Gain extra benefits by becoming a Supporting Member Click here find out how!
Classic Performance Products Classic Parts
Ciadella InteriorsAmerican Auto Wire Classic Industries
Chevs of the 40sDanchuk Catalog
Hellwig Products IncPerformance Rod & CustomEcklers AutoMotive
Nu-Relics Power Windows
Impala Bob's Bob's Chevy Trucks Bob's Chevelle Parts Bob's Classic Chevy

Username Post: Compression        (Topic#346422)
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
08-05-17 04:25 PM - Post#2702965    

Car had a miss so I pulled plug wires and found that #3 was the culprit. I pulled the plug and I was very sooty. I checked to see that there was spark to that point. There was spark there so I changed the plug. Still had the miss so I checked compression. All cylinders were 125 except #3.It was 65. The valves have recently been adjusted.

I reset #3 according to the book and it did not help. I readjusted #3 until I could just turn the pushrods. The compression was still only 65lbs.

The engine has about five hundred miles since complete rebuild.

Someone please tell me that I overlooked something simple.

1951 styline deluxe sport coupe w/54 engine & powerglide


 

Bel Air kiwi 
"2nd Year" Silver Supporting Member
Posts: 3577
Bel Air kiwi
Loc: New Zealand
Reg: 04-24-14
08-05-17 07:33 PM - Post#2702987    
    In response to Airlifter

Hi Airlifter, Personally I would loosen off the lifters on No3 to make sure they let the valve seat. Say to spec or 5-10 thou loose. Also spin the pushrods to make sure they are free and hopefully still straight. And check you haven't got a broken valve spring. Then redo the compression.

If that doesn't fix it then you need to do a wet test to see if that changes anything. It's just the same compression test with a few squirts of oil in the bores. (Just do No3.)

With the engine running does it make a chuff chuff sound out the exhaust?

Or does it do the same in the intake?

Is there water in the oil, looks like mayonnaise?

You could also look for bubbles in the radiator to check on the head gasket, but a chemical sniff test like a teekay is more accurate.

I am hoping you pooched the setting on the No3 valves as otherwise that's sounds quite serious with the comp down 50%

Cheers Kiwi



48 3100 RHD, 51 Deluxe 4DR RHD, 51 Bel Air parts car, 52 Bel Air P-Glide LHD. Others 23T, 32 Tudor, 58 Edsel pacer 4DR HDT, 79 F250 351C RHD. 69,70,82 Capri. No mobile, no TV, and no Jap cars.

And when it was laid to waste, they called it peace.


Edited by Bel Air kiwi on 08-05-17 07:41 PM. Reason for edit: No reason given.

 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
08-06-17 02:59 AM - Post#2703002    
    In response to Bel Air kiwi

I loosened the adjustment until I could spin the push rods before I did the last compression test. I did not notice anything different at the exhaust.

I did not check for broken valve spring. Will do that today. I will also do a wet compression test.

The oil looks good.

Thanks

1951 styline deluxe sport coupe w/54 engine & powerglide


Edited by Airlifter on 08-06-17 03:03 AM. Reason for edit: No reason given.

 
50hotrod 
"5th Year" Silver Supporting Member
Posts: 909
50hotrod
Age: 60
Loc: Wisconsin
Reg: 07-25-11
08-06-17 04:58 AM - Post#2703008    
    In response to Airlifter

  • Airlifter Said:
Car had a miss so I pulled plug wires and found that #3 was the culprit. I pulled the plug and I was very sooty. I checked to see that there was spark to that point. There was spark there so I changed the plug. Still had the miss so I checked compression. All cylinders were 125 except #3.It was 65. The valves have recently been adjusted.

I reset #3 according to the book and it did not help. I readjusted #3 until I could just turn the pushrods. The compression was still only 65lbs.

The engine has about five hundred miles since complete rebuild.

Someone please tell me that I overlooked something simple.



Did you run the engine after the corrected valve adjustment?

You might have accumulated soot on a valve and seat in that cylinder.





Well, you know what's wrong with the world today

People done gone put their Bible's away

They're living by the law of the jungle not the law of the land

"Simple Man" By Charlie Daniels



 
VANDENPLAS 
Frequent Contributor
Posts: 1705
VANDENPLAS
Age: 38
Loc: ontario canada
Reg: 07-29-09
08-06-17 11:04 AM - Post#2703039    
    In response to 50hotrod

Perform a leak down test to find out for sure if you have a valve or bottom end issue

If it is a valve as shitty as it is to fail after 500 miles a head come off easy

" The chain in those handcuffs is made of high tensile steel. It will take you ten minutes to hack through it with this, if your lucky. You can hack through your ankle in fivei



In the land of the blind the one eyed man is king 👑


 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
08-06-17 05:22 PM - Post#2703100    
    In response to Bel Air kiwi

Did a wet compression test and it was still only 50lb.

