used the REPOP w-30 intake (Parts Place) I think, because the aftermarket aluminum intake was an inch too tall and would crush down the seal on the air cleaner too much for my taste.

 

If you would have used the drop base you wouldn't of had that problem.Just saying.

 

He didn't say. I know the power brake take off is loose so that's one point. He said around the carb and intake. Plus the cruise control port. I probably need to change all of the vacuum lines. The carb is newly rebuilt and can't get secondaries to kick in but I need to fix all leaks first. I got a felpro gasket which is a one piece metal pan. Says to use rtv pretty much around all ports top and bottom. Got any tips?

 

My carb was fresh rebuilt also and the smoke test showed leaks at the choke housing was pretty bad but none at the intake. My answer to what intake is recommended only depends on how detail oriented the OP is when the puts on the OAI hood. A drop base is certainly a good idea and much cheaper. My main concern for him is that a test was done to verify the intake is in fact leaking before all that intake replacement work is done. Sounds like the list of power brake take off, cruise control port ( and maybe diaphragm), could be enough to mess up the tuning. Joes point on the adjustments to the carb linkages (after you fix the leaks) is good. He always is an excellent source of accurate information.

 

So I've decided to remove the intake and install new gaskets after the tune up shop quoted me $517 for this. I've done this before on 350 Chevy's, not much diifferent right? I bought the Fel Pro brand metal turkey tray and rubber end gaskets. Googling I thought I found the proper sequence for tightening the bolts, basically from the ends inward back and forth, but, I did see a diagram that shows starting from the center and going outward....which is best? I also found somebody said to discard the rubber gaskets for the ends and use the Permatex copper gasket maker....thoughts on this? Also, the gasket came with a small tube of black RTV which appears to not be enough to go around all ports on the heads and intake. Do I need to use RTV around all holes on both sides of the gasket?

 

You do realize that all of these questions are answered in the 1972 Chassis Service Manual, right? It's the first "tool" you should buy for this car.

The "best" torque sequence is the one the factory specifies.



The installation of the metal gasket requires careful attention to the location of the four bosses near the corners. These fit into holes in the heads to properly locate the gasket. Failure to do this will cause leaks. Sometimes aftermarket gaskets have the bosses located incorrectly, so dry fit the gasket first. Use RTV around the four water ports, with beads on both sides of the gasket.

 

Also note that the turkey tray gasket seals by crushing the raised ribs around the ports when the intake is tightened onto the heads, so you have to ensure the gasket is correctly placed prior to setting the intake manifold down.

 

When you go to remove and install, its best that you have a buddy to help. They are heavy as hell and tough to place by yourself. If you use the rubber end seals, do not over tighten, I use weather strip cement between the rubber seal and the block, nothing between the seal and manifold. Others run a 1/4 in bead of RTV across the block and throw the seals away.

 

Interesting. I mean the picture. It's sure not from the 72 CSM as it clearly shows EGR on the intake.

 

I never said that picture WAS from the 72 CSM.

 

Maybe not, but immediately before that you said which kind of implies that it was. Anyway, the torque sequence works.

mcox8051 - here's a link for you to peruse. Oldsmobile V8 Engines

 

Reading waaay too much into that.

The part about the CSM was a none-to-subtle jab at the OP.

The picture was the first one I found on the web, responding to the OP's complaint that he had seen conflicting data.

 

How about using an engine hoist to put the manifold on using a plate on the carb space. That would take the weight issue off the table. A little more work can save a lot of work. I really like aluminum! This Air Gap barely clears the hood. The air cleaner bumps into the hood insulation. It's tight but it DOES fit.

 

Nice ride! Poor doggie! Engine looks and sounds great. How much taller is that intake than my stock iron one? I wonder about the Performer manifold. They have to be several pounds lighter........Just checked Edelbrock's site. The Air Gap has a pad height of 5.52" and has no provision for A/C bracket, the Performer has a height of 4.95". Looks like for my application the Performer would be best, if I decide not to install an OAI hood later. Does anybody know the pad height on my stock iron intake? Sorry Joe, but I don't have my service manual yet and I doubt that info is in there.

I'm about to pull the trigger on the Performer intake. Should I buy the recommended gaskets or should I use the turkey tray? Will my stock Quadrajet fit the new intake? I have an electric choke on it, can I close off the hot exhaust gas ports or should I not do this?

Just found the height info on the iron intake from 442.com, it's 2-3/4", and they say the Performer is 4-1/2" (Edelbrock states 4.95"), so the Performer is at least 1-3/4" to 2-1/4" or so taller, depending on who's measurement you go by, hope this doesn't cause any problems. z11375ss says his Air Gap, at 5.52", just touches the insulation on his hood so I should be in good shape clearance wise. I like to keep things somewhat original but with the weight savings and added performance (still not looking for speed, just want good response and reliability, and the aluminum intake will look better), still may go with the Performer, as long as my Qjet will work on it.

 

Mcox. Do you have a part number for the turkey tray/ from Felpro? Is the gasket a separate part from the tray or is it all in one? Seems like there are a lot of different gaskets out there although I haven't seen any of them called "turkey tray" except in these threads.

 

MS96004 Valley Pan gasket.

 

Thanks Other Eric

I can't wait to see whether I have another (re-usable) turkey tray under my current manifold. The 5 trays I already got from the 99 cent store probably would require a lot of modifications to fit without silicon...

 

The lock out could be preventing the secondarys from working, it requires the choke to be fully warmed up. It is hidden behind the choke housing and can easily be removed. Also check secondary opening with someone in the car and engine shut off, but warmed up. Have them step on the gas all the way while you look down the secondary with a flashlight to make sure the throttle plates are fully open. Good luck

 

The 1968-72 Olds Qjets do NOT use the lockout on the secondary throttle plates shown in the photo above. They use the lockout on the secondary air valves, on top of the carb, which I pointed out back in Post #8 in August.

 

EVEN BETTER if the lockout is on top. I would consider removing it to take it out of the equation, 40 year old components don't always work as intended. You can always re-install the lockout if you're sure it wasn't the problem, just tap out the roll pin. A couple pictures of your engine might help others notice if anything looks out of place. Good luck.

 

First, GM is not in the habit if installing parts that aren't needed. The lockout is designed to prevent the secondary air valves from opening until the engine is warmed up. Second, it is trivially easy to LOOK at the tab and see if it is retracted or not once the engine is warm. There's no need to remove or disable anything. Third, setting the lockout tab clearance is part of a proper carb rebuild and adjustment and is described in the CSM and the carb rebuild instructions and specs.