Engine Cleaning prior to Assembly

[Matt Wilson]

Well, I'm finally at the point where I'm going to assemble my engine soon (265 flathead six), and I'm cleaning the block in preparation.

 

I'm wondering....how do you clean the passages/little "chambers" at the back of the block, shown in the photos?  These are on the right-rear of the block and are the ones that connect the circular opening for the road draft tube (or positive crankcase ventilation in my case), the rear cam bearing bore, and the lifter chamber.  Those chambers or pockets are all connected, but there is no way to getting easy access to them.

 

I spent over two hours today (maybe close to 3), spraying brake parts cleaner in those areas, reaching in there as best I could with my fingers (could only get a single finger in at a time), trying to rub or scratch loose the old oil and chunks of caked-on soot and exhaust debris, sometimes using a rag soaked in cleaner, wearing gloves much of the time, but not always, because I couldn't feel the debris with a glove on.  I got a majority of the crud out, but there's still more to address.  Every time I thought I got one area clean, I could reach in there and find more loose particles.  Wouldn't be surprised if some of what I felt was sand left from the original casting, but I don't want it in my engine.

 

When I resume the job, I think I'll try using a couple of my Dremel wire brush attachments, but even those won't reach all of the nooks and crannies, and then I'll have to be sure I don't leave behind and stray wires.  I might also take some of my engine cleaning brushes (from a kit I bought) and bend them 90 degrees to into those areas.  I have been hesitant to use Scotchbrite pads for fear that I won't get all of the debris out - that stuff sometimes really clings to rough surfaces such as castings.

 

Eventually, I guess I'll get all of the crud removed, but I'd sure like to hear how you guys clean this particular area of the engine.

 

Thanks!

 

P.S.  I found the last photo to be a little humorous.  When I first looked at it, it was on my phone (smaller) and was vertical, and it reminded me of the egg-laying creature from the Alien movies - the one that latches onto its victims' faces.  Lol.

 

 

 

Edited December 7, 2023 by Matt Wilson

[desoto1939]

Since you already have taken the engine apart I would take the entire block to an machine shop or and engine builder and have the entire dipped in cleaning solutions to clean-out the old grease and junk that you can not see and easily get at with your hands.

 

This will clean the block completely so you will have a better idea if anything else need to ordered.  It also cleanout the scale and rust on the inside of the block.

 

Spend the money now you will appreciate that you did later on.

 

Just my 2 cents on input.

 

Rich Hartung 

[Doug&Deb]

I agree with Rich. Nothing any of us can do will get the block as clean as an engine shop can. Definitely worth every penny.

[Sniper]

I would talk with the machine shop about what effects any cleaning will have on the block.  The old hot tanks were caustic and you needed to, at least, replace the cam bearings.  Newer stuff can involves shot blasting, which means you need machine work.  Just be clear on the effects and what you need to do.

[Dave72dt]

rifle and shotgun cleaning brushes can be used to clean long passages.

[soth122003]

1 hour ago, Dave72dt said:

rifle and shotgun cleaning brushes can be used to clean long passages.

Dave beat me to it. Use those and a can of oven cleaner. Just follow the directions. Then when done rinse well. Matter of fact, spray them fist and then other areas of the block and you can watch the progress on the outside to decide when to flush the passages. best guess would about 2-3 hours.

 

Joe Lee

Edited December 7, 2023 by soth122003

[kencombs]

I remove all the plugs wherever they are, soak the whole thing with a mix of diesel and Gunk Super Concentrate.  I use a spray setup that used air to vacuum the mix into the nozzle and spray into every niche and passage.    Let it set at least 24 hours.  Then rinse with a pressure washer and hot water if available.  Repeat.   Then soak it again and use the pencil stream nozzle on the pressure washer, directing it into every little place like those.

 

Finally, hot water and dish soap scrub with all the little brushed I own!  Then rinse and blow dry.

[Sniper]

Oven cleaner works well, I just buy the cheap dollar store stuff.

[Matt Wilson]

Thanks to everyone for the replies so far.  I guess I should have been clearer up front by saying that the block has already been machined and been through the machine shop's cleaning process - actually cleaned twice at two different shops.  The rest of the block came back pretty clean, but not these areas.

 

I have an engine cleaning brush kit with brushes that are like rifle and shot gun brushes.  Had not thought of oven cleaner.  I'll buy some on the way home this evening.

