1936 Chrysler Airstream C-8 Convertible Restoration

[VW4X4]

Well with fuel mileage, there is a ton of things to consider.   Right off the bat, IF I got that bad of fuel mileage, I would look very closely at two things:  One, the condition of the engine.  Two, the  engine peak HP at what RPM., verses the speed at which the engine runs most.   Remember your speedo was not correct for an overdrive unit.  Therefore I suspect the overdrive could have been added.  This may lead to a miss match of gear ratios.   That say, I don't completely recall, but  the 4DR cars VS the 2 dr coupe, VS the overdrive cars all had different rear axle gear ratios.  Random mixing  these axles can really kill fuel mileage, even with a overdrive.

 

ERIC

[maok]

I get roughly around 13gpm (17-18l/100km)but my driving is mainly stop start, slow speeds(under 35mph)and generally with 4 or 5 passengers. Also, I have electronic ignition and a progressive weber 32/36 carb.

 

And my Airstream is the 6 not 8

Edited February 23, 2022 by maok (see edit history)

[Professor]

My driving is mostly at 60 mph with very little start and stop.  I always use the overdrive (lift off the gas at 40 MPH or so in high gear and the hit the gas again) and I rarely stomp the fuel.  In this car, for the most part, I drive very cautiously.

 

One of my next steps is to remove the head and check the condition of the engine.  Also, I have never adjusted the valves so I have absolutely no idea what condition they are in.

 

Joe

[VW4X4]

4 hours ago, Professor said:

My driving is mostly at 60 mph with very little start and stop.  I always use the overdrive (lift off the gas at 40 MPH or so in high gear and the hit the gas again) and I rarely stomp the fuel.  In this car, for the most part, I drive very cautiously.

 

One of my next steps is to remove the head and check the condition of the engine.  Also, I have never adjusted the valves so I have absolutely no idea what condition they are in.

 

Joe

Joe,

         A simple compression test is all you need the check the rings and valves.  Pulling the head is not needed, for testing.

[VW4X4]

On 2/22/2022 at 10:02 PM, maok said:

I get roughly around 13gpm (17-18l/100km)but my driving is mainly stop start, slow speeds(under 35mph)and generally with 4 or 5 passengers. Also, I have electronic ignition and a progressive weber 32/36 carb.

 

And my Airstream is the 6 not 8

MAOK,        I'm very interested, in your  electronic ignition, and carb. Mod.   Can you post pictures of these?

                          ERIC

 

[Professor]

Thanks Eric.  I am getting water vapor coming out my crankcase draft tube (no water in the oil at all) and I suspect the head gasket may have a small leak so I want to pull the head anyway.  While I am in there, I want to check valve guide wear and ring ridge.  Mostly, I want to pull the head to confirm whether or not my head gasket is leaking.

 

Joe

 

12 minutes ago, VW4X4 said:

Joe,

         A simple compression test is all you need the check the rings and valves.  Pulling the head is not needed, for testing.

 

[Roger Zimmermann]

Are you sure that it's water vapor? With some blow-by, there is probably oil vapor from the crankcase.

[VW4X4]

Just now, Professor said:

Thanks Eric.  I am getting water vapor coming out my crankcase draft tube (no water in the oil at all) and I suspect the head gasket may have a small leak so I want to pull the head anyway.  While I am in there, I want to check valve guide wear and ring ridge.  Mostly, I want to pull the head to confirm whether or not my head gasket is leaking.

 

Joe

 

 

Water vapor is part of the exhaust gasses .  If it is coming out the draft tube, that means the rings would be leaking.

(Rings always leak  some, even when new )   A compression test would show this...

[Professor]

Thanks Eric.  Here is what is interesting... I put some green dye in my radiator and the water vapor coming out of the draft tube turned green.  Typically, I get a kind of gelatinous mass glopping out of the draft tube.

 

I will perform a compression test and a leakdown test before I pull the head regardless.  I will post the compression test results as soon as I do the test, probably this weekend.

 

I fully expect I will need to rebuild this engine, but honestly, if I can avoid it, I will.  Part of me looks forward to rebuilding an engine again and part of me thinks that if it isn't broken, don't fix it.  What would be bad would be for me to paint the car and THEN find out that I need to rebuild the engine.  Pulling the front clip will most surely create some paint issues... it would be far easier to rebuild the engine before I paint.

 

Joe

[Piaras]

Do a compression test first. Once that is done dry, add a teaspoon of oil and do it again. Note any pressure difference. A leak down test would tell you how bad the rings are, but you need to buy or borrow the leak down test rig. Marvel Mystery Oil, Engine Restore, Rislone.
Pierre

Edited February 24, 2022 by Piaras (see edit history)

[Piaras]

Try some Bars Leak? How much water are you using?

