Topic: Mechanics: Can engines be roughly dated by measuring parts wear?

[Kaze]

==> Is there a way to be relatively sure of your engine's mileage by testing the wear on parts?

My engine came from a parts bike, and I have no idea whether my odometer is the original partner of that engine.

I suppose that my bike's compression may not be a fair indicator, because it sat in a damp climate for at least 10 years before I got it. Then it took me another couple years to get it to a rideable state. It was 125-120-120-125 after I put it all together, but I haven't tested it since. (No tester at the moment). I have not sent an oil sample for testing yet, so I can't say what sorts of metals are swimming around in there (yet).

Obviously the condition of the engine would change if the previous owner was a brodie peelin', wheelie flinging, front wheel stoppie mofo... but generally speaking, I'd like to know if there are tests that a person with the right tools could do to measure wear on certain parts and come back with "Your engine is about 11k miles old" or even "Your engine is between 10k and 30k miles old".

[Don R]

 I would guess the wear amounts would be very dependent on oil changes and tune-up frequency. A motor with flooding carbs and gassy dirty oil will show significantly more wear than a well-tuned machine.
 You may however, tell if it's a worn engine near wear limits or a babied engine that's close to new specs. I just trust what I have and try to take care of it until it gives me a reason to look inside.
 Cam lobe wear might be an obvious tell.  With a fixture and a dial indicator you might be able to measure actual valve lift through the rocker adjuster holes and avoid a tear down.
  My thought is, just ride it.

[newday777]

So this kinda sounds like you are doing this motor install to flip the bike??
There really isn't any way you be realistic in this and point and say how many miles by wear.

[calj737]

==>I have not sent an oil sample for testing yet, so I can't say what sorts of metals are swimming around in there (yet).

Pointless endeavor. If you have only recently "resurrected" this motor, run it strong and fully for 300 miles. Change the oil AND filter. Take the old filter and cut it apart. Run a magnet over the pleats to determine if there's any ferrous metal. If not, Ride the bike for another 1-3,000 miles. Swap the oil and filter and repeat the cut/magnet trick.

Don't look for problems; address them if they surface. These are reasonably hearty little motors and unless someone absolutely flogged it constantly, put 10s of thousands of neglected wear on it, it will be just fine. Keep up with the recommended maintenance and keep detailed records for yourself about plug colors, oil investigations, and cam adjustments. These things will tell you more about the wear and tear on the motor than an oil analysis.

Case in point: I had a German sedan that a shop swapped the injectors for me (engine had 330,000 miles on it). Inadvertently, the Tech didn't extract the old O ring and it plopped down into the valve train. Installed a new O ring and injector. Fired up the motor and after a few seconds, yup, bad miss and idle. Head scratching, repeat. Same results. After discovering the issue, the head came off and went next door to the Machine shop.

The Machinist there after inspecting the head, guide, valve confirmed the valve was bent and guide was damaged. He was surprised that kind of damage could occur on such a "low mileage" vehicle. I asked him why he felt that. He said, the head looks like it has 25-30k miles on it due to wear. When I told him he was off by a factor 10, he fell over.

Moral of the story: use quality oil, be diligent with your maintenance, and things will last. (I gave the car away with 544k miles and it was driven another 60k before getting totaled in a body accident).

[HondaMan]

I, too, ran an engine - Ford's 200 CID straight 6, 1978 build - nearly 480k miles before the State of Colorado outlawed it: pissed me off, I wanted that 500k trophy...it ran perfectly, reliable as a hammer. The only thing that ever wore out was the valve cover gasket, made of cork. It twice disintegrated from age.

[ekpent]

I, too, ran an engine - Ford's 200 CID straight 6, 1978 build - nearly 480k miles before the State of Colorado outlawed it: pissed me off, I wanted that 500k trophy...it ran perfectly, reliable as a hammer. The only thing that ever wore out was the valve cover gasket, made of cork. It twice disintegrated from age.

Was it a 200 ci or 300 ci Mark ?  I had a Ford work van at a job I had as a long run driver with a 300 straight 6 and it had well over 325,000 on it when I was done with it and the only problem with the engine was when it blew out an oil pan gasket and things got a little messy on the back coming home with some burning smoke oil also off the muffler.  Called it a Michigan undercoating treatment !  The shop replaced the oil pan also while it was off because they are not the best metal in the world.

[Kaze]

All right. I will accept that there are too many variables to find out what I wanted to know. Knowing won't make it run any better or worse anyway. I'll concede that it's best to just do what I can do from now on.

I suppose if the neurosis gets the better of me, I can always just sell the house and just replace every part with new ones from cmsnl.com... (that was a joke)

[Kaze]

NewDay:
Not exactly. This is a sentinmental project. The K6 motor has been in there for a few years now. I just didn't ask before because I wasn't using this forum for help until recently.

Compression on the old K7 motor was extremely bad. I was albe to get it running but only on 3 cylinders and there was a loud metallic sound that was clearly not meant to be there. Not reckoning that there might be useful online help (because there didn't use to be) I declared the K7 engine "dead", and swapped it out with the parts-bike engine (K6). Compression for the K6 engine was within 10%, so I have been working with that ever since.

Now of course there are several Youtube videos on how to perform a top-end rebuild on a CB750, but there weren't when I needed them, and I didn't know about you lot. Moot point now, I've just got this one engine now.

[Kaze]

(As for the 200ci straight 6, my 66' Falcon Futura had one too. The car wore out around it, but the engine was fine.)