Edited December 8, 2023 by Matt Wilson

[Dodgeb4ya]

Best answer...

A good machine shop that will clean that block and all it's hidden sludge in the oil galleries and all water passages too.

I'd have them clean all the rods, cam, crank, lifters, oil pan,timing cover, pick up and head too.

Don't let something wipe out a bearing or too..

Cleanliness is a must when rebuilding a engine...no dog or cat hairs either?

 

[Matt Wilson]

3 hours ago, Dodgeb4ya said:

Best answer...

A good machine shop that will clean that block and all it's hidden sludge in the oil galleries and all water passages too.

I'd have them clean all the rods, cam, crank, lifters, oil pan,timing cover, pick up and head too.

Don't let something wipe out a bearing or too..

Cleanliness is a must when rebuilding a engine...no dog or cat hairs either?

 

Well, it's already been to two different machine shops for various work including cleaning at both shops.  Obviously, neither shop did that great a cleaning job.  Everything I've read and heard over the years (including from experienced engine rebuilders) is that, whoever is doing doing the final assembly should expect and plan on doing a thorough cleaning of the machined block AFTER the shop has done their cleaning.  The limited engine building experience I've had over the years has shown me why this is the case.  With all this in mind, I have had every expectation that I'd need to clean it myself, to be sure it's done right but this one area of the engine is particularly difficult.

 

And yes, dog hair is something I've been concerned about, as we have a Corgi that sheds like crazy.  As much as I love that little dog, my plan is to stay away from her when I'm in the midst of my cleaning sessions, and I'll probably take off my clothes in the freshly-cleaned garage whenever I come inside, to avoid picking up hair.  Might also need to keep the house free of hair (vacuumed) a little more than usual.  I'm also thinking about building a little clean room inside my garage, with the intent that it will be spotless.

Edited December 8, 2023 by Matt Wilson

[Dodgeb4ya]

The engine tear down/assembler owner like myself and others always needs to check over all engine machine shop work.

And you have done so.

If your shop leaves oil sludge in the block I'd be right back there asking...why is there still this nasty sludge left in my block when I asked that you clean it really good?

I need this block properly cleaned...can you try again?

If they can't...some discount on the bill and off to another "competent"  shop.

I have a very good machine shop I have used for over 40 years.

Lucky me..?

[soth122003]

Since your engine is free standing like that, you can position it for best spray application. Then move it for the next shot. When you are ready use the brushes and scrub the passages and other areas. When done, I would use boiling water poured into the passage then move it to the next passage/spot. After all that I would get some fogging spray or light oil and use it in the passages to prevent any rust build up while waiting to assemble the engine.

 

I will say that Easy Off is no joke on baked on oil and sludge. prior to the self cleaning oven this was a once a week chore for moms or young uns on an allowance.

 

Joe Lee

[Matt Wilson]

45 minutes ago, Dodgeb4ya said:

The engine tear down/assembler owner like myself and others always needs to check over all engine machine shop work.

And you have done so.

If your shop leaves oil sludge in the block I'd be right back there asking...why is there still this nasty sludge left in my block when I asked that you clean it really good?

I need this block properly cleaned...can you try again?

If they can't...some discount on the bill and off to another "competent"  shop.

I have a very good machine shop I have used for over 40 years.

Lucky me..?

Yeah, revisiting the shop would be the best way to go about it, I suppose.  The first shop was six years ago and the second shop was a year ago (this project has really been dragging out).  I could still take it back to either shop, especially the second shop (being more recent), but I don't want to deal with the delay, as I have a short window of time off from work coming up, when I really need to get this thing done, and I still don't trust that they will get it as clean as I want it, so I'm doing it myself and not waiting on them.  The second shop did a great job of boring and honing the cylinders (which the first shop didn't do very well), along with other good work, but not so much on the cleaning.

 

And I agree - lucky you.  I went through quite a few shops, getting them to do various aspects of this job because I was unhappy with the quality of work I was getting.  As you mentioned, I did check EVERYTHING that was done.  I had some measurement tools already, but I bought more, just so I could check all of this stuff.  I even bought and learned how to properly use a dial bore indicator to measure my cylinder diameters and came up with the exact same numbers as the shop.  I bought radius gages so I could check the filet radii of the crankshaft journals - that's how I found that my first shop did such terrible work, as many of the radii were jagged, not smooth and those that were smooth'ish were well below the minimum radius requirement per the manuals, and both conditions are a recipe for disaster in the form of cracked/broken crankshaft due to fatigue.  Ok, I'm just venting at this point, and I could go on with other examples.