Pierre

 

Edited February 24, 2022 by Piaras (see edit history)

[Professor]

I was never a fan of Bars Leak unless it was an emergency.  I would rather find and fix the problem.  I remember my father using this Bars Leak to keep our old tired jalopies on the road.... then... someone gave us a VW bug and our days of using Bars Leak were over.  LOL

\

 

1 minute ago, Piaras said:

Try some Bars Leak?

Pierre

 

 

[Piaras]

It is temporary but could do until you are truly ready to rebuild the engine. In any case a compression test comes first.

Pierre

[VW4X4]

12 minutes ago, Professor said:

Thanks Eric.  Here is what is interesting... I put some green dye in my radiator and the water vapor coming out of the draft tube turned green.  Typically, I get a kind of gelatinous mass glopping out of the draft tube.

 

I will perform a compression test and a leakdown test before I pull the head regardless.  I will post the compression test results as soon as I do the test, probably this weekend.

 

I fully expect I will need to rebuild this engine, but honestly, if I can avoid it, I will.  Part of me looks forward to rebuilding an engine again and part of me thinks that if it isn't broken, don't fix it.  What would be bad would be for me to paint the car and THEN find out that I need to rebuild the engine.  Pulling the front clip will most surely create some paint issues... it would be far easier to rebuild the engine before I paint.

 

Joe

Joe, glad to see you understand the consequences of body work before the mechanical work. Don't take that lightly.   Any shop I worked for, always charged a lot more if the body was in good condition, mainly because they had to take the time to be extra careful with everything they did.

        On another note, what needs to be said here, is flat head motors, on there best day, did not last very long.  Your more likely to find bad valve guides and bad rings, than anything else.  30,000 miles and these engines are shot.  With a lot of upgrades, I'm guessing 50,000 miles may be possible.  

ERIC

Edited February 24, 2022 by VW4X4 (see edit history)

[Grimy]

If your motor oil does not resemble a milkshake, I'd retorque the head, probably twice, get it hot and change the oil--then monitor for the same symptoms.

 

If your head gasket was replaced with a non-asbestos reproduction, the repro gaskets with some form of plastic replacing the asbestos need to be retorqued several times, maybe up to 5 times, before they seal correctly.  At least that's my experience.

[Professor]

Definitely no milkshake oil.  The oil is the correct color.  I love the idea of re-torquing the head to see if it makes a difference so I will give this a shot.

 

2 hours ago, Grimy said:

If your motor oil does not resemble a milkshake, I'd retorque the head, probably twice, get it hot and change the oil--then monitor for the same symptoms.

 

If your head gasket was replaced with a non-asbestos reproduction, the repro gaskets with some form of plastic replacing the asbestos need to be retorqued several times, maybe up to 5 times, before they seal correctly.  At least that's my experience.

 

[Bloo]

Checking and re-tightening the head bolts was part of a tune up in those days. Re-torquing too after torque wrenches came along....

 

[Grimy]

I always retorque when "overnight cold" to avoid stretching the threads in the block, and try to put about 100 miles on the car between retorque sessions.  For prewar cars, about 60 lbs/ft is the most I'd want to apply, despite some higher numbers that circulated in the 1970s and 1980s.

[maok]

6 hours ago, VW4X4 said:

MAOK,        I'm very interested, in your  electronic ignition, and carb. Mod.   Can you post pictures of these?

                          ERIC

 

The electronic ignitions is a Pertronix module, simple to install and set and forget.

 

The carb mod is Tom Langdons kit - Fuel Related (langdonsstovebolt.com)

Carb conversion will need a competent tuner to dial it ii, especially correctly jetting it. I made some mods to the adaptor, opened it up some.

 These pics are from my '37 Dodge but its the same kit. You will need to remove some of the choke mechanism to clear the hood side, the Dodge did not need any changes.

[VW4X4]

Moe,    Thanks for posting that info.    I've talked to Pertronix  more than once about electronic ignition.  My car is converted to 12V negative ground.   As soon as I start asking a little difficult questions, they, (like a lot of tech. support today) are clueless and just about hang up on me..   AS for the carb.  IT looks like there is an adapter on the bottom of it?  Do you have any specs on it?  ITs Max. CFM, ITs mean CFM?   