I turned the engine a few times with the compression gauge installed and let set for a few hours and the pressure stayed at 50.

I backed the adjustment off enough to get a little clearance and tried it again. Still no joy.

Thanks everone

1951 styline deluxe sport coupe w/54 engine & powerglide


 
Bel Air kiwi 
"2nd Year" Silver Supporting Member
Posts: 3577
Bel Air kiwi
Loc: New Zealand
Reg: 04-24-14
08-06-17 08:03 PM - Post#2703117    
    In response to Airlifter

Hi Airlifter, No rise with oil means you are not normally looking at rings. So that sounds as if it's a valve, bad head gasket, or possibly a big hole in a piston, but that is not so common.

Did you re-torque the head after running it for a while?

Have you turned it over by hand to confirm that both valves on No3 are opening and closing. And have clearance when closed.

Do you have a TeeKay, sniff tester or can you borrow one. That would confirm combustion gass in the coolant which is a head gasket normally as they usually boil when the head is cracked.

To make a simple leak down tester I braize an airline fitting into an old spark plug with the porcelain broken out. Do that under a rag as the porcelain shard will cut your eyes badly. I squish them in a big vise.

Turn the motor so the distributor is pointing at TDC for No3 and confirm both valves are closed. Take off the radiator cap, oil filler cap and aircleaner.

Start with about 50-70 Psi. Put your fitting in the plug hole with the handbrake on and in gear or park so the motor stays still.

If the air comes out of the carb, intake valve. If it comes out the exhaust pipe, exhaust valve. if it bubbles in the radiator, head gasket.
If you can hear it in the rocker cover then its piston/rings/or head gasket.

Unfortunately nothing in the rules says it has to be just one thing.

Cheers kiwi








48 3100 RHD, 51 Deluxe 4DR RHD, 51 Bel Air parts car, 52 Bel Air P-Glide LHD. Others 23T, 32 Tudor, 58 Edsel pacer 4DR HDT, 79 F250 351C RHD. 69,70,82 Capri. No mobile, no TV, and no Jap cars.

And when it was laid to waste, they called it peace.


Edited by Bel Air kiwi on 08-06-17 08:07 PM. Reason for edit: No reason given.

 
steve65 
Contributor
Posts: 670
steve65
Age: 59
Loc: new westminster bc
Reg: 09-25-13
08-07-17 06:48 AM - Post#2703146    
    In response to Airlifter

dont most compressions gauges stay at the highest reading untill you press the release valve? Try that same test again and press the button and see it its still holding.

Steve Duncan
65 Impala SS Convertible
Ermine White/ Black Top
357 4 spd auto

www.picturetrail.com/steved65


 
50hotrod 
"5th Year" Silver Supporting Member
Posts: 909
50hotrod
Age: 60
Loc: Wisconsin
Reg: 07-25-11
08-07-17 07:48 AM - Post#2703153    
    In response to Airlifter

  • Airlifter Said:
Car had a miss so I pulled plug wires and found that #3 was the culprit. I pulled the plug and I was very sooty. I checked to see that there was spark to that point. There was spark there so I changed the plug. Still had the miss so I checked compression. All cylinders were 125 except #3.It was 65. The valves have recently been adjusted.

I reset #3 according to the book and it did not help. I readjusted #3 until I could just turn the pushrods. The compression was still only 65lbs.

The engine has about five hundred miles since complete rebuild.

Someone please tell me that I overlooked something simple.



Was it a local shop that did the engine rebuild? If so, I'd contact them.



Well, you know what's wrong with the world today

People done gone put their Bible's away

They're living by the law of the jungle not the law of the land

"Simple Man" By Charlie Daniels



 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
08-07-17 09:53 AM - Post#2703160    
    In response to 50hotrod

I have been in contact with them and they have been working with me. I am taking the car to them, hopefully, this week to do a leak down test and give a diagnosis.

I am going to be gone for a couple weeks so it might be a while until I get back to working on the car.

