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Head Gasket Replacement


skydrojas

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I have done some research and all signs are leading towards head gasket replacement, but wanted to get some advice while I am thinking about it.

The back story...My 47 D24 sat for about 2 years and every once and a while I would try to start her with no luck. I recently replaced the battery and ground wires and was able to get her started, but the intense smoke filled the garage so bad, that I had to stop the car. I check the compression on all cylinders and here are my results:

1 - 0 psi

2 - 90 psi

3 - 75 psi

4 - 75 psi

5 - 65 psi

6 - 70 psi

I pulled the head and the 1 cylinder has a stuck valve, but all others seems to be opening and closing OK.

2 questions...1) how do I unstick the Valve?   2) while the head is off, is there anything else I should look at as far as maintenance? 

 

Thanks!

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Edited by skydrojas
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Take the side covers off so you can see what you are doing and to make sure there isn't something you can't see that is causing the problem.

Turn the engine by hand until you can see that the stuck valve should be closed,but isn't.

Use some sort of penetrating oil (Kroil is good) in a squirt can to try to lube the valve stem at the top of the engine as well as through the valve inspection/adjustment ports,and then take a hammer with plastic faces and gently tap on top of the valve to get it to seat. Patience is more of a key word than "brute force" here.

Lube the valve stem again once it bottoms,and then spin the engine over by hand to open it again. If it closes on it's own,lube it up again and spin it over several times to make sure it doesn't stick again. Lube up all the other valve stems while you are at it. If they weren't all dry,none of them would have been stuck.

Finally,consider hand-lapping them all while you are at it to bring your compression readings up. You already have the head and the side covers off,so why not?

You can do it using one of those sticks with the suction cups on them to spin the valves,and something like Dykem Lay-Out Blue like machinists use so you can visually see when each valve is making full contact with the seat,but the lay-out dye and the stick with the rubber suction cups are cheap,so it's no big deal.

You might want to buy a magnet on a telescoping handle to make it easier to deal with the valve keepers,but you can use that on a bunch of stuff,so it's not a "special" tool.

Edited by knuckleharley
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Thanks for the great info, I will be looking into this this evening.

 

I lubed up the valve she is moving again nice and smooth. One other question...What are the recommendation for cleaning the valve and pistons while still in the engine? I have only ever cleaned and restored during rebuilds. As you can see in the above pics I have some nice crud on the valve heads.

Edited by skydrojas
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5 hours ago, knuckleharley said:

Take the side covers off so you can see what you are doing and to make sure there isn't something you can't see that is causing the problem.

Turn the engine by hand until you can see that the stuck valve should be closed,but isn't.

Use some sort of penetrating oil (Kroil is good) in a squirt can to try to lube the valve stem at the top of the engine as well as through the valve inspection/adjustment ports,and then take a hammer with plastic faces and gently tap on top of the valve to get it to seat. Patience is more of a key word than "brute force" here.

Lube the valve stem again once it bottoms,and then spin the engine over by hand to open it again. If it closes on it's own,lube it up again and spin it over several times to make sure it doesn't stick again. Lube up all the other valve stems while you are at it. If they weren't all dry,none of them would have been stuck.

Finally,consider hand-lapping them all while you are at it to bring your compression readings up. You already have the head and the side covers off,so why not?

You can do it using one of those sticks with the suction cups on them to spin the valves,and something like Dykem Lay-Out Blue like machinists use so you can visually see when each valve is making full contact with the seat,but the lay-out dye and the stick with the rubber suction cups are cheap,so it's no big deal.

You might want to buy a magnet on a telescoping handle to make it easier to deal with the valve keepers,but you can use that on a bunch of stuff,so it's not a "special" tool.

Great advice here. Oil those valve stems really well before you reassemble the head and gasket. Once you get the engine started and run for a while, you should be okay. After that, try to run the car often because sitting and not using it for long periods creates problems. Good luck to you.

John R

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2 hours ago, skydrojas said:

Thanks for the great info, I will be looking into this this evening.

 

I lubed up the valve she is moving again nice and smooth. One other question...What are the recommendation for cleaning the valve and pistons while still in the engine? I have only ever cleaned and restored during rebuilds. As you can see in the above pics I have some nice crud on the valve heads.

I had a stuck valve once as well and while I had the head off I picked up a grill brush with wire bristles on one side and a scraper on the other and went to town on cleaning the deck and piston tops.  I tried a variety of products including Seafoam until the deck was free of all hard carbon deposits. Just make sure to keep the cylinders and valves lubed while you do this.

