Kurt, you may not have noticed my quote of Steve Christ in post #1 about the manganese, but thanks for mentioning it because I totally forgot to discuss what manganese does in cast iron.

Manganese serves more than one purpose. Sulfur is almost always undesirable - it makes iron & steel weak at higher temperatures. (This turns out to be desirable in free-machining steels, but then they are not suitable for welding.) Manganese combines with any sulfur present to form manganese sulfide which floats to the top of the melt and is skimmed off, so manganese acts as a purifying agent in the melt and is added to most cast iron for this purpose.

Additional manganese that remains in the casting does act as a hardening agent. The amount of hardness is not what we expect from quench-hardening, but it does give a more tough, wear-resistant block. This additional hardness might even make the machining go better. A modern rigid boring bar with a carbide bit should not even notice the difference. I do not think that manganese affects the other topics discussed so far.

It costs $$$ to add the extra manganese, so only the blocks that needed it for high endurance would have gotten it.

 

Yes, I can agree on the flywheel and brake drum relationship, ok on oil filtrering, but don't forget the air filtering far more important where cylinder and ring wear is concerned. I still have to agree with you and the others that the materials used to cast the blocks are better. If you would pull apart a flat head Plymouth or Chrysler engine you would have seen the relative softness of the castiron, they were the worst of the lot for wear, at 60,000 you had to rebore them. It just has to be the materials used by the manufactures.

 

kotzy, don't you miss the oil bath air cleaners? Positive crankcase ventilation is another change that helped engines live longer.

The materials have not changed so much as the process control. The automotive industry pinches every penny it can. On the trailer towing forum there was a thread on welding hitches to frames and, after a lot of posts, it turns out that Ford has resisted moving away from plain low-carbon steel frames until very recently. Design techniques and process controls have come a long way, but my guess is that only 10% makes the vehicle better and the other 90% is used to make it cheaper. (This is not so bad as it keeps prices down and keeps Ford & the others in business. The 10% still has given us vehicles that go hundreds of thousands of miles, while the flat-heads rarely made it to the first 100K mark.)

 

Interesting. So if they stuck extra manganese in the FT / mirror 105 blocks, we end up with a harder, more durable block. So can we agree that it's manganese, not nickel, that's making the difference?

I also know the later mirror 105 blocks had a propensity to crack the oil passage that leads up to the rocker assembly. Might this provide any useful information?

 

'96 t-bird rotors warped on-demand... known issue with most Fords around that time. Go out and buy aftermarket from Napa, never an issue again. Even made-in-china rotors were 10 times better than the stockers, based on my own experience.

Why? Consistency in the alloy, I'm willing to bet.

 

Kurt, You are correct, there is no free lunch. The extra wear resistance that helps the FT / mirror 105 blocks go for high miles does make them more brittle, hence more prone to crack. The 391 that was in my '68 F-350 when I bought it was a Ford factory rebuild in 1973 and it was still running (with a few bad valves) at over 400,000 miles - and without any serious blow-by at that.) I would expect that the 427 side-oiler blocks do not have the extra manganese as they really were not intended to do the 100K+ mileages.

If there are still some "nickel believers" out there, we could do some testing. I have a "105" & a 390 that I could cut samples off of. I'd have to "call in a favor" so I hope everyone is satisfied that nickel is not present in any serious quantity in any Ford block.

Art, I agree about consistency in the alloy. (Low alloy, in this case. Control of impurities is still important.) In the first half of the 20th century, the foundry-man in charge of the melt threw in scrap and additives "by eye", based on experience. Coupons were taken for wet chemical analysis, which took hours of time. Most castings had cooled by the time the composition of the melt was known. If the guy controlling the melt composition had a bad day, there were a lot of marginal castings made. By the 1950's spectroscopes were used: an arc struck on the coupon gave off light which was passed through a prism (or diffraction grating if any physicists are reading) and printed on film. Then an expert "read" the spectrum and reported the composition of the melt. This still took enough time that casting compositions were still hard to control. For the last 30 years, an attachment on a scanning electron microsope does the spectroscopy and a computer does the analysis in less than a minute. The time to pump down the vacuum in the chamber is the biggest delay and all this is done before any pouring. If there is an error in compositon it is corrected BEFORE the pour.

Consistency is the key and computer-automated analysis is almost instant. Even in the '30's they accurately knew that was in the castings, but it was "after-the-fact". With regard to China, let me make a simplistic observation. They have "dark ages" foundrys that do not even do any analysis, but if an American (or European) company has set up a plant there, it will have the latest technology. In my industrial experience (semi-conductors, 30 years ago) we put the most expensive automated equipment into our Korean plant. This was NOT because their labor rates were cheap - even then the Korean labor rates were catching up with our Bay Area labor rates. It was because the work ethic was much better in the Orient - they had pride in putting out quality product far beyond the American labor force.

 

I have an excellent suggestion on the hardening theory. Not everyone has a freekin brain I seen some stupid chit in my day. Here's a scenario for you.. Egine is hot a &^%$ (*******) pulls into a gas station, the engine is spewing, he lets it finish (engine running) finally manages to get the cap off and plops a hose in and starts flooding the insanely hot block with nice cool water.

 

OUTSTANDING!!!

This theory is in first place, way ahead of anything else discussed so far. We all know that idiots do this now and then, but I bet they do not tell their mechanic or machinist.

 

I can say I seen it done... if it work hardened the block is anyones guess LMAO.. but I'm sure of one thing.. that engine was short lived after that LOL

 

Pouring cold water into a hot, empty water jacket is a perfect way to accomplish quench hardening. (No need to consider any other method of hardening.) If the engine is sufficiently hot, the entire amount of coolant in the block evaporates in a flash when the pressure is relieved.

