How does my idle sound?

[bholland80]

Hello Corvair Forum...First Post!

I recently became a Corvair owner and have been reading threads and trying to educate myself. A big thank to everyone who contributes here. This is my first classic car so I'm slowing moving from having zero idea of what I'm doing to at least being capable of the basics.

I just did an oil/filter change and put in new plugs. Would like to get some feedback from the forum on how the car is sounding. I've watched a couple Youtube videos I found, but am not sure what a well tuned Corvair is "supposed" to sound like. I've had some issues with the powerglide transmission being slow to shift at low speeds and fluid leaks so hoping that getting it to the right fluid levels will correct that (and then investigating where the leaks are coming from).

Here are two videos I took after getting it running yesterday for the first time in months:
Video 1: https://www.dropbox.com/s/gtnfxa7le5pt2 ... 7.MOV?dl=0

Video 2: https://www.dropbox.com/s/5g1gg85annick ... 8.MOV?dl=0

Also, some pics of the car just because:

Thanks all. Looking forward to being part of the community here!

Bill
Kenmore, WA
64 Corvair Monza Convertible

[terribleted]

The first video sounds like high idle (chokes active) the second sound like regular curb idle. Both sound like the speeds are in the realm altho this idle speed if the car is in neutral may be a little low. It is fine if the car still idles smoothly in drive. Idle speed on Powerglide cars is adjusted with the trans in drive. If you do not have factory Corvair Shop Manuals you should get some . For a 64 model, I am guessing based on the trim in the photos (please state the car and engine you are asking about when posting it makes giving a good response easier), you need the 1961 Corvair Shop Manual and the 1964 Shop manual supplement. Adjust the idle speed per the shop manual using a tachometer.

You do have a noisy lifter. I would operate the car a little bit and see if the tapping noise goes away after a little driving and perhaps as much as 1 hour of operation. If not the next step is to adjust the valves ( I recommend running adjustment...not in the manual.... look for youtube videos about same ). If the lifter is still noisy after properly adjusting the valves , you will need to find out why it or they are noisy. Could be a number of causes from bent push rod, wear on rocker arms, valve stems, valve guides, to sticky gummed up lifters, to loose dropping valve seats. Many times, particularly it the car has been sitting a lot, only operation to get things well lubricated, moving, and fresh oil everywhere is all that is needed

[bbodie52]

Welcome to the Corvair Forum!

I have also attached a few applicable sections of the 1961 Corvair Shop Manual (the base manual for 1961-1964 Corvairs) and 1964 Supplement - Chevrolet Corvair Shop Manual in case you need them.



I would like to encourage you to expand on your post and tell us more about yourself, as well as about your Corvair. Your personal assessment of your mechanical skills and abilities would help a lot. Members of the Corvair Forum love to be helpful in assisting other Corvair owners with technical support and advice, but it helps if we have some understanding of your technical background and mechanical abilities, your Corvair-related knowledge, etc. Helping us to know more about you, your Corvair, and you plans for your Corvair will help us to write comments to you that are tailored to your needs and experience. Knowing where you live also helps, as your location may suggest some possibilities or solutions. Detailed photographs of your Corvair, including interior, trunk, and engine compartment would be great!

The link below will provide you with a list of useful websites that are Corvair-related. Some of the links will lead you to an extensive technical library that will allow you to download shop manuals and other technical references in Adobe Reader (.pdf) format at no cost. There is also a link that will help you to locate nearby CORSA (Corvair Society of America) club chapters. While the Corvair Forum can be very helpful as you work on your Corvair, having local friends and contacts in your region who are knowledgeable about the Corvair can also be very helpful. These family-friendly CORSA club chapters often offer picnics, group scenic drives, technical training and assistance, car shows, and competition events that can greatly enhance your enjoyment of Corvair ownership. You will also find a list of essential Corvair parts suppliers.

Common and Useful Corvair Websites

viewtopic.php?f=225&t=6007



https://www.corvairsnorthwest.org/

Corvairs Northwest is one of the biggest and most active Corvair Clubs on the west coast – with many interesting get-togethers for our members throughout the year.