 You can also have your head milled for some added performance, probably for under $200.  I also replaced my head bolts which you may want to do depending on their condition.  There are some made for a GM application that I used that were reasonable in price (unlike ARP).  If you search the threads here you can find the part number.  Lastly, it’s a nice time to give the head a new paint job :)  

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4 hours ago, skydrojas said:

What are the recommendation for cleaning the valve and pistons while still in the engine? I have only ever cleaned and restored during rebuilds. As you can see in the above pics I have some nice crud on the valve heads.

Get it running again,get it up to normal operating temperature,and then take something like a soda bottle where you can cover the opening with your thumb,fill it part way with tap water,and slowing dribble,and I DO mean "dribble",as in "NOT POUR" a few drops of water into the carb at a time while you operate the accelerator with your hand. You will get a "feel" for it as you do it.

You will know you are done when it quits throwing out a cloud of  dark smoke from the tailpipe.   That will be your carbon disappearing. White smoke is the water. Black smoke is the carbon.

Your engine doesn't appear to be that coked up,but you will see more than you expect coming out the tailpipe because there will probably be a certain amount of backfiring that will also clean out the exhaust manifold,exhaust pipe,muffler,and tailpipe.

I also recommend pulling your plugs after you have done this and take a look at the electrodes. Sometimes they can suffer a bit from this process because they will be full of carbon too,when you start doing this,and they are at ground zero of the explosions and the thinnest metal involved. If they are questionable,replace them.

Edited by knuckleharley
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5 hours ago, Fastback50 said:

I had a stuck valve once as well and while I had the head off I picked up a grill brush with wire bristles on one side and a scraper on the other and went to town on cleaning the deck and piston tops.  I tried a variety of products including Seafoam until the deck was free of all hard carbon deposits. Just make sure to keep the cylinders and valves lubed while you do this.

 You can also have your head milled for some added performance, probably for under $200.  I also replaced my head bolts which you may want to do depending on their condition.  There are some made for a GM application that I used that were reasonable in price (unlike ARP).  If you search the threads here you can find the part number.  Lastly, it’s a nice time to give the head a new paint job :)  

Odd, I replied to this but it didn't look like it was posted. I did pick up a can of flat black to give the head and water neck a shot to clean it up a bit. I thought about the bolts, but shockingly the bolt screws came off very easily and appear to be in great shape. I am guessing the gasket was replaced before and maybe they didn't tighten to spec, maybe that's the reason for compression issues. If I keep her longer term, I will plan a complete rebuild and engine clean up. under the hook is kinda dirty and wiring appears to be original.

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10 minutes ago, greg g said:

There was just another head gasket thread, use the search function to look that up, was a pretty complete how too.

Thanks I will. The valves seem to be moving freely now. 

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My old gasket was copper on both and I noticed my new gasket has a copper side and blue side. It does not state which side up on the gasket, does anyone know if it matters?

Also should I use some type of sealing compound on the head gasket to ensure a proper seat? I always had mixed feelings on this.

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While the engine is exposed as you have it, I recommend looking at the valve sealing surfaces. Do they look like this valve image below? Pitted in the centre? Not good.  You can rotate the engine by hand, as each valve opens, stop. Get a flashlight and a magnifier if needed,  and inspect both valve and seat surfaces for wear.  Take some pics and report back if you can.

vdKf0yBjv1V7zdTOlJTquT3uUqEsxpbBwIFGsVvc

 

With a few more bolts removed, the intake and exhaust manifold will easily lift off. Rotate the engine by hand. Stop when both valves are sealed in one cylinder. Piston will be at TDC. Both valves will be seated at this point.  Get a larger sized syringe. Fill it with kerosene. Using the syringe, push kerosene in a controlled manner, around both the intake and exhaust valve seat areas. Using a flashlight, look up under the valves in the ports in the block. Look for leaking kerosene. Good sealed valves will not pass kerosene or any other liquid. Wipe up any kerosene with rags. Don't over do it with the kerosene and end up getting it in your cylinders. Rags in there helps.

Below here you can see how I put shop towels into the cylinders to keep the jugs clean while I de-carbon'd everything with a brass wire wheel in a drill. Extreme caution must be used to ensure no brass wheel wire bits get in into the cylinders. They likely get down in around the piston rings and create havoc. I shop vac'd the area several times. Then wiped everything clean several times.

6IjY65shaYJ-b-PVv8D3l14aalO-boTwWBzEXOzi

A good lapped, sealing valve will show a surface finish like this below, with proper lapping. See the duller finish in the centre of the valve seal area? This is from the lapping compound.

I did these with the infamous rubber cups on a stick, tool. You can see my drill with wire brass wheel on the floor in the background of this pic. I have three different sized wire brass wheels to get in and around tighter areas.

