Clean Water Jacket

Roadster Rich

Roadster Rich

Senior Member
I have my latest engine with the head off and ready to replace with a 5.5 compression head. Checked valve clearances and will plastigage the crank and rod journals this weekend. The water jackets are rusty, but pretty clean of rust debris. I have rodded around with a coat hanger and do not find loose rust in the engine water compartments. Vacuumed with a small nozzle everywhere I could.

Should I fill the engine block with evaporust or vinegar and let it sit for a few days then dump/flush. Or is it best left alone? If I do try to clean the water jackets, is it OK to let the cleaner fill the radiator and sit also where it finds its level with the top of the block or should I try to cap off the entry point to the engine block?

I may be worrying about nothing, or causing more problems doing something like this, so just wanted some advice.
 
Use compressed air to blow out the passages really well. An air gun with a piece of brake line as an extension to get deeper inside works well. Flush with water and you should be good to go.
 
"The water jackets are rusty, but pretty clean of rust debris. I have rodded around with a coat hanger and do not find loose rust in the engine water compartments."

One can never have a cooling system that is too clean. The engine will never be easier to access than when out of the vehicle. I like your idea of soaking with Evaporust for a couple of days.
 
I use and old speedometer cable in drill,work in all the openings. then air and also use a small vacuum attachments to suck out debris. works for me.
 
I did not know about the coolant system cleaner, but it seems like the original stuff would be the best if I am opened up and can let it set for a day or two.

anyone know the capacity of the block alone without the head and capped off at the entrance tube? I would think it might be done with 1 gallon??? or will I need 2.

I did pay a lot of attention to that area on the back of the block right behind cylinder 4. I think it is patent but not sure just how big the passage should be. I can run the coat hanger wire through it.

Also blowing out with as small a tube that I can get attached to my compressor may be smart. I will have to roll it out of the shop, and I think pretty important to really seal off the piston and valve area when doing it.

Thanks for all the suggestions.
 
back flushing the block separately from backflushing the radiator when you get the mechanical cleaning and/or the evaporust treatment done would also be my recommendation. I still got chunks out after extensive cleaning.
Bob
 
Yaap says to take a piece of braided steel cable, fray the end a little bit into a brush, chuck it into a drill and clean away. A good idea.
 
Brentwood Bob said:
back flushing the block separately from backflushing the radiator when you get the mechanical cleaning and/or the evaporust treatment done would also be my recommendation. I still got chunks out after extensive cleaning.
Bob
Click to expand...

Spot on
Doing them separate during cleaning provides a cleaner system in that you're not chasing crud from engine to rad, rad to engine, engine to rad and round and round.
 
You must log in or register to reply here.
Back
Top