Puzzle Time

[My427stang]

Did you actually check to see if the rotor was seated properly and try to push it down?

I took a buddies 462 and showed him "what I built it to do" LOL and after a hard 2-3 shift, it did much like your and I initially thought I broke it.  Turns out the rotor was slightly loose on the shaft and lifted.  I gave it a good once over, pushed it down and life was good for years.  Ultimately, we put a new tighter rotor on it but I would make sure. 

And yes, I may not have showed it, but I did miss a heartbeat or two when I thought I broke his engine after some bravado about not being afraid to let it eat....LOL

[Diogenes]

You'd think after all these years, acquiring all these hard-earned lessons, that I'd actually remember those hard-earned lessons ALWAYS START AT THE BASICS!    So I will re-assemble the front of the engine and go back to basics. At least this isn't wasted time, as the radiator needs a proper cleaning and the front of the engine could use some detailing as well, and I have learned a few things (hopefully I'll remember what I learned the next time).

Fuel or spark seem likely. The head gasket issue came to mind also.

A gasket set is on its way, and then I can continue with the puzzle.

It is a pain in the ass when these things happen, but as long as its not an excessively expensive problem, tracking down the cause and correcting it can be  an enjoyable experience--I just hope I'll still be thinking that when this is resolved.

[frnkeore]

Since all you have done, has checked out good, here is a pretty easy test you can do, loosen the bolts that the header flange, both sides or at the collector, if headers and see if it will start and run.

When I was a mechanic, I had a Buick come in with no power and over heating, after a lot of head scratching, to turned out to be that the muffler had pluged up.

As for the head gasket, pull all the plugs and have someone spin the engine over. Check for moisture or water coming from a cyl, another easy check but it could have been just over heating that caused it to blow the water.

[Diogenes]

UPDATE:

Buttoned the timing cover up and all back together. Timing is set at TDC for the time being.

Pulled carb and gave it a good cleaning and put it back together, nothing appeared out of order, got it back together (rebuilt it about a month ago). Tried starting the car, same issue, it ran, sort of, but wouldn't idle so shut it off after maybe a minute. Every exhaust port on exhaust manifolds had similar heat, so seems to be combustion in each cylinder.

Performed compression test, all cylinders around 140-145lbs. I've not done a leakdown yet. May swap carbs, but all I've got is an old Edelbrock 750 on the shelf and not sure of it's condition.

Had a spare set of new ignition wires on the shelf, swapped them out--no change.

Pumped probably 10-12 oumces of fuel into a jar and let it sit for a while, looking for possible water contamination, but nothing separated out after about 20-30 minutes.

Seems like carb/fuel issue or possible valve issue (don't appear to be any broken springs). Still investigating....

[Stangman]

Unless you have a lot over overlap on that cam I think 140 is a little on the low side. I’m thinking around 175-180. I could be wrong.

[1968galaxie]

With 140 psi compression test - perhaps the cam was installed one tooth off on the timing chain - this could certainly cause
a low compression test - if the tooth was off retarding the camshaft.
Just a thought to explore.

[Diogenes]

I wasn't sure how many times I needed to crank on the test, so I saw 140-150 after a few cranks and stopped. According to an article I read, "A 9:1 compression ratio cylinder is compressing the air and fuel mixture to about 132 psi at sea level". My engine is just short of 10:1, but I've seen some different info as wll. When performed, the engine was cold of course. The cylinders were all similar. Perhaps I need to re-test.

[pbf777]

        Compression tests are of a comparator nature, solely relative to the singular engine at hand, and there are many factors that are at play in providing the resultant number.  The important thing is to be consistent in ones' execution so as any variable in the the numbers represented provide an indicator of the functionality of the engine at hand.   

        The 140-145, and being consistent across the board is more than ample to provide reasonable driveability including idle operation, so a "retest" wouldn't be warranted if the only concern were the number value, again consistency is what one is looking for.  Compression testing is generally only going to be indicative of gross cylinder pressure lossage, and I have experienced instances where the compression test resulted in no significant signal of an issue, but then following up with a leak-down test revealed a problem; though admittedly for the level of difficulty you seem to be experiencing in the driveability one would have anticipated if it were the result of a cylinder leakage issue, that the compression test would have shown an issue, and then normally one then utilizes the leak-down test to better define the potential problem.   

