Just Can't Get This Pig Running

[WinginEngineer]

Hey all, it's been a while. Quick catch up of where i am... I bought my 62 Corvair 700 as a pair with two identical cars. One engine had been torn apart for rebuild and looked like it was missing parts. The other engine was literally sitting in the trunk of one of them. I took the trunk motor, cleaned it up and put it in the car. Ran a compression check and had 0-20psi on all cylinders. OK, shoulda checked before I put it in the car, but lesson learned.

Tore the trunk motor out and tore it down. Measured everything out and it was all actually really good with exception of really worn rings (0.090" gap if I recall) and a spun main bearing. So I got new rings, all new gaskets, new rod and main bearings, and a new crank. I then ordered up a set of reman heads and slapped it all together. Rebuilt the carbs, replaced the tank and lines, and went to fire my new beast up with my new hightorque starter... and nothing. Would not start. Spent a couple weeks fiddling with just about everything I could before I ran a compression test again and realized I was 0psi on all cylinders... on my new rebuild motor. I was very depressed about this and too frustrated to think straight. That was all about a year ago and I hadn't touched the car since.

Fast forward to about a month ago and I finally convinced myself to go dust it off and try again. I started with the valves as I started thinking that may be the cause over the past year. I bought a fancy dandy scope on Amazon, pulled the plugs, stuck the scope in and took a peek. Sure enough, valves were still open at TDC. OK, adjust the valves and check compression again... now I have the following:
Cyl 1 = 140psi
Cyl 2 = 130psi
Cyl 3 = 125psi
Cyl 4 = 130psi
Cyl 5 = 130psi
Cyl 6 = 140psi

Now that seems kind of low to me as most rebuilt motors I've done are around 140-190psi. Mind you, this is my first air cooled. But even at 120-130 I would expect that to be enough to run, even if poorly. So I tried to fire it up... nothing again. Got a bunch of bangs comin' back up my carbs, but no coughing and definitely no starting. Fiddled around and realized I'm an idiot and set my firing order on the cap CCW instead of CW. OK, fixed that, still no fire. Then I noticed one of my rebuilt carbs was leaking gas.

Dang it anyway. Tore the carb off, opened it up, gasket was clearly leaking and oh, by the way, driver's side accelerator pump plunger was torn. Brand new. Whatever, got a new rebuild kit and did it all over again, this time soaking the bowl gasket in oil first.

Put it back together and still no fire. Of course when I say no fire I'm ignoring the pop back I had that caught the "priming" cup of gas in my hand on fire and spread pretty flames all over my garage. Thank god for the 5 extinguishers spread around.

So help me out guys. I can't get this pig started. I've been working on this car for almost 3 years and I can't even get it to start. I'm reaching the end of my rope.

I have at least some compression, I have, or should have, fuel (poured it by hand to make sure I had gas, just in case, hence the "priming" cup). I know for a fact I have spark on all 6 cylinders. I know for a fact my timing is set to 8 degrees BTDC (should be 13 according to the book, but 8 should get it started at least). I now know my firing order is correct. My points are set to 0.019" gap and lord only knows how many times I've checked that.

But the car still won't start. All it will do is spit and pop back up the carbs and even then only about every 5th or 6th revolution, if then.

HELP!!!! I'll take any suggestions at this point!

[steve57]

If your backfiring thru carb you need to stop what your doing. You took the engine apart, did you get the crank and cam gears properly aligned? I understand this can be an issue. Have you checked # 1 cylinder is coming up to fire with rotor in correct position? Sometimes you just have to completely start over.

[WinginEngineer]

So the reason I'm here is because I agree with you... it's time to stop and think instead of destroying something (else).

Thanks to my handy dandy scope I know for a fact #1 is traveling on the compression stroke with spark matched at 8 degrees BTDC on the same stroke.

I guess I could have missaligned the cam. I certainly wouldn't dismiss the idea without confirming at this point. Although I can say if it was off it can't be more than a tooth or two.

I love being able to watch my combustion chamber functioning

I just wish it told me what was wrong.

The thought of pulling that engine back out a 3rd time to check the cam gear is making cry on the inside though

I'll check as much as I can elsewhere before I go down that road. But if the nut ain't cracked by then, out she comes...

[bbodie52]

Are you working using a Corvair shop manual, or just "winging it" based on your prior experience with other cars? Your logon name "WinginEngineer" would suggest you don't work with a shop manual at hand. Most experienced Corvair owners, shadetree mechanics and professional mechanics ALWAYS work with a shop manual on-hand and in-use, and refer to it often. Shop manuals and many other Corvair technical references can be downloaded for free in Adobe Reader format using the following link...

