Flathead block cleaning....

1

1936 ford pickup

Senior Member
Hello,.

New to the Flathead V8.

Removed head and need to clean block as best I can.
Please let me know back how best to clean block.
My thoughts so far are: use razor blade to scrape off all gasket material.
Do I use wire brush with hand drill (or Dremel tool) to remove carbon buildup.
Any help with thoughts on this are much appreciated.

Thank you,

Bruce
 

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As far as block cleaning, heads off i used a shop vac with a 3/8 fuel line and a long screw driver and sucked a lot of crap in the bottom of the block with the vac.
 
Remove the intake and really clean the valley . It’ll give you a good indication of the bottom end condition. Be prepared for a chore . I also use a metal coat hanger , straighten it out and wiggle it down and rotate with a pair of pliers than use the vacuum with a small hose .
 
Has this been sitting for awhile - what is the history on it? It sure appears to have a lot of rust all over everything. It also looks like it has had water in at least a couple of the cylinders.

It this is the case, I'd be tearing it down, figuring out what it needs and doing a proper rebuild. I don't think "cleaning" is going to magically get rid of what appears to be a lot of rust on everything.
 
Hello Bored&Stroked,

I Purchased this (rebuilt flathead V8 engine) 16 years ago and stored in my garage in dry conditions until I placed engine in my '36 Ford pickup and started driving in 2021 going to local car shows. I have only put 375 miles on this engine and the high heat flat white paint that I sprayed on the exhaust manifolds was looking kind of dingy. I wanted to remove and repaint both exhaust manifolds. I removed driver side exhaust manifold and inside exhaust was clean and dry. I removed passenger side exhaust manifold and had water in it. I pulled all 8 spark plugs and shined flashlight in all 8 spark plug holes. 7 of the 8 cylinders looked clean and dry. Cylinder #2 is the one that had slight rusty water and carbon buildup inside. I did a compression check and compression was as noted in an earlier Thread of mine. I suspected a blown head gasket so removed head and now want to clean block and head mating surface and remove carbon buildup and rust areas. Engine always started right up, ran fine and never overheated. I had planned on removing both heads, cleaning block and head mating surfaces and installing new Navarro aluminum heads and gaskets using my existing studs. First head removal magna flux test showed cracks in cylinders #1 and #4 in head.
 
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Ok, you're talking about cleaning the deck, or head face of the block. Some of the responses are for deep cleaning the sludge from the bottom of the water jacket in the block.

Remove the head gasket and a wire brush in an electric drill works well for cleaning things up. Scrape anything that needs it and it shouldn't be too difficult.

I have a scraper that takes a standard one sided type razor blade and that works pretty good.

Edit: Your motor seems to have suffered from less than perfect storage. Water has got in it. I would be tempted to pull all the valves and give them all a good cleanup and a light lapping into their respective seats. Hopefully you will not need any new parts, just cleaning what you have will be ok.

If you don't pull the valves, and are using a wire wheel, only wire wheel the cylinders that have the valves closed. Then you won't throw debris down the inlet port behind the valve.

Rereading your post, you found water in the exhaust. You found cracks in the head. Are you confident the water in the exhaust was caused by the cracks in the head?

Personally I'd be inclined to give the whole motor a tear down and close inspection especially if putting expensive parts on it. Will the Navarro heads fit on the stock length studs? Some heads require long studs at all locations.

Mart.
 
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Hi Mart,

Thank you for clarifying for me, yes I was meaning to clean the deck, or head face of the block. I have the same scraper with the one sided razor blade and that worked well for the head face. I will also be cleaning the cylinders, piston tops and water jackets in the block as best as possible too, taking their advice.

Bruce
 
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Before you spend a lot of elbow grease on gaskets and carbon, let's find out it the rust in the cylinders is bad enough to require going to the machine shop. Take each piston to the bottom and scrub out the bore with kerosene and a copper scrubber until the bore is shiny. Get in there with a flashlight and look for cracks, especially near the studs. Run your fingernail around inside the bore to feel for cracks or grooves. If there are deep rust pits that you can feel with your finger tip, you probably need to clean up the bores. If it is borderline, put it back together and see how bad it smokes when you run it.



A good steel putty knife would be a good tool for removal of gasket material stuck to the block or the heads. Same tool would be good for removing much of the carbon from the piston tops. Feel free to use wire wheels of various sizes for carbon in the combustion chambers on the heads and for final clean off of the piston tops. Cleaning the block would be easier with the studs out, but you were very lucky to have gotten the heads off without wringing off one or more studs; It is worth the extra scraping time to not have to pull the studs.



I would not use any tool such as a Dremel that might leave steel filings or abrasive material down between the piston and cylinder wall.



The above responses address getting crud out of the water jacket. It tends to settle to the bottom, particularly towards the back. Keep after it with coat hanger and vacuum or whatever until you are ready to scream, then keep at it for another hour.
 
