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Cleaning block for new headgasket. Any chance of this to work?

6K views 13 replies 7 participants last post by  SupraFiend 
#1 ·
Hello, i am trying to change headgasket on my 5ME engine. Right now i am trying to get it clean enough to be put together, but i am not too happy with how the surface on the block is looking. I have scraped with razors, used scotch brite pads with different kind of solvents but getting it absolutely clean seems almost impossible. There is some pitting around the coolant passages that i am a bit unsure of how bad it is... Getting the engine out and having it resurfaced is not something i would look forward to do...

Since i don't have much experience with what you can get away with in these circumstances i would appreciate some comments and thoughts on what you guys think it looks like and how you would have proceeded :thumbsup: Is there any chance that i can get away with just putting it together looking like this and be fine for a year or two before having to fix it again?



 
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#4 ·
Thanks! :thumbsup: Cylinder head cleaned up a lot better than the block did at least. I'll give it a try since i can't really get into any more advanced restoration and have the engine sent away at the moment anyways :)

Is copper coat recommended in this case?
Scotch Bright is the best way,IMO.
None of my books mention this at least so i don't think so. Just some silicone around the oil passages is what is recommended there. Yes, that was what worked best. But the images above are the result of like three days of scrubbing :sadsmilie And it is looking a lot better now than when i started at least. But now i kind of feel like i can't get it any better.
 
#5 ·
As long as you are not using a metal head gasket, it should be fine. Also, I have never heard of it saying to put silicone around the oil passages. That is a bad idea. If it gets in them, you will have big problems. There are just a couple of spots at the front where the timing cover meets the block that usually get a very light smear of gasket sealer, and that is it.
 
#11 ·
The Toyota repair manual says "liquid sealer" and Haynes says RTV type sealeant which i after searching found to be some type of silicone. It also suggests to apply towards the timing cover as you mentioned besides around the oil passages. Perhaps only sugested there for the 5MGE? (i have a 5ME) I used some high temperature silicone, but did keep your comment in mind and not applying any amount that would risk of getting into the oil passages :) So much appreciated as it did make me reflect on this being a potential issue!

Yeah that is fine for a fibre head gasket - make sure both surfaces are scrubbed and rinsed clean with brake cleaner and then install the gasket. Don't add any extra sealer or other products.

If you wanted to get it cleaner in the car, you can use a large honing stone (basically a big heavy flat piece of cast iron that you move across the block deck by hand) with polishing compound, usually 120 then 300+ grit in 2 stages. That can get it clean and flat enough for a MHG.
I like the idea, and i was thinking of doing something similar but with some 400 grit wet sand paper and a plane of glass, but since the alignment dowels did not want to come loose so easily and me not being sure if i could get i flat enough anyways i scrapped my idea. Do you perhaps have a link or something to a honing stone that could work? All i get when searching is stones for sharpening knives and similar.

That pitting around the coolant jacks is actually quite bad. I hope you are serious about wanting to do this in a year or 2 as that is the most likely scenario here. I personally would do what Funky suggested if you can get an appropriate tool, or remove it and have a machine shop do it properly. I don't even recommend people use fibre head gaskets at this point to be honest, they are all crap and will seep in time. Especially if you have pitting like this. If you are not going to deal with this right, I'd try a few coats of copper spray on the best made in japan HG you can find (don't spray the block), on both sides. Silicone won't fly, but I've never had any issues running the copper spray.
I'm not saying that i want to :) But if it comes to that then i guess i will have to find a way to do so. At the moment i am a bit limited to working on the car outside when the weather allows and i have no access to a engine hoist or anything. Now at least i know that the block would need some work and can plan for that in advance :) Do you perhaps have some link to copper spray that could be used for this? Is it the same used for not making bolts seize up from heat?
The headgasket i got now is a "Stone" and the paper that came with it says it was made in Japan :) Not sure if good or not but at least did not feel low quality to the touch. Not sure when made though. Could be older than my car itself... Does not seem to be a huge assortment to choose from when it comes to the 5ME unfortunately.


Anyways i got the engine back together today. And it runs and seems pretty ok! I changed oil and will continue to check if the oil gets contaminated with water (which was the original issue). However my water pump is really bad. The pulley to the fan can move like 10 degrees and it could probably give up and break the shaft any second now, so i can't test drive it that much yet. I recieved a message yesterday that the new one i ordered at least have arrived in europe so i hope to have it early next week :)
 
#6 ·
Yeah that is fine for a fibre head gasket - make sure both surfaces are scrubbed and rinsed clean with brake cleaner and then install the gasket. Don't add any extra sealer or other products.

If you wanted to get it cleaner in the car, you can use a large honing stone (basically a big heavy flat piece of cast iron that you move across the block deck by hand) with polishing compound, usually 120 then 300+ grit in 2 stages. That can get it clean and flat enough for a MHG.
 
#7 ·
But how would you adequately keep the compound from falling down into the cylinders and oil passages? Seems to me that's only something you'd do with a bare block out of the car.
 
#9 ·
You set the crank so all the pistons are down a bit, this lets you wipe it out of the bores after. Then use some gasket maker to plug up all the water jacket and oil holes, flatten these plugs with a razor blade after they are dry - then you can start polishing. After you are done use a small pick to pop the plugs out.
 
#10 ·
That pitting around the coolant jacks is actually quite bad. I hope you are serious about wanting to do this in a year or 2 as that is the most likely scenario here. I personally would do what Funky suggested if you can get an appropriate tool, or remove it and have a machine shop do it properly. I don't even recommend people use fibre head gaskets at this point to be honest, they are all crap and will seep in time. Especially if you have pitting like this. If you are not going to deal with this right, I'd try a few coats of copper spray on the best made in japan HG you can find (don't spray the block), on both sides. Silicone won't fly, but I've never had any issues running the copper spray.
 
#14 ·
Well its redundant now if you've put it back together, but good for others searching in the future...


https://www.permatex.com/products/g...rmatex-copper-spray-a-gasket-hi-temp-sealant/

I don't normally use it, but I do in cases like yours where I can't repair an iffy block or head, or where I'm reusing a metal HG. Most of those come with a soft coating that tries to do what this spray does. That coating generally doesn't survive being installed and removed and the spray is a good replacement IMO.
 
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