Head gasket Repair - How to clean the block deck with the pistons installed.

[BogusSVO]

Head Gasket Repair
How to Clean the block surface
Pistons installed.


This is for a composite gasket, NOT a MLS.

The subject block is a 4G63, 7 bolt

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First roll the crank over till all 4 pistons are at mid stroke

Now find some sort of grease, I am using wheel bearing grease

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Get a finger full

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Now smear it into a seal around the wall of the cylinder and piston

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Now as the block deck is cleaned, the grit will not work down on the rings.

Now the head alignment dowels need to be removed, find something, back side of a drill bit, large bolt, or a ¼ drive socket, Is should be close to the ID of the dowel.

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Now take vice grips and clamp onto the dowel.

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Start with wiggle movement, going to a twist when you feel movement,

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Walk the dowel out of the block.

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I prefer a long hard back body board with 80 grit sandpaper.

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Now go over the deck surface with light to moderate force to remove the gasket residue.

Use different angles across the block.

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Once all the residue is removed, rotate the engine over, so one pair of pistons is at TDC.

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Now with rags, or blue paper towels, wipe the grease away, Wipe the Pistons at TDC, and the walls of the cylinders that are at BDC

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Now rotate the crank 180*, and repeat.
Do this till you can see the top ring on the piston at TDC.

Once the grease is cleaned up, Wipe the cylinders with a blue paper towel with clean engine oil on it.

Use a solvent, such as brake cleaner, and wipe the block deck.
Install the head alignment dowels back in.

You are now ready to install your head gasket, and finish your build.

 

[KevinRR]

Thanks for writing this up, this is a lot better then what I use to do when I changed a headgasket.

 

[Clever Gs-t]

Nice write up!!! Very good detail.

 

[EclipseOwner95]

No disrespect to a "Wiseman" but JMO, this is an absolutely horrible idea, and do not recommend that anyone do this.

80 grit!? Maybe 180, and even that is still outrageously rough, a simple scuff down with a green scotch brite pad is more than adequate, and doesn't run the risk of metal getting into the engine.

Not to mention this might work on joe schmoe's car running a stock head gasket with a moderate amount of power, try doing this and using an MLS, or making some extreme power and I guarantee it will fail.

Again, no disrespect, but there's a reason why you take your head and block to the machine shop to get PRECISION milling and decking done, not running a board with sand paper over it, if it wasn't important, machine shops wouldn't be doing it.

 

[Junfan]

Nice writeup Bogus as usual.

 

[BogusSVO]

EO95...You are right this way would not work for a MLS gasket, I have coverd that in a diffrent thread.

http://www.dsmtuners.com/forums/cyl...-deck-4g63-cast-iron-block.html#post152790451

This method will be just fine with the use of a composite head gasket.

If you have an old block laying around, try it.
You will not have enough weight/force on the body board to have the 80 grit cut/groove the block surface.

The 80 grit will not load up as much as 180 or 220 grit

Even your green scotch brite will leave grit/fibers and gasket debris in the cylinders.
When this method is done properly, once done you will still see the "stain" the old head gasket left on the surface.

 

[EclipseOwner95]

We'll agree to disagree. It's JMO, I see your other thread about decking the block and it looks like you obviously know what you are talking about. I just don't agree with this method, and know others that would cringe if this method was used on their cars as well. But that doesn't mean that people won't be sucessful using it.

Good idea of clarifiying that this method is for composite gaskets, not MLS.

 

[BogusSVO]

EO95.... Thans for pointing out that I did need to make the distinction for it to be used with a composite gasket.

If they cringe at this method, you should see how most are cleaned in most repair shops, with a Rol-loc

 

[bastarddsm]

If they cringe at this method, you should see how most are cleaned in most repair shops, with a Rol-loc

Lol true story. I love when dumbasses use it on aluminum, gouge the shit out of it, and then wonder why shit leaks.

If ## skittish about the sanding block, use a razorblade.

 

[BogusSVO]

Lol true story. I love when dumbasses use it on aluminum, gouge the shit out of it, and then wonder why shit leaks.

I like those guys.....

 

[bastarddsm]

. You'll like this.

I was working a motorcycle shop for a while last summer. We had two YZ80's that need cranks. I did one the owner did one. He was about 3 hrs faster than me. He also didn't disassemble the trans and inspect it, and he also cleaned the gasket surfaces with a rol-loc, and didn't even clean the parts afterwards. Just hondabonded it, and put it together. Guess which one leaked coolant at the base gasket before it was even started? And then it was back a week later cause a trans bearing seized up. ol. Thankfully that shop is no long open.

 

[TSITurbo95]

Great write up as usually Dale, thanks!!!!

 

[efrainz28]

What about the oil and coolant ports? I would think debris from the sanding would fall in there and possibly cause future engine damage.

 

[AUTOMODSGST]

efrain z28 is right what about the oil and water ports

 

[bryanwheat]

efrain z28 is right what about the oil and water ports

Having a little debris in the cooling ports won't hurt a thing, BUT you can flush them out after installing the head . As for the oil port (there is only one) which can either be blocked with a piece of paper towel or grease. After the work is done you can crank the oil pump sprocket with a drill and oil will flow thru the passage if you want to flush the passage.

 

[EGLTAWLN]

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these are the results of this garage decking method i achieved.

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i decked this block using this method and instead of the long hand sander, i used a 13x13 porcelin tile that is FLAT. i spray adhesive onto the tile and applyed 80 grit sandpaper it take it down. it took three sheets of 80 grit paper and 1 hour of labour. i stacked the tiles on top of eachother and ther pile weighed probably 20-30 pounds. after i got down to flat, i switched to 150 grit to finish.

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[4gfun]

What kind of sander am I asking for? Do I just go to Lowes and get one or an auto parts store. How long is the sander...about the size of the block?

Can I just use a small block sander? I guess that wouldn't be a good idea maybe?

Is the 80 grit Auto sand paper?

Thanks

 

[BogusSVO]

Ask for a "stiff back long body board" It should be in the auto body section.

 

[DSM_GSX01]

I just use a sharp ass razor blade. Then i spray brake clean or something on a clean rag and wipe it down.

 

[99gst_racer]

I too have always used a razor blade in the past. And I was careful enough to not need grease, but it did take a long time.

I always thought Rolocs were OK to use on the deck of an iron block to remove composite gasket residue. Is this not true? I can't imagine soft plastic can cause damage to iron, but maybe I'm wrong.

 

[4gfun]

Thanks all...I have used the razor blade method in the past too. Kind of curious about this though.

 

[bryanwheat]

I use a fine wire wheel on my drill after using a razor blade. It surprisingly works well on the iron deck and aluminum surfaces too.

 

[-red97rum-]

I just use a sharp ass razor blade. Then i spray brake clean or something on a clean rag and wipe it down.

^ That's how I've always done it. I've installed mtsu MLS's on used and abused stock decks using the razor/brake clean method with no issues.

 

[4gfun]

I use a fine wire wheel on my drill after using a razor blade. It surprisingly works well on the iron deck and aluminum surfaces too.

Is something like this ok?

I have it at my disposal...this is why I ask.

http://www.greatnecktools.com/upload/products_images/CBC2.jpg

 

[bryanwheat]

Is something like this ok?

I have it at my disposal...this is why I ask.

http://www.greatnecktools.com/upload/products_images/CBC2.jpg

Those are a lot more abrasive than the one that I use. The bristles are real fine on it and it is a wheel, not a cup.