1973 V7 Sport Cylinder Relining Millennium

[moto-uno]

  And if the metric isn't available , 1 1/16" would probably do . Any pawn shop should have a selection :) . Peter

[jacksonracingcomau]

You can remove the pistons with the rods still bolted to the crank. Many ways to do it, from "reasonably" force tapping them out with a socket to a wrist pin tool. I have always "carefully" tapped them out with a socket and "lightish" hammer.


Tom

Many a rod bent from hammering pins out, weird problems ensue
Heat is your friend, just electric heat gun, push pin out with fingers

[Chuck in Indiana]

^^^^^ this

[Scout63]

This is a great thread with good information. When my v7 finally comes out of storage and onto the lift, the first order of business will be sending the cylinders off to Millennium.  I ordered new rings from Stein Dinse per Charlie’s recommendation.

[cliffrod]

When I did my V7 Sport cylinders, I was really broke and couldn’t afford issues.  But I had trouble with at least 2 head gasket failures.  So I extended the time between stages of torquing head bolts from 10-15 min to a few hours.  It made a big difference in how much more gain I produced with each stage of torquing.  Then I rechecked torque after getting engine to temp and cool-down.  No more failures.

The other advice btdt I would offer is to err on the side of caution if you see any significant chrome flaking-related damage in the bottom end.    These cranks are originally nitrided or surface hardened, so the journals should have no surface imperfections.  If any chrome is embedded in the bearing shells or there are any noteworthy lines in their surface, know that the debris which  produced them had to pass through the oil pump to reach the crank bearing to make the damage..….   Having that stuff embedded in the walls of the oil pump to come loose later can negate whatever casual cleaning you do at this point.    Having to turn the crank and lots more later is not cool.

I never checked my rod bearings or anything else when I did my cylinders.  Being new to Guzzi, I had no idea and no one available & familiar with the chrome bore issues at that time to advise me otherwise.  Back then, many people still weren’t convinced it was as big a problem because their bikes were still just fine.  It was still a “can fail” issue vs the “will fail” issue it is now.

Using the original pistons has much to do with the condition of the lands between the piston rings.  If there is evidence of fatigue, that’s where problems can easily occur.  I removed and installed pistons with rods still installed in engine.  Not difficult.  As noted, gentle heat makes it simple.

Hopefully things will look good inside your engine.  But if they don’t, they won’t heal.  Like Charlie said, it becomes really $$$$ to replace everything in there after the fact.

[Antietam Classic Cycle]

What happened to Gilardoni?

Nothing has happened to them, but understandably, supplying cylinders kits for 50 year old Guzzis isn't a high priority for them. Once in while they run off a batch, but usually just Eldo kits. They're doing Ambo kits less all the time and haven't made V7 Sports sets for a few years. It's been at least a decade since they last did a batch of V700 kits.

You can remove the pistons with the rods still bolted to the crank. Many ways to do it, from "reasonably" force tapping them out with a socket to a wrist pin tool. I have always "carefully" tapped them out with a socket and "lightish" hammer.

Always wanted to get a wrist pin puller like from the old days. A round band and a screw like shown in the manual, don't seem to be available anymore.

I simple but effective piston pin puller can be whipped up at the local hardware store. PVC pipe nipple, long carriage bolt, large flat washer and nut. As Martin wrote, warming the piston is a huge help.

[Richiez22908]

When I did my V7 Sport cylinders, I was really broke and couldn’t afford issues.  But I had trouble with at least 2 head gasket failures.  So I extended the time between stages of torquing head bolts from 10-15 min to a few hours.  It made a big difference in how much more gain I produced with each stage of torquing.  Then I rechecked torque after getting engine to temp and cool-down.  No more failures.

The other advice btdt I would offer is to err on the side of caution if you see any significant chrome flaking-related damage in the bottom end.    These cranks are originally nitrided or surface hardened, so the journals should have no surface imperfections.  If any chrome is embedded in the bearing shells or there are any noteworthy lines in their surface, know that the debris which  produced them had to pass through the oil pump to reach the crank bearing to make the damage..….   Having that stuff embedded in the walls of the oil pump to come loose later can negate whatever casual cleaning you do at this point.    Having to turn the crank and lots more later is not cool.

