?

Log in

No account? Create an account

[icon] I did what?! - Patti
View:Recent Entries.
View:Archive.
View:Friends.
View:Profile.
View:Website (pattib.org).

Security:
Subject:I did what?!
Time:11:24 am
My Ducati! For those who have a long memory, I'm restoring a 40-year-old Ducati that was pulled out of someone's barn last summer. I've been ignoring the project for a while, but recently picked it back up. My goal is to do a cosmetic restoration but not get the bike running, though I'm doing my best to keep everything in good condition so that I don't do anything that would prevent it from running in the future.

The bike is completely in pieces right now-- the frame is in a shopping cart, the gas tank is on the floor, the wheels are here and there, the motor is on a furniture dolly, and a zillion small parts are in a box. I'm slowly cleaning it up so that I can put it back together and make it a showpiece.

One of my projects for this weekend is to work on the bike... in particular to get the motor looking good. Cleaning the fins and all the fiddly motor bits is a real bitch, so I started taking things apart. After a while, I decided I was going to pull the cylinder head... why not? How hard can it be? Four bolts later, and the head is off.

And then, I bumped the cylinder itself, and it moved. "Really? It's that easy?" Apparently it is. The cylinder itself is now sitting on the floor.

I'm totally not a gearhead; I generally prefer to pay someone to do all my vehicular maintenance, unless it's stuff that doesn't have anything to do with the vehicle moving or stopping. (e.g. I'll deal with lights, radio, windows, etc.) I have never in my entire life seen the inside of an internal combustion engine that I own.

Having said that, as far as I can tell the motor is in good shape. I don't see any obvious ugliness on the piston although it does have a few small scrapes and dings-- is that normal, or upfuckimation? The cylinder liner looks good, etc. There's a little bit of crud on the valves, but not a lot. And everything moves easily.

Is there anything in particular I should pay attention to when I put it back together so that I don't damage anything? Remember, I don't care if it runs right now-- if I ever get it running, I assume the engine will have to be rebuilt. I don't want to do anything that will make that harder, though.

Oh, here are some photos:

pistonpiston2head
comments: Leave a comment Previous Entry Share Next Entry


rmd
Link:(Link)
Time:2007-09-02 07:26 pm (UTC)
not sure, but i pointed a couple of vintage-motorcycle-gearhead friends at the post.
(Reply) (Thread)


rmd
Link:(Link)
Time:2007-09-02 08:23 pm (UTC)
sounds like you're messing with the primal forces of nature, mister beale.

to quote:

we looked at her post. quoth the ducati-head: *stop* what you're doing, don't take anything else apart, put it back together, and it'll prolly run.

(reply to previous comment)
actually, now she's prolly gotta re-time the valves, which is a bitch on those things. for clod's sake, don't take it any more apart.

(Reply) (Parent) (Thread)


whipartist
Link:(Link)
Time:2007-09-02 08:28 pm (UTC)
Thanks!

It's most assuredly not coming any more apart. And it won't run yet because the kickstarter is broken off, almost certainly because the gear broke. Sebrings are known for that.
(Reply) (Parent) (Thread)


gunga_galunga
Link:(Link)
Time:2007-09-02 07:29 pm (UTC)
It's weird that the top of the piston is scuffed like that, although I doubt it will hurt anything. I wonder what it's from. Actually, the valves & the piston look remarkably clean with little or no carbon buildup.

Getting the piston back in the cylinder may be more tricky than it was to get it out. You may need to get a piston ring compressor. They're like $5-10 at your local Autozone, though. You can see what one looks like here.

If you take the piston all the way out by unbolting the connecting rod cap, be very careful to not scratch the crankshaft as that would be bad and would require you to remove it and polished. I don't know how it is set up on the Ducati, but on a lot of engines the cap slides off the bolts leaving the bolts exposed to hitting the crankshaft as you pull out the whole thing. Not sure if this makes sense, it's easier with a drawing. This diagram is pretty good. As you can see if you take off the rod cap, the bolt will be exposed.

Awesome project. I suspect you would be surprised at how little extra effort it would take to get it actually running. It's a pretty cool feeling to have an engine start that you had in pieces and put back together.
(Reply) (Thread)


whipartist
Link:(Link)
Time:2007-09-02 07:43 pm (UTC)
According to the Ducati singles restoration book I have, you can just compress the rings with your fingers. There's a little bit of carbon buildup on the intake valve, but the exhaust valve is pretty much perfectly clean.
(Reply) (Parent) (Thread)


filthy_habit
Link:(Link)
Time:2007-09-02 07:32 pm (UTC)
Disclaimer: All impressions are based on a high-school class where we took apart and reassembled a lawn-mower engine, plus my additional experience of having completely dismantled my 1968 Mustang V8 289ci engine and having successfully put it back together again.

Based on your pictures, it looks to be in fabulous condition.

All the pistons do is compress the air/fuel mixture, so dings and crud on the top won't harm anything. Holes would be fatal. If there were significant deposits, such as carbon, you might want to clean it off, but a few scraches won't hurt. The important thing is that the piston rings are in good shape and form a good seal.

The valves look nice, too. Very nice. What you don't want to see is scratches and nicks where the valves are seated as these can cause leakage---something you definitely don't want, especially on the intake side. The valves should form a nice, smooth seal when closed. To make sure, you can easily get some grinding compound and re-seat the valves. I used to use a power-drill with a little suction cup thingie to spin the valve. Works great!
(Reply) (Thread)


vespa59
Link:(Link)
Time:2007-09-03 06:58 am (UTC)
It looks like it's in great shape! Don't worry about having to redo your timing... it was already bad (which is why the top of the piston looks like that - a while longer and it would develop a hole).

When you put it back together, put some 10W-30 on the rings before pushing them in to the cylinder. When you tighten the bolts, make sure you do each one a little bit at a time, evening them up in a cross pattern. That is, tighten #1 a half turn, then #3, then #2, then #4, and repeat until they're quite snug, but don't muscle them on. If you want to do it correctly, get a torque wrench and look up what they're supposed to be torqued to. Also, there should be a gasket between the cylinder and the motor, and probably one between the head and the cylinder.

If you decide to fire it up again, it'll need valve adjustment and timing set.
(Reply) (Thread)

[icon] I did what?! - Patti
View:Recent Entries.
View:Archive.
View:Friends.
View:Profile.
View:Website (pattib.org).