Some good advise regarding the deck.

For the water jackets, I'll add get a 2ft length of braided cable and chuck into a drill. Splay the end a bit. Get it into the water jackets and let it do its thing. That's a good start to loosen things up. Keep scraping, prodding, etc. with screw drivers, air guns etc. You will be shocked how much will come out of those water jackets.
 
Wire wheel ans brushes on a drill. Get some music and a bar stool next to the engine. I used welding rods and long screw drivers and long wire brushed use to clean guns, to clean out the inside of the block. You will get a great sense of satisfaction when you are done. When I was finished, I took it to the machine shop and they dipped it before they started.
 

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My main concern would be as follows: If that one cylinder has a lot of rust in it, where did the water come from? Does the head gasket look to be blown . . . or did it come from someplace else? What can you tell us about water in that cylinder - any history of issues? Any milky oil, etc? What does the head look like - can you tell if it had a blown head gasket or not?
 
1936 ford pickup said:
Hello Bored&Stroked,

I Purchased this (rebuilt flathead V8 engine) 16 years ago and stored in my garage in dry conditions until I placed engine in my '36 Ford pickup and started driving in 2021 going to local car shows. I have only put 375 miles on this engine and the high heat flat white paint that I sprayed on the exhaust manifolds was looking kind of dingy. I wanted to remove and repaint both exhaust manifolds. I removed driver side exhaust manifold and inside exhaust was clean and dry. I removed passenger side exhaust manifold and had water in it. I pulled all 8 spark plugs and shined flashlight in all 8 spark plug holes. 7 of the 8 cylinders looked clean and dry. Cylinder #2 is the one that had slight rusty water and carbon buildup inside. I did a compression check and compression was as noted in an earlier Thread of mine. I suspected a blown head gasket so removed head and now want to clean block and head mating surface and remove carbon buildup and rust areas. Engine always started right up, ran fine and never overheated. I had planned on removing both heads, cleaning block and head mating surfaces and installing new Navarro aluminum heads and gaskets using my existing studs. First head removal magna flux test showed cracks in cylinders #1 and #4 in head.
Click to expand...

I'd be suspect of the rust around #2 cylinder exhaust valve. Clean the rusty area well and inspect the block for a crack there. Good luck.
 
Hello,

Here is a photo of the head. When I removed this head the head gasket came off in pieces. I could not tell if it was blown or not. When I removed the exhaust manifold to repaint it, I noticed some water inside the exhaust manifold.
I then drained the oil in the pan and found water in the oil. Radiator had oil in the water. #2 cylinder was the main one with rust. #1 and #4 combustion chambers had hairline cracks that were discovered at magna flux time. History issues were me starting to see rusty water with condensation come out of exhaust pipe at start up and gone at warm up. Engine always started right up, ran fine and no overheating. I only noticed this due to removing exhaust manifold. I have only put 375 miles on this engine.
 

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Hello,

History of this engine was as this is what I was told....I had Purchased this engine some 16 years ago from a man in Fresno, Ca. That man told me his son had rebuilt it and then sold it to a farmer whom welded a coupling to the flywheel to run a drive shaft to operate a pump to irrigate his fields. I was told the farmer had only run it about 8 hours when the farmer had passed away and his wife contacted the Fresno man to come and get it if he wanted it. I purchased after seeing the engine upside down on a wooden pallet with the oil pan removed. You could see the hone marks in the cylinders and everything appeared to be very clean and/or new, The Intake Manifold was on so I could not see down into the valley. My plan was to remove both heads now, due to #1 and #4 crack in head combustion chamber, clean block and head mating surfaces as best I can (engine is still in my '36 pickup) then install new Navarro heads, gaskets, hardened washers and nuts. H&H said their Navarro 59A heads will work with my stock length studs. This engine is a 239 which has the 3 3/16" bore.
 
From looking at the head, it obviously had water sitting in it - so where did the water come from? From looking at the amount of crud on the deck (around/in the water jacket holes), it has had a lot more than 8 hours on it - it may have never been rebuilt.

My concern is whether or not you have a cracked block - or maybe just a leaky head gasket? Tough to tell from my end, but that is what I'd want to know.

I don't like the trail of rust coming down from that exhaust valve - as it could be that the valve bowl has a crack, water is leaking into it and then past the valve into the cylinder. This is about the only explanation I can think of for why the rust is below that valve (but who knows). I'm just suspect is all. It would also explain the water in the exhaust manifold . . . which probably seeped there from the bowl as well.

You could try to just clean it up, throw it back together and see if the water leak is magically cured (least expensive route). If you get lucky, you get lucky. If not, then the engine will need to be taken down and if there is a crack in the block - depending on where it is, it might be able to be fixed.

Personally, I would not get my hopes up for just a head gasket fix, unless MAYBE the head was cracked and that is where the water came from.

Best of luck!

B&S
 
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