Intake Manifold Re-build

Hey Guys,

I've been restoring a 66 Pontiac 2+2 for about 3 months now.  I've recently pulled the intake manifold off and I want to clean it up and make it almost new.  I just have a question regarding a white hardened substance where the coolant runs thru it.  Is this just really old coolant thats gone bad?  I can't seem to get it out.  I can wire brush it but can't get it perfect.  Any chemicals that I can use to get it out ??
Matt  

It is most likely corrosion.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

What can I do about it ?  

you have several ways to totally clean the intake...

around my shop.. i use heavy duty cleaner degreaser from smart and final... in a big food tray.. or a bus boy tray if the parts are small enough to fit...    with one of the round end cleaning brushes from them also..    

once you get it the first fuel layers of grease and grime off..    pour off to use on another dirty part the dirty cleaner degreaser... wash the part in hot water... (a 5 gallon bucket from the bathtub)    let it dry and spray on more... work that area and wash with hot water again...   if you still have corrosion.. you can take it to a machine shop .. and have it sand blasted..  soda blasted..   i like soda blasting better ... less chance of any getting stuck.. and into the engine later..  washes out with hot water..    if they sand blast it.. in their cabinet.. be sure they put it in their pressure washing machine... to get any sand out of the corners...     if you take it in after you clean it...  they are likely to be more accepting of an intake for cleaning..  they have to pay to get sludge hauled away..   take them a greasy part.. they don't want anything to do with it... unless its a complete engine job..  i know.. i worked in an engine builder..

i warn against having them bake and shot blast the intake...  i don't think you will like the finish on the machined areas..  shot blasting is a huge machine that throws tiny steel balls at the parts as they rotate ... it throws them at 200mph or so.. maybe even faster...   if the parts did not rotate..  it would wear holes in them..    different shot blast machines create different finishes..  but the parts have to be grease free first.. so you might talk to the machine shop... or engine rebuilder... and take a look at some of the stuff coming out of the shot blaster and tumbler..  you have to tumble the parts to shake out any shot...  

Sand blast or acid dip is going to be the best way.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

When I worked at my folks airport they had 50 gallon drums of "Gunk" for aircraft engine parts. Put it in on Wednesday and pull out a spotless cylinder on Thursday. After that, The wire brush on my Craftsman grinder is my best friend, especially for smaller parts.