I never checked my rod bearings or anything else when I did my cylinders.  Being new to Guzzi, I had no idea and no one available & familiar with the chrome bore issues at that time to advise me otherwise.  Back then, many people still weren’t convinced it was as big a problem because their bikes were still just fine.  It was still a “can fail” issue vs the “will fail” issue it is now.

Using the original pistons has much to do with the condition of the lands between the piston rings.  If there is evidence of fatigue, that’s where problems can easily occur.  I removed and installed pistons with rods still installed in engine.  Not difficult.  As noted, gentle heat makes it simple.

Hopefully things will look good inside your engine.  But if they don’t, they won’t heal.  Like Charlie said, it becomes really $$$$ to replace everything in there after the fact.

Yeah not sure how I can check the bottom end without at least taking the piston rods off. So we’ll see. So far I the pan and “filter” no visible chrome shards so keeping ju fingers crossed. Also with only 12k original miles, aside from chrome damage if any, I would assume the pistons should not be worn. But we’ll see. I’ll definitely be careful and patient with the torque wrench. What’s the recommended torque on those?

[Antietam Classic Cycle]

What’s the recommended torque on those?

On what specifically? Head nuts? Rod nuts? Head nuts - 29-32 ft. lbs. is the factory spec., I use 32. Rod nut torque depends on what rod bolts/nuts you have - early with lock plates under the nuts or late with self-locking nuts.

[Richiez22908]

Ok grabbed the right socket and got those 26mm caps off... but having a bit of a struggle with the 10mm hex bolts underneath. Could not get enough leverage on my good Allen wrench and don't want to strip them (nightmare!) so will get a 10mm hex socket and give it a shot tomorrow. Other than that, any tips on loosening those?

And yeah Charlie, meant the heads... thank you!!

[Cam3512]

Ok grabbed the right socket and got those 26mm caps off... but having a bit of a struggle with the 10mm hex bolts underneath. Could not get enough leverage on my good Allen wrench and don't want to strip them (nightmare!) so will get a 10mm hex socket and give it a shot tomorrow. Other than that, any tips on loosening those?

And yeah Charlie, meant the heads... thank you!!

It’s dry under those caps.  When doing a head retorque I give a shot of WD40 down into the hex nut so my socket doesn’t get stuck down there.  I know you’re removing the heads, but for future reference. 

[Richiez22908]

It’s dry under those caps.  When doing a head retorque I give a shot of WD40 down into the hex nut so my socket doesn’t get stuck down there.  I know you’re removing the heads, but for future reference.

Yeah I was wondering... I'll shoot some down there now this way when I get the right socket tomorrow hopefully it'll be a little freed up.

Thanks!

[Antietam Classic Cycle]

The cylinder stud often comes out with the nut, but that's no big deal. There should be a washer under the nut, usually stuck to/in the head.

[Richiez22908]

Didn't get to do much today but did get the right socket and got those nuts off no problem... thankfully. Hoping to get a bunch done tomorrow.

Thanks everyone again!!

[Richiez22908]

Ok so got one off today... and there is a chunk of Chrome missing right at the top. Might get to the other tonight but going away until Sunday so might be then.

Since I have not seen any of this piece of chrome in the pan or elsewhere... how do I know if my engine is torn up?

And we'll see if any is missing from the other as well.

[cliffrod]

I know this isn’t the result you wanted but this is why we rang the bell in no uncertain terms.  I am really glad you didn’t just decide we all needed to shut up and left the forum to ride in peace.   That peace wouldn’t have lasted long.

As far as how far to go inspecting your engine, that’s one of those personal decisions & judgment calls that you’ll have to make.   I was completely ignorant about looking into the rest of my engine-  I just swapped cylinders & pistons and hit the road.  So I paid the FULL price- literally and figuratively.    You can check things and if nothing is bad, costs in parts, gaskets and seals won’t be that much.  The time spent off the road is always a drag.  But you may be happier in the long run knowing that all those 50 yr old seals and such are not going to be a never-ending source of aggravating new leaks when you can least afford to deal with them.  You’ll also know your bike much better and that’s never a bad thing.

Hang in there.

Edit- meant to add with the chrome loss being at the top of cylinder and generally above the rings, the majority of lost chrome probably went out through the exhaust.  It’s tougher for it to migrate past the rings and into the bottom end without leaving some obvious damage to pistons, walls, etc.  Losses at or below the cylinder wall area where the rings travel are the real  danger to the rest of the engine.   