In addition to our monthly meetings at Sizzler in SouthCenter and our board meetings at Tatoosh Grill in Fife – We get together in February with our sister club North Cascades Corvairs for the Sweetheart Cruise tour and gathering. Each year we enjoy a Spring Tune-up Day when we meet at Kent Sullivan’s fabulous Corvair Garage which has a car lift open to our members for tune-ups and minor repairs. Then in April or May one of the 7 Northwest regional Corvair clubs hosts a Corvair Econorun tour with a car show and banquet included. June is our club picnic at one of our member’s home – providing lots of Corvair conversations and tire kicking opportunities. In July we host our own unique Orphan and Discontinued Car Show at the beautiful showgrounds at Griot’s in S. Tacoma We feature a large variety of seldom-seen 20th Century vehicles through 1990

In October we feature a Fall Cruise with awards given for the first and second place winners as we dine together afterwards at a local restaurant. November features our popular Fall Tune-up Day and Potluck lunch at the home of one of our members. A trunk swap meet is also part of the day’s activities. In December we have our Christmas Dinner Party for another day of feasting and fellowship and FUN.

MAY 20 2020 - AUG 05 2020 — MONTHLY CNW MEMBERS MEETING
Sizzler - Tukwila

Monthly CNW Members Meeting
Each 3rd Wednesday of the month, Corvairs Northwest holds it’s general member meeting at Sizzler in Tukwila. We arrive between 6pm and 7pm to have food, then get down to the updates from the Board of Directors. We’re usually wrapped up anywhere from 7:30 to 8pm each time.

Sizzler - Tukwila
16615 Southcenter Pkwy, Tukwila, WA 98188
32 min (25.8 mi) via I-5 S

[SeamusNZ]

Hi there from New Zealand. Your engine sounds exactly like mine did when I first got it running after many years. I have found air cooled engines including Corvairs to be a little rattly. However yours, and mine at the time does have a little lifter noise (rattle) that will generally be fixed up with a hot running adjustment as per the Clarke’s manual.

Hope this helps.

Cheers SeamusNZ


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[bholland80]

Hey Guys,

Appreciate the replies and welcome.

I've been experiencing as issue: The car starts fine and idles well, but after driving it for a couple minutes, if I come to a stop sign and try to accelerate it will stall. It will "hot start" back up with and if I keep the RPM's up will start moving again. This doesn't happen right when starting out. I found a couple other threads that talked about a similar issue, but didn't see anything definitive (but it did point me in the right direction of things to check).

I've reviewed the shop manual around the "tune up" section as well as the one covering carburetor operation. I should say that before buying this car and attempting to start diagnosing my problem I couldn't tell you how a carburetor even worked (but I'm learning...slowly. ha). Here's what I've done to start troubleshooting:

- Removed air filter to be able to see carbs
- Left carb choke valve appeared to be stuck and wouldn't fully open after starting it and letting it idle and warm up (some carb cleaner spray has seemed to remedy this as it now fully opens)

It's raining in the nice PNW this morning, so I've just been working in the garage to see if there are adjustments I should be making before trying to see how it drives again. In looking at the tune up section of the manual, it definitely appears like there are adjustments that are needed, but would like some feedback please. I feel like there might be multiple issues at hand.

On the right carb, the fast idle cam never makes contact with the throttle. Also, the idle screw does not touch the throttle once the choke is off and the throttle is clearing the cam (apologies if I'm getting these terms wrong). Here is a picture:

Here is a picture of the left carb that seems to show a different (proper?) adjustment:

Once the engine was warmed up and both choke valves were fully open, I blocked the top of each carb one at a time. When blocking the right carb, the engine struggled and almost died and I could feel a strong suction. On the left carb, I felt light suction, but the engine didn't really change at all when blocking that carb (sounded the same like blocking it had no impact).

After turning the engine off, on the right carb I saw fluid and bubbles at the base by the black (gasket?):

It also had a gas smell and was sort of smoking or almost like clouds of vapor (link to video):
https://www.dropbox.com/s/qml6sq67ba2hb ... 8.MOV?dl=0

Sorry if that was long or too detailed, but would appreciate thoughts from the group on the best place to start or what some of those things above might be pointing to. Thanks all!

