Cleaning Block Surface when Block is in Car

Kai

That Limey Bastard
Staff member
As above really - block is in the car, head is off, head ready to go back on, but block still has remnants of gasket on it.

Someone who shall remain nameless advised me to use 600 grit wet & dry with WD40 on it to remove the crud, but that seems like a dangerous idea, what happens to the gunk? Sure, if it does down a water passage, then you can flush that out, but what happens if it goes down an oil passage? You end up with fine grained sand in the block, surely?

I've got a gasket scraper, but am loathe to use it on the block until someone tells me if i'm doing it right!
 

NTRA08

TWINKY
Jun 10, 2008
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Ian is right A sharp scraper. And for the junk that gets in the cylinders. I packed the cylinders with paper towels. And what made its way in I took it out with compressed air and a shopvac.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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I wouldn't be too stressed about the Bores as most of the crap will Vacc out, if you're really concerned some grease will seal the pistons to the bores then wipe out taking the crap with it.

Ditto on the small Oil hole at the front of the deck.

Block off the Oil drains and the gap at the timing case, the water jacket can be washed out.
 

thedave925

Since 9/16/05
Nov 9, 2005
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I suggest cutting up a huge sponge like used for tile grout work, that does great to block off the oil passages and it won't just fall in like paper towel wads.
Shop vac and compressed air like above mentioned. No need to be overly anal, just keep that vacuum handy.
Tapping the block threads and cleaning with a vacuum is also a good idea for later.
 

IJ.

Grumpy Old Man
Mar 30, 2005
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spongebob.jpg
 

crisp

existentialincrementalist
May 25, 2007
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Ohio
p1325189_1.jpg



...I even used a WIRE WHEEL (small bits w/Dremel) to clean the pistons on a previous job... and held the shop-vac near the wheel the whole time. I also put some oil around the pistons (starting at TDC on piston being tackled) then carefully crank them DOWN and WIPE the dust captured in the oil on the cylinder wall as the rings "stop" anything from getting by. (Of course, SHOP VAC as much away after each small segment of scraping, etc...)

Work slowly, keep wiping away excess (from inside to outward motion) and consider a little WD40 to "moisten" surfaces, and help TRAP dust/scrapings in suspension for careful cleaning without getting into holes and such. I also clean threaded areas carefully before moving on, often "chasing" threads (both stud & holes) after they are "clean" to make sure. (crud on thread flanks can screw up torque values...)



G/L!


-crisp
 

mark3

New Member
Aug 12, 2007
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essex
www.mobilemechanic.org
Kai;1324310 said:
As above really - block is in the car, head is off, head ready to go back on, but block still has remnants of gasket on it.

Someone who shall remain nameless advised me to use 600 grit wet & dry with WD40 on it to remove the crud, but that seems like a dangerous idea, what happens to the gunk? Sure, if it does down a water passage, then you can flush that out, but what happens if it goes down an oil passage? You end up with fine grained sand in the block, surely?

I've got a gasket scraper, but am loathe to use it on the block until someone tells me if i'm doing it right!

I didnt mean do that to your Golf!! Unless you fitting MLS theres no need to prepare the block that much for stock gasket...

I used a sharp gasket scrapper to remove the remnants of gasket from block, these where too big to go anywhere, i then prepped the block with 600 grit and WD40 for the MLS i fitted, you only needed to used gasket scrapper for a stocker!
 

Velocityfreak

New Member
May 28, 2009
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New Hampshire
As everyone above has mentioned,

600 grit works well to prepare the surface for the next gasket, just be sure to grab as much dust as you can. I have done this on a 4age, with no problems after.

even if you miss a little bit, the aluminum dust wont kill the engine. Just be sure to clean it up the best you can. It will probably all get blown out after the first couple hundred strokes.

You want to use the 600 grit on a wooden block, and sand in one motion, that way all of the surfaces recieve the sanding at the same time preventing any high or low spots.
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
1
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Valley of the Sun
Velocityfreak;1336305 said:
As everyone above has mentioned,

600 grit works well to prepare the surface for the next gasket, just be sure to grab as much dust as you can. I have done this on a 4age, with no problems after.

even if you miss a little bit, the aluminum dust wont kill the engine. Just be sure to clean it up the best you can. It will probably all get blown out after the first couple hundred strokes.

You want to use the 600 grit on a wooden block, and sand in one motion, that way all of the surfaces recieve the sanding at the same time preventing any high or low spots.


I didn't know the 7M had an aluminum block ;)
Learn something new from the noob village know-it-all every day.

I highly advise NOT sanding the block...it's difficult to keep the strokes even and not create an uneven surface. Plus, it's not the metal dust so much, but the grit from the sand paper...that will do a number on your bearings if it get in the oil passages.

Freak - this is a SME tech section...I warned you not to post in the tech sections until you learned more about the 7M motor. This is not a 4AGE.

Last warning...that is unless you would like a week off to reflect and read the TSRM on the 7M.
 

thedave925

Since 9/16/05
Nov 9, 2005
626
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East Bay, Cali
Did mark3 miss post 10?
Does surface prep have to be as detailed as the 7m for other engines too?
Who knows what thread i just got done reading???
 

Velocityfreak

New Member
May 28, 2009
33
0
0
New Hampshire
Velocityfreak;1336305 said:
As everyone above has mentioned,

600 grit works well to prepare the surface for the next gasket, just be sure to grab as much dust as you can. I have done this on a 4age, with no problems after.

even if you miss a little bit, the aluminum dust wont kill the engine. Just be sure to clean it up the best you can. It will probably all get blown out after the first couple hundred strokes.

You want to use the 600 grit on a wooden block, and sand in one motion, that way all of the surfaces recieve the sanding at the same time preventing any high or low spots.


jdub;1336383 said:
I didn't know the 7M had an aluminum block
Learn something new from the noob village know-it-all every day.

I highly advise NOT sanding the block...it's difficult to keep the strokes even and not create an uneven surface. Plus, it's not the metal dust so much, but the grit from the sand paper...that will do a number on your bearings if it get in the oil passages.

Freak - this is a SME tech section...I warned you not to post in the tech sections until you learned more about the 7M motor. This is not a 4AGE.

Last warning...that is unless you would like a week off to reflect and read the TSRM on the 7M.

Im referring to the aluminum dust from the sandpaper. But anyways, thanks for the break off. Im still studying my little ass off.
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
10,730
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38
Valley of the Sun
Velocityfreak;1343145 said:
Im referring to the aluminum dust from the sandpaper. But anyways, thanks for the break off. Im still studying my little ass off.

LOL...you got more sideways moves than a desert rattler. Sure, that's what you meant :rolleyes:

Might be best for you to quit while you're ahead. Also might be a good idea for you to refrain posting in the Tech sections till you can make it a bit more clear as to what you exactly mean.

BTW - multiquote is a bit more effective when you want to quote multiple posts. Fixed that for ya too ;)
 

IJ.

Grumpy Old Man
Mar 30, 2005
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jdub;1343155 said:
LOL...you got more sideways moves than a desert rattler. Sure, that's what you meant :rolleyes:

Might be best for you to quit while you're behind. Also might be a good idea for you to refrain posting in the Tech sections till you can make it a bit more clear as to what you exactly mean.

BTW - multiquote is a bit more effective when you want to quote multiple posts. Fixed that for ya too ;)

fixed ;)