My Blue CORSA-500 :)

[cvair4life]

Ok Folks I'm posting some videos of my car that I made last winter on day that was probably 15°F or so.

Any thoughts on the intermittent smoke on the left head? Also, it warms up (exhaust heat on the hand method) much slower than the other head.

[UNSAFE]

Hard to tell for sure from the video. It does look kinda like the smoke is mostly from one cylinder because of how it puffs.

I'd determine which cylinder it is first by checking the plugs.

It could be something like bad/broken rings or valve guide/seal problem. It may also be caused by a stuck valve or worn down cam lobe not letting a valve open. If an intake valve isn't opening it will suck oil in past the rings even if they are Ok.

Does it feel like it's running on all six ?

As much valvetrain noise as you have that may be the problem. A vacuum gauge might help to check it out but I think I'd find the bad cyl first and then with it running look to see if the rocker arms are moving the same as the other rockers.

Regardless I'd recommend a complete valve adj. Likely I missed a few things but that's a start.

[cvair4life]

thanks Kevin.

It does feel like it's running on all 6... but then I wouldn't know the difference. My 140 that I blew-up was a bit stronger... but then I KNOW that engine was sick for sure!

I know I need a valve adjustment for sure... along with a full tune-up. Here's the story:

In 2001 I tore this motor down to the block (didn't separate) and replaced/did the following:
Rings
Honed cylinders (not bored)
Bearings (crank)
New valve guides on almost all the valves
A couple new valves
A couple new valve springs
Had valves ground and matched to seats
New Lifters on all accounts
New plugs
Partial rebuild on carbs (just the basics - I did a full rebuild 3 years prior to that)
New copper gaskets on block and head

That's about it really... I've never been able to adjust that clatter out of the car...
BTW I replaced the Lifters post-mortem with the engine in the car don't know if that's good or not.. it was hard to get the old lifters out

[cvair4life]

OK so I've done a compression test on cylinders 1, 5, 2, and 6.

I did the test as follows:
Remove spark plug (dirty! note to self... get new plugs and blow out carbon)
Hand tighten compression tester
Pull wire from Coil
Crank engine for 3-4 seconds
Read dial
Replace plug

For each of the cylinders I tested I was getting to right on 150 psi.

I still need to get in behind the carbs on 3 and 4 to see what they are at.... my question for now is what type of PSI are all of you getting on your cylinders? I'm guessing 150 is good but is that good for a Corvair???

Will update soon with the other 2 cylinders.

[cvair4life]

Some pictures of recent work... not beautiful but it's something

[terribleted]

Smoke...hmmm... black perhaps...or white? A dead carb can cause uneven warm up. Plugged jet or internal carb circuits or flooding on the cool side, resulting in black smoke or white smoke (rich or lean), but not firing properly in any case and therefore not getting warm or sharing its part of the load. This of course means the other side heats up faster as well, since the other side doing all the work. I have known owners that have driven Corvairs for a long time and not realized they were only running on 3 cylinders (thought the cars were just a bit under powered and/or worn). Try the "hand" test. At idle place your hand over the top of each carb in turn blocking off the air flow into it. There should be an even amount of suction from side to side (ie suction when you cover the right carb should be similar to when you cover the left). If this is not the case the weak side has issues, likely carb related. When you cover a plugged up carb you dont feel much suction and the cars idle may decrease a little but generally does not quit running. If you have 1 bad carb when you cover the good one you feel good suction and the engine will usually shut down as you seal the top with your hand.

You can try revving the motor and popping your hand on top of the bad carb to instantly block any airflow a few times. This will sometimes dislodge a blockage allowing the carb to function again.

[cvair4life]

Hi Ted. Thanks for the insight. I just pulled, bathed, cleaned and rebuilt both carbs so hopefully I'll have that issue tucked away soon enough. Kevin said I need to adjust the valves so I'll do that as well. New videos sooner than later :)

Oh.. just realized I hadn't responded to the black/white smoke question. Watching my video above again it's white smoke for sure. So running lean I suppose

[terribleted]

Valve adjustment is always a good idea.

