sealing a crack in a 59AB

[B-O-B]

Looking for suggestions on sealing a crack in # 8 piston bore about an 1" long & halfway down the bore so that the block can be pressure tested. Block has been magged twice & baked & washed. Appreciate all suggestions.
Thanks,

B-O-B

[JSeery]

Only way to repair it that I know of is to sleeve it.

[B-O-B]

We are going to bore & sleeve it but want to just seal the crack before we pressure test it. Don't need all that much pressure.

[flatheadmurre]

Piece of rubber 2 pieces of wood and drive in a wedge between them so the rubber is pressed against the cylinderwall.

Add silicon gasket before you install the contraption if it leaks first try...

It will all go away with the bore anyhow so just patch it up.

[BILL WZOREK]

Take a piece or rubber / 2 pieces of pipe ( diameter close to bore )
Cut pipe length wise / put the rubber against crack / 1 piece of cut pipe against that / the other pipe across the bore / between the two get a small turn buckle and turn tight to push against the pipes

[D. Jones]

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I would clean it with acetone and then make a cover patch of JB Weld pushing some into the crack if possible. Or better, if you can reach the crack from a water hole in the top of the block scrape the area as clean as possible and then put the JB Weld on the inside so the pressure pushes it into the crack. If you don't use too much pressure I think it should work. Boring will remove the JB Weld in the old bore. Second thought, You may be able to make a damn out of modeling clay leaving it open at the top of the crack then put some epoxy, possibly JB Weld, in the damn and then heat the epoxy with a hair dryer until it thins and runs in the crack., I haven't tried thinning JB Weld with heat but, do use the hair dryer trick when patching tight wood cracks with epoxy.

[BILL WZOREK]

I'm a slow typing >>>

[Johnnydidd]

I would pin it, that way you know the crack wont travel. I have had great luck with pinning.

[Mart]

Could you not just ignore it? Wouldn't it, even with the crack, hold enough pressure to show a crack elsewhere?

I'll put my hand up and state I'm purely guessing, never tried pressure testing.

Mart.

[JSeery]

I like the rubber seals over the crack with some type of backing. I would just take it easy on applying to much pressure to the cylinder wall.

[41ford1]

I concur with Mart. You already know that crack is a problem. Run your pressure test to see if there are others.

[Karl Wolf]

Originally Posted by Mart

Could you not just ignore it? Wouldn't it, even with the crack, hold enough pressure to show a crack elsewhere?

I'll put my hand up and state I'm purely guessing, never tried pressure testing.

Mart.

I have pressure tested a LOT, and I agree with Mart. You'll be able to ignor the leak from that crack. The in flow of pressure will be greater than the one leak can pass...

You could squeegee some epoxy into the crack if you wanted.

Karl

[flatheadmurre]

I dont know how you guys do your pressuretesting but i want to be able to leave the block over night pressurized to ensure theres no hidden leaks i missed.

Submerging and looking for leaks is fine but a small leak internally that just gives a few bubbles into an exhaust port is easy to miss.

[29AVEE8]

Trying to get a block to hold pressure is I believe a very tall order. It likes to get out of all of the thru stud holes, water pump bolt holes, and around the plates. I, while no expert have tested quite a few by simply applying pressure and squirting soapy water, windex etc. You can buy an inexpensive borescope to check the exhaust passages. Wish you luck, let us know how it turns out.

[B-O-B]

I'll pass along all the suggestions. The block is @ the machine shop & the machinist a a very thorough German guy. The shop has a very good reputation for quality however he admits to not having done one lately.
Thanks everybody.

[Fordestes]

b-o-b,
I'll share one of my secrets with the Ford Barners , You have stated you can pressure test ! So set up your pressure test and mix up a dab of your favorite goo , such as J b weld
Now ! Take an air conditioner evac. pump or maybe a shop vac. and reverse the pressure test, put a vacuum on the block and draw the compound into the crack and let it dry, I was broke down about 1000 miles from home years ago a cylinder cracked due to a casting flaw, I had a choice to either repair it or walk, I had the pan off so I pulled the head and removed the piston put the head back on with a used gasket
bought a cheap shop vac. and some J.B weld used a little gasoline to clean the crack
as best possible, proceeded to vac. the epoxy into the cracked cyl. let set overnight smoothed the area put it together with new gaskets and drove home. I realized I may not live much longer so hopefully a few little bits like this can be passed on to future car nuts like myself, I have used this in commercial trade for various applications and has proven to work every time. Understand this is NOT meant to be a permanent fix for a cracked cylinder, although it has bought me quite a few beans and biscuits over the years, I call it (Estesizing) LOL.
Good luck
Fordestes

[barnfind]

And the first annual MacGyver JB award goes to........... Fordestes!

http://en.wikipedia.org/wiki/MacGyver

Love it!

[Fordestes]

Thanks,
I learned from the one of the best , My late father, He taught me to Think outside the tool box. I remember once we were crossing the Arizona Desert at night in an old mercury , my pa seldom drove less than a hundred m.p.h when all of a sudden the car just quit, he tuned it up before we left Oklahoma and always put the old points and cond. in the glove box, the points came apart, we searched the car from end to end and could not find the old points, so my pa took a bobby pin from my mom's hair and made a makeshift set of points to get us to a service station quite a ways down the road, the old Merc. wouldn't hardly do 30 miles per. but nevertheless we got to civilization, the man at the station asked if pa wanted him to install the new points, pa said ok I am a little tired from the all night drive, when the man looked at what he had
made the serv. man said Mr. if you made that work you sure as hell don't need me to put these new points in for you! I remember it well it was around 1962 , I miss my dad , he was not only an engineer but a heck of a good mech. I sure wish I had listened more to what he tried to teach me.
Fordestes

[Karl Wolf]

Originally Posted by flatheadmurre

I dont know how you guys do your pressuretesting but i want to be able to leave the block over night pressurized to ensure theres no hidden leaks i missed.

Submerging and looking for leaks is fine but a small leak internally that just gives a few bubbles into an exhaust port is easy to miss.

Plug up all the water holes and introduce about 30 lb. air pressure into the water jackets. Use a spray bottle with a bit of soap in water and spray all over... Combustion areas: obvious, also pan rails behind where the valve springs live, and exhaust ports.

Look for bubbles... Take your time, they can be sneaky.

As an addendum to checking the exhaust ports you can see, you can also plug the outside of the block and fill the exhaust ports with water, you could find bubbles.

My block off plate holds pretty well and I will bring the pressure up to 75 lbs. and check again.

Karl

[Fordestes]

might try doing a hydrostatic pressure test, Fill the block with water and pressure test no doubt will see where the cracks are seeping from, we used to hydrostatic test diesel engine heads and blocks the water would shoot out the cracks, I am wondering how much pressure a flathead ford block will stand without blowing the sides out?
what are you guys using pressure wise? My cheeks start to pucker about 40 pounds with water in the block. I was thinking about pushing it up to about 80 but the sides of
the block look like a good place to burst.