Worst Case Scenario - Chrome Cylinders?

[Furbo]

'Back in the Day', (snaps red suspenders, lites pipe... ;-T)

You could go with iron liners relatively inexpensively. You should be able to get a quality VW piston set as well.

It's not perfect, but it's realtively cheap, and you needn't worry about flaking bores. You will need a GOOD MACHINE SHOP tho....if the guys are under 40, and clean shaven, you should prolly go somewhere else...

[Vasco DG]

'You will need a GOOD MACHINE SHOP tho....if the guys are under 40, and clean shaven, you should prolly go somewhere else...

 ;D :BEER:

Pete

[Antietam Classic Cycle]

'Back in the Day', (snaps red suspenders, lites pipe... ;-T)

You could go with iron liners relatively inexpensively. You should be able to get a quality VW piston set as well.

It's not perfect, but it's relatively cheap, and you needn't worry about flaking bores. You will need a GOOD MACHINE SHOP tho....if the guys are under 40, and clean shaven, you should prolly go somewhere else...

I looked into doing liners vs. replating a while back. Here's what I was quoted:
- sleeves 98.00 ea.
- bore cylinder block, install sleeve, bore and hone sleeve to match piston: 110.00 ea.
- total 208.00 ea. side

Since Millennium charges $209 per bore to replate in Nikasil, sleeves are a non-starter for me.

 

[Furbo]

I looked into doing liners vs. replating a while back. Here's what I was quoted:
- sleeves 98.00 ea.
- bore cylinder block, install sleeve, bore and hone sleeve to match piston: 110.00 ea.
- total 208.00 ea. side

Since Millennium charges $209 per bore to replate in Nikasil, sleeves are a non-starter for me.

 

Well...yeah, but I STILL save $2 the other way......

[RayB]

Also compare the life of Nikasil vs iron bores.
I'd never choose iron over Nikasil - especially for about the same price

[twhitaker]

Also compare the life of Nikasil vs iron bores.
I'd never choose iron over Nikasil - especially for about the same price

One major reason they went with chrome (then Nikusil) in aluminum bores was because of aluminums better thermal conductivity over iron.

[LonerDave]

Thought I'd bring everyone up to speed on the 850-T.  Been a while... :(

Removed the heads, jugs and pistons to inspect.  Left bore and piston looked fine, but right side showed some damage.  Looks like something had gotten into the chamber, bounced around, eventually made it past the rings and "smeared" itself between cylinder and piston skirt.  The piston wasn't so much scored, as there was a "deposit" of material on it.  The cylinder did show some scoring (a small patch, maybe 1 inch square).  Removed front cover to replace timing chain and did find some small chunks of metal in bottom.  Chain was sloppy enough that it had started wearing the inside of the case.  Suspect it was a piece of that that had gotten into cylinder.

I ordered a set of Gilardonis shortly after the options were discussed months ago.  Turns out that just as I ordered them, we entered one of those dry spells where Gilardoni kits are hard to find.  I waited, but understandably, the vendors were unable to predict when they might get them back in stock, so I went the re-plating route.

US Chrome in Fond du Lac has cylinders and pistons now.  Should be done in a week or so.  Very nice folks there, BTW (thanks Scott, Klaus and Mark!).

Ordered a set of Deves rings from Eish.  Another great supplier.  Should get them in next day or so.

Heads are being done by local shop.  New Kibblewhite guides and valves.  ETA - a week.

So, if everything goes according to plan (does it ever?), should be buttoning this up in the next few weeks.

Now we move to break-in procedure.  Don't think this topic is quite as contentious as which oil to use  :), but would appreciate any thoughts on the best way to seat the new rings.  Deves says their rings are made of Swedish steel alloy.  Bores are NiCom (Nickel Silicon Carbide).

What say you?

Thanks.

Dave

[Late to the party]

Did any of that noxious flaky garbage make it into the oil circulation network? If so, you've got other work to do.  :beat_horse

At the very minimum the oil pan needs to be dropped and the oil pump removed and inspected.

I would remove a bearing cap and check there as well. Bearing failure is never pretty... or cheap.

[Antietam Classic Cycle]

Did any of that noxious flaky garbage make it into the oil circulation network? If so, you've got other work to do.  :beat_horse

At the very minimum the oil pan needs to be dropped and the oil pump removed and inspected.

I would remove a bearing cap and check there as well. Bearing failure is never pretty... or cheap.

 :+1 If the engine is out of the frame, I'd tear it completely apart to clean out the sludge trap (oil filter or not) among other things.

[twhitaker]

Take a close look at the sludge trap and the rocker pins as well.

[Late to the party]

LonerDave, are you getting the message here? Setting flaky chrome deposits loose in your engine is nothing to be trifled with. I don't mean to tell you your business, but installing a new and expensive set of jugs and slug atop a possibly compromised lower end is to court disaster. Without taking aggressive action to determine whether any of that flaky chrome stuff (a) is present, and (b) has damaged any of your bearing surfaces, we're talking taking a chance with imminent, catastrophic failure.

But, it is your bike, after all.

Godspeed.

[LonerDave]

Engine still in frame.  I need to remove crank to inspect sludge trap, right?  Can I do that without removing engine?

[Antietam Classic Cycle]

I need to remove crank to inspect sludge trap, right?  Can I do that without removing engine?