In a gas station, I have seen a plume of steam coming out from a radiator go 50 feet high. (Not my rig, of course! I tried not to laugh as I walked back to my rig, only to find my surge tank had a crack and there was a stream of coolant squirting out. Soldered it up in the motel parking lot, trying to be thankful that my engine was not affected.)

If the engine is kept running after the coolant exits, the cold water is on one side of the cylinder wall and the running engine could have easily gotten the cylinder walls above the critical temperature for cast-iron.

 

You lads are getting a bit ahead of me, I just typed up a message and lost it, oh well try it again. In answer to Archie's questions about oil bath air cleaners and pcv systems. No I'll never miss an oil bath air cleaner, they are only about 80% effective if I remember the studies against around 97% for a paper element. Yes paper can become clogged on dusty road operation, on hard surface they will last far beyond thier recommended life. Some think they can blow them out, however those particles which imbed themselves in the media take a bit of paper with them when doing this and the effectiveness is gone. I don't think much of K+N for the same reason. I had a 1954 Ford with a small Y block in 1957 when the paper filters came out, don't remember by which of the filter companies, in 57 Ford joined in and I altered my 54 base somehow to use the paper.
PCV systems are the result of the auto industry utilizing the armed forces developed Donaldson valve to production vehicles. Road draft tubes were for the most part ineffective until around 35 miles per hour, and city speedlimits were 25 and enforced. What were we doing to engines, sludging them up and let me tell you it was bad. A couple of hours on a valve job digging that stuff out of the chambers to find the springs, and you were coal black, the miners were not as dirty. Finally I remember one of my engineer friends telling me that if they were developing a part and someone found a way to shave a quater of a cent off the cost they were ready to party, yes I know how they think about stuff. All this is a bit off subject but I think we will all learn something.

 

kotzy, I could not agree more with every last point you made.

I started this thread and I will certify that all these points are related to cylinder wall hardness. The air filter & PCV items would lead some to think that old cast iron was softer than the current stuff. Marketing people want to brag that everything gets better every year - that is part of how they sell cars. When it comes to cast-iron, not that much has changed in a long time. Most abnormal wear in old iron is the result of something else rather than the cast iron's hardness.

If we checked with the flat-head guys, I'll bet somebody has done a fresh bore job in a flathead with a perfect rigid-honed cross-hatch, used modern low-tension (moly?) rings & modern oil, installed a PCV system and a paper air cleaner. This engine should be capable of running up the high mileage that its modern descendents can do.

 

Well I had to cool off for a few days ..and working some crazy hours..I'am glad to see this thread still going.. My water and oil theory still stands with me..

And while at work last night I had also thought about cylinder Carborizing... Carborn from whatebver source in either the Oil from contamintates..Or from the product of Cast..Overheated cylinder walls..Via..whatever..Carboration can start at as little as 800* depending on the depth of the hardening you want to obtain.. usually a few ten thousands of an inch over a 5 or 6 hr time period... Yes that short of time !!

When i went into tool and die making before I had my Engine shop.. I would case harden gage blocks ..before grinding to final demintion and finish..with an oven set at 1000* and place the material to be hardened in ceramic holders.. and incase them in carbon dust...

Case and point.. Cylinder heat ..available carbon..= case hardening...

I have seen it..I have done it.. Thats about the best this dummy can come up with...

RJ

 

Oh and on a quick not..you guys have to excuse my spelling this morning..It was a 14 hr shift last night..with 4 hrs of sleep..

But can someone tell me what overheated oil turns into?? CARBON!!

I'll be back in a few..I have to get on the Mower..and get some lawn done...the Neighbors are getting jealuos of my Hay growing!! LOL

RJ

 

Glad to have you in this thread, Russ. We need to tap some of your experience with hard cylinder walls.

Your understanding of carburizing is correct, but it applies to a low-carbon steel, which only has around 1/4% of carbon. For steel to be hardenable, it needs to have from 1/2% to 1% carbon, so carburizing as a way to get the surface of a low-carbon steel up to the proper percentage of carbon to quench-harden it. (Most tapered roller bearings are carburized - this gives them a hard, wear-resistant surface, with a tough core.) More than one percent of carbon in iron does not help it quench-harden. When you are up to the 3% to 4% carbon that is in most cast-iron, more carbon definitely makes no difference.

The question no one answered yet is: Does the whole cylinder wall seem to be harder, or is the top (or bottom) harder? Redmanbob's suggestion that compounding a severe overheat by quickly filling an empty, hot block with cold water, gives the violent quenching that would be required for quench-hardening. Russ did not mention it in his description of carburizing, but after the 1,000-degree soak, the piece has to be heated up to at least a dull red (1,600) and then quickly quenched to low temperature. Note that we are a temperatures where aluminum would be starting to melt!

If anyone has a scrap block with a hard bore, doing a "scratch" test with a file on the hard bore would reveal if it is harder at the top of bottom and if the bore was harder than another surface of the block. From Russ' post in the original thread that this one forked from, the hard layer is often thin enough to be honed through and then bored.

Summarizing our theories:

o Oil adding carbon - should give a hard lower cylinder, but only if quenched with cold water.

o Crome transfer from chrome rings should give a hard upper cylinder, and would have to either be quenched, or have some kind of strange work-hardening.

o Simple quench hardening (Redmanbob's suggestion) could harden the entire cylinder, or it could favor the top where the temperatures are probably higher. I favor this explanation at this point, but there is still plenty of time for other ideas.