View Full Version : Sr20det head cleanup
I've teachers this quit a bit, but everyone has a different opinion.
So I am changing my headgasket and have pulled the head to get resurfaced but the block I really wanted to avoid resurfacing. I'm using a metal headgasket so I know the surfaces have to be mint.
But what I wanted to know is what should I use to clean up excess gasket? I used a plastic scraper but it's about tapped out and there's still a lot of gasket left can I spray "gasket remover" directly onto the block? I just worry about it getting into passages. And I've heard bad things about 3m pads.
Thanks in advance.
brndck
02-09-2016, 10:29 PM
I use a razorblade and a ton of caution
jr_ss
02-10-2016, 07:44 AM
A razor blade works great. I've also used a sanding block with fine sand paper, obviously taking precautions by stuffing rags into the cylinders to catch debris. They also make scotch brite pads that you can install in a drill to remove gasket material. Everything should be done using caution as stated above.
derass
02-10-2016, 09:01 AM
What scares the shit out of me is debris falling into the coolant and oil passages.
KAT-PWR
02-10-2016, 09:16 AM
A razor blade works great. I've also used a sanding block with fine sand paper, obviously taking precautions by stuffing rags into the cylinders to catch debris. They also make scotch brite pads that you can install in a drill to remove gasket material. Everything should be done using caution as stated above.
Although this *may* work it is not a very good idea, especially for a metal gasket application. Sanding blocks are flexible and not straight, and I would never go near a drill for a head gasket. Use brake clean and a NEW razor blade to clean gasket material.
Buy a mechanist straight edge, yes this is a specific straight edge, no a ruler/etc will not suffice.
Check with feeler gauges, IIRC in the .002 range. Check the head end to end on both sides and the middle, do the same width wise, then the same diagonally across the head to check for straightness.
Get yourself a nice thick piece of glass, I believe glass is usually very close to perfectly straight when manufactured. Set up the glass on a nice hard, flat, level surface and check the glass for straightness with the straight edge, adjust as necessary.
Head surface in RA from a machine shop is usually around 50RA or 150grit.
Adhere sand paper to your leveled glass and run the head back and forth
Cometic recommends 50RA or finer, and I'd assume most MHG manufacturers advise the same.
jr_ss
02-10-2016, 01:38 PM
A rigid sanding block does not flex. I should've specified what I used as to protect people from themselves. A block of steel machined flat with sandpaper adhered to it doesn't flex.
However, I've never had a headgasket issue with my method. Everything should be done in moderation. I don't expect one(atleast one with common sense) to go out with a flimsy knock down splatter sanding block.
KAT-PWR
02-10-2016, 02:26 PM
A rigid sanding block does not flex. I should've specified what I used as to protect people from themselves. A block of steel machined flat with sandpaper adhered to it doesn't flex.
However, I've never had a headgasket issue with my method. Everything should be done in moderation. I don't expect one(atleast one with common sense) to go out with a flimsy knock down splatter sanding block.
Yeah unfortunately in today's day and age, you really have to be very specific. If you can, ideally a piece of steal slightly larger than the size of the head would be easiest.
SoundEfx
02-10-2016, 04:34 PM
How do you prevent the 'shavings' from getting into the oil and coolant passages? I think that was a question the OP asked.
kashira kureijii
02-10-2016, 04:48 PM
scrape it all off carefully, then put a small wire brush attatchment onto a cordless drill, and lightly clean it up ( the drill doesn't spin super fast, so it is easier to use without gouging anything), it's kinda the same as what everyone says with the sandpaper and shit. If you do it, you must get a smaller finer wire brush and do it lightly. It makes it look very nice. definitely don't use a screwdriver or anything super solid when scraping the excess stuff off as it will gouge the soft aluminum
I suppose you could put a little piece of shop towel in the passages, just make sure it's big enough not to go in, buff everything else, then pull the little pieces and buff around the passages. that'll sorta help minimize the shit that gets in it
jedi03
02-10-2016, 07:24 PM
I usually do the razor blade and blow out the passages...I have used the 3m rubber or plastic...I don't remember what they are made of...scrubbers then go over it with shop rag and brake clean or lacquer thinner and look carefully at everything to make sure is nice and clean...never any issues!
ultimateirving
02-11-2016, 12:26 PM
I used a mirror and rubber cemented sandpaper to it and ran the head over it until I got a nice clean finish on the head.
SoundEfx
02-11-2016, 12:58 PM
I can't remember where I saw it, but I thought that someone used a 'rubber' type of drill attachment while polishing metal. It was initially used to remove surface rust because it isn't as 'tough' as a wire wheel.
Has anyone used this before or even know what I'm talking about? lol
jedi03
02-12-2016, 05:41 PM
a Rolloc I think is the name...they also have sand paper but the rubber one is the one I have used
mewantkouki
02-12-2016, 06:29 PM
In car: plug passages with shop towels and use a shop vac while scraping.
Out of car: turn block sideways and use shop vac while scraping.
Don't use steel razor blades on an aluminum head. Use gasket remover and a carbide scraper. It's a square edge and less likely to shave the aluminum. Plastic razor blades are handy too.
Kingtal0n
02-12-2016, 07:46 PM
Plug holes with paper towels, not old greasy used shop towels IMO
Razor blade and brake cleaner since 1998, use paper towels to wipe wipe wipe the brake cleaner away and check them for filth as you blade it up
mewantkouki
02-17-2016, 03:53 PM
Do these look like old greasy rags idiot? I don't recall typing "stuff used greasy shit into an engine" anywhere. The difference between a shop towel and a paper towel is the absorbency and the fact that it doesn't tear apart as easily when it gets wet. A square edged carbide scraper will ALWAYS be better than a razor blade for removing gasket material. That's not even worth arguing about. Try one and find out.
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