VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Engine Block Flush

With the head off and the radiator out. A squeaky clean cylinder head and new radiator sitting in the "waiting room". How is the best way to flush the block (not removed from the car). I don't want the old crud in my new stuff after installation?
Also I cannot find my timing marks.

After doing your flush..should go to the top dead center..stick the head back.good to go

install a outlet filter on the water out before the radiator easy to clean can find them on e bay or order . the best thing i ever used have them on all of my old chevys . it does no good to clean the radiator and have a teaspoon of trash plug it up . over a period of time we have collected a hand full of trash from a frend of mines 41 . hope this helps

Great idea. I have seen them on ebay before. I am trying to figure out how to flush the stuff out before assembly right now.

Our friends visited today. With their help we got the car outside, ran the hose full pressure from the thermostat housing ( no stat) out the bottom hose outlet. No radiator. Reversed the flow a few times. All was very clear and without rust or chunks.
Will this suffice?

for all your trials & tribulations in this, I sure hope so, so you can begin HAPPY MOTORING. !!!!!!!!!!!!!!!!!!!!!

If there is anything left in there it must be from krypton

mike lynch......

Can't always get all the crud out of the block, but it sounds as thou you have done what you could...Last time I did a radiator I used some miratic acid ( pool stuff ) worked great...Full strength for a couple of minutes and flush with plenty of baking soda...Crud just flushed out...Couldn't believe what came out...work's good now...

You would have to tell us that by removing the expansion plugs and seeing what is inside.
What I found on the bottom of the water jacket on my '39 wouldn't have flushed out with just water pressure in a hundred years. Seeing the head is off and manifolds loose the plugs are right in front of you. All the acis in the world wouldn't clean the stuff out.

35's have expansion plugs? The head is on but no mani's yet. Please explain.

I found an old post where 1-1/4 or 1-1/2" soft plugs were in question. 1 or 2 on the driver side and 1 in the back of the block. Nothing mentioned in my repair manual though. VCCA rules! I never heard of muriatic acid. But it was suggested to run baking soda though.
Mike, you're right. I am ready for some happy motoring.

Just removeing the side plugs will be OK.
The baking soda neutralizes the acid, does not clean.
The acid will not touch any packed rust.

K

found this old post thread about flushing a 35 Chevrolet block and rad by wisebri.

mike

I tried to solve my overheating problem by doing the below:

1. Running all sorts of rust removal products through as a "flush".

2. Replaced the radiator.

3. Replaced the water pump.

4. Re- timed the engine.

5. Removed both hoses and ran garden hose water full force aprox. 75 lbs. pressure as a flush through both ways.

6. Changed out temp. gauge bulb.

Nothing worked! It still overheated until I removed the head. There were large sheet rust chunks hung up on the head gasket and in other smaller holes. I was surprised to find that after all that I had done.

1. I drained all remaining fluid from the block.

2. I removed all large chunks that were blocking the holes in the block.

3. I used a vacuum cleaner to suck the block's remaining chunks out.

4. I used water from the garden hose full force to flow through each and every hole. (I suggest that you spray down all pistons with WD 40 and cover with a shop towel the piston holes. I used a vacuum to suck all crud and water from each piston after removing the shop towel. I re-sprayed each piston with WD40 as soon as using the vacuum. I then used air pressure to remove any remaining water and oil. I used splash proof goggles, too.) I again re- sprayed all with WD 40.

The Head:

1. I removed all rust chunks.

2. I air blasted all passages.

3. I used a wire to run through all water passages while re-blasting with air.

4. I sand blasted through all water passages. Again air blast.

5. Ran water at full blast through every hole.

Use appropriate safety equipment.

6. Reassembled with new head gasket. Followed torque procedures

The result was it ran very cool. Normal.

Your story is more common than typically thought. Even rebuilt engines that have been hot tanked can have rust and other chunks in the cooling passages. Don't assume the cooling system is clean until you thoroughly check particularly if over heating.

That is the only way....bite the bullet and do a complete job.
For the engines that have them the left side freeze plugs should also be removed.

MIKE
good to to review, its hot over here in CALIF, and the past few car shows have been in high 90`s to 100 degrees
and yes, you see cars come in full steam!
by 10am it`s 85 degres
cars waiting in line dont stand a chance.

and the most important thing after all the flushing backwards and forwards, steel rodding water jackets, freeze plugs taken out and poked around inside block. Cylinder head trued 100% straight, new head gasket installed correctly and torqued to the right numbers in the correct sequence. new thermostat 170--180 installed.

lastly.....you cannot cool an engine without a fan drawing air heavily thru the core.

Phil Lipton did all the research and testing on the 36 chev truck fan to verify that it worked.

Miss this step and you wasted all your time doing all the other

mike lynch

Hi- I just had my block machined and cleaned with all the plugs out etc. It still had a bunch of "black clay" material that was really hard to remove --- I poked, dug, and cleaned as best I could--------not trying to scare you but it was pretty pasty. If it matters, it had sat for many years without running.

Years ago the left side of the block in my 1939 cracked. I found a new bare block to install. After it was done I broke out the side of the old block. There was about three inches of rust on the bottom of the water jacket that looked lke packed in coffee grounds. I had previously flushed out the system with strong old fashioned radiator/cooling system cleaner. It never touched the rust.