 

I live in the Dallas-Fort Worth area and you'd think that with so much competition, the shops would do better work, but I found that this is simply not the case.  An experienced builder once talked about using different shops for different aspects of his engine machine work, with each shop having different strengths and weaknesses, and I now know what he meant.  When I rebuilt my first flathead 20 years ago, I had a machinist who was pretty sub-par in several ways, and had a terrible attitude on top of that.  He had come highly recommended, and I have no idea why.  I avoided him this time, but found several others whose attitudes were generally better (sometimes a lot better - truly nice guys), but the quality of workmanship still wasn't up to snuff.  This project has been fun and a huge learning experience for me, but I don't think I'd want to do another one - although I suppose I now know more about where to go to get what types of work done, and I know a LOT more about what questions to ask and how to state my requirements.

 

Giving credit or blame where it's due, I will admit that I've made my share of major mistakes on this engine build and had to pay (in terms of money and delays) to get those things corrected.  I'm also particularly picky, but several of these machine shop mistakes were truly terrible and you don't have to be picky to reject those.

 

Anyway, I'll get the block cleaned and then on to the assembly, which I look forward to.

Edited December 8, 2023 by Matt Wilson

[Dodgeb4ya]

Times certainly have changed.

I know a lot of good machine shops have disappeared...probably a sign of the times.

Not much machine shop work needed these days compared to the past.

I know you are careful in what you do.

I guess you have no choice but to do it yourself.

If so I'd use really good quality brushes that the bristles don't fall off into the galleys or other areas of the block.

No wire brushes...might lose a wire or two somewhere and might end up in a bearing.

I would use lots of super clean and or brake cleaner.

It will be slow and messy buy do-able...

Ya gotta do what ya gotta do!?

[Matt Wilson]

8 hours ago, soth122003 said:

Since your engine is free standing like that, you can position it for best spray application. Then move it for the next shot. When you are ready use the brushes and scrub the passages and other areas. When done, I would use boiling water poured into the passage then move it to the next passage/spot. After all that I would get some fogging spray or light oil and use it in the passages to prevent any rust build up while waiting to assemble the engine.

 

I will say that Easy Off is no joke on baked on oil and sludge. prior to the self cleaning oven this was a once a week chore for moms or young uns on an allowance.

 

Joe Lee

Thanks, Joe!  Yes, having it removed from the stand makes it possible to reposition the engine, which is what I've been doing.  That's extremely helpful.

 

I had not thought of boiling water (to effectively rinse the passages, I guess).  I wonder if it would be almost as effective to use a hose with spray attachment hooked up to my water heater, which is right near my work area.  If I turn up the heater to the highest setting, I think that gets me 165-deg water (if I remember right).

 

And I have two sprayers (knock-offs of the Sure-Shot brand sprayer) that hold a quart of liquid and operate under air pressure.  I have solvent (just bought two 1-gallon jugs of CRC brake cleaner) that I will put into one, and WD-40 that I will put into the other one.  When done cleaning,  I will spray WD-40 all over and into the passages.  I know WD-40 is only for short-term trust prevention.  I fully expect to be assembling the engine in the next few weeks.

[Los_Control]

I agree with @Dodgeb4ya ... it will be all manual cleaning with various different tools.

I would think that possibly compressed air & a vacuum cleaner would be very helpful.

Also solvents such as brake clean or acetone to loosen the crud, only a petroleum based product. then quality brushes that will not fall apart during use.

Bailing wire to probe the galleys, screw drivers, picks & probes ..... All manual work.

 

I would be scared to use any water inside the engine, to much chance to cause rust issues on any machined surfaces .... may end up with a bigger issue then you are fighting now. Even though you can wipe down & oil the obvious  places, will be hidden places you wont see or be able to reach.

 

Once you get the inside and nice and clean then ready for paint, here is a decent video showing preparing a engine for paint.

Possible using the map gas torch may be a useful tool in cleaning your block?

 

His block is also fresh out of a machine shop and looks cleaner then yours. I imagine different states have different regulations on what products can be used in a dip tank.

Also your engine is 50 years older then his, has seen more years of wear & tear. You may never get it that clean.

Get what you can and remember it is cleaner then it was before.