      ERIC

[maok]

30 minutes ago, VW4X4 said:

Moe,    Thanks for posting that info.    I've talked to Pertronix  more than once about electronic ignition.  My car is converted to 12V negative ground.   As soon as I start asking a little difficult questions, they, (like a lot of tech. support today) are clueless and just about hang up on me..   AS for the carb.  IT looks like there is an adapter on the bottom of it?  Do you have any specs on it?  ITs Max. CFM, ITs mean CFM?   

      ERIC

I'm not sure what difficult question you need to clarify regarding the Pertronix. Its a simple and easy conversion and reliable (in my experience with 3 different installs in the last 5 years) when installed 'correctly'. Many Pertronix failures are most likely from incorrect installs.

 

Regarding the carb, its a weber 32/36 copy, so search for the weber specs. Biggest limitation is the adaptor and manifold, if one could modify the manifold with a wider opening and better adaptor then performance improvements can be made. I have chosen this option for its reliability and fuel economy, not all out speed performance.

 

[VW4X4]

3 hours ago, maok said:

I'm not sure what difficult question you need to clarify regarding the Pertronix. Its a simple and easy conversion and reliable (in my experience with 3 different installs in the last 5 years) when installed 'correctly'. Many Pertronix failures are most likely from incorrect installs.

 

Regarding the carb, its a weber 32/36 copy, so search for the weber specs. Biggest limitation is the adaptor and manifold, if one could modify the manifold with a wider opening and better adaptor then performance improvements can be made. I have chosen this option for its reliability and fuel economy, not all out speed performance.

 

Moe,

  Your obviously using there plug and play units, and you don't realize some of the engineering that has been done for you, with these units.  I've never seen these fail ether. Having converted to 12v with reverse polarity, those plug and play units would burn instantly.  Mention that to there tech support people, and they run for there life.  The plug and play units would not work under any circumstance with my car.   Its really not that difficult to adapt, but with out all  the specs .  for the units that are available, I would end up guessing at what would be easiest to adapt.  This can get costly...  I'm not willing to spend excessive money with a company that  has  poor tech support.

 

ERIC

 

 

[maok]

1 hour ago, VW4X4 said:

Moe,

  Your obviously using there plug and play units, and you don't realize some of the engineering that has been done for you, with these units.  I've never seen these fail ether. Having converted to 12v with reverse polarity, those plug and play units would burn instantly.  Mention that to there tech support people, and they run for there life.  The plug and play units would not work under any circumstance with my car.   Its really not that difficult to adapt, but with out all  the specs .  for the units that are available, I would end up guessing at what would be easiest to adapt.  This can get costly...  I'm not willing to spend excessive money with a company that  has  poor tech support.

 

ERIC

 

 

I think we are hijacking Joes thread with this off course discussion.

 

If you have limited knowledge and experience and you need help with the Pertronix setup, start a new thread, I am happy to assist.

[Professor]

Hi Moe, Eric,

 

I deleted a few posts just to make certain things stay on track.  Both of you have been an amazing help to me and I’d hate to see any negative feelings.

Speaking of amazing help… I am off to re-torque my head.  I will report the how much, if any, the torque settings were off.  I sure hope this helps the excessive water vapor.  I wouldn’t mind at all if I didn’t need to pull the head for awhile.  🙂

 

After I re-torque the head, I will go for a run to warm the engine and then come back, pull all the plugs, and do a compression check.

 

I will update this thread later today.

 

Joe

[Professor]

So…. I re-torqued the head.  Every single inside row head nut was lose enough to require a 1/8 to 1/4 turn to get to 60 ft lbs, and a couple were closer to 1/2 a turn.  I don’t know if this will really make a difference in the water vapor in the crankcase, but I will find out shortly since the oil breather cap always has a bit of a milky film on it, as does the down draft tube.  I did not have a chance to check the compression; I will do that tomorrow.

 

Joe

[Piaras]

That is a HUGE amount of rotation to get to torque! Basically the nuts and studs were gone on vacation. Hopefully the gasket is still in good shape. 
Pierre

[VW4X4]

21 minutes ago, Piaras said:

That is a HUGE amount of rotation to get to torque! Basically the nuts and studs were gone on vacation. Hopefully the gasket is still in good shape. 
Pierre

I'll second this.... I'm surprised the spec. is so low....  IIRC (If I Recall Correctly) , the six cylinder has a much higher spec. 

The torque spec on the rod bearing caps, with the six cylinder actually  caused a lot of the rod bolts to stretch when I was building those engines.  May have a problem like that here.

 

ERIC

 

[Bloo]

The presence of the dye is the smoking gun and is a big deal. I wouldn't be too upset about a little milky stuff in the breather as long as the oil looks good. That is pretty common. There's water in the air, and also water as a by-product of combustion that can get past the rings.