Yes, the pressure reading stays on the gauge until it is released. Sometimes have brain fade and overlook the obvious. Lol

1951 styline deluxe sport coupe w/54 engine & powerglide


 
Toqwik 
Silver Supporting Member
Posts: 233
Toqwik
Loc: Middleburg, FL
Reg: 05-14-17
08-07-17 06:16 PM - Post#2703246    
    In response to Airlifter

Sounds to me for some reason you have a valve that is not closing for some reason. Guide too tight, bad spring, something. Hopefully there isn't a nut down there that was dropped that is holding it open. Don't ask me how I know.

Contentment is the smother of invention


 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
09-11-17 12:26 PM - Post#2707402    
    In response to Toqwik

Finally got the car to the builder to get leak down test. He checked numbers 1, 2 and three to get a comparison. All three read about 20% leakage. This seems a little high for a freshly rebuilt engine. Found one valve spring out of the boss on the bottom. He put it back in place but it made no difference. Still 50 lb. compression on number 3.

I had to leave and he said he would call tomorrow.

Any thoughts on next step?

Thanks

1951 styline deluxe sport coupe w/54 engine & powerglide


 
Shepherd 
Contributor
Posts: 942

Loc: Lake George, NY
Reg: 11-11-15
09-11-17 12:46 PM - Post#2707405    
    In response to Airlifter

One question I would ask is whether air could be heard escaping into the crankcase or out the exhaust or up the intake tract, this is the normal procedure for pinpointing the source of a bad leak down.



 
VANDENPLAS 
Frequent Contributor
Posts: 1705
VANDENPLAS
Age: 38
Loc: ontario canada
Reg: 07-29-09
09-11-17 12:49 PM - Post#2707406    
    In response to Airlifter

At this point I would pull the head and inspect
You can pull the head with the manifolds installed
Just be heavy is all and take a good look at the insides

Like kiwi stated if your lucky it's a head gasket issue
Maybe a bent or stuck valve

Was this a full brand new rebuild with new parts? Or a ring job and lap the valves?

Saw it more the once when I worked at jaguar a v12 with low mileage that sat for a long time , and then was drive get carbon stuck between the valve and seat and cause it to run rough

We would do a motorvac on it the drive it in 2nd gear on the Hwy. The smoke show out the exhaust was incredible !!!

New plugs afterwards and that v12 purred just right for a day or two !!!lol


A long shot if this was a full on rebuild but a possibility if it was just cleaned up

Or a collapsed lifted? Bent push rod?




" The chain in those handcuffs is made of high tensile steel. It will take you ten minutes to hack through it with this, if your lucky. You can hack through your ankle in fivei



In the land of the blind the one eyed man is king 👑


 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
09-11-17 03:16 PM - Post#2707417    
    In response to VANDENPLAS

This was a full rebuild with all new parts.

1951 styline deluxe sport coupe w/54 engine & powerglide


 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
09-12-17 03:53 PM - Post#2707510    
    In response to Airlifter

They are going to pull the head Thursday. Is it possible that an extremely rich mixture could cause a valve to stick? Also, is it possible that a vacuum leak could cause a valve to stick? I have never heard of this but I have a reason for asking.

1951 styline deluxe sport coupe w/54 engine & powerglide


 
VANDENPLAS 
Frequent Contributor
Posts: 1705
VANDENPLAS
Age: 38
Loc: ontario canada
Reg: 07-29-09
09-12-17 05:24 PM - Post#2707515    
    In response to Airlifter

Not that I have ever seen or heard of but anything is possible



" The chain in those handcuffs is made of high tensile steel. It will take you ten minutes to hack through it with this, if your lucky. You can hack through your ankle in fivei



In the land of the blind the one eyed man is king 👑


 
2blu52 
"16th Year" Silver Supporting Member
Posts: 18140
2blu52
Age: 84
Loc: Montana
Reg: 03-12-02
09-12-17 05:28 PM - Post#2707517    
    In response to Airlifter

  • Airlifter Said:
They are going to pull the head Thursday. Is it possible that an extremely rich mixture could cause a valve to stick? Also, is it possible that a vacuum leak could cause a valve to stick? I have never heard of this but I have a reason for asking.


A vacuum leak is a primary cause of burning valves, it causes a lean out condition. Who installed the intake exhaust manifolds?


"PEACE IS THAT GLORIUS MOMENT IN HISTORY WHEN EVERY ONE STANDS AROUND RELOADING"

THOMAS JEFFERSON


 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
09-12-17 06:10 PM - Post#2707519    
    In response to 2blu52

A mechanic friend helped me install the manifolds. We checked for vacuum leaks with carb cleaner.