Ntl0klfhvw50ZfJWem10L5jBlNs28sY68jWUMrnN

In the end mine looked like this below. Head gasket was sprayed with orange spray, gasket sealer. I would never, reuse head bolts. That's just me. The bolts are designed to stretch, once they are torqued to proper spec. Bolts only stretch right so many times. Then they break. If you re-use head bolts you might well be sweating bullets when you go to re-torque them, two and three times later. After they have heated and cooled a few times. Praying for no breakage.

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Edited by keithb7
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17 minutes ago, The Oil Soup said:

Does anyone have a source for the GM head bolts?

Found these on another old thread...curious if they worked...

https://www.summitracing.com/parts/pio-pg-362-25/reviews/?sortReviews=Newest

https://www.amazon.com/ARP-Head-Bolts-Chevy-396/dp/B001T68KLK?tag=viglink121987-20

I am thinking of the first set. There are reviews that people have used them for the dodge. and they are cheap.

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54 minutes ago, skydrojas said:

My old gasket was copper on both and I noticed my new gasket has a copper side and blue side. It does not state which side up on the gasket, does anyone know if it matters?

Also should I use some type of sealing compound on the head gasket to ensure a proper seat? I always had mixed feelings on this.

If that's the FelPro gasket I believe it goes copper side down. I had the gasket kit opened for my 201 a couple of weeks ago and that was the only way it could go on properly.

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On ‎10‎/‎3‎/‎2017 at 9:05 PM, keithb7 said:

keithb7

Couldn't get a clean shot of the valve without getting in and removing them. Having said that, the valves aren't in bad shape but do have some wear on them.

My question to the team is...

Is it worth changing the valves?

Are there any advantages to changing them or disadvantages if I don't?

I have everything cleaned up and ready to reinstall the head, but wanted advice on the valves before I proceed.

Thanks for the great input for this project!

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1 hour ago, skydrojas said:

Couldn't get a clean shot of the valve without getting in and removing them. Having said that, the valves aren't in bad shape but do have some wear on them.

My question to the team is...

Is it worth changing the valves?

Are there any advantages to changing them or disadvantages if I don't?

I have everything cleaned up and ready to reinstall the head, but wanted advice on the valves before I proceed.

Thanks for the great input for this project!

Lap the old valves. Any that won't clean up need to be replaced.  No need to spend money you don't have to spend.

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The valves in my '53 appeared old. They had the DPCD logo on them. I figured they had served their time. My car needed a valve grind job. With the current price of machining services I decided it made more sense to buy all new valves versus grinding them. I bought mine at Andy B. 

If you can get your old valves to seal properly, holding liquid as described, I agree there is no need to replace them at this time. 

Valves that don't seal result in low cylinder compression. Low horsepower and torque. Rough idle. Increased fuel burn and I believe increased emissions. 

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7 hours ago, keithb7 said:

The valves in my '53 appeared old. They had the DPCD logo on them. I figured they had served their time. My car needed a valve grind job. With the current price of machining services I decided it made more sense to buy all new valves versus grinding them. I bought mine at Andy B. 

If you can get your old valves to seal properly, holding liquid as described, I agree there is no need to replace them at this time. 

Valves that don't seal result in low cylinder compression. Low horsepower and torque. Rough idle. Increased fuel burn and I believe increased emissions. 

I hadn't planned on needing to this deep into a project, but all of this makes absolute sense. I assume I will need to remove the valves in order to lap properly. Do I need to compress the springs in order to remove the valve? is so, what would be the right tool to use? This is my time playing with a Dodge and a flathead so I don't want to assume it's like my ford FE. I am also reading through the shop manual, but real world comments sometimes are better.  Thanks Again!

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If the valves look good I'd probably clean everything up and put the head back on and drive it. When you start with the "as long as I'm this far..." think you can create a pretty deep rabbit hole. Unless it's really needed get it back running and enjoy it. It's not that difficult to pull the head again later if you decide you have more valve issues.

Just my 2 cent's worth...

Merle

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46 minutes ago, skydrojas said:

I hadn't planned on needing to this deep into a project, but all of this makes absolute sense. I assume I will need to remove the valves in order to lap properly. Do I need to compress the springs in order to remove the valve? is so, what would be the right tool to use? This is my time playing with a Dodge and a flathead so I don't want to assume it's like my ford FE. I am also reading through the shop manual, but real world comments sometimes are better.  Thanks Again!

You already have the head off and have to replace the head gasket,so IMHO,it doesn't make any sense to NOT lap the valves. The cost is minuscule ,and when you button it back up you will know you can probably drive the car for years and not have to worry about this again..