[Richiez22908]

I know this isn’t the result you wanted but this is why we rang the bell in no uncertain terms.  I am really glad you didn’t just decide we all needed to shut up and left the forum to ride in peace.   That peace wouldn’t have lasted long.

As far as how far to go inspecting your engine, that’s one of those personal decisions & judgment calls that you’ll have to make.   I was completely ignorant about looking into the rest of my engine-  I just swapped cylinders & pistons and hit the road.  So I paid the FULL price- literally and figuratively.    You can check things and if nothing is bad, costs in parts, gaskets and seals won’t be that much.  The time spent off the road is always a drag.  But you may be happier in the long run knowing that all those 50 yr old seals and such are not going to be a never-ending source of aggravating new leaks when you can least afford to deal with them.  You’ll also know your bike much better and that’s never a bad thing.

Hang in there.

Edit- meant to add with the chrome loss being at the top of cylinder and generally above the rings, the majority of lost chrome probably went out through the exhaust.  It’s tougher for it to migrate past the rings and into the bottom end without leaving some obvious damage to pistons, walls, etc.  Losses at or below the cylinder wall area where the rings travel are the real  danger to the rest of the engine.

Well look at you adding some good news there at the end!! 

I really appreciate it. Yeah would have been great to see nice perfect cylinders under there, but at least I'm glad I took it apart. And I know I could have reacted better at being reminded of the risk... but glad I gave in and just did the right thing. And am glad that I was prodded in no uncertain terms.

I was wondering where the heck a chunk like that could have gone... and out the exhaust definitely make sense.

As far as tearing into the whole engine... I might be I over my head. I was a certified GM mechanic in my youth, but its been a while. But with all the manuals and this forum, maybe!

I do have to say, on another positive note... these damn things(knock on wood) ARE really easy to work on, like everyone says. With the orientation, transmission, shaft drive, pushrods, and the overall build, it's like 1/4 of a small block. And, considering its 50 years old, damn well put together. Everything is robust and over engineered. On my Ducati I stripped two hex bolts just installing a tail tidy. Nice work Moto Guzzi.

[cliffrod]

These early engines require attention to detail but are very straightforward to address.  If you can follow instructions and work on more modern engines, you should be fine- these are much like part of a regular V8 engine.   they’re actually made to worked on without tearing the entire machine apart every time versus the huge PIA that many other bikes are.   I’ve often wondered if the origins of this engine configuration for military applications included an edict of simplicity to service without removal from the chassis.

Reading about later Guzzi v-twin engines makes me happy to stay with the old, outdated stuff (….). Lots of good advice available online now, which helps even more.

Check the other cylinder, then probably pull at least 1 rod cap to check bearing/crank and go from there. 

[Antietam Classic Cycle]

If that bike was in my shop, and I opened it up and found the cylinder in that condition, it would get a complete engine rebuild. Lots of chrome has been scraped into the oil and the only way to clean it all out is by tearing it down completely.

No good news to add at the end., sorry. 

[guzzisteve]

Definitely check the oil pump.

[Chuck in Indiana]

Sorry.. but I, too, will pile on. Guzzis are very easy to overhaul, and I would do it. It's not a major expense if you can do it yourself, and you will know what you have.

[Richiez22908]

If that bike was in my shop, and I opened it up and found the cylinder in that condition, it would get a complete engine rebuild. Lots of chrome has been scraped into the oil and the only way to clean it all out is by tearing it down completely.

No good news to add at the end., sorry. 

We'll see. But as was said, it was at the top... and no sign of it scraping past the rings... so how could it be in the oil?

I'll see what the other one looks like. A complete rebuild is likely beyond my ability and nowhere nearby to do it.

In addition to the cyls and piston rings, which Millennium is handling... It would be main and rod bearings, check cam and crank for damage. Anything else?

[lucian]

I find heating the pistons underside with a heat gun makes the pins push out easy .

[Antietam Classic Cycle]

We'll see. But as was said, it was at the top... and no sign of it scraping past the rings... so how could it be in the oil?

I'll see what the other one looks like. A complete rebuild is likely beyond my ability and nowhere nearby to do it.

