Flushing engine block
 

I have my radiator off for cleaning and repair, what if anything can be done to flush the engine with the radiator remover. I've never done it except with the radiator installed. Just wondering if any of you have done it. Wouldn't want any drudge in engine to go back into radiator. give me some clues as what it would help or a waste of time. Al

Re: Flushing engine block
 

BTW it's on my 41 Ford flathead

Re: Flushing engine block
 

first put a garden hose in the top outlet of the head and flush engine backwards from it's normal flow, next do it the other way. if you are looking for something to do. remove the water pumps and use a small diameter hose to get into the block behind the water pumps and flush out each side

Re: Flushing engine block
 

I've never done this, but some have had good luck filling the block with Evaporust.

It would really help if you would take the head off. If you did, you could really get in deep into the water jackets with a long screw driver to scrape out the crud that settles in the back of the block.

Re: Flushing engine block
 

you can do the same crud removal with the water pumps off and a stiff wire

Re: Flushing engine block
 

Scraping and prodding is a good idea if you have the engine torn down far enough to do it. Otherwise, I agree with Tim and say fill it with "Evaporust" (Or maybe "Rust-911" which is a concentrate and a bit cheaper). Let it sit a day or two, and then hit it again. It did the job on a '51 Mercury engine I picked up.

It will turn black when you drain it, so you will know it's working.

Re: Flushing engine block
 

I did a serious volume flush hooking my pool filter discharge up to the 4 hoses coming out the motor, one at a time, in both directions. Mice had made nests in the block with fiberglass insulation, a lot of crap was pushed out.
You can only use what you got

Re: Flushing engine block
 

One important detail to consider. If your plan is to only flush the engine with water you will not get the drudge out of the engine unless the water pumps are removed. All of the built up crud located at the bottom of the block will not come out due to the design of the water pumps. Even if you fill the block with any type of rust remover to get the junk out the pumps need to be removed. One plus you do have is the lower drain plugs on the block if you open those up some flushed material will come out. But with the pumps off blasting the block with water into the openings in the front face of the block will remove a huge amount of junk easily and fast.
Ronnieroadster

Re: Flushing engine block
 

Agreed. I'll try to find the picture of the crud I got out before the block went to be cleaned. It must have been filled from water from a muddy river after a hard rain storm. It was literally mud and crud and silt.

Re: Flushing engine block
 

Thanks Tim. Al

Re: Flushing engine block
 

Dad and I attacked a torn down 21 stud with a 9 hp Pressure Washer and a long Screwdriver. The amount of sediment in the bottom rear was shocking. You could tell much of that had been there for decades. I don't see any kind of chemical flush and a garden hose doing much to the lion's share of it, but it probably can't hurt.

What I learned from that experience, is just how much crap can accumulate in one of these old flatheads, how important it is to use modern antifreeze, and keep them flushed the best you can in order to prevent a ton of sediment buildup. That, and when you do tear one down, go at it caveman style, with a strong pressure washer and a long screwdriver!

I liked the idea above, where a guy said he emptied his swimming pool through the engine! That was rich, creative and just might work! lol

Good Luck!

Re: Flushing engine block
 

Ditto Mike!
My 2 cents......
Aggressive cleaners will soften some sediment, removing it from the rear of the water jacket could present a challenge without the heads removed. My flathead V8 Block was an older resto not driven much over the last 30 years,
It was treated to a through flush with evaporust product before I bought it. I needed to pull the heads to resolve another issue. I could see stuff in the water jacket so I dropped a magnet down and pulled up a lot of debris. So I flushed it again with the heads and pumps off using with a special long reach tip. I was amazed of how much junk was still trapped in between the cylinders. I started by using a long reach magnet, long screwdriver, and the pressure tip until the water ran clear but still wasn’t satisfied, I was still getting material from the rear with a magnet so I pulled the engine. Allot more material was removed esp from the area around the last two cylinders when I inverted the engine to clean and flush. If not removed this could have ended up in my radiator....I’m using Gano filters just in case!

Re: Flushing engine block
 

I ran a Gano Filter (screen filter for the cooling system) on the mustang back in the day, and do not recommend them. They are okay if you check and empty them constantly, but about all they did for me was clog up and restrict flow. I revved the engine really hard with it once, and it was enough of a restriction to build pressure and pop the radiator hose loose... stranding me beside the road.

I can't imagine how often you'd have to remove/clean them on an old flathead.

Good Luck

Re: Flushing engine block
 

Along with the long screw driver, I've used a long piece of copper grounding wire and chucked in a drill. I've also used one of shop vac reducers with some clear hose to vacuum the crud as I scrapped. This worked really well.

Overall, my block was hot tanked twice and baked once after I scraped and prodded for a few hours.

Re: Flushing engine block
 

Boy Iv'e got a lot of options, now to see which to use. Heads ain't coming off, probably water pumps. I reverse flushed it and only a little color at first, then clear water. The block was boiled out when rebuilt about 8 yrs. ago, so I'm pretty sure it' ok. Radiator was clean inside, but had a small leak under top tank on left bank. car has never ran hot before. Al

Re: Flushing engine block
 

Speedo cable on a drill motor

Industrial hot water pressure washer with chemical degreaser for block washing if you can get near one,Ive saved plugged radiators with the washer

Re: Flushing engine block
 

I run the pressure washer with a stainless tube size as a brakeline on it...very easy way to get down into the tight areas.
After that into a caustic cleaner in a 100 gal utrasonic tank...a couple of hours later they look a lot better :)

Re: Flushing engine block
 

From my experience that will not clean the stuff out of the water jackets. Most of the blocks still have stuff in there from the factory and several rebuilds (tank cleanings). There is casting wire and core sand, etc. My guess is that over the years these serve as a damn/retainer that further plug things up. The only thing that gets it out of there is scraping it out. Now, if the reduced flow is not bothering you and it stays in place, just flushing it out might work.

Re: Flushing engine block
 

Well up jumped the Devil, radiator shop called me, radiator shot. Big leak and several small ones. Got a 3 core aluminum Champion on it's way, have some good reports and not much bad. It's not a show car to be judged, so aluminum will work, especially for $800 less.

Re: Flushing engine block
 

Good luck with that. Aluminum will not cool as well as a brass radiator maybe you will get lucky. Flatheads' like to get warm since the exhaust ports are super-heating the coolant. The radiator is the most important part of the system.