COMMON AND USEFUL CORVAIR WEBSITES

viewtopic.php?f=225&t=6007

Compression Readings:

Fast forward to about a month ago and I finally convinced myself to go dust it off and try again. I started with the valves as I started thinking that may be the cause over the past year. I bought a fancy dandy scope on Amazon, pulled the plugs, stuck the scope in and took a peek. Sure enough, valves were still open at TDC. OK, adjust the valves and check compression again... now I have the following:
Cyl 1 = 140psi
Cyl 2 = 130psi
Cyl 3 = 125psi
Cyl 4 = 130psi
Cyl 5 = 130psi
Cyl 6 = 140psi

Now that seems kind of low to me as most rebuilt motors I've done are around 140-190psi. Mind you, this is my first air cooled. But even at 120-130 I would expect that to be enough to run, even if poorly...

1965 CORVAIR CHASSIS SHOP MANUAL SPECS...



So your Compression Test results are nearly perfect for a new engine!

WOW! You can even see the dipstick inside the dipstick tube,
and if you look closely you can see the bottom of the dipstick projecting into the oil pan area!

If you enlarge the view of the Visible Corvair Engine drawing, you can see the timing mark dot on the aluminum timing gear. The Woodruff Key position on the camshaft gear is even correct!

Left-click with mouse to enlarge for better viewing. Click a second time for maximum enlargement...

» Sat Jun 08, 2019 10:55 pm

So the reason I'm here is because I agree with you... it's time to stop and think instead of destroying something (else).

Thanks to my handy dandy scope I know for a fact #1 is traveling on the compression stroke with spark matched at 8 degrees BTDC on the same stroke.

I guess I could have misaligned the cam. I certainly wouldn't dismiss the idea without confirming at this point. Although I can say if it was off it can't be more than a tooth or two.

Your cam timing comments are a concern. With good compression test results and a properly inserted/timed distributor, confirmed spark at the plugs, and fuel in the carburetors, you should be able to get some signs of life.

[WinginEngineer]

Gee, thanks for the confidence Brad

I'm kidding, mostly. I can't fault ya for pokin' that stick. I know I come off as sn idiot most of the time. I'm a back of the clasroom type of guy.

To clarify, the screen name WinginEngineer refers to the fact that I ride and have an obsession with Goldwings and the fact that I am a real life mechanical engineer (with my secondary focus having been in powertrain engineering)

Prior to getting my degree and settling down behind a desk I spent 8 years as a HVAC and appliance technician (fully certified with master tech certs in both HVAC and appliances).

Off the professional circuit I've been working on cars my whole life. In fact I put myself through college running an amature shop out my driveway (and those customers still come to me regretably). So I may not be the world's best mechanic, but I'm not TOTALLY incompetent. With that said, I'm only 34, which means I cut my teeth on technology. This ain't my first classic, but most of my small block toys from the 60's and 70's had edelbrocs or holleys and always went straight to solid state ignition. I'm TRYING to keep this one pure. The corvair is my dream car.

Now with a little more context of ME, let's get back to business...

I don't do anything without instructions. My ability to follow those instructions may be questionable, but I always read them. I have a fat stack of 3 ring binders with all the shop manuals from Corvainiacs printed out in 'em. That's where I got the timing and point specs (0.019" for new points and 13 DBTDC for the powerglide). That said, the page you shared is not familiar to me. Where is that located so I can flag it?

As far as the cam, I know it can't be more than a tooth or two off because I can watch the valves working and to the naked eye they look in time.

I just cannot say for sure that I didn't miss a tooth or two because A. I'm an idiot. B. I have a bad memory. C. I rebuilt the motor while unemployed after a layoff. I was stressed, depressed, and not running on all 8 cylinders.

It's possible I screwed up, but if I did I didn't catch it. My brain said those marks were lined up per the book at the time. My brain is pretty unreliable sometimes though...

[bbodie52]

The tune-up chart you asked about was in the 1965 Corvair Chassis Shop Manual - SECTION 6 - ENGINE, on page 6-2 (attached).