1951 styline deluxe sport coupe w/54 engine & powerglide


 
50sChevys 
"15th Year" Gold Supporting Member
Posts: 1990
50sChevys
Age: 82
Loc: Central Texas
Reg: 03-23-02
09-13-17 06:20 AM - Post#2707553    
    In response to Airlifter


What's your no. 3 plug telling you, i. e., oily, rich, lean, or maybe you haven't ran it long enough.

50s Chevys My 33 month build http://www.picturetrail.com/sfx/album/view/245176 9...


 
50hotrod 
"5th Year" Silver Supporting Member
Posts: 909
50hotrod
Age: 60
Loc: Wisconsin
Reg: 07-25-11
09-13-17 07:00 AM - Post#2707555    
    In response to Airlifter

  • Airlifter Said:
They are going to pull the head Thursday. Is it possible that an extremely rich mixture could cause a valve to stick? Also, is it possible that a vacuum leak could cause a valve to stick? I have never heard of this but I have a reason for asking.



Rich condition would not cause any problems other then spark plug fowling in the short amount of time you had the engine running.

A vacuum leak can burn the valves as already mentioned but would also affect the idle of the engine. Did the engine idle ok?

Kinda sounds like the repair shop is looking for ways to get around blame for the problem.



Well, you know what's wrong with the world today

People done gone put their Bible's away

They're living by the law of the jungle not the law of the land

"Simple Man" By Charlie Daniels



 
2blu52 
"16th Year" Silver Supporting Member
Posts: 18140
2blu52
Age: 84
Loc: Montana
Reg: 03-12-02
09-13-17 12:39 PM - Post#2707575    
    In response to Airlifter

  • Airlifter Said:
They are going to pull the head Thursday. Is it possible that an extremely rich mixture could cause a valve to stick? Also, is it possible that a vacuum leak could cause a valve to stick? I have never heard of this but I have a reason for asking.


"I have never of of this but I have a reason for asking"
That is an interesting statement, possibly if you tell us the reason for asking we could find something that helps here.


"PEACE IS THAT GLORIUS MOMENT IN HISTORY WHEN EVERY ONE STANDS AROUND RELOADING"

THOMAS JEFFERSON


 
Airlifter 
"2nd Year" Gold Supporting Member
Posts: 415
Airlifter
Age: 72
Loc: Tazewell county, Virginia
Reg: 06-07-15
09-13-17 03:12 PM - Post#2707592    
    In response to 2blu52

  • 2blu52 Said:
  • Airlifter Said:
They are going to pull the head Thursday. Is it possible that an extremely rich mixture could cause a valve to stick? Also, is it possible that a vacuum leak could cause a valve to stick? I have never heard of this but I have a reason for asking.


"I have never of of this but I have a reason for asking"
That is an interesting statement, possibly if you tell us the reason for asking we could find something that helps here.



You probably figured out the reason. This is what the builder was suggesting.

I was having problems with idling for a while but it seemed to be ok after we adjusted the carburetor. As I mentioned earlier, we checked everywhere for a vacuum leak.



1951 styline deluxe sport coupe w/54 engine & powerglide


 
Bel Air kiwi 
"2nd Year" Silver Supporting Member
Posts: 3577
Bel Air kiwi
Loc: New Zealand
Reg: 04-24-14
09-13-17 04:02 PM - Post#2707598    
    In response to Airlifter

Hi, did you check the actual running of the engine with a sensitive vacuum gauge.
Sometimes it can be very hard to find vac leaks when you are not sure if they are the real cause.

lean mixtures can cause overheating of individual cylinders and that may affect a valve, but sticking would be unusual. Lack of assembly lube could have caused stem galling and this is also common with long sitting engines.

The soft tap on the top of the valve will tell you whats going on there.

It is always a good idea if you are bringing an engine back to life. Pull the plugs and lube the bores lightly, take off the rocker covers and make sure the valves are lubed and moving freely before you try cranking it.

You can turn a runner into a rebuilder by dry starting something that has sat for a long time.

Cheers kiwi

48 3100 RHD, 51 Deluxe 4DR RHD, 51 Bel Air parts car, 52 Bel Air P-Glide LHD. Others 23T, 32 Tudor, 58 Edsel pacer 4DR HDT, 79 F250 351C RHD. 69,70,82 Capri. No mobile, no TV, and no Jap cars.

And when it was laid to waste, they called it peace.


Edited by Bel Air kiwi on 09-13-17 04:03 PM. Reason for edit: No reason given.

 

Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

1287 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.283 seconds.   Total Queries: 17   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 01:00 PM
Top