Engine Cleaning prior to Assembly

[Matt Wilson]

2 hours ago, Sniper said:

Vinegar removes light rust.

Thanks.  And I guess it won't etch the surface enough to make a difference with the honing hatch marks?  Vinegar is a weak acid.  I suppose for a brief moment applied with a rag, it wouldn't hurt.

 

I saw other forums talk about using ATF, or a mix of ATF and acetone, or penetrating oil to remove rust.  I will probably try those first. 

 

Some forums even talk about using Scotchbrite or steel wool, but I hesitate to do that for fear of compromising the crosshatching.  But I welcome input on this.  Hopefully I didn't already compromise it with the steel wire brush (though I doubt it, as it was just hand-held, not on a drill) and I just did it for probably less than a minute.

 

I have a feeling I'm worrying over nothing, but I'm just aggravated and trying my darndest to make this all go right.

Edited December 21, 2023 by Matt Wilson

[Dartgame]

You might want to take a look at evaporust. I've been using it to clean engine tins and hardware, works pretty good and washes with soapy water, and then blow dry.

[Matt Wilson]

37 minutes ago, Dartgame said:

You might want to take a look at evaporust. I've been using it to clean engine tins and hardware, works pretty good and washes with soapy water, and then blow dry.

Thanks, yes, that was actually another thought I had, right after I posted my last message.  I will probably start with that, since I have some on hand.  I've had good success removing light surface rust from sheet metal parts, using a rag soaked in Evaporust, without having to let the part soak.  Any heavier rust does require soaking.  I don't want to let the block soak in it for any length because when I've previously done that to portions of the block or head, rust areas developed a black coating on them they wouldn't come off.  The Evaporust website says this can happen sometimes due to carbon molecules migrating to the surface, and that it is no issue, but I don't trust that it wouldn't behave as some kind of abrasive in the cylinder.  To avoid that, I just won't let it soak.

[Matt Wilson]

I'm out in the garage, rubbing the bores with lint-free paper towels soaked with Evaporust and it's doing nothing to the rust dots and smears, and wherever I can see those types of things, I can definitely feel them with my finger tips.  The dots are definite bumps, and the smears feel almost like sand paper.  They don't look that bad visually, but they feel BAD.  And if I feel them, then so will the rings and pistons.  I don't see how any amount of rubbing with cloth and chemicals will remove those.

 

I spoke to my machinist just now.  He said using water, then trying to use WD-40, then bagging up the block was the worst thing I could do.  Even though I flooded the whole thing with WD-40, he said he's not surprised at the outcome, saying that WD-40 is marginal at best for this kind of thing.  His only recommendation is to try to use some fine Scotchbrite to remove the rust hills.  He didn't think the Scotchbrite would cause an issue with the crosshatching.....but he didn't sound all that certain.

 

I can probably knock off the rust peaks, but what about the valleys?  Seems like those will still contain abrasive rust particles that will eventually come into contact with the rings.

 

Anyone have other suggestions?

 

I've made my own nightmare.

Edited December 21, 2023 by Matt Wilson

[FarmerJon]

This may be an unfortunate slowdown, but dont get too fustrated.  These things happen, and in the end are just minor bumps in the road. Worst case, you pay to have it lightly honed again. Bummer, but not the end of the project.

 

I would be wary of vinegar, or CLR type products, as they can be difficult to neutralize and will cause much more corrosion after a few days. 

I personally would lothe to use scotchbrite in a honed cylinder, as it might take the tooth off it, making the rings hard to seat.

If you didnt have the engine bored, and you still have an old ring or two, I might, carefully, put a ring in the cylinder, square it up, and push it down the cylinder. The ring's natural tension should scrape off anything too proud of the surface.

A new ring would also do.

 

Remember,  these old engines will run with all sorts of poor internal conditions. 

 

If remember correctly, the first year or so of SBC v8s had chrome rings that often didnt seat well. The factory warranty solution was to pour baking soda down the carb and rev the piss out of it till it stopped smoking.

 

Makes me think...Maybe baking soda on a toothbrush might scrub it off. 

 

As far as using water on machined iron parts: SOP at many machine shops is to use HOT water, usually after the hot tank to get the corrosive cleaner out of all the nooks and crannys. This is followed by being thoroughly dried off by compressed air. WD40 is better than nothing, but just barely. I rub fresh cylinders down with motor oil. Dont worlly about lint and dog hair, you will clean the bores again before you assemble. 

The big take away is: plastic bags are bad. 

Bagging a block may seem like you are being diligent to keep dust off your freshly cleaned engine, but it really is trapping any moisture in. I cover things I am working on with a Tshirt rag. Once OHV heads are on, i may use masking tape to close up the ports.