[cvair4life]

Hey everybody. So we had the blue car in the shop today and fixed a few things.

Got the electric fuel pump in and running :)

Put the oil pan back on and sealed up - I used time-serts on a couple holes... that was slick :)

Now the question: How do I set the carbs up properly? When we finally got it fired over... it was "idling" at like 4000 rpm... like a dead run give or take...

[cvair4life]

So just to make sure I've got my screws in... or correct :)

When I go to fire the car up I need to zero both screws & then back out a couple of turns?

[terribleted]

No you need to follow the carb rebuilding instructions in the shop manual actually to get an initial set on the idle speed screw (but you can just guesstimate this one until you gte it going ans synchronize the carbs). The mixture screws start initially at 2.5 turns out. After you get the motor running well and synchronized the carbs you can turn the mixture screws in untill the rpm drops slightly then turn back out 1/4 turn.

The motor generally will not run with the mixture screws all the way in. A 4000rpm "idle" means either the timing is way to far advanced and/or the idle speed screws are turned too far in. Remember that the timing is set at proper idle speed, so, you may have to adjust timing and carb speed screws a few times to get to where you need to be. Keep in mind that the speed screws should be adjusted pretty evenly ( if they are not fairly even once the carbs are synchronized then there is a carb problem in one or the other). Once you have synchronized the carbs adjust the speed screws for a proper idle speed. When you do this you MUST turn each the same amount in order to keep synchronization. Carbs can be synched with a vacuum gauge or a carb synchronizer tool (I like these alot and they are not very expensive) or some say by listening to them thru a rubber hose (might work but my ears are not that good:) ).

[cvair4life]

No you need to follow the carb rebuilding instructions in the shop manual actually to get an initial set on the idle speed screw (but you can just guesstimate this one until you gte it going ans synchronize the carbs). The mixture screws start initially at 2.5 turns out. After you get the motor running well and synchronized the carbs you can turn the mixture screws in untill the rpm drops slightly then turn back out 1/4 turn.

I don't have the shop manual... so I'm guessing the 2.5 turns is referring to a starting point of all the way closed or bottomed into the threads?

A 4000rpm "idle" means either the timing is way to far advanced and/or the idle speed screws are turned too far in.

It ran and idled @ approximately 1000 rpm before I rebuilt the carbs last month. I have not changed, moved, or messed with the dist at all since it was running before. I put new cap and rotor in it just before I stopped driving it a few years ago...
People have said that the Corvair engine should idle a bit slower - around 700? What do you think on appropriate idle speed?

Carbs can be synched with a vacuum gauge or a carb synchronizer tool (I like these alot and they are not very expensive) or some say by listening to them thru a rubber hose (might work but my ears are not that good:) ).

I picked up a Unisyn last month from Rafee. I have a basic idea about how it works and how to use it - but it's a very loose general idea. Can you give me any input on how to use the Unisyn? My carbs are jetted to the next size bigger than stock (can't remember what that is now.. seems to be a "58" that comes to mind??? ) Basically I understand that the red float in the tube should be as close to the same level on both sides as possible. I've read that the goal should be to get the float to the 1/2 way mark on the sync tube if possible...?

[terribleted]

You really should get a repro shop manual. It is extremely usefull and can save you lots of work and rework. Not very expensive either and yes 2.5 turns refers to bottom the mixture screws all the way in and turn out 2.5 turns.