 

 

[kencombs]

One cleaning method that seems to be in vogue these days at machinist/rebuilders is oven baking.   It does remove all traces of oil and general gunk, but I've seen some cases where the accumulation in passages, nooks and crannies was turned into ash.  Sounds like what you may have.  

 

The only cure is meticulous handwork as you've found.   And you're right, it is the builders task to assure all things detrimental to machined surfaces are removed.  

 

If it was baked, or even hot tanked insufficiently, solvents won't do much as the part of the 'dirt' that solvents attack is already gone.   It will need scraping, gouging and brushing.   Then a hot water/soap wash.  JMHO.

[61spit]

I had a block that was supposed to have been tanked and cleaned and it didn't look like it at all. I took it back and they baked it and brought it back. Looked like a brand new casting. Perfectly clean and beautiful.

[Matt Wilson]

Thanks again to everyone.  Los_Control, thank you for posting the video.  That was interesting.  I never knew about heating the block with a MAPP torch to remove moisture before painting.  I will definitely do that on mine (and the head).  I guess that means I need to do it before assembly, so that the torch doesn't damage gaskets and such that will be in the path of the flame.  I had been planning to do the paint after assembly.  Also, good suggestion about using bailing wire and picks.  I have those things.  My dad bought a set of picks that look like dental picks, and he gave them to me.  They could be very useful for this.

 

And to everyone - I will use brushes to scrub all the hidden areas and work and work at it till all foreign material is out.

 

I don't think it was baked in an oven, as there was still wet oil in one of those passages.  It just didn't get cleaned all that well, but I'm going to remedy that.

Edited December 9, 2023 by Matt Wilson

[Matt Wilson]

Follow-Up:

 

I finished cleaning the block last night.  I kept a mental tally of how many hours I spent on it over the last two weeks, and it came out to about 28 hours.  Of that, the first 15 or 16 hours were spent on those three "chambers" that were the subject of my initial post.  I had to spend so much time because, every time I thought that area was clean, I could spray more brake parts cleaner in there, scrub with a wire brush and come up with more grit.  With a mirror and light, I could see a couple of dark patches that looked like baked-on oil.  Those seemed to be the source of the grit, so I sprayed that whole area with oven cleaner, till it was foaming out of all those openings, doing so with the block in different orientations every few hours, and leaving it to soak for several hours each time (per the oven cleaner instructions for cleaning of cold surfaces).  Then I hosed out the oven cleaner with water.  To my amazement, that didn't get rid of the gunk.  So I just had to keep at it the hard way, using wire brushes by hand, a wire brush on a Dremel, and using some dental picks to tediously scrape across every square inch, and paper towels and cotton towels with lots of brake cleaner (dozens of cans and also a couple 1-gallon jugs sprayed from one of my Vaper sprayers, which is a knock-off the SureShot sprayer).  Eventually, I got to the point where I couldn't produce any more grit and it looked visually very clean, so I was satisfied that it was good to go. 

 

Then I moved on to the rest of the block, which went much faster.  I used brake cleaner and hand-held wire brushes to clean the crankcase and valve tappet areas, getting in all the little divots and such, and using "pipe cleaner" brushes from a Moroso engine brush kit to clean the various oil gallery passages.  Despite the block being cleaned at two different shops, there was still a lot of black gunk that came out of all of those areas.  Not impressed with the professional cleaning.  I couldn't find the cylinder bore brush from that kit (don't know where I could have put it?), so I used a kitchen brush of similar shape and size that did ok, and also a kitchen sponge with soap and water.  I then followed up all of this with a soap-and-water cleaning of all those areas (using the sponge), except the oil passages, as I felt they had been pretty well-cleaned the first go-around with brake cleaner.  I was pleased that the sponge came back from all of that looking clean and basically new.  That means I had done a good job with my initial cleaning.

 

I then hosed off all the soapy water with the hose sprayer on the "full" setting (forceful stream) and also sprayed out the oil passages.  I figure this would help to dislodge any remaining particulates and get them all to drain onto the ground below.  Finally, I used my other Vaper sprayer to spray about a half-gallon of WD-40 all over the block - outside, inside the crankcase, valve tappet area, cylinders, oil galleries, etc.  The whole thing got completely soaked in WD-40.

 

I finally feel satisfied that it's all clean and ready for assembly.  I double-bagged the block with heavy-duty (3-mil) 55-gallon trash bags.