 

Good luck!

[Matt Wilson]

Thanks, Farmer Jon.  I appreciate the encouragement.  It's definitely needed.  I spent this afternoon and evening scrubbing the cylinders with a stainless steel wire brush (hand-held, no power tools).  I tried scotchbrite in one area and didn't like how it seemed to polish the surface a bit too much.  The wire brush didn't do that, so I used it to get nearly all of the rust protrusions off.  Took a fair amount of scrubbing in some places.  I did actually follow up with a quick once-over using the scotchbrite in each cylinder to get any remaining protrusions, as I was having trouble getting some with the brush).  Hopefully none of that did anything negative to the crosshatch finish.  I will say the bores don't look as brilliantly bright as they did before the scrubbing.  They are now a kind of dull gray color, but crosshatching is still easily visible.  That dull gray may be debris from scrubbing with the brush and I'll see if it comes off and cylinders brighten up when I clean them.  And yes, the bores were all recently bored and honed to a larger-than-standard size.

 

You mentioned compressed air.  I didn't use it and that's probably where I went wrong, along with using a plastic bag.  Although when I rebuilt a flathead 20 years ago, I used a bag and never had an issue, but I only used water on the cylinders, not the whole block (but wasn't hot water) and I think I used compressed air to dry that out quickly.  I didn't use WD-40.

 

Now all the rust bumps seem to be gone, but upon close examination, the remaining stained metal can be seen, as shown in the photos, but I have to hold the light at just the right angle to see the staining.  The presence of stains means to me that there is a little bit of pitting, although it may be microscopic in depth.  After all the scrubbing, I used the pick in the photo to probe the stains and in some cases, there was a bit of an increased drag as the pick passed over some of the stains.  To me, that means the pitting is probably a bit deeper in those areas, although probably (hopefully) still microscopic.  I'm hoping those don't cause any issues with ring function.

 

Any thoughts on whether honing would be warranted?  I will try calling the ring manufacturer tomorrow to see what they say.  It seems to me that a lot of assembled engines would have comparable amounts of rust from sitting, and they do just fine, but their rings are seated in by that point, whereas mine are not.

Edited January 1 by Matt Wilson

[soth122003]

If you are that worried about the cylinder. Go to Harbor Freight, spend $25 and buy a cylinder hone. Smear the cylinders with engine oil and re crosshatch the bores. With a hone it will take you about 2-3 minutes per bore and it will remove the spots and maybe clean up the pits. Also a hone takes a long time to remove even a .001" as it is a polishing tool used to clean and polish bores. It is not used as a bore tool to remove material to resize the bore, so you will not make a difference on the bore size. 

 

As far as WD 40 goes, it is a Water Displacement formula #40 not a true lubricating compound, though most people use it as such. As mentioned before with the bores and other machined areas, it is best to use engine oil to keep it rust free.

 

Joe Lee

[Matt Wilson]

I spoke to a tech rep at the ring manufacturer this morning (JE Pistons).  I was hoping he could tell me whether or not the crosshatching being visible means I'll still have proper ring break-in.  He wouldn't give me any answer without seeing it in person.  I completely understand that, but figured it was worth a try. 

 

He recommended I call the machinist, so I did and he said it would probably be best to re-hone, to be on the safe side.  He said the minimum material removal is in the 0.0003 - 0.0005" range (3 - 5 ten-thousandths).  That's not too bad, I suppose.  So I will probably take it to him to do that.

[Matt Wilson]

2 hours ago, soth122003 said:

If you are that worried about the cylinder. Go to Harbor Freight, spend $25 and buy a cylinder hone. Smear the cylinders with engine oil and re crosshatch the bores. With a hone it will take you about 2-3 minutes per bore and it will remove the spots and maybe clean up the pits. Also a hone takes a long time to remove even a .001" as it is a polishing tool used to clean and polish bores. It is not used as a bore tool to remove material to resize the bore, so you will not make a difference on the bore size. 

 

As far as WD 40 goes, it is a Water Displacement formula #40 not a true lubricating compound, though most people use it as such. As mentioned before with the bores and other machined areas, it is best to use engine oil to keep it rust free.

 

Joe Lee

Thanks, Joe.  I thought about buying a ball hone and doing that, but I will just take it to my machinist to have him do the honing.