Bill

[bholland80]

One other quick thing to add...I saw in another post the suggestion to make sure fuel was getting into the carb. I held the choke valve fully open and moved the throttle. Both carbs had a strong squirt of fuel shoot out.

[SeamusNZ]

Hi there,
Two things worth checking.
1. The fact that the idle screw is not touching and effect the cam could be due to the linkage being out of whack. As I said eatlier, this is an absolute and critical must for proper operation.

2. Sounds like you have air leaking from the carb that has little suction. I suspect that the plastic spacer sitting between the carb and manifold may be cracked or loose. I would start there.

Cheers

SeamusNZ


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[terribleted]

Hi there,
Two things worth checking.
1. The fact that the idle screw is not touching and effect the cam could be due to the linkage being out of whack. As I said eatlier, this is an absolute and critical must for proper operation.


Cheers

SeamusNZ


Sent from my iPhone using Corvair Forum mobile app

I agree. The throttle lever MUST be able to come up and hit the idle speed screw. It should actually go far enough to contact under the carb base even with no idle speed screw installed. If the throttle rod under the car forward of the trans or the rod from there to the cross shaft are out of adjustment this can happen. Does it still not return to the idle screw with the cross shaft disconnected from the accelerator rod? How about if you disconnect the L side link from the cross shaft does the right one go up far enough to contact now. I see a new screw holding the carb throttle lever on the carbs throttle shaft. Was the throttle plate removed from the shaft and/or the shaft replaced during rebuild? If so is the throttle plate installed upside down? There is and up and a down on these. The edges are cut at an angle. When properly installed the flats of the throttle plates angled faces contact the carbs bore not the point at the end. This would cause the lever to not return fully. You need to find the bind or contact that is keeping the lever from going fully to its stop and fix it.

[bholland80]

Hi SeamusNZ & terribleted, thanks for the replies!

Those pictures were taken while the linkage attached. I will remove and see how they operate and then attempt to adjust per the tune-up instructions. I watched the tune-up video on youtube (not the really-really old one, but the one from the late 80's) and now have a better understanding of how the linkage can be adjusted and the importance of detaching it to work on each carb independently.

I'm curious if the above could have a such a large impact on one carb that it would no longer work at all? I mean, when I blocked the left carb there was basically no change in the engine. Looking at the plugs on that side they were pretty clean compared to the right. If that left carb is squirting fuel when the throttle is engaged, what would be preventing it from "working".

EDIT: Edited to add that the carb that seems to "leaking" or bubbling at the bottom is the right one where you can feel suction (and it basically kills the engine when it's blocked). The left one seems to just be hanging out :)

Thanks,

Bill

[64powerglide]

Is there gaskets on both sides of the plastic spacer??

[bholland80]

Hey Jeff, can you elaborate on what spacer you're talking about? Thanks!

[terribleted]

The squirt you see when you actuate the throttle is the accelerator pump pushing gas into the carb to start acceleration. At idle there is no fuel delivered there. Fuel is delivered thru the idle passage. It is possible (even likely) to have a carb base with a blocked idle circuit. it will function off idle but not at idle. Common issue, need to get the passages all clean. I have had a couple over the years that refused to unblock.

[SeamusNZ]

Hi Bill,

believe me, the carbs on these things and the linkages in between are critical and can behave in strange ways if not adjusted or breathing correctly.

Corvair engines are very capable of running on one carb and as a result one bank of cylinders without sounding horribly rough.

A mixture of a vacuum leak combined with a poorly adjusted linkage will cause the exact problems you describe. If you have twin pipes you will also notice that one pipe is much colder than the other, simply because the cool side is not burning any fuel and as a result taking any load.

Don’t panic, the symptoms that you describe are very common with these engines.

Eliminate any vacuum leaks that you may have on one or both carbs and reset the linkages and throttle settings as per the book and you will be surprised at the result.

You need to get to a point where the idle screws are operating and adjusted exactly the same on both sides and that the engine falters or stalls if you place your hand over either carb.

