Head/block interface, how clean is clean?

[MantaGreen97]

So now that I'm cleaning everything up and getting ready to reinstall parts and everything, I'm wondering about how clean I have to get the cylinder block where the head gasket/heads mate?

Reading a How-To thread on a Grand Am forum it states I should be cleaning with acetone and a razor blade (which I did) until little to no gasket material is left; and that the surfaces should be very clean.

I'm just wondering how clean that is though, lol. Because using the acetone and the razor I'm not getting to like bare-metal-clean really, and I don't want to be too aggressive and cause problems. I also have some Permatex Gasket Remover (which is like a gel type stuff that sprays out of a can) but haven't used it much 'cause I'm not really sure I want that to get into the cylinder bores and the water jacket and mix with stuff later...

Here's a pic of how clean I have the left/front head at the moment, I'm having trouble getting any more of the dark areas off but I'm wondering if I have to or should be, or if it's clean enough as I have it now. I was thinking the area directly around the bores is the most important to ensure compression and no coolant going in there, but I'm just making sure...



Sorry if this sounds like a stupid question, it's just that I've looked about quite a bit and see pictures of the heads off but they are always immediately after the heads come off it seems, never what they should look like when cleaned. The heads are brand new btw, so they don't really need any cleaning, except I think I should spray them down with some brake cleaner or something similar since there is a light film of gucky oil on them, from the packaging process I suppose.

[lampy]

scotch brite pads or emory cloth work well, the block is cast iron so you dont have to worry about it like you would if it was aluminum. The best thing for clean up is a tool made by 3M use it in a die grinder or drill its a round scotch brite pad fits in a holder takes a lot of the work out of clean up. hope that helps.

[tractorman]

I agree with lampy. People will tell you to use a razor blade and acetone (or something like that)... but that's because those people are not mechanics. While that method can work... it's a tedious pain in the A$$, and you'll never get the surfaces as clean as they really ought to be. The standard throughout the repair industry is to use a scotchbrite pad on a die grinder. It'll throw off a little bit of abrasive, which should be blown off/out... but it'll make those deck surfaces shine. If you have an air compressor, this is the way to go... just be careful and don't get to aggressive. If you see sparks, back off a bit.

Now, if you don't have compressed air, it's going to be more difficult. In that case, I'd suggest that your razor blade method is a good start. Follow that up with some medium-grit (300-ish) emery cloth, and you'll be good to go. It's impossible to clean gasket surfaces and entirely avoid spreadding crud, gasket material, and abrasives around... but try to keep it to a minimum.

[Carlspike]

Get that thing as clean as you possibly can. 3M also makes a disc that is made of some rubber substance and has little finger things coming off of it. The yellow one is the one you want. I used that to make sure I didn't get any abrasives in my engine. If you don't have air then you can use a drill, it takes longer than with air but it's way faster than a razor blade.

[IsaacHayes]

Try not to get any abrasive dust into the cam area as that will circulate through the block and destroy bearings!! Masking tape and paper would be a good idea.

[MantaGreen97]

Get that thing as clean as you possibly can. 3M also makes a disc that is made of some rubber substance and has little finger things coming off of it. The yellow one is the one you want. I used that to make sure I didn't get any abrasives in my engine. If you don't have air then you can use a drill, it takes longer than with air but it's way faster than a razor blade.

Hey yeah I got some 3M Roloc stuff from Napa I have a friend that works at a shop and he was telling me to get either the green scotchbrite type pads or the green plastic/rubber Roloc that you're talking about^ (except green not yellow). They didn't have the green 07474 Roloc ScotchBrite-type ones but they had the Maroon and I got those, but they seemed a bit harsh so I also got the green plastic Roloc 18734, and it turned out to be all I needed

http://products3.3m.com/catalog/ca/en001/auto_marine_aero/-/node_GSJVKH91QBgs/root_VJ3G0N3T7Ngv/vroot_G75KJBMR4Kge/bgel_GSYQZ4JD29bl/gvel_WMFC5FMK16gl/theme_ca_en_automarineaero_3_0/command_AbcPageHandler/output_html

Worked fine on a drill though near the dipstick I had a hard time getting it in there, but I bent the bracket on the dipstick one way and the other and just managed to squeak it in there.

The above pic is the "Before", this is the "After":


Did I do good?

The only thing I'm slightly worried about is that I took off some of the paint on the one piston at TDC. You can see it in the top right corner of the piston that's up top. Is that going go cause a problem? I'm wondering if that is paint at all though or if it's just carbon buildup? (Because I always thought the piston would be silver/metal coloured?) I was a lot more careful in back and barely touched the TDC piston at all, but I'm still wondering about that bit of black I took off on the one on the front bank.

Try not to get any abrasive dust into
the cam area as that will circulate through the block and destroy bearings!! Masking tape and paper would be a good idea.

Yeah I put slightly damp paper towels in the bores of the cylinders as well as in the valley area. I think using the plastic Roloc minimised the debris though, or at least made it larger so as to let the oil filter take care of some of it.

The same friend that recommended me to use the Rolocs, told me a good thing to do is to change the oil again at a pretty close interval to make sure anything that did get in, gets out.

[silvergtjrad]

I took off some of the paint on the one piston at TDC

Its carbon buildup on the pistons, nothing to worry about scratching off.

[Superdave]

I use a wire wheel and a drill.. works every time.

[tractorman]

Ya' did good. Don't worry about the piston- that's just carbon.

[MeMadMax]

Heres another "After"

[MantaGreen97]

Wow nice clean blocks there guys I guess it would have been a lot easier with the engine out of the car...

Since the stuff on the piston is indeed just carbon, as I had speculated, should I go ahead and remove that on the pistons, or should I even bother? I mean it's just going to get like that again, after the engine starts running, right?

Anyway gonna start putting stuff back together today, finally. Been a bit lazy recently, heh.

[IsaacHayes]

I'd clean it off as less carbon = less hotspots for pinging and detonation.

But becareful remember the pistons are aluminum and it is much softer. I don't think our motors have coated pistons.

[MeMadMax]

You can maintain "Somewhat" clean pistons by using Seafoam in your gas. That stuff can knock just about anything off, frees up sticky lifters on cars that have been sittin awhile(dump it in the crank), cleans out varnish carbon inthe chambers(dump it down the intake PAST the MAF!!!) etc etc. *Caution* however if you dump it down the intake on a high mileage motor where the Rings are in question, it could knock all that carbon out that was actually the only thing that was sealing the chambers lol

[GPXSS]

I would clean everything but you run the risk of getting it stuck down between the piston and cylinder wall where you cant get it out. You did a good job though on the deck.

I use a rotozip with the angle attachment and the red stotchbrite wheel. Im not sure if they sell them anymore, but it takes off surface gunk on contact.

[scoopy03]

I use a wire wheel and a drill.. works every time.

thats one clean engine there