OldOldsLover

Hi,
Before I install the 455, I wanted to make sure the internal coolant area is clean.
The radiator has some crap in it and it has clogged up the bottom area.
I have the engine out now so it won't be difficult to pop out some freeze out plugs are stick a coat hanger etc to see if there's crap in there.
IDK how much access I will actually have.
If it seems bad I can pull the heads to try and physically scrap around the cylinder coolant areas.
Has anyone ever done anything like this?
How well did it work?
Thanks
OldOldsLover

edzolz

Yes you can pull the freeze plugs and dig around with a stiff wire to remove any sediment build up in the block. Have a garden hose with a spray head to wash out the block thoroughly. You will be surprised how nuch crap is still in the block, even after having it hot tanked.

OldOldsLover

Thanks
Do you think i should pop out the freeze out plugs in the head too?
I'm thinking that the sediment crap will br lower than the heads.

ELY442

Yes, pop all the freeze out plugs while you have the engine out. It's a lot easier. Replace all freeze out plugs with the brass type. They sell a kit for this to do the whole engine and heads.

Sugar Bear

The sediment will be low vs in the heads but definitely take advantage of replacing all the frost plugs while they are accessable.

Good luck!!!

BillK

ool,
It is pretty rare to see much buildup in the heads. Most of it is usually in the back lower corners of the block where there is very little circulation. I am working on a 455 block right now that must have had a couple of pounds of junk in it. My hot tank and shot blaster wouldnt even get it out. I had the block on an engine stand and just had to do what you are saying. Coat hanger, shop vac and tons of air.

My concern with doing it on an assembled engine is that it will be impossible to get all of the left over crud out and who knows where it will end up

matt69olds

If the engine is assembled, cap all the openings with duct tape. Stuff paper towels into the exhaust/intake/carb openings, then tape them up.

If you do pull the heads, follow the same procedure, just be extra careful with your taping process. You will need to throughly clean the oil if you want the tape to stick. Make sure the lifters won’t fall out of the block when you flip it over, it might be best to remove them first (label the location so you can reinstall them in the same bore!), lots of compressed air, shop vac, you can get it cleaned out.

bccan

I have never performed this type of cleaning but it seems a pressure washer would be effective (?)

OldOldsLover

I took off the WZ exhaust manifolds, popped out the 6 block freeze out, removed the water pump, removed the heater control valve on the intake, removed the thermostat housing and thermostat.
Used a garden hose with a standard adjustable spray nozzle.
I could feel with my finger that there wasn't a ton of stuff inside the block behind the freeze out plugs.
When I hosed it out, it looked like small rocks came out, but when you squish them between your fingers they disintegrated.
I think I was calcium or minerals from the hard water here in Las Vegas.
I used the coat hanger but it didnt seem to dislodge anything else.
I'm going to go back in there with the coat hanger another day just to be sure it decently flushed.
Thanks for the replies, suggestions, etc.
OldOldsLover