K&W block sealer, impressive results, but lasting?

[GB SISSON]

I just tested a 59AB after treatment with K&W block sealer. When I bought 8 blocks from a neighbor there were also two complete 'running' engines. This 59ab and an H six in the mix. Upon starting the 59ab on my run stand, she started steaming out of the driver side bank and it got worse. Milk shake oil on the dipstick.... traced it to #6 cyl. Was busy with work and 3/4 done on the woodie wagon project so it sat. Pulled the head last month and found #6 had a nice thick sleeve in it and what looked like a pipe plug tapped into the area between the cyl and the valve pocket. The seat was machined into this and the crack went about 1/2" into the pocket past the seat. I wish I had taken pictures. Anyways to me the main work was done and it looked good. One of the members here had sent me his speedway motors pressure test kit on loan so I hooked it up. With soapy water mix in a spray bottle I saw suds coming from the threads of the pipe plug and some on the crack into the valve pocket. I had read threads here extolling the K&W, so thought I'd try. Followed directions to a T and even did the block cleaner rinse first. Fired it up tonight and man, what a smoothie. Not a hint of steam and no milkshake at all in an oil change and flush of the pan. Since this wasn't just a 'fix a crack with snake oil ' approach do I have some chance that this will last? I have an untitled jailbar tow truck here on my 10 acres with a good tranny and no engine. Thinking of putting this 59ab in her and maybe running her pretty hard for a test. What are your results with this sealer?????

[Kurt in NJ]

I have had it do amazing repairs, missing 1/2 inch head gasket-- went 2 years till the guy came into some money--- another car was so bad it would geyser over 10 feet out the radiator on startup, tried several treatments and gave up, parked car-- 8 months later I was looking for a used radiator cap and noticed it was still full -- got the key and it started, ran good, no steam, no building pressure--- that car got sold, was still running a year later till it tried to move a tree

[deuce_roadster]

I don't know if this is the same stuff but the guys at Seattle Radiator gave me a can of a re labelled powder product called "Northern Seal Guard" that they recommend for a newly rebuilt engine to seal places like our head studs in the flathead. One of the guys working there had a small Japanese car that he blew the head gasket in, he put some of this in the radiator and it was still running fine after a year. They said it is a ceramic product that will NOT clog the radiator. They claim the metallic powder stuff you buy at O'Reiley's will as they see a lot of it in work brought in. Also said all the radiator shops have had this stuff for a very long time and it used to be called something else.
Similar story as to Kurt's response #2.

[GB SISSON]

Thanks, that is encouraging! One plus is my run stand has a beater radiator and it leaks a lot less now, also it wouldn't be a big loss if there was some clogging. They have you rinse and flush out the K&W so there will be no additional sealing down the road. Should I add something that stays in for a belt and suspenders approach. Some stuff like 'bars leaks' recommends running it year 'round.

[Kurt in NJ]

You rinse before the K&W, drain it let it dry after, you can save the drained and use it for another treatment--- drain, dry

[alanwoodieman]

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looking forward to the results of your test with K&W, I have been using barrs leak aluminum sealer for years in my flathead rebuilds to seal studs, head bolts seems to do ok.

[GB SISSON]

Originally Posted by Kurt in NJ

You rinse before the K&W, drain it let it dry after, you can save the drained and use it for another treatment--- drain, dry

That's right. That is what I did. After running with the sealer, let cool and drain. Let sit 24 hours and fire it up with new water. I did the run with #6 plug pulled as suggested on the can. It was after the block flush cleaner that I had to flush completely. I wish I had thought to save the used sealer. Makes sense.

[TomT/Williamsburg]

Most if you know How H&H flatheads who claim that there isn't a cracked flathead block that they can't fix. I wonder if he uses this sane stuff?

On another note, I would not want to pay his prices for a rebuild on a block that was cracked but hey, that's me.

So does anyone have any real world experience with this stuff recently? If it really works well man, I would have saved a LOT of time and money on cracked blocks ....

[KiWinUS]

Forget the brand name
What is it?
Sounds like sodium silicate

[petehoovie]

See > http://www.myhonestmechanic.com/arti...k-sealer.shtml

Which one to use???



Which one to use???

[wga]

KW has the same ingredients as Irontite http://www.irontite.com/store/index....roducts_id=142


Got mine from NAPA



Used the cleaner and ceramic sealer several years ago. No problems. Used their cleaner, reverse flush, etc. Follow the directions, no short cuts.

[GB SISSON]

Ran it last night at an idle and it started overheating after about 20 minutes. Still no steam from exhaust and not a hint of a bubble in the radiator (except for the short boil). Today I used my heat sensor gun on it after I started it up. At idle the driver side would climb up to 210 and beyond.... while the passenger side was still staying at 165 max. No thermostats, plain water in system. Cool day in low 40s, big truck radiator and truck fan with shroud. As soon as I increased speed to maybe 800-1000 rpms the driver side cooled down to match the pass side. The idle mixture screws seem to affect it (rich/lean)but I'm thinking water pump? If exhaust gasses were getting into water causing overheat, wouldn't increasing the rpms make it worse? It is quite dramatic the difference between the two sides. If the rad is clogged on that side, wouldn't the tanks equalize things? If the block is plugged, why would it start cooling with rpms? Perplexed....

[Bruce_MO]

I’m liking the water pump theory. If the pump is not generating much flow, that side will obviously be a lot hotter. And when you rev up, you’re putting a lot more energy into moving water and it starts to establish circulation. I’ve seen some pretty corroded or broken impellers. Unless you knew the condition of the pumps, I’d think it’s a good possibility. And I’d use the IR gun on the top and bottom of radiator on both sides(careful around the fan) to see values when you speed up. If the bottom of the radiator on the “hot” side started to cool off when you increase RPM, you could assume that side isn’t blocked.

Lastly, I hear you can buy or rent a tester that can check for combustion gases in your coolant. Probably more scientific than the bubble test. I think you just sniff the filler neck with the cap off. Search FB to find out more. Good luck. I love those IR guns! Very useful

[Rustedjunk]

I'll have to keep this in mind. Thanks for posting this.

[GB SISSON]

Is there a small diameter hole like 3/16" somewhere on the pump? Seems like it. I took that pump off to mount the block off plate when performing the pressure test. To be honest I didn't even look at the impeller. Just set it face down and reinstalled it with same gasket with a bit of permatex on the block face.

[GB SISSON]

I replaced the water pump. The one I pulled looked fine, but the fins on the impeller were about 1/4" away from the pump's body. I had a fresh looking one with the fins much closer like 3/32". Now both sides get hot at the same time so I shut it off at about 208 degrees and climbing. Maybe the tired old rad got clogged by the block sealer. I have read a lot here about the role of thermostats in cooling. I have another radiator in a parts truck. Maybe I try a set of those 170 degree subaru jobs????? I don't even have a need for this engine, so why do I continue to try all this? I just can't let IT win.......

[mfirth]

Lets face it GB, sometimes we just GOTTA work on flatheads ! m

[GB SISSON]

I've even heard that some become obsessed.....

[vilanar]

Those big trucks are way cool !!!
Nice shirt !

[mfirth]

Yup, you've got Flatheaditus........no known cure....Thanks 4 the pics of your very kool rides & shop. Had a pal in the early 60s with a 46 pickup with full race flatty.......i was hooked @ 15...............................m