snickell

Installing a new H/G on my 22rec, but carbon is caked around the edges of the cylinders, on the surface of the pistons, and up in the combustion part of the head. What's recommended for scraping this out? Or should I leave it alone?

Also, the FSM says "use a soft brush and solvent" for cleaning the mating surfaces of the head&block.... does soft mean "plastic"? What's the recommended solvent / brush type to use here?

Here's pictures of the combustion chambers... does this look ok?







Thanks a ton everyone, this is my first H/G job, and its been more 'ok' than I'd guessed, but I'm just nervous about doing this part right.

sam333

Boy, that really scrubed that piston top clean.

If you are not going to take it to a machine shop for a valve job( cleaning), I would use a degreaser like gunk engine cleaner first and a plastic parts brush, then follow up with a lye cleaner like purple power to remove the carbon( nothing else will work as well as lye to remove carbon).

Dont use metal brushes anywhere except on the studs. Dont even lay the head on is mating surface unless its on clean wood or cardboard.

For the mating surface I would use green scotch bright and solvent( by hand only).

Do you know what caused your coolent leak ( could you see a spot that the gasket blew)? If you cant I would have the head pressure checked for cracks, and even if you dont, you need to check the head for flatness( use a machinest straight edge, a ruler wont work). You should check the deck( block mating surface) for flatness too.

If you dont want to disassemble it ( take out the valves ) you can still clean some of the carbon under the valves by rotating your cam untill each set of valves are open.

To clean the piston tops use wood or plastic scraper and purple power( use a rag to soak up liquid so it does not drain down around your pistons. Block top use a metal paint scraper and scoth brite ( sharpened) but be carefull. Just watch it when using scotch bright around oil and coolent openings ,it sheds alot.

snickell

The FSM calls for "liquid sealer" in a couple spots around the H/G. Is this ultra grey RTV? Or is this something else?

stackedyoda

I used sea foam deep creep penetrating liquid and steel wool to clean the top of the block/pistons and it worked pretty well for me. i also stuck pieces of rag in all the oil holes before doing so, then flushed the cooling system when i was done.

MudHippy

From the 93 FSM:
Those locations are at the front of the engine block where the timing chain cover meets the cylinder block.

From another FSM:
In other words, Ultra Black RTV(maximum oil resistance).

874runnersr5

these work greattt for cleaning parts with gasket residue on them.

rworegon

What are the 'these' you refer too???

874runnersr5

oppsies. fixed

sam333

What are they called and where can you get them?

sebastianholmes

Easy off brand oven cleaner is the absolute BEST thing to clean gunk off a motor. It works a thousand times better than an degreaser. use it and a still plastic brush or wire brush and youre good to go!

Oh be sure to keep a hose nearby or wear gloves, its VERY acidic and if it stays on your skin for a while it burns, not pleasant! lol

EDIT: scoth brite pads and copper scouring pads also work quite well

rworegon

3M Scotch-Brite™ Roloc™ Bristle Disc www.shop3m.com

Be very careful using these on an assembled block so the abrasive does not fall into the cylinders, oil or water galleys. The can do damage to aluminum heads also...... I prefer not to use them.

sam333

Oven cleaner works really well at removing carbon ,but it is so corrosive ( base) that it can discolor /etch/ eat away aluminum if you are not carefull. Oven cleaners have alot of lye in them. You can buy lye cleaners in the auto parts store ( purple power) great on carbon ,but are not as strong as oven cleaner.
If you use oven cleaner make sure you remove ALL of it with a good wash of water(hose) and vinager. If you leave any on the mating surface of the head it will corrode badly.

MudHippy

Every time I hear someone mention using oven cleaner it makes me chuckle. I think to myself "I guess you've never used it on aluminum, because man what a mess! You'll be hand scrubbing those parts anyway, just to remove the discoloration and funky residue build-up from putting that crap on them. So just how good of an idea is it really?".

snickell

Thanks MudHippy, I just couldn't find this in my '85 FSM. Is there a separate section where they list parts or something? My FSM just says "liquid sealer" in the cylinder head installation section, and maybe I haven't found the other section... Sorry 'bout that.