Cheers

SeamusNZ


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[bbodie52]

I have attached a couple of manuals to supplement the information you will find in the Corvair shop manuals and shop manual supplements. The 1965 Corvair Assembly Manual - CARBURETOR & FUEL SYSTEM contains a number of technical detail drawings. These illustrations may help you to better-visualize and understand the various fuel system assemblies. Some of the pictures below may also be helpful.

Much of the DELCO ROCHESTER - Models H, HV Carburetor Service Manual provides detailed functional explanations of each of the subsystems within the carburetor, to help you to understand the purpose and function of these various components, such as the choke mechanism, accelerator pump subsystem, etc. The booklet describes what takes place as the engine warms to operating temperature, and how the carburetor functions change from an idle condition to off-idle acceleration and open throttle cruising. In a modern engine, electronic fuel injection and electronic sensors tell an onboard dedicated computer what the engine needs as driving conditions change. The computer makes pre-programmed changes in fuel delivery and ignition timing to maintain a proper fuel/air mixture to maximize performance and stable engine operation at various throttle settings and engine speeds. But in the 1960's there were no electronic programmed computer systems that were pre-programmed to respond to throttle position and sensor inputs. Everything was based on mechanical linkages and vacuum/airflow conditions that changed carburetor and distributor operation. The mechanical carburetor attempted to continuously adapt itself to varying temperatures and changing driver demand inputs via the throttle linkage. This booklet provides a functional explanation that describes how this takes place within the mechanical carburetor. It also describes some of the design changes that took place over the years to improve the operation of these carburetors between 1960 and 1969.

Carburetor Base Insulator and Gaskets.jpg (56.62 KiB) Viewed 838 times

The fast idle cam only comes into contact with the throttle linkage to hold it open to preset levels when the engine is cold or warming to normal operating temperatures. The choke mechanism and fast-idle cam initially shift into position on a cold engine when the driver opens and releases the throttle one time before turning the key to start the engine. As the engine warms up, the automatic choke mechanism gradually disengages the choke and associated fast-idle cam. On a warm engine they are disengaged completely. At this point, the throttle linkage comes into contact with the idle-speed screw, which maintains warm engine idle speeds when the engine is running but the car is not being driven.

Carburetor Throttle Linkage.jpg (14.67 KiB) Viewed 838 times

Rochester Carburetor.jpg (42.09 KiB) Viewed 838 times

Classic cars had a different way of doing things in the 1950s, 1960s and earlier, when compared to modern techniques utilizing sensors and computer technology to control fuel injection and ignition systems. There was a series of books that were published in the 1960s and 1970s that focus on basic principles of automobile design and function. These books covered basics associated with carburetors, ignition systems, suspension and brakes systems, etc. When I was a teenager I read through many of these books and they gave me a good understanding of the principles and functional designs that were common in the cars that I was interested in, including the Corvair. Once I read through these books, the shop manuals made a lot more sense to me as I began to understand how things function and what I was trying to accomplish in working on my Corvair. This series was published long ago (1960s-1970s) by Petersen Publishing Company, which was also associated with Hot Rod Magazine. With titles like Petersen's Basic Cams, Valves and Exhaust Systems, Petersen's Basic Ignition and Electrical Systems, and Petersen's Basic Carburetion and Fuel Systems, I was a teenager that found myself devouring much of the series to teach myself the basics that could be applied to most 1970s and earlier vehicles. The material in those books are now somewhat dated because of the change to computer-controlled electronic fuel injection and other sophisticated technologies that have been introduced in the subsequent decades. But I do feel a Corvair owner or any classic car owner could benefit from the material in these books. Many of them are listed as available on Amazon.com. If you would like to consider the possibility of reading through some of this material, the following link may help you to find what you're looking for. The cost of these books is low, and the investment in time that you might make in reading them may help you to develop a foundation of knowledge that will help you to leap ahead in your DIY maintenance efforts on your Corvair.

https://www.amazon.com/s/ref=nb_sb_noss ... pany+basic

ebay https://www.ebay.com/sch/i.html?_odkw=b ... c&_sacat=0