headgasket change question: probably dumb

[George]

This is probably a real stupid question, but what do you use to clean the mating surfaces of the head and block when you change your headgasket.

[myHonda1]

acetone. or gasket remover <---comes in a spray

[red97tj]

i was told to always deck the head to make sure it's flat. i took mind to an auto parts store w/ a small machine shop to do mine for $50 for a set of heads (gotta love guys that are used to only working on v-8's)...and i normally use a razor blade scraper on the block.
good luck

[George]

Somebody said to sand it down... would that be another option?

[red97tj]

when i think of sanding i think of removing metal w/ sand paper which i wouldn't recommend since you're making the surface uneven...if you're just talking more of buffing to get some minor gasket residue then that's okay.
i just like scraping on the block since it's easy & quick. i haven't tried the gasket remover spray so i can't say if it's quick & easy either.
i would recommend getting the head ground down since it's aluminum & can
warp easily from overheating which is probably why you need to change the head gasket in the first place.
good luck

[88cr-rex]

i was told to always deck the head to make sure it's flat.

Milling . . .

You can but you are obviously decreasing the combustion chamber.
Gasket remover and a scraper are perfect for just about anything, this is including cometic gaskets as well as copper (don't know if they actually make them for hondas . . .)

[Lude-icious!]

you can check if your head is square with a straight edge, but milling it is still a good idea...scrap the gasket off, make sure you get ALL of it, another usefull tool is those nice nylon wheels you can get for the die grinder and for a regular angle grinder...they don't take metal off, just paint rust or in this purpose unwanted gasket crap!

[red97tj]

Milling . . .

You can but you are obviously decreasing the combustion chamber.
Gasket remover and a scraper are perfect for just about anything, this is including cometic gaskets as well as copper (don't know if they actually make them for hondas . . .)

actually the shop used a stone grinding wheel which takes less material off...and yes it does decrease the combustion chamber, but i haven't had any issues w/ my zc & it has been over a year of daily use.
i don't know about copper gasket for d15 but i have one for my one of zc's that i'm trying to build up.

[mark7901]

i was told to always deck the headX2 Any machine shop should be able to mill this for you.

Milling . . .

You can but you are obviously decreasing the combustion chamber.



ya, by like 5 million nano meters....If it is done correctly, you would never even notice.

[George]

you can check if your head is square with a straight edge, but milling it is still a good idea...scrap the gasket off, make sure you get ALL of it, another usefull tool is those nice nylon wheels you can get for the die grinder and for a regular angle grinder...they don't take metal off, just paint rust or in this purpose unwanted gasket crap!

Yeah, my friend had one of these... it seemed to work great on the new head, i will use it again on the block tomorrow, as long as i can get the stupid cranl pulley bolt off ( my compressor isnt big enough)

[George]

Oh yeah and 3 layer metal y8 headgaskets ftw.... no residue.

[bigdaddi]

watch out with those gasket removal 3M Roloc disc, on aluminum they tend to remove metal also and cause the head/block to be wavy, i've had 2 motors someone used those on and ended up getting the block deck milled also to correct this. it is better to just use a scraper on aluminum....

[wanger]

Probably too late to help but...

The machinist I took my head to only does aluminum engines. I figured he'd know the best way to clean the block. Basically he told me to use a scraper or wood chisel and not to file, sand, or use any rotary discs on the aluminum.

I tried spray gasket remover and its not very effective, plus that is nasty stuff and you need to be careful about letting it get inside the cylinders or oil passages... the spray can be hard to control.

Keep the shop vac suction where you are scraping and don't get carried away and gouge the metal. When you are done scraping, remove all oil residue with brakecleaner or acetone.

If you are just swaping the head you dont need to machine it, but if you blew the gasket its worth the cost and effort to take it to a shop for testing and resurfacing... its not a job anyone likes to do over when you missed a crack or warpage that could have been milled out.