        Scott.

[My427stang]

Agree it doesn't sound like compression

However, why the TDC for timing?  I'd likely verify your timing mark is correct with a piston stop.  Set static timing to something correct after verifying marks, then fire it and see if it's stable and correct.  Also look and see if it behaves different with vacuum advance if equipped.

Look at rotor, rotor button, cap button, Ohm all wires, could also be a shorted pickup.  Just check one thing at a time, but rule out spun balancer and look for stable timing with a light

[e philpott]

TDC is not a good timing setting for anything, set it at 15 base timing for testing

[Mr Woodys Garage]

Always Hesitant To Offer Suggestions, Usually A Big Waste Of Time, As No One Listens, Only Argue And Disagree. The Guys On This Forum Have Stepped Up And Done A Good Job With Suggestions Pertaining To Your Problem. No One, However, Has Suggested Checking The Running And Cranking Voltage Supplied To The Ignition Coil/Pertronix. Im Sure The Response Will Be "Its 110 % Perfect, New Wiring, Not Related,Etc" But Its A Whole Lot Easier To Check The Basics Than Tear The Front Or Heads Off Your Engine. For Arguments Sake, Lets Assume Its Pretty Much Original Wiring Harness And Wiring To The Coil. I Believe You Mentioned That It Is A Galaxie, Meaning It Has At Least 60 Year Old Resistor Wiring In The Ignition Circut, And The Ignition Switch Has Probably Been Turned On And Off More Than A Few Times. Pretty Good Chance That It Is NOT Getting The Proper, Or Consistant Voltage Through The Ancient Switch And Resistor Wire. I Will NOT Get Into The Discussion On How Many Volts A Pertronix Requires To Operate Efficiently, But, It Should Be Easy To Get Out The Volt Meter And See What Is Supplied At The Coil. (Engine Off, Cranking, And Running) Do An OHM  Test Between The Distributor Housing And Engine Block While You Have The Meter Out. Pertronix Picks Up Its Ground Through The Distributor Housing (Make SURE The Small Ground Strap In The Distributor That Connects The Former Breaker Plate To The Mounting Screw Is Present) It Not Unheard Of For There To Be A High Degree Of Resistance (Poor Ground) Between The Distributor Housing And Block) Hot Wireing The Coil Will Also Be A Quick Way To Determine If Ignition Voltage Is A Possible Culpret. While Pertronix Is A Decent, And Relatively Trouble Free Ignition Setup, They Have Been known To Have Issues Like You Described And are Experiencing. They Will Start And Run, But Not Run Well, And Fire The Coil At Less Than Optimum Timing. They Are Like Any Other Part, They Can And Do Fail. It Was Suggested To Switch To Points To Trouble Shoot The Issue. ALways A Good Idea To Carry A Set And A Condensor In The Glovebox)  Why Not Order A New Pertronix Unit, And, After Verifying Proper Voltage At The Coil, Install It And See How It Runs. Worse Case Is You Would Have A Spare Unit To Carry In The Glovebox. Easier Than Changing And Setting Up Points In 90 Degree Heat or Pouring Rain.  People Always Comment On How Much Better And Smoother Their Engine Runs After Installing A Pertronix,And, They Usually Do. Who Is To Say A Bad Or Defective One Cant Make It Run Worse? (Trust Me, They CAN)
  You Also Could Have Got A Bad Tank Of Gas, Which Is Not Out Of The Ordinary These Days. Just Another Possibility/Suggestion To Check. Also, Please Give Some Consideration To The Suggestions Above About Low Cranking Compression. It Sounds Like It Is A LOT Lower Than One Would Expect. Possibly When The Engine Was Built, A 71 And Newer Timing Set Was Used ( A Set With The Built In Emission/ Retarded Lower Gear.) Those Are Usually Identified By The Timing Mark/Dot And The Key Way Slot Not Being 100% Lined Up) It Is A Small, But Noticable Difference, That Has A BIG Impact On Performance, Fuel Economy, Etc. Makes A Gelding Out Of A Stallion. Use Of The Later Style/Emission Timing Set Results In Lower Than Optimal Compression Numbers. If They Were All Pretty Much The Same, When You Did The Compression Test, Then You Were Most Likely Doing The Test Correctly.  On The Very Possible Chance That The Emission Timing Set Found Its Way Into Your Engine, Then Its Discovery May Be The Silver Lining To The Current Issue That You May Not Have Recognized, And You Can Change It Out Sometime, Or The Next Time The Engine Is Apart. It WOULD Be/Is Worth Your Time To Correct. JMHO