[Tracksnblades1]

I, too, ran an engine - Ford's 200 CID straight 6, 1978 build - nearly 480k miles before the State of Colorado outlawed it: pissed me off, I wanted that 500k trophy...it ran perfectly, reliable as a hammer. The only thing that ever wore out was the valve cover gasket, made of cork. It twice disintegrated from age.

Was it a 200 ci or 300 ci Mark ?  I had a Ford work van at a job I had as a long run driver with a 300 straight 6 and it had well over 325,000 on it when I was done with it and the only problem with the engine was when it blew out an oil pan gasket and things got a little messy on the back coming home with some burning smoke oil also off the muffler.  Called it a Michigan undercoating treatment !  The shop replaced the oil pan also while it was off because they are not the best metal in the world.

The 200 six was a timing chain engine. I’m thinking both the early 4 mains and the later 7 mains engines..

The 240 and 300 were steel timing gear engines. No chain… Some later 300s had piston cracking problems if the old pistons were used in a rerring with taper…

[HondaMan]

Yep, mine was the 200 CID with 7 mains and a gigantic 1-bbl carb (7/8" throat!), top speed at 5000 feet altitude was 84 MPH. But, it would do it all day without any complaint, as I found out when i got some distant consulting jobs to work on machines 100 miles away from here.

That 300 CID is like its big brother: everyone I know who had/has one won't share it with anyone else, either.
The 240 CID dominated the Ford sedans around here, it seemed to like the high altitude and ran until the cars dissolved around them. I knew a couple of them that were past 400k when I met them, and 10 years later were still commuting to work daily.

[PeWe]

I should open engine covers for inspection.
A good engine when parked might have rusted inside during all years.

Start it then can harm it.

If oil has been too thin, valve guides can be worn, ex especially. Upon that long intervals, hot climate to make it worse.

[Tracksnblades1]

We used to change oil in the 750s every 1000 miles using Vavoline or Castrol 20w-50 with SE and later SF ratings…
The tired ones ran straight 50 to keep the oil light off at an idle…

But that was back when we were all immortal and rode like it….😏

[rotortiller]

You can get a rough estimate from the top cylinder ridge where the rings do not make contact provided it is the original bore. Another rough estimate area is the clutch basket wear area where the clutch plate tabs hammer back and forth. As others pointed out a complete tear down is the only way to know the complete condition of the motor. These bikes are reliable so if it runs and rides nice with no blue smoke , enjoy the beast.

[Stev-o]

(As for the 200ci straight 6, my 66' Falcon Futura had one too. The car wore out around it, but the engine was fine.)

Back in the day, my Dad had a '63 Falcon with a six too, had a "three on the tree". It was his daily driver and my older brother drove it too, before buying his first car. Dont recall what happen to it, must have just been sold off when my Dad bought a '67 Mustang Fastback [with a 289 V8]

[bryanj]

In all the years i have been working on Hondas i have never found a ridge at top of bore except for one little 75cc runabout that did 150,000 miles in 3 years

[MauiK3]

The old Chrysler slant six was another engine that seemed to never wear out. At the shipyard I worked in they were used in what were called "chore boy" trucks, little heavy duty flat bed trucks for transporting parts around, sometimes very heavy parts. During the heyday years I think they ran 24/7, never shut off, purr like a kitten.
More recently, before I retired from DOT here on Maui we had some mid 90's Chevy trucks with the small V-8, I forget the size, with over 250k on them, purred like a kitten. The motors did not fail, stuff like A/C compressors, alternators etc. did but not the engine or even the transmission.

[HondaMan]

In all the years i have been working on Hondas i have never found a ridge at top of bore except for one little 75cc runabout that did 150,000 miles in 3 years

Me, neither: I have seen (in my own 750) where the hone marks wore off in the bores but were still visible at the very top of the cylinder: it had 80k+ miles on those bores. But - I couldn't detect any wear: using both my bore gages and the [bore gages plus micrometer] methods, I couldn't find any diameter difference between the top-of-travel for the upper rings and the top-of-bore where the rings never touch it. I suspect the hone marks were only a ten-thousandth or so deep, barely visible at top-of-travel for the upper ring in the end.

Once these liners 'cure', they simply don't shift size nor shape. This is how good engines last so long - like many old straight 6 engines used to. I have on in my JEEP, too, the 4.0L version. It's another hammer-like tool.

[rotortiller]

http://forums.sohc4.net/index.php?topic=110778.0

[Kaze]

I didn't use to care about these things. All I wanted was to ride my motorcycle. Mileage? My bike had 145k miles on it but it went 125mph, so I figured it must be fine. Oil leaking from the front of the engine? Nothing I can do about that, I'll just change the oil more often. No baffles in the pipes? Good. People can hear me. Rain? Pffft. I'll ride around the drops.

...am I in that "Wild Hogs" movie?!?!

[Kelly E]

I didn't use to care about these things. All I wanted was to ride my motorcycle. Mileage? My bike had 145k miles on it but it went 125mph, so I figured it must be fine. Oil leaking from the front of the engine? Nothing I can do about that, I'll just change the oil more often. No baffles in the pipes? Good. People can hear me. Rain? Pffft. I'll ride around the drops.

...am I in that "Wild Hogs" movie?!?!

Are you William H Macy's character?

[Kaze]

He does get the hot girl.
Besides, I would never use voice commands to search for "alternative specs" in a coffee shop.

[Stev-o]

He does get the hot girl.

His wife was "desperate" and went to jail!

[Kaze]

Marisa Tomei is in jail? QUICK! Get the horses and the dynamite! We gotta break her out!!!

[Kelly E]

Marisa Tomei is in jail? QUICK! Get the horses and the dynamite! We gotta break her out!!!

Call up the two youts to go save her in the Pontiac Tempest.