 

As for WD-40, my intention was to displace the water that I just used for cleaning the engine, not as a lube.  I can't tell you how many sources (numerous) recommended the use of WD-40 after water-washing the block, including a local highly reputable engine builder I spoke to in person a couple of years ago, who says he pressure washes his blocks and then sprays generous quantities of WD-40 and has no rust issues.  I also read several articles and watched several YouTube videos by pro builders, most of which said the same, along with all the readers/viewers' comments to these articles and videos.  I figured with all that testimony, it must be the way to do it (despite my gut telling me otherwise, honestly).  No more water for me - except for the cylinders themselves, to remove honing grit, but I will use hot water and will blow dry them immediately with compressed air and oil them down, not WD-40.

 

Geez, a hard lesson.  Seems like I've learned a few of those with this build, but so far, none were insurmountable.

Edited December 22, 2023 by Matt Wilson

[soth122003]

The WD 40 will work very short term. It is too thin to make a long lasting barrier as it will evaporate and or run off leaving a to thin protection that will be over come by humidity and water vapor in an area. All most all tech bulletins and manuals I've read will say to use soapy water to clean and then warm/hot to rinse. Then apply a film of oil, grease, primer what have you to prevent rust from forming. Everything I have read not one mentioned WD40.

 

Joe Lee

[Sniper]

For anyone following along in this Saga might be wise to clean the block before you go to the machine shop. When I had the Machine Shop redo the kingpins on my 51 I had to run them through my parts washer and cleaned it all up. When I took it there The Machinist asked me if I had blasted the spindles and uprights. I told him no I just ran them through my parts washer that's how clean they were. If you clean the block first then when all the Machine Works done you just give it a final clean and Assemble.

[Matt Wilson]

Following up on this topic to describe the progress (or regress, as the case may be).  Sorry - another long post....

 

I took my block back to the machine shop to remove the cylinder rust that I had caused.  He honed all the cylinders, removing 0.0005 (half-thousandth) from most and closer to 0.001" from #6.  He and I discussed using Line2Line piston skirt coating to take up the excess clearance.  He highly recommended it as a durable long-lasting coating, which matches what I've read too (good for the life of the engine).  Ok, no problem.  I can deal with that.

 

But I have a dial bore gage, so I decided to take my own cylinder measurements when I got home.  I found that all six bores have a "bulge" near the top, as seen in the image below.  This "bulge" makes the diameter about 0.0006 - 0.0007" larger than the rest of the bore over a distance of about 2" vertically.  Below the bulge, the diameter drops back down, almost to it's value at the top (but not quite).  I called the machinist and he acknowledged the presence of the bulge and said that it has to do with the diamond hone equipment he uses not being great for opening up the bores by very small amounts.  His boring/honing machine is brand-new as of last year and did a fabulous job on my cylinders when I brought him my new pistons at that time.  The taper and out-of-round were no more than 0.0002" total variation, but now opening up the cylinders by such small amounts to clean up the rust was not a job the machine is suited for.  In any case, he said he only measured 0.0005" in the bulge, not 0.0007" that I was getting and that it would be fine.  I'm confident in my measurements.

 

I'm using a set of thin modern rings with thicknesses of 1.5 mm top, 1.5 mm 2nd, 4 mm oil (0.058", 0.058", 0.157").  It's a little tough to find specs on thin rings, but what I can find indicates only small amounts of taper are acceptable, ranging from 0.0002 - 0.0008".  These are for recent-model Fords, VWs and Chevy LS engines.  And that allowable taper is over the entire cylinder length, whereas the bulge in mine are over only 2" length, so probably a worse situation.  In the old days, with thick high-tension rings, taper of 0.010" or even 0.020" was acceptable.  I called the ring manufacturer, JE Pistons, and talked to two people - one said the rings would be fine, and the other first said they would be fine, but then inexplicably made a 180, saying he wouldn't run them in my "bulged" cylinders.  Neither one could give me a taper spec.

 

Finally, I spoke with someone familiar to some of us, who is respected and does lots of work on these engines, including upgrades to use modern pistons and rings, and he said the bulge was too large for modern rings, especially considering the short distance over which the bulge takes place.  He said the lower tension won't follow the diameter variation, leading to poor ring sealing and shorter life.

 

If I decide I can't use the cylinders as they are, then my only option is to buy new larger pistons and have the cylinders bored to a larger oversize.  I think I'm inclined to do that, based on the info I've gotten so far, but I wanted to ask you guys and gals for your input before I make such a big (expensive) decision.  Keep in mind that I'm rebuilding this engine for longevity, as I intend to drive it and put miles on it.

 

Thanks for your input.

Edited February 26 by Matt Wilson

[FarmerJon]

What pistons are you running that takes the modern sized rings? 

What size is your bore currently? 

 

[Dave72dt]

Fairly obvious you have a direction you're leaning towards, and you want some verification to justify your decision.  If I was your machinist I know what direction I would go in but I'm not and I'll leave it at that.  You've already talked to at least 4 experts.  Unless one of us is an engine machinist or an engineer well versed in piston and ring technology, all you'll get from us is an opinion based on what we think we know.

