Any advise on cleaning hardened crud off the inside of my heads? I have the heads off and can soak them in a solvent but dont know what is safe to use without damaging the aluminum.

Thanks in advance,

Regards

Jude

I got some good ideas here: http://www.ultimatesubaru.org/forum/showthread.php?t=40245&highlight=head+clean

 

if I had to do it again... probably use a pocket knife (rounded tip) to carefully scrape the high points of the gasket material off.

 

Then I would use 800ish grit sandpaper with WD-40 on a plate of glass (or similar flat object) and use round motions(wax on/wax off ) to wear the gasket material off.

 

good luck

Thanks for the reply.

Im ok with the gasket material,its the baked on hard black stuff down inside the galleries Im after.When I was a kid,we used stuff cauled caustic soda,but cant find it anymore and anyway they were Iron heads and would stand a lot more abuse.BTw the big subject for discussion that time was if we could put a man on the moon.

Jude

When I did mine (just a few weeks ago now) I used a 1" putty knife with a soft blade to get the big stuff off, and then a green scotchbrite pad (synthetic steel wool) to get the small stuff off. It took a little while, but I was able to get the head surfaces looking pretty dang good.

 

I had a razor blade scraper handy just in case, but I never really needed it. The putty knife had a bit of a bevel built-in, and it worked just fine.

 

Take your time (if you can) and enjoy the process. It was nice to also take before-and-after photos, so I can really remember the difference.

If you don't mind paying someone, an engine shop will acid bath them for not too much. They come out looking brand new!

For the head mating surfaces and the chambers, 3M makes special cleaning disks you can chuck into your drill. They are some sort of impregnated plastic/rubber stuff that works wonderfully. There are three different grades: Green for iron, yellow for aluminum, and I don't know what the white is for.

 

For cleaning the ports and stuff, remove the valves, hose the ports with brake cleaner, and use a small wire brush. It can't get everything out, but it's darn close.