Each year Chevrolet technical writers made improvements in the Corvair Shop Manual. There are a lot of flaws in the 1961 Shop Manual that made it look more like developmental draft engineering notes than a final product that should be distributed to field mechanics. This was particularly true of the wiring schematics in the 1961 book, which are terrible. The schematics in the 1962-63 supplement and in the 1964 supplement improved a lot in the first supplement, and little more in the 1964 supplement when the 1962-1964 Spyder wiring changes actually began to appear in a published manual. The 1965 Corvair Chassis Shop Manual continued to show refinements in the sections that applied to the Corvair front suspension and powertrain that did not change significantly from the earlier model years. Of course it also covered the major changes that appeared in 1965. I tend to refer to the 1965 book a lot, and then backtrack to earlier editions that cover earlier design specifics.

The Corvair shop manuals guided me through my first engine overhaul and Powerglide transmission rebuild in 1969-1970 when I was 16 years old. I learned then to always read through a procedure and then have the book at-hand when I work on a car. This attitude was reinforced as I served as an electronics technician in the Air Force for 24 years. The Air Force always stressed working ONLY with the appropriate Technical Orders on-hand when performing a troubleshooting, fault isolation and repair task. It really helps to refresh your memory and follow the guidelines and illustrations. Personal experience and help and advice from sources like the Corvair Forum are also invaluable and helps to keep a project moving rather than stalling when you feel like you are running out of ideas. (When you came up with zero compression on all cylinders after an engine rebuild, the first thing I thought of was a too-tight valve train adjustment, which seems to occur often on this Forum as a source of trouble when an engine will not start or seems to be running on only a few cylinders).

Sometimes it helps to take a breather and look over the Shop Manual, Corvair Assembly Manual, and other available references on the Internet for new ideas. Hopefully some experienced voices will surface here on the Forum to assist you with resolving your problem. I hope it is not a cam timing issue, since correcting that is such a pain on a Corvair engine. I remember checking and confirming the correct camshaft timing 3 or 4 times before moving on with an engine overhaul. The idea of having to remove the engine and split the cases again to correct a timing gear misalignment is something I would rather not contemplate!

With reference to your Honda Goldwing obsession, I often tell people who are experienced auto mechanics that working on a vintage Corvair for an automotive mechanic is something like working on a motorcycle for the first time. There are similarities, but... the age of the technology behind the Corvair, the air-cooled nature of the beast, multiple carburetors, differences in drive-train, aluminum components, etc. makes switching to a Corvair something like switching to a motorcycle (I ride a Yamaha FJR-1300 and a Suzuki Hayabusa).

If you have good compression, correct valve and distributor timing, ignition spark, no vacuum leaks, and fuel in the carburetors (without flooding), success should be on the horizon. Let's hope a logical fault isolation process will get you there. Then I have a GE Monogram microwave oven with an apparent blown fuse or other power supply issue that maybe you can help me with. And then there is that KitchenAid refrigerator with a circulating fan or control relay problem that I need to look at... and then there is my need to replace our aging heat pump...

Corvair Timing Marks

Left-Click image to enlarge

viewtopic.php?t=9351

Re: Cam Question Revisited!!! HELP
Post by Bob Helt » Thu Feb 05, 2015 12:21 pm

Hi Wbabst,
You asked where this is documented. Well it is well documented and defined in my book, THE CLASSIC CORVAIR which really should be in everyone's library. It's available from Clark's and other major vendors. My book contains many other engine overhauling and upgrading information that will be helpful. I suggest that you get a copy. You might also be interested in my other book, CORVAIR SECRETS that contains a lot of information on this TDC problem and other strange stuff.
Bob Helt

The Classic Corvair: Ninth Edition Paperback – December 13, 2002
by Bob Helt (Author)



https://www.amazon.com/Classic-Corvair- ... way&sr=8-2


Crank/Cam timing marks problem

http://corvaircenter.com/phorum/read.php?1,687938

[61SuperMonza]

I agree with Brad, it is very easy to miss index the crank and cam due to the type of gear design of crank and cam gears. I have done this myself. This is why you check this before continuing with assembly. I now check this as well as using a degree wheel to ensure proper cam timing. In very rare cases you may need an off set cam key to get it right. The other issue may be a bad crank or cam gear. Did you replace these before reassembly? Yost a thought.

[61SuperMonza]

Your compression is not the issue.