 

[maok]

I'm sure you know it, important thing is that all the bolts/nuts are evenly torqued down.

 

Another thing you should do is to attached a vacuum gauge to the inlet manifold, it should give you an idea on the engine condition and tune.

[Piaras]

Book shows 55 - 60 ft/pds for the nuts and 60 - 70 for the cap screws. So you should be fine in that respect. Recheck again after a couple heat cycles in case that composite gasket settles a bit again.

Pierre

[VW4X4]

36 minutes ago, Piaras said:

Book shows 55 - 60 ft/pds for the nuts and 60 - 70 for the cap screws. So you should be fine in that respect. Recheck again after a couple heat cycles in case that composite gasket settles a bit again.

Pierre

Pierre,   YOur assuming the hardware is in good condition.  After 80years or so, unless you remove the hardware and at least inspect it, there is no telling what is happening.... Specially if the next re-torque requires any significant difference.

     I can't wait to see what the compression test is like...  I think this is going to tell us what's really going on..

 

ERIC

[Piaras]

That is true. Can only hope that the studs and bolts are not too corroded. Usually if there was no air getting to those areas, any free oxygen will have been consumed and limited rusting will have occurred. If this redo of the torque works, then later I would MAYBE remove one bolt and stud for inspection. I have done that before with no ill affects on other engines. 
Once that compression test has yielded some results, what gets done going forward will be decided. I love spending other peoples money though!

Pierre

[VW4X4]

13 minutes ago, Piaras said:

. I love spending other peoples money though!

Pierre

LOL    I'm sure a lot of people do....   I'm a little bit unusual in the fact that I like to fix things spending the least amount of money.    Since I was a kid with no money, its has become my specialty.  Although sometimes your just better off, and have to "bite the bullet", when a lot of things need replaced..  .   I'm always got a kick out of people who replace parts, that can clearly be inspected for wear, just for the sake of having everything  "NEW", only to find the replacement parts are made in China...  

 

ERIC

 

[Piaras]

I will raise my hand on being cheap too.

My first car I bought with my newspaper money. Worked my way through university etc. Mom and Dad taught us to stand on our own two feet.

Pierre

[Professor]

27 February Update:

 

I took the chrysler for a short drive to warm it up, removed all of the spark plugs and measured the compression on each cylinder.  Note that I could only measure the pressure pulses since the pressure holding valve was not working.  This said, I clearly have an issue:

 

Cylinder.    Pressure in PSI

1.                        64

2.                       59

3.                       16

4.                       67

5.                       52

6.                       59

7.                       55

8.                      64

 

I measured twice and obtained the same readings.  I will check to see what the issue is with cylinder 3, but I cannot imagine a future that does not involve me starting the tear down once this semester ends. The issue could be something simple like a valve adjustment, but honestly, I would prefer to go through the engine myself to make certain it is as perfect as I can make it.  Regardless, I will do some simple troubleshooting and report my results back.  Here are some images of the plugs.  The expanded image of all the plugs has plug 1 on the left and 8 on the right.

 

 

Edited February 27, 2022 by Professor (see edit history)

[Bloo]

I am extremely skeptical of any compression gauge that doesn't screw in, or that doesn't hold pressure. Compression gauges are limited in the in the information they convey, and too often more information gets inferred than is actually there. Nevertheless, it certainly does sound like valve trouble from your description.

 

How much has this car been driven in recent times? Quite a bit or could it still be awakening?

 

1). At least pull a side cover and verify that you do NOT have a valve too tight on the suspect cylinder. Do it before you drive more. A tight valve will burn. If you have put quite a few miles on in recent times, then go ahead and adjust them all. If not, adjust any that are too tight and leave the others alone unless they are a ridiculous amount loose. Revisit the valve adjustment after you have driven it more.

 

2) A proper leakdown test could tell you what is causing the trouble for sure, but there's a 99 percent chance it is a burned valve if it cannot be fixed by valve adjustment.

 

3) I wouldn't completely rule out head gasket trouble, considering it was loose. That doesn't matter too much because to fix a burned valve you have to pull the head.

 

4) You can replace one burned valve and lap it in if the rest of the engine is solid and the valve seat is still intact. I would lap all of them if I was in there. They would have done all of them back in the day.

 

Of course if you know the engine is tired, maybe it is best to rebuild the whole thing. I wouldn't be in a hurry to condemn it though. Engine overhauls are expensive, and perhaps more importantly on a older car they are long and drawn out. Do you want to spend 2022 rebuilding an engine or driving the car?

