Wildguzzi.com
General Category => General Discussion => Topic started by: brider on September 10, 2015, 11:15:55 AM
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There's a LOT of data out there on the problems with flaking chrome, and how to deal with it (re-sleeve, re-chrome, re-jug up to 949cc, etc), but I couldn't find any testimony as to the reliability of existing chrome-bore bikes that seem to still run fine.
Example: I've looked at several old Loops with anywhere from 10k to 50k miles, and in the case where they still run "good", is it possible that if the compression is still in the "good" range, that the original chrome bores will still do just fine? The mental discussion is always "Do I need to re-cylinder this rascal, and factor that into the price.....". :Beating_A_Dead_Hors e_by_liviu
Thanks! Please direct me to a relevant discussion if I've missed it, and I have looked at GB's site.
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This was my experience. I bought a T-3 in 1989 after it had sat indoors for about five years previous. It had 32K miles. At about mid 60K my left side started smoking a bit and kept getting worse, (but never bad and only under acceleration and never had an increase oil use and it always ran good) until when checked out with around 76K miles the left cylinder was flaking chrome.
Had the engine redone with the big bore nicisel kit and now have 104K on it and it is running great.
The only thing I would have done different is to of had balancing done as it does increase vibration, but still not bad except it almost always makes my nose itch like crazy.
GldierJohn
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Example: I've looked at several old Loops with anywhere from 10k to 50k miles, and in the case where they still run "good", is it possible that if the compression is still in the "good" range, that the original chrome bores will still do just fine? The mental discussion is always "Do I need to re-cylinder this rascal, and factor that into the price.....". :Beating_A_Dead_Hors e_by_liviu
Loops will run "good" and still be nearly totally knackered. The compression may still be in the "good" range... for a while. But, it will rapidly drop into the "poor" range as they are used. Been there, done that. Repaired that even more.
Compression/oil usage isn't the real issue - it's where the flakes of chrome go. Loops have no oil filter, only a fine mesh strainer screen. That does not stop the majority of flakes, the tiny flakes will then find their way through the oil pump, to the main bearings, camshaft (which runs directly in the crankcase), etc., causing abnormal wear and requiring crank grinding, oversized, bearings, new oil pump, reground cam, etc.
It boils down to this: replace the cylinders now and spend around $1k, or "just run it", let the flakes of chrome do their damage and spend $3-4k. You might choose "do it now" and still find that damage has already happened. I've rebuilt several "well maintained", low mileage (20k or so) engines that still had excessive wear on the crank journals. Cost also depends on how much of the work you can do yourself.
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Compression/oil usage isn't the real issue - it's where the flakes of chrome go. Loops have no oil filter, only a fine mesh strainer screen. That does not stop the majority of flakes, the tiny flakes will then find their way through the oil pump, to the main bearings, camshaft (which runs directly in the crankcase), etc., causing abnormal wear and requiring crank grinding, oversized, bearings, new oil pump, reground cam, etc.
Of course, I forgot about the lack of a filter on the Loops. Your point is taken. Thanks!
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If you find a Loop you really like that still has chrome cylinders talk to the seller about agreeing on two prices. One if the chrome is still intact and another if the chome has flaked. Then pull the heads and check.
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If you find a Loop you really like that still has chrome cylinders talk to the seller about agreeing on two prices. One if the chrome is still intact and another if the chome has flaked. Then pull the heads and check.
THIS ^^^^^^^^^^^^^^^^^
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If you find a Loop you really like that still has chrome cylinders talk to the seller about agreeing on two prices. One if the chrome is still intact and another if the chome has flaked. Then pull the heads and check.
Even if hasn't flaked yet, it's not a matter of "if", but "when" it will. I just bought an Ambo with original chrome cylinders. Told the PO not to even start it, and I had the Gillardoni kit installed immediately. I never even heard the bike run before I parted ways with a bunch of cash. With all the real world evidence presented here from Charlie, who repairs these bikes for a living, you'd be a fool to keep running the chrome.
Most of the sellers aren't even aware of the issue, or are in denial, and won't budge on the price due to the chrome cylinders.
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Here's a 100% accurate way to test if original chrome bore cylinder will flake or not:
Drop them into a bucket full of water, if they sink to the bottom, they'll flake. :evil:
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My experience with the T was similar to John's: It began to smoke on one side at about 60k. With no oil filter, there was a risk I'd find serious trouble, but no -- everything in the bottom was clean and tight. I used the Gilardoni kit and Mike Harper rebuilt the heads.
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Here's a 100% accurate way to test if original chrome bore cylinder will flake or not:
Drop them into a bucket full of water, if they sink to the bottom, they'll flake. :evil:
That's like the old sure fire test for radio vacuum tubes, throw them over your shoulder and if they break they were good.