 

After all that, my hands are dry and cracked from the brake parts cleaner, and my finger tips are a little raw and sore from rubbing the rough casting surfaces so much to check for presence of grit.  I also have various little cuts and nicks from the sharp edges around the block.  Typing kinda hurts.  I tried using the best chemical-resistant gloves I could find at the parts store, but they didn't hold up to brake cleaner for more than a few minutes.  It was a futile effort.  Plus, with the gloves on, I couldn't feel the grit to be able to tell if I needed to do more cleaning.  Exposure to chemicals for that long can't be good, but I didn't know what else to do.  I didn't want to use soap and water for all of that initial cleaning, for fear that the sensitive parts of the block would start to rust.  At least I was outdoors, so I wasn't breathing it much;  my exposure was mostly limited to the exposure through the skin.  If I were to do more engine work like this, I would have to come up with something better.

Edited December 18, 2023 by Matt Wilson

[kencombs]

On 12/18/2023 at 3:03 PM, Matt Wilson said:

.

 

 I didn't want to use soap and water for all of that initial cleaning, for fear that the sensitive parts of the block would start to rust.  3

Not to worry, soap and water has been the 'gold standard' used by quality engine builders for years.   It has been found to be the only reliable method to remove all residual honing fluid, along with the grit it carries.   Use hot water, blow and wipe clean immediately and lightly oil the machined surfaces.   Your WD40 is perfect for this.

[Matt Wilson]

1 hour ago, kencombs said:

Not to worry, soap and water has been the 'gold standard' used by quality engine builders for years.   It has been found to be the only reliable method to remove all residual honing fluid, along with the grit it carries.   Use hot water, blow and wipe clean immediately and lightly oil the machined surfaces.   Your WD40 is perfect for this.

Thanks, Ken.  I watched several YouTube videos and they usually recommended soap and water, but it just made me nervous - fearing that I would cause a rust problem by trying to use the best cleaning method out there.   So much of this scrubbing took such a loooong time to get all the black gunk and grit out of the numerous corners, I didn't think I could move along quickly enough from one area to the next to keep things from rusting.  In any case, like I said, I did go back and clean most of the block with soap and water (not hot though) after the more detailed initial cleaning with brake cleaner.  I especially gave the cylinders a very thorough soapy water scrubbing, as I know honing grit is not easily removed.  Maybe I should have done a soapy water cleaning of the oil passages, and maybe I still will.

[Matt Wilson]

After the above post, I decided I would use hot, soapy water to do a second cleaning of the oil passages, since I had only cleaned those with brake parts cleaner, and since soapy water is generally thought to be the best way to do these things.  I pulled the plastic bags off the engine and to my horror there was a lot of rust.  I'm in disbelief because, after I flushed out the block with water the other day, I completely drenched it, inside and out, with WD-40 before I bagged it.  As I said previously, I used about a half-gallon of it.  Apparently that wasn't good enough.

 

Needless to say, I did not use water to clean the oil passages tonight, contrary to my original plans.  I will avoid using water to clean engine parts going forward (except cylinder walls, as I understand that to be about the only reliable way to remove honing grit).  So tonight, I instead used brushes and more brake cleaner to go through the oil passages, mainly to get rid of any new rust that I couldn't see.  As I did so, rust-colored cleaner came running out of those passages.  I also scrubbed the heck out of the cylinders, but couldn't get rid of all the little dots that you can see in a couple of the photos.  I did a lot of scrubbing with hard plastic bristle brushes, and even scrubbed a little with a fine steel bristle brush, but those dots wouldn't go away.  That disturbs me, as I don't know if those will cause any issues.  It's hard to tell if I can feel them or if I'm feeling the remnants of the supposedly lint-free cloths I used (soaked with brake cleaner) to get rid of the surface rust that was all over the cylinders.  In any case, I'm really unhappy that those dots are there.  Not sure if they will interfere with ring break-in, sealing or longevity.  The remaining rust in areas such as in the crankcase or tappet chamber can probably be hand-wiped off or brushed off, but the cylinders really concern me. 

 

I was on cloud nine a few days ago, after getting the block cleaned up and bagged.  Now I'm down in the dumps.  I feel like this has been a potentially huge set-back.  I have another couple of weeks off from work, during which I have been planning to assemble most of the engine, and now it seems like that's in jeopardy.

Edited December 21, 2023 by Matt Wilson

[Sniper]

Vinegar removes light rust.