[Los_Control]

10 minutes ago, Dave72dt said:

all you'll get from us is an opinion based on what we think we know.

I'm really good at that 

[Matt Wilson]

10 hours ago, FarmerJon said:

What pistons are you running that takes the modern sized rings? 

What size is your bore currently? 

 

I'm running some custom-made forged pistons by JE Pistons.  The bores are about 3.482", which is nearly 0.045" oversize from the original bore size for this 251 block that I'm using to build a 265.

[Matt Wilson]

9 hours ago, Dave72dt said:

Fairly obvious you have a direction you're leaning towards, and you want some verification to justify your decision.  If I was your machinist I know what direction I would go in but I'm not and I'll leave it at that.  You've already talked to at least 4 experts.  Unless one of us is an engine machinist or an engineer well versed in piston and ring technology, all you'll get from us is an opinion based on what we think we know.

You're right, I am leaning in a direction and yes, I've talked to 4 people.  I question whether the two from JE Pistons were "experts," as one is a salesman (although he seems to be knowledgeable) and the other one is in tech support but changed his answer for no apparent reason, and neither person could give me a taper spec (seems like that would be basic available info).  The other two I spoke to are machinists, but again, one gave me one answer and the other gave me the opposite answer.  The one who directed me to re-do it all with new pistons, rings and overboring was the only guy to give me some technical reasons that sounded pretty solid.  The others literally just said "it'll be fine" or "I wouldn't use them as is."

 

I'm thinking that, as painful as it is (financially), I should lean toward the side of caution by buying new pistons, rings and having the cylinders bored more oversize so they will (hopefully) be straight and round.  At this point, as you alluded to, I am kind of looking for confirmation that this is the right decision so that my wounds won't hurt as badly as I'm licking them.  On the other hand, if someone has some really good reasons that I don't need to go that route, I'm still open to listening.

[9 foot box]

   This shows the difference in bore and stroke of engine cubic inches. In order to use the pistons, you could buy Melling cylinder sleeves. I would like to see one of the pistons. I like the original style pistons with four rings. But you would need to find .060” over size after the cylinders are rebored. Sorry to hear of your problem. I’d give you another block. I’m trying to reason how a simple hone to clean up the cylinders, turned out like it did. Rick D.

 

Edited February 28 by 9 foot box

[Dodgeb4ya]

Did your machist fab up a torque plate for honing the block?

Wonder how much distortion of the cylinder walls will be after the head is torqued.

Answer to question # 1....no.

It would be a $$$% custom fabrication.

I'd assemble and run it.

You are digging way to deep IMO.

Modern engines....be real careful.

 

[Sniper]

He spent beaucoup dollars on custom JE pistons and rings.  Not sure a torque plate is uncalled for?  If it was stock pistons and rings I'd agree with you, but I think this build is a little more intense than a stock one.

 

I bet the Freewheeling Tony Smith has a torque plate.  Not sure he loans/rents it out though,

[Matt Wilson]

Thanks, guys, I appreciate the inputs.

 

The machine shop did not use a torque plate.  One was not readily available at the time, and I didn't see it as necessary.

 

As for digging too deep, I would agree if I was running OEM-style pistons and rings, but I will be running modern forged pistons and modern low-tension rings.  The first person who told me that my rings would not tolerate my misshapen cylinders was Freewheeling Tony Smith.  He works with these engines an awful lot (machine work, assembly, etc.), including the incorporation of upgrades to use modern parts like I'm doing.  He really seems to know his stuff and has an excellent reputation in the Dodge/Chrysler flathead community.  Since my last post, I also received word from someone who knows a Total Seal tech rep, and he conveyed my situation to him.  The rep said the same thing - that the rings are not forgiving of this type of situation, and he recommended I immediately get the bores straightened.  Of course, that will require I get new, larger pistons and rings.  Sigh....  If I want to use modern rings, it seems that the old standard of several thousandths of taper or out of round being acceptable is no longer applicable.

 

I've also read some things to indicate that torque plates are recommended (some say necessary) for low-tension rings.  I don't know if that's really 100% true or not, but in any case, since I will be re-doing this aspect of the engine, I asked Freewheeling Tony if he has a torque plate for this engine.  He said he doesn't, but would enjoy fabricating one and would rent it to me.  I plan to go that route.  With all the effort and money I've put into the rest of this engine, I figure I'll go the whole nine yards on this part of it too.  It will be a couple of months or so before he has time to make it.  That will work out ok, because it will be a couple of months before new pistons would arrive anyway.