In addition to the cyls and piston rings, which Millennium is handling... It would be main and rod bearings, check cam and crank for damage. Anything else?

In the fourth photo, it appears that the chrome is worn thin about half the way down the cylinder, what I call a "starry night". Lots of light colored specks showing though the darker surface. All of that chrome would have gone into the oil.

As was mentioned by guzzisteve, check the oil pump for damage too.

[Richiez22908]

In the fourth photo, it appears that the chrome is worn thin about half the way down the cylinder, what I call a "starry night". Lots of light colored specks showing though the darker surface. All of that chrome would have gone into the oil.

As was mention by guzzisteve, check the oil pump for damage too.

So I guess I keep disassembling and hope I can get it back together. If I can't I'll ship it all to you in Maryland, lol.

[cliffrod]

But I also said-

As far as how far to go inspecting your engine, that’s one of those personal decisions & judgment calls that you’ll have to make.   I was completely ignorant about looking into the rest of my engine-  I just swapped cylinders & pistons and hit the road.  So I paid the FULL price- literally and figuratively.    You can check things and if nothing is bad, costs in parts, gaskets and seals won’t be that much.

And earlier, I also mentioned concerns about checking the oil pump for any chrome-related issues like Steve just mentioned.

My V7 Sport ran great for a while after I didn’t do a complete service when I swapped the cylinders.  Then it didn’t & it started making fatal noises.  Not cool.  Then it cost a gob of money for parts that were lots less $$ in the 90’s than they are now. 

The smart money (aka Charlie’s opinion) is to do the whole thing.  Then you’ll be done and know what you have.  The other end of the spectrum is to do less than the whole thing and hope for the best.  I wasn’t even hoping for the best.  I was naive enough to think I had fixed things.  I was wrong and paid for it. 

Right now,  I’ve got this Guzzi tractor here with an old Eldo 850 engine and my V700 Corsa Record project.  Both are chrome cylinder engines that turn over fine and would likely run as is with nominal work.  More than one non-guzzi person has said “aw hell, quit worrying so much.  That’s too cool to not just crank it and see what happens.  It’ll probably be fine.”  Nope.  Until I’ve been completely through them, I won’t be starting them.   I know how bad it can go.   That’s where I am on the “judgment call” I mentioned earlier.    Maybe the cylinders will be fine and going all through it will be overkill.  But then I’ll know what I have and know that I’ll be saving money in the big picture. 

That’s simply the reality of these early Vtwin chrome bore Moto Guzzi engines.

[Richiez22908]

So as far as the remainder of the rebuild. What is the best manual to have or resource online. Any step by step? We managed to get this far with the original shop manual supplemented by a later Chilton for different but similar models.

That original one is very cryptic at best, lol.

[Antietam Classic Cycle]

So I guess I keep disassembling and hope I can get it back together. If I can't I'll ship it all to you in Maryland, lol.

You might find this helpful: https://www.thisoldtractor.com/projects_roy_smith.html

[Richiez22908]

You might find this helpful: https://www.thisoldtractor.com/projects_roy_smith.html

Thanks... found this too. Its in German but can add translated subtitles.

https://www.youtube.com/watch?v=xs4HAhhPKH4

[Scout63]

I’ll add my 2c here as well.  I found the Guzzi motor (1979 G5) remarkably simple to rebuild and this forum an excellent resource.  I used a Haynes manual and the Guzzi factory shop manual and parts book. Gearboxes are more complex, wheel building an acquired skill, and crabbing the frame a fiddly affair first time through. All that being said, I would strip that Sport down to the crank and not only make sure everything is ok, but also have the chance to check and renew oil seals, the top end  the sludge trap, clutch, swingarm bearings, unjoint and carrier bearing and wheel bearings.  The model is a desirable classic worth preserving right, and your relationship with the bike will be solid once you are done.

[cliffrod]

From 1992/93 to the past 2-3 yrs, I only had a reprint of the factory parts manual, service manual and a Haynes manual for my V7 Sport.   Resources like ThisOldTractor, Guzziology, WG and such are all relatively new to me. 

Of all the times to be able to get good help & advice to go through an old Guzzi like yours, I don’t think it’s ever been easier or faster to get viable help to do it properly.  Not a bunch of urban legend stuff.  It’s a lot different than it used to be.

I get the more money and time angles.  Just hang in there.