You will need a valve spring compressor,a "spinner" with rubber suction cups to spin the valve,a magnet on a expandable rod like a radio antenna to catch any wayward valve keepers,valve-lapping compound,and Dykem lay-out blue. If you want to get anal about it,a magnetic dial indicator base and a dial indicator so you can check the valve springs before you take them out by rotating the engine by hand and seeing how high they get raised. Now would be the perfect time to replace any weak valve springs. You can probably just buy a whole stet of valve springs cheaper than the magnetic base and the dial indicator,but they are useful for other things also,and once you have them they are paid for and don't eat anything.

You will also need an exhaust manifold gasket.

And maybe most important,a factory service manual and/or a Motors Automobile Repair Manual that covers your year car. Spend a day or two reading what both have to tell you about doing valve jobs,and let it sink in a little before spending any money.

Below is a link to lave lapping tools for sale. The simple wooden ones with rubber suction cups are plenty good for occasional jobs,and cheap.

https://www.google.com/search?q=valve+lapping+tools+for+sale&ie=utf-8&oe=utf-8

The machinist layout dye and the valve lapping compound can be bought at your local auto parts store that sells the tools if you decide to buy the tools on-line,but now might be a good time to become known to the local parts guys at your local NAPA store. Unlike most auto parts stores these days,the guys at a NAPA store counter usually know enough to give you advise if you get stuck,and might be able to help you out in other ways in the future. No retail web site in another state is going to offer those services on a personal level.

Don't knock the value of personal contacts.

 

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One point about which side of the gasket should go up - I believe only one side facing up will allow all of the coolant passages to line up.  Aside from that, I will say that I spoke with George Asche earlier this year, and he recommended coating the head gasket with Permatex Aviation Gasket, using a brush.  Of course, I don't know what type of head gasket he normally uses.  He also recommended tightening the head bolts in 10 in-lbs increments, instead of the usual 3 increments.  I guess maybe it clamps up the head gasket more evenly.  If you aren't familiar with George Asche, he's an old-time Dodge/Chrysler flathead racer and rebuilder.  He has raced and rebuilt these engines since the '50's.  He says he has rebuilt hundreds of them, and I don't doubt it.

Edited by Matt Wilson
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36 minutes ago, Matt Wilson said:

One point about which side of the gasket should go up - I believe only one side facing up will allow all of the coolant passages to line up.  Aside from that, I will say that I spoke with George Asche earlier this year, and he recommended coating the head gasket with Permatex Aviation Gasket, using a brush.  Of course, I don't know what type of head gasket he normally uses.  He also recommended tightening the head bolts in 10 in-lbs increments, instead of the usual 3 increments.  I guess maybe it clamps up the head gasket more evenly.  If you aren't familiar with George Asche, he's an old-time Dodge/Chrysler flathead racer and rebuilder.  He has raced and rebuilt these engines since the '50's.  He says he has rebuilt hundreds of them, and I don't doubt it.

Thanks! You are correct, I actually took a minute and looked that gasket in comparison to the block and it does only go on one way. I did pick up the permatex coating as well and thanks for the info on torqueing increments, that'll help out.

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3 hours ago, Merle Coggins said:

If the valves look good I'd probably clean everything up and put the head back on and drive it. When you start with the "as long as I'm this far..." think you can create a pretty deep rabbit hole. Unless it's really needed get it back running and enjoy it. It's not that difficult to pull the head again later if you decide you have more valve issues.

Just my 2 cent's worth...

Merle

Thanks, I am going to take one more close look at them before I decide what to do. Thinking inspecting them for any real damage or wear might be a good idea to be safe before I go crazy.

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4 hours ago, knuckleharley said:

You already have the head off and have to replace the head gasket,so IMHO,it doesn't make any sense to NOT lap the valves. The cost is minuscule ,and when you button it back up you will know you can probably drive the car for years and not have to worry about this again..

...

 

My suggestion wasn't about cost savings. It is more about labor savings. If there is no apparent valve seat damage, and it was running fine before the offending stuck valve, why go through several hours of added labor "just because it's easier now"?

I agree with you that it wouldn't add any significant cost to the project, unless he doesn't have the necessary tools and supplies to do the job. Buying, or renting, a valve spring compressor, lapping tool, lapping compound, and etc., would add a fair amount of cost to the job. And if the spring compressor requires removal of the manifolds then you will need more gaskets, and possibly replacement studs if some break. At that point you "might as well" replace all of the studs, mill the manifold surfaces for flatness, polish the ports, ... How deep is this rabbit hole?

Merle

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