[Diogenes]

        Compression tests are of a comparator nature, solely relative to the singular engine at hand, and there are many factors that are at play in providing the resultant number.  The important thing is to be consistent in ones' execution so as any variable in the the numbers represented provide an indicator of the functionality of the engine at hand.   

        The 140-145, and being consistent across the board is more than ample to provide reasonable driveability including idle operation, so a "retest" wouldn't be warranted if the only concern were the number value, again consistency is what one is looking for.  Compression testing is generally only going to be indicative of gross cylinder pressure lossage, and I have experienced instances where the compression test resulted in no significant signal of an issue, but then following up with a leak-down test revealed a problem; though admittedly for the level of difficulty you seem to be experiencing in the driveability one would have anticipated if it were the result of a cylinder leakage issue, that the compression test would have shown an issue, and then normally one then utilizes the leak-down test to better define the potential problem.   

        Scott.

Your comments align with what research I've done, though I'm no professional. When doing my compression test, I just tried to use a consistant amount of cranking. The first cylinder I got to around 145 and stopped, and kept repeating on all remaining cylinders. I could've kept cranking, and it would probably have kept climbing. I was just trying to be as consistant as possible during my test.

There are some indicators that it may be a carburetor issue, but I don't have a known good carb to toss on it at the moment. At present, I need to walk away from it for a while. The high heat and my growing frustration is not a good combination. I will definitely update findings once I continue; that is a pet peeve of mine, doing research on an issue and finding people who have posted with similar problems, but never provided their findings and what resolved the issue.

Other suggestions are on my radar as well.

Timing is at TDC simply because I had it apart and it has yet to run properly to adjust timing to the 16 degrees initial I had it set at originally.

[fryedaddy]

i had a problem hard to figure out.car was getting hot under heavy throttle.could not figure out why till i raised the hood and revved the engine.it was sucking the bottom radiator hose shut when i gave it throttle causing overheating and misfire.i put a spring out of a flex hose in the bottom hose and it fixed it

[pbf777]

     

At present, I need to walk away from it for a while. The high heat and my growing frustration is not a good combination. I will definitely update findings once I continue; that is a pet peeve of mine, doing research on an issue and finding people who have posted with similar problems, but never provided their findings and what resolved the issue.

Other suggestions are on my radar as well.

      Yes, I can understand one becoming frustrated in chasing these sorts of drivability issues, but like I suggested just start with the simple big stuff, rule one possibility out at a time and work your way to narrowing it down, in a systematic process, this rather than jumping around chasing every suggested possibility as stated on the internet and ending up just chasing your tail! Remember the basics and the value in the statement of: if you've got compression (pistons going up & down, valves open & close, and you've captured the atmosphere in the cylinder under pressure, all of which you seem to have established), then if you've got fuel and air with a spark, you''ll have fire!   

      But yeah, we can keep throwing out possibilities all day, but that's just not how one generally succeeds at addressing driveability problems most effectively, ................really.   

      Scott.

[Barry_R]

I would probably triple check that distributor gear.  I now recall running on that lost timing.  Reset it (thought the hold down was loose) and it did the same thing - ran OK then retarded after a couple pulls.  Turned out like the previous guy noted - pin sheared and it kind locked into a new location, until load came up and it turned some more.  Looked perfectly OK from the outside.