If the motor ran at 1000 RPM before you rebuilt the carbs and now runs at 4000RPM there is likely something VERY wrong with your rebuilding adjustments. 4000 RPM by the way is like 50+ MPH in high gear are you using a tachometer to see this RPM or is it just a guess? If you do not have a tach GET ONE. Most likely misadjusted fast idle cam (step 17 page 6M-7 of the 65 main shop manual). I would remove the carbs and recheck all the mechanical adjustments step by step per the shop manual. Idle speed should be 450-500 for 95HP standards, 600-650 for 110 and 140HP standards and "Idle speed on engines with automatic transmission should be set as low as possible to obtain a smooth idle and prevent creep in drive or harsh shifts during transmission operation" Shop Manual Engine Tune-up page 6-2. I have found this to be between 650 and 800 RPM depending on the car.

Using a Unisyn:
With engine running at idle and warm (do not worry about idle speed much at this time but it must be an idle say under 1500rpm and ideally more like a proper idle speed) :

Step 1. Remove left primary carb rod from cross shaft (this should be the adjustable rod the non adjustable one should be used on the right primary). (if the engine is a 140 disconnect linkages to secondarys and wire them closed)

Step 2. Place the Unisyn on top of the right carb and adjust the Unisyns center plate so that the red bubble is pulled up into the center of the tube.

Step 3. Now place the Unisyn on top of the left carb and while holding the carb rod up so that the throttle arm is against the idle speed screw, adjust the idle speed screw so that the red bubble is centered in the Unisyn's tube.

Step 4. While still holding the left carb rod up again place the Unisyn on top of the right carb if the bubble is still centered go to Step 5. If the bubble does not pull up to the center repeat steps 2 and 3 over until you get a result where the Unisyn's bubble is centered regardless of which carb you set it on.

Step 5. While still holding the left carb rod up so that the throttle arm is against the idle speed screw, adjust the rod by twisting the adjuster so that it just enters the cross shaft hole and re-install it in the cross shaft. Recheck that both carbs still pull the Unisyn bubble to the same spot. If not repeat the process more carefully:0

Step 6. Adjust idle speed to desired level. Do this by adjusting right and left carb idle speed screws in or out the same amount to reach the desired idle. Right and left screws must be turned the same direction the same amount in order to maintain synch.

Carbs jetted at 58?? That is a very large jet size. Most vair carbs are jetted between 48 and 51.

[cvair4life]

Ted - You're a gentleman and a scholar. I'll obtain a Shop Manual when funding is available :)

For the time being I'll wing it and see if it's the idle screws being in too far and holding the idle speed up there. My guess is yes but I'm in Vegas working until Wednesday next week before I get home to even look into it.

In the mean time I'll be posting pics and videos of the past few weeks and asking questions so I can jump into it all with a game plan.

[terribleted]

When you rebuilt the carbs how did you adjust them? Kit instructions are ok but often somewhat lacking. Every adjustment is important, needs to be the same on both carbs, and need to be done mostly in order. Careful following of rebuild instructions usually results in carbs that work well and are generally not the source of any remaining problems. Even turning the idle screws all the way in will not result in a 4,000 rpm idle. Perhaps 2,500 or bit more.

[cvair4life]

I haven't got around to the carbs yet... just tinkering at the moment til I can break away from my jobs

Today my brother came down to work on some odds n ends. We put a brand new wiring harness in for the trunk and it's doing some goofy stuff:

Turns on both head lights on passenger side and nothing on the driver in one state of the HI/LOW switch. The other state turns off both passenger side bulbs and turns on High Beam only on driver side....
No turn signals ever...
No running lights ever... (it's a 68 with the side markers... something that doesn't exist on the 66... Yeah I didn't know that til today)

Everything is very well grounded on clean metal screwed into the frame.
Harness is brand new (Clarks)
Plugs all appear to be well soldered
Already threw out old harness DOH!

Before battery died totally... the horn ground at the steering wheel would spark and make the horn grate but not fire (prob amperage from dead battery) Prior to that it was lighting both head lights on the driver side... but we didn't have everything grounded right then...

I suck at electrical to be quite honest... but I can read schematics... anybody have it for the 68 500 trunk harness?