 

 

Edited February 27, 2022 by Bloo (see edit history)

[Professor]

Thanks @Bloo, I ordered a new compression gauge from Amazon mid morning today. I should have it middle of this week. I will rerun the compression check and perform a leak down test. Assuming it is a valve issue, I will pull the right front tire, access cover and side plates to take a look inside. 
 

I have driven this car a great deal recently, perhaps 300 miles last week and 200 or so each week for at least the past few months. I noticed an issue just yesterday which made me think something had changed. 
 

Standby for an update next week!

 

Joe
 

31 minutes ago, Bloo said:

I am extremely skeptical of any compression gauge that doesn't screw in, or that doesn't hold pressure. Compression gauges are limited in the in the information they convey, and too often more information gets inferred than is actually there. Nevertheless, it certainly does sound like valve trouble from your description.

 

How much has this car been driven in recent times? Quite a bit or could it still be awakening?

 

1). At least pull a side cover and verify that you do NOT have a valve too tight on the suspect cylinder. Do it before you drive more. A tight valve will burn. If you have put quite a few miles on in recent times, then go ahead and adjust them all. If not, adjust any that are too tight and leave the others alone unless they are a ridiculous amount loose. Revisit the valve adjustment after you have driven it more.

 

2) A proper leakdown test could tell you what is causing the trouble for sure, but there's a 99 percent chance it is a burned valve if it cannot be fixed by valve adjustment.

 

3) I wouldn't completely rule out head gasket trouble, considering it was loose. That doesn't matter too much because to fix a burned valve you have to pull the head.

 

4) You can replace one burned valve and lap it in if the rest of the engine is solid and the valve seat is still intact. I would lap all of them if I was in there. They would have done all of them back in the day.

 

Of course if you know the engine is tired, maybe it is best to rebuild the whole thing. I wouldn't be in a hurry to condemn it though. Engine overhauls are expensive, and perhaps more importantly on a older car they are long and drawn out. Do you want to spend 2022 rebuilding an engine or driving the car?

 

 

 

[maok]

2 hours ago, Professor said:

Thanks @Bloo, I ordered a new compression gauge from Amazon mid morning today. I should have it middle of this week. I will rerun the compression check and perform a leak down test. Assuming it is a valve issue, I will pull the right front tire, access cover and side plates to take a look inside. 
 

I have driven this car a great deal recently, perhaps 300 miles last week and 200 or so each week for at least the past few months. I noticed an issue just yesterday which made me think something had changed. 
 

Standby for an update next week!

 

Joe
 

 

As I mention in my previous post, stick a vacuum gauge on the inlet manifold, this should verify or not your valve sealing or other issues.

 

Also, all those numbers look too low, they should be +80psi

Edited February 28, 2022 by maok (see edit history)

[VW4X4]

What I do with engines at this stage, is to put the bad cylinder around top dead center. Block the wheels, put it in gear, pull the E-brake, and put compressed air into the spark plug hole. If you hear air coming from the draft tube or oil filler, the rings on that cyl. are bad. Air out the carb. means an intake  valve is loosing pressure.. Air out the exhaust would be an exhaust valve loosing pressure.   You may even get bubbles in the cooling system, at the rad. cap. which would mean a bad head gasket.  This may be called a leak down test, I don't know, I've been doing this before the word "leak down" was invented.

 

Eric

 

[Bloo]

On 2/27/2022 at 7:53 PM, VW4X4 said:

What I do with engines at this stage, is to put the bad cylinder around top dead center. Block the wheels, put it in gear, pull the E-brake, and put compressed air into the spark plug hole. If you hear air coming from the draft tube or oil filler, the rings on that cyl. are bad. Air out the carb. means an intake  valve is loosing pressure.. Air out the exhaust would be an exhaust valve loosing pressure.   You may even get bubbles in the cooling system, at the rad. cap. which would mean a bad head gasket.  This may be called a leak down test, I don't know, I've been doing this before the word "leak down" was invented.

 

Eric

 

 

That's exactly the same thing, just without a regulator for convenient control and a gauge to convert leakage air to percent.

 

All I would really add to what VW4X4 said is that unlike valves, the rings will ALWAYS leak enough to make significant noise, so don't interpret some hissing there as a bad engine. If you don't have the regulator you won't be able to quantify how much they leak. That does not matter because a 16 PSI cylinder is 99% not "rings", unless there is a bunch of broken ring lands or a hole in the piston or something like that. It is no doubt a valve problem, and most likely a burned exhaust valve.

 

Always check for tight valves first though.

 

Edited March 3, 2022 by Bloo (see edit history)