[WinginEngineer]

See Brad, THOSE pages, with the timing set, ARE familiar. Those links you put up are exactly what's in my 3-rings and what I use for everything I've done. I ain't dumb enough to touch the engine and trans in a car I've never worked on before without detailed instructions. In fact, you should see the state of my "Small Block Chevy Engine Overhaul" book and my "GM Hydromatic Rebuild" book. No matter how many times I've done those the book still comes out every time. I just missed that specification page. I spent a long time lookin' yesterday too

To your point about the schematics, I wound up making my own taking the only good chunks from all of the above

Your instinct was spot on about the valves too. Lets just say some folks have different definition of "no rocker movement" and mine was wrong round 1. Round 2 I followed your video from an old post... that's when my compression came back. "No rocking horse movement" was a much better way to word that

Oh well, from that spec page I now feel really good about my 130psi compression, which hurts my brain even more.

So now..
1. I know my compression is spot on.
2. I know the intake valve is opening during the intake stroke, both are closed the entire travel of the compression stroke, and the eaust valve opens just as the piston starts ascending for the exhaust stroke
3. I know my spark is timed to fire 8 degrees before top dead center on cylinder 1
4. I know my firing order is set per the shroud in a clockwise rotation from #1 position
5. I know my point gap, for my brand new points, is 0.019"
6. My spark tester shines bright on all six cylinders
7. I'm fairly confident in my valve lash
8. I know the fuel pump is delivering fuel to the carbs and filling the bowls
9. I know my accelator pumps are jetting fuel down the carbs when pumped
10. I do not have any pouring gas to indicate the floats are not seating the needle valves

But all of that brings me back to the big question: WHY THE HELL WON'T IT START??? OR EVEN COUGH???

Even with starting fluid and a gas cup she just laughs at me.

What am I missing from the must-have-to-run checklist?

[bbodie52]

Did you remember to insert the rotor before you installed the distributor cap? Silly things like that do happen! I once rebuilt a distributor and installed the centrifugal advance weights upside down. The car started and idled well, but when I attempted to drive it it was like driving into a wall of Jello! The higher I revved the engine, the weaker the engine became!

I discovered the nature of my mistake when I rechecked the timing. The base timing was good, but I discovered when I revved the engine the timing mark went the WRONG WAY! That is how I discovered that you could create a centrifugal retard mechanism by installing the weights upside down!

Have you confirmed the presence of a spark at each spark plug?

[WinginEngineer]

Yes, spark is confirmed at all six cylinders using a spark light between the wires and plugs. So I have to believe the rotor is seated...

Keep 'em comin'. You're gonna turn on my oh spit light eventually...

[steve57]

Have you tried this? Remove plug from #1 cylinder , bring it up on compression stroke and line up timing marks at 8 degrees BTDC. Put plug in plug wire, ground to engine, loosen and rotate distributor back and forth to fire plug. Don’t forget to turn on ignition switch. If timing is correct you should have spark.

[WinginEngineer]

Steve, what I did was similar.

First, I pulled the #1 plug and watched the valve timing with my scope using my remote starting trigger. I bumped the engine in until it was starting the compression stroke.

Then I put the plug back in and put my spark light on it. Then I gently bumped the motor in until the light triggered. When I say "gently bumped" I mean I slapped the trigger so it barely contacted and I was getting between no movement and maybe a starter tooth of movement each bump.

The first light trigger happened way retarded, probably 15 degrees ATDC. But that told me definatively my spark was on the compression stroke at least.

So I tweeked the distributor CCW and slow-bumped a full revolution until my timing mark was visible, then went back to gentle bumping until the light triggered again. Second trigger was just barely retarded.

I continued the process in sequence until it triggered at 8 degrees BTDC. At that point I figured it was good enough to start. Usually you can get a motor to start reliably anywhere past about 6 degrees BTDC.

I stopped at 8 because the timing indicator on the block only goes to 9. Rather than guess where 13 would lie, I figured I should get it running first, then use my timing light set to 13 degree advance to know it was right.

I'm open to the idea I did something wrong there, so if something sounds off, by all means speak up.

[64powerglide]

Lets see, i'll set the distributor to fire before the intake valve closes. That should work fine except for the backfire.

[WinginEngineer]

Lets see, i'll set the distributor to fire before the intake valve closes. That should work fine except for the backfire.

Um... huh? How'd'ya figure? Unless I have really misread the situation, intake is shut before the compression stroke starts, stays closed all the way through the stroke, then stays closed until after the exhaust stroke.

The distributor is set to fire at 8 DBTDC on the compression stroke. That's about 180 degrees after the intake valve closes and at least 400 degrees before it opens again.

What's making you think the valve is open when it fires?

[61SuperMonza]

I may have missed it, but have you replaced your plugs and wires. Have the plugs gap been checked? Not to say you haven't checked this, but given what you have said the engine should fire. Very perplexing.