VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 1931 loss of power

This post is about fixing the problem but also how to correctly use the search feature.
After driving my car (first time after 8 year of work) I began to lose power on acceleration. The engine sounded like it was sucking air and coughing, but no back fire. I remember reading this in a post earlier this summer, however I can't find the posting in either the regular search or the advanced search.
How do I find the posting?
How do I fix the power loss?
Thanks

Are you using fresh gas? If not that is the first suspect.

Is the idle smooth? If so check the entire ignition system. Start at the points to be sure the contacts are clean and good shape. Next every connection or terminal. They should be clean and tight. Check the distributor cap and rotor they should be clean. If all is in good condition you should have a "snappy" spark when you hold the distributor end of the coil wire 1/2" from a ground and you open and close the points. If you still have a weak spark, change the condenser and make sure the case is grounded. If that does not solve the problem. Then consider the coil (in most cases it is not the problem).

If you still have the problem advance the timing and try again.

If you have a rough idle then check the valves, rocker arms, push rods to see if they are all working as they should.

If the above does not solve your problem come back here telling us what happened or didn't happen.

I will start going thru your check list. But check two things off the list I will say the engine starts fine and idles smoothly.
I put in a half a tank of fresh gas in at the beginning of June.
thanks

Hi randorchev,

Here are some topics related to power loss:

https://vccachat.org/ubbthreads.php/topics/248745/1

https://vccachat.org/ubbthreads.php...ch/true/1929_Lurching_Bucking#Post179182

https://vccachat.org/ubbthreads.php.../Search/true/Re_Loss_of_power#Post173299

https://vccachat.org/ubbthreads.php/topics/160248/1


Here is what I used for the Advanced Search options:

Under Forum(s) to search - selected 1929-32

Under Keyword Search Terms - Power Loss

Under Display Name Search - left it blank

Under Date Range , started with -

Newer than 1 Year(s)
Older than 1 Week(s)

Clicked on Submit, and looked through the topic headings for ones that might be appropriate.
Returned to the Search page and moved the date range one year at a time -

Newer than 2 Year(s)
Older than 1 Year(s)

And so on.
A lot of what Chipper just mentioned is rehashed in these posts.

Hope this helps, Happy Motoring,

Dan

I posted this last fall and didn't work on the car until this spring again.
The car seems to start fine and idle ok. Once it is in gear no power- hesitation and dies.
I checked timing plugs points etc.
Then I checked cylinder pressure.
I have 60 pounds in #1 and #6 nothing in 2,3,4 and 5.
This sounds like a major problem. Blown head gasket or cracked head...
It doesn't look like I will be drving this summer.

Before you start rebuilding everything I would check that the valves are properly adjusted and that they are opening and closing properly. Also, when you checked the cylinder pressure did you do a dry and a wet test? Lack of pressure can be rings that are stuck, valves that are sticking open or not properly set up, improperly torqued head, etc. The fact that you have so many cylinders at zero makes me wonder what your problem is?

That is very typical of blown head gasket. For many years a fiber type head gasket was supplied. Without metal protecting the gasket material from combustion the gasket will eventually fail. Make sure that the head and block are flat, then buy a head gasket with metal ring around each cylinder hole and metal clad on both faces.

I suspected slightly open valves. So I backed off the rocker arm nuts so that the valves wouldn't open on #1 ,2 and 3 to compare. I still had 60 pounds in #1. #2 and #3 still had zero.
I will order new gaskets and start the disassembly.

Do the sumptoms sound typical of a blown head gasket.
The car starts and idles normal. You wouldn't think there was a problem until put into gear. It seemed to be ok in reverse but
not in 1st gear.

I am guessing that it is running on two cylinders but does not have enough power to do anything but idle under no load. Yes these engines will run on two cylinders particularly 1 & 6 which are 360 deg apart.

As Chipper said above, your problem is very typical of a blown head gasket, especially between cylinders 2 & 3 and 4 & 5. If your engine has the junk reproduction Teflon head gasket that was available in the late 1980's and early 1990's then no doubt a blown head gasket is your problem.

I pulled the head off this weekend. There are two chucks of gasket missing about 1/2 to 3/4 of an inch between 2&3 and 4&5.
There was a silicon sealer applied to each side of the gasket which plugged up some of the water holes.

I've already recieved the head gasket and other gasket sets from the Filling station.
How much rework should I do on the head? New valves, springs
guides.

The first thing we need to know is what type headgasket was used. Was it all paper material or did it have metal around the cylinders. The aftermarket headgaskets are prone to make a breech as you noted.

I think I would have the valve setup checked for serviceability. Also check to see if the head should be "decked", same for the block.

Inspect the tops of the pistons for carbon buildup.

Now a general inspection of all components as you reassemble the engine.

Let us know if you find anything.

LOOSE THE TUBE OF SILICONE.

Hello randorchev,
If you have been reading the posts regularly, you may remember that Vetteman61 had to replace a head gasket. He was successful, but almost skipped preparing the bolts and holes. Cleaning and chasing the head bolts and holes are important so as not to chance breaking any bolts. Also retorquing bolts after engine warmup is suggested to make sure the gasket seal remains tight. If you wish to review Vetteman61's and other's posts, look through postings made in April 2013. Good Luck

He is a link to photos of the head gasket.
http://rschaub.wix.com/1931chevrolet-fenders
There was no metal in the concstruction of the gasket.
I guess there better question would have been what should I look for as worn parts.
Supposedly the engine was rebuilt before I bought the car. I've had less that 10 hour running the engine.

After the push rods are out should the valve lifters slide out of the block?

When replacing the new head gasket should I use any kind of gasket sealer.

Thanks

Yes.

Take your time in the reassembly process. I think I am of the opinion right now that the engine should be removed and total disassembly. If stupid mistakes were made at one place, it is likely this was the state of assembly of all of the engine.

As to the blowing of the head gasket, that is an easy call. I would never use a composition headgasket. Due to the location of the blowout it is likely the head is warped.

The lifters are removed by lifting them up out of their holes.

Your work is cut out for you.

On the Teflon composition head gaskets that were manufactured back in the 1980's and early 1990's, they were a sales gimmick that didn't work. Even if the head was milled flat and the block was decked, the Teflon composition head gaskets blew out between cylinders 2&3 and 4&5 almost immediately. The Teflon composition head gaskets could not take the combustion chamber pressures and temperatures, and the head gaskets would actually burn with an ordinary kitchen match as well.

I respectfully disagree with Ray on this one. Those headgaskets didn't hold up even if everything else was right on. For a while in the 80s that was what you could buy or was supplied in a new gasket set. There were plenty of instances where those gaskets failed. So even the most experienced mechanics were duped.

Chip, At what point do you disagree?

Ray,
Removing engine and totally disassemble.

I'm getting ready to put the cylinder head back on. Does the head gasket go on dry or should I use some kind of gasket sealer.

I also have a question on the water flow holes between the block and the head. there are two holes in the head in front of the first cylinder. But the block holes look to be plugged.
There are two images attached here.
rschaub.wix.com/1931chevrolet-fenders
Is the block correct or were the holes plugged?

Thanks

The corroded areas on the block that look like plugged holes are not holes.

I thought they might have been holes. The head has holes in that location and so does the head gasket. But no holes in the block.

What about the question of the head gasket assembled dry or with some kind of sealant.

Thanks

Nope, there are no holes at that location on the engine block.

On the gasket sealer, depending upon the type of gasket that you are using, you can either use a sealer (like Copper Kote) or no sealer.