Yes, crankshaft  has to come out of the crankcase in order to access the sludge trap. Engine needs to be removed.

[LonerDave]

LonerDave, are you getting the message here? Setting flaky chrome deposits loose in your engine is nothing to be trifled with. I don't mean to tell you your business, but installing a new and expensive set of jugs and slug atop a possibly compromised lower end is to court disaster. Without taking aggressive action to determine whether any of that flaky chrome stuff (a) is present, and (b) has damaged any of your bearing surfaces, we're talking taking a chance with imminent, catastrophic failure.

But, it is your bike, after all.

Godspeed.

Loud and clear, LttP.  :)  FWIW, I saw no evidence of chrome flaking.  Just scuff mark on bore.  But understand how nasty chrome bits can be.  Sounding like "buttoning up" is best delayed.  Guess it's further INTO the woods I go!

[Chuck in Indiana]

Loud and clear, LttP.  :)  FWIW, I saw no evidence of chrome flaking.  Just scuff mark on bore.  But understand how nasty chrome bits can be.  Sounding like "buttoning up" is best delayed.  Guess it's further INTO the woods I go!

It won't take long, and we'll all feel better.. ;D

[Late to the party]

It won't take long, and we'll all feel better.. ;D

850T, right? Tonti frames come apart so nicely. You'll have that engine out in no time. Get ya a bunch of banker boxes and freezer bags to put everything in. Some Sharpies and masking tape to label it all (and to touch up your eyebrows with). I know it's better to be riding that damn thing. But the weather's warm and the days are long. Put the game on the radio and some beer in the fridge. This won't hurt too bad.

[LonerDave]

Thanks for the encouragement, guys.

Deep down I knew that skipping the sludge trap and bottom end would nag at me, but you know how it is when you think you see light at the end of the tunnel.  Sometimes I have to remind myself that wrenching on them is one of my favorite aspects of vintage bike ownership.

I'm lucky to have other bikes to ride while working on this one.

Life is good.

[Chuck in Indiana]

Life is good.

That is a freakin fact, pal.. ;-T

[Antietam Classic Cycle]

Here's a great 850-T3 engine rebuild "how to" by Greg Bender:
http://thisoldtractor.com/projects_roy_smith.html

[twhitaker]

If you go through it and don't find one flake of chrome, at least you know there is none there.

If you take it all the way down don't, I repeat DON'T, be tempted to bead blast the block. That could be a very expensive lesson.

[Greg Field]

Yes, take it out of the frame and check the crank and clean out the sludge trap. You will be happy for many years that you did, even though it seems unnecessary at this time.

Break-in: Warm up the oil as gently as you can as you ride to the steepest, biggest hill available. At the base of the hill, shift up one gear to really load the rings, and roll on hard to seat the rings as quickly as possible. Then, coast down to the base again and repeat, repeatedly. Then, change out the oil.

[LonerDave]

Finally picking up where I left off in May.  Work on the bikes was suspended as we "enhanced" our garage from a 2-car to a 5-car.  Two bays are set off from the others and now form a dedicated shop.  Hog heaven.

Removed crank for inspection and cleaning of sludge trap.

Trap is a bit less than a third full.  Good, I guess, for a 52k motor.  There doesn't appear to be an insert to remove, so I assume I just get the sludge out of there?



I have no experience evaluating crankshafts so can't say much about the condition or usability.  Bearing surfaces don't appear burned or gouged.  They do appear to have what I'd call "scoring".  Not deep, but visible.  Surfaces on connecting rods and front and rear bearings is in same condition - scored, but not burnt or deeply scratched.



Rear (flywheel side) crank surface:



Front (timing side):



Crankpin:




Connecting rod big end:







Rear bearing:







I assume I'll need at least the crank polished, maybe ground.  And that I'll need new bearings (main - front and rear), con rod shells.  Don't know about small ends.

Figure I'll take the crank to the same shop that did the heads and ask them to measure and assess.  May also spend $200 for a couple micrometers and a bore gauge (Fowler brand) to at least practice measuring myself.

Will be checking oil pump next. 

Would love it if anyone with more crankshaft experience (just about everybody!) cares to weigh in on condition and next steps.

Dave

[Don G]

I would suggest that you take your crank, main bearings and rods along with a list of the specs. to a competant engine rebuilding shop, or a decent machinist who knows how to measure something and have the components checked for dimension, possibly you may find that you are still in spec. and may get away with a polish and new rod bearings, check the wrist pin bushings for size and the wrist pins for wear, while your at it check the rocker pins too. Good Luck ;-T DonG

[Chuck in Indiana]

^^^^^
Agreed. I've seen worse looking stuff, but you'll know nothing until it's accurately measured.

[redrider90]

What the good father says.  ;D I *have* heard of chrome bores holding up for a long time if used regularly. I've seen what happens when the chrome lets go. It's not pretty. Takes out the bearings, crank, rocker pins, oil pump... you get the picture. I'm a cheap barstid, too.. but I wouldn't take that roll of the dice. ;)

I assume only big block used chrome. What were the years and models that had chrome?

[Antietam Classic Cycle]

I assume only big block used chrome. What were the years and models that had chrome?

The earliest small-blocks had chrome bores too. Big blocks with chrome bores: V700, Ambassador, V7 Special, Eldorado, 850 GT, V7 Sport, 850-T, 850-T3.