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Here's a 100% accurate way to test if original chrome bore cylinder will flake or not:
Drop them into a bucket full of water, if they sink to the bottom, they'll flake. :evil:
Test Guzzi OEM shocks the same way!
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Here's a 100% accurate way to test if original chrome bore cylinder will flake or not:
Drop them into a bucket full of water, if they sink to the bottom, they'll flake. :evil:
<MontyPythonOn>
"She's a witch! She's a witch!"
</MontyPythonOff>
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Even if hasn't flaked yet, it's not a matter of "if", but "when" it will. I just bought an Ambo with original chrome cylinders. Told the PO not to even start it, and I had the Gillardoni kit installed immediately. I never even heard the bike run before I parted ways with a bunch of cash. With all the real world evidence presented here from Charlie, who repairs these bikes for a living, you'd be a fool to keep running the chrome.
Most of the sellers aren't even aware of the issue, or are in denial, and won't budge on the price due to the chrome cylinders.
Cam no argument on that they will flake and the motor should not be run until the cylinders are Nikasil coated or replaced. However if the OP pulls the cylinders and see's the bores are pristine and the chrome has not flaked the motor most likely can be run without to much drama after the top end is freshened up. If it has flaked total disassembly should be done. Its nice to know before you dive in.
My Eldo, 850T and T3 hava all had either Gilardoni cylinders and/or Millennium re-plating of the stockers before ever touching the starter button. The big difference is I didn't buy them as runners like the OP is trying to do. mine were projects from the start.
If the seller isn't aware of or in denial of the ills of chrome plated cylinders and doesn't want to work with you on price because of them move on. It is far better to wait for another deal instead of paying a premium and then potentially spending another 4K on a total engine rebuild.
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My first exposure to the issue was with my '69 Ambassador. Bought the bike in April of '97 with 36,360 miles on it. The previous owner had put 3000 miles on it in 13 years. I put that many on it in the first two months I had it. Compression on both cylinders was already low - 120 psi. A few years later I followed Pat Galbraith and Joe Kenny down the BRP to Guzzis in the Blue Ridge. I noticed on that trip that it was way down on power and would get hot enough on the hills that I could smell it. 54k miles on it at the time.
Back at home, I checked the compression again - 90 psi. Tore it down and found a large crescent shaped area of chrome missing from the top of both cylinders. When I removed the cylinders, the top ring of both pistons fell out in three pieces. Dropped the pan and oil line/oprv, removed the cap from one con-rod. Very little wear, no embedded flakes that I could see, oil holes open, rod journal measured within spec. and had no scoring. New Gilardonis, bottom end buttoned back up, heads rebuilt. That was 54k miles ago now.
I consider myself very lucky that the flaking chrome didn't destroy the engine in that 18k miles. Could be my 1000 mile oil change interval flushed the better part of it out, before it got circulated through the engine. Whatever happened, I wouldn't do it again and wouldn't recommend trying it yourself.
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If the seller isn't aware of or in denial of the ills of chrome plated cylinders and doesn't want to work with you on price because of them move on. It is far better to wait for another deal instead of paying a premium and then potentially spending another 4K on a total engine rebuild.
Agreed. Personally, it's a gamble I'm not willing to take. For ME, peace of mind is huge when it comes to owning and riding vintage bikes. That's why Charlie (or Mark Etheridge) has touched all my old Guzzis first. I don't need the stress of "will this engine blow up" because I rolled the dice.
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Keep this in mind. Crankshaft bearings are expensive. The engine block is machined to hold the camshaft without replacement bearings. Chrome runs thru the oiling system and works like sand destroying all bearings and an engine block.
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I'm really glad this topic came up. And while we're talking about it, are most of you just draining oil roughly every 1000-1500 miles or are you dropping the pan and cleaning the screen too.
Or some mixture of the two, like dropping the pan every third? I've been told by multiple people that frequent oil changes are the secret to longevity but I am not looking forward to dropping that pan every 1000 miles.
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I change the oil about every 1500 miles and didn't ever drop the pan until I rebuilt the top end at 60,000 miles. I've dropped it twice since then -- at roughly 5,000 mile intervals -- and the screen has always been absolutely clean.
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They're completely reliable. I've had one holding up one corner of the porch for at least 20 years of continuous duty. Still works good. :thumb:
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They're completely reliable. I've had one holding up one corner of the porch for at least 20 years of continuous duty. Still works good. :thumb:
That's great. I have two old /5 jugs being serving as bookends on one of my garage shelves. Very sturdy!
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What do you do with old pistons? Back in the 20th century they made nice ashtrays.
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Reusable pistons get stashed away just in case Gilardoni kits ever stop being available, same with old cylinders. I donated several pair of cylinders to Mark @ Moto Guzzi Classics when he was having pistons made and cylinders replated.