1973 V7 Sport Cylinder Relining Millennium

[Richiez22908]

Ok so since I was read the riot act(with the best of intentions and probably saved me a lot of trouble), going to bite the bullet and get the cylinders replated my Millennium. Got a quote for $600 including sending the pistons and them checking the piston fitting afterward and ring spacing... so not bad.

Will post every step, screw up, bungle and win here for reference for those that come after.

Got the pan off to check for chrome. Doesn't look like much of anything but a few tiny bits. Anyone with better eyes please take a look... anything I should be worried about?

Working on valve covers an beyond now... so we'll see how the cyls look inside.

[Richiez22908]

[Dave Swanson]

Excellent move! 

My V7 Sport was my first Guzzi 20 years ago.  I was told to promptly replace the cylinders with Gilardonis, which were available then.  I really didn't have the budget for it, but knuckled under and took the best advice I ever received on the forum.  When I removed my barrels the bores looked like new - the bike only had 900 miles.  When I looked at the hard chrome surface under magnification there was evidence of micro pits that had popped off.  My 900 miles V7 Sport engine block would have been turned into scrap metal if I hadn't listened. 

[Antietam Classic Cycle]

I've gone that route on at least eight Guzzis now and Millennium has always done an excellent job, no issues whatsoever. Do measure your pistons carefully and compare them to the specs. published in the factory manual. Pay particular attention to ring groove widths.

[Richiez22908]

I've gone that route on at least eight Guzzis now and Millennium has always done an excellent job, no issues whatsoever. Do measure your pistons carefully and compare them to the specs. published in the factory manual. Pay particular attention to ring groove widths.

Will do!! Good I idea to make sure they're not a mess before sending off.

12k miles, only 1k since its been resurrected and runs great so fingers crossed all is well.

[Richiez22908]

Ok so valve covers off… gotta go get a 1” socket.

My 14 year old daughter is becoming the best assistant ever… so turns out it’ll be a good bonding experience.

[Richiez22908]

Was considering Gilardoni first... but can't find them anywhere and no indication of them returning any time soon.

Found these... they seem to be the same but without the valve relief that the Sport has. The company says they will add it for me if I shoot some pics of my OEM Pistons.

I think I'd rather stick with the originals, if they're in good shape. But if not, does this seem like a viable option?

https://gtmotocycles.com/products/gilardoni-piston-cylinder-set-82-5mm?_pos=1&_sid=d69fd5431&_ss=r

Unless someone knows where a set specifically for the V7 Sport is hiding. ;)

[czakky82]

That’s what I’m running.

[Richiez22908]

That’s what I’m running.

So you ordered those and had them machine in the relief or you don’t have a sport?

[guzzista]

If your pistons don't meet specs on the ring groove widths as Charlie mentions, you could get a set of new pistons with rings to match the Millenium Nikasil job. Maybe other folks who have used those Asso pistons can pitch in with their feedback

https://www.ebay.com/itm/173694313413?hash=item2870fce3c5:g:BlMAAOSwKphcFoKz

[Antietam Classic Cycle]

Ok so valve covers off… gotta go get a 1” socket.

My 14 year old daughter is becoming the best assistant ever… so turns out it’ll be a good bonding experience.

1" is close but no cigar. 26 mm.

Was considering Gilardoni first... but can't find them anywhere and no indication of them returning any time soon.

Found these... they seem to be the same but without the valve relief that the Sport has. The company says they will add it for me if I shoot some pics of my OEM Pistons.

I think I'd rather stick with the originals, if they're in good shape. But if not, does this seem like a viable option?

https://gtmotocycles.com/products/gilardoni-piston-cylinder-set-82-5mm?_pos=1&_sid=d69fd5431&_ss=r

Unless someone knows where a set specifically for the V7 Sport is hiding. ;)

They look like Ambassador sets, which are actually 83 mm and have a slightly lower compression ratio (9.2 vs. 9.6 IIRC). The extra 8 cc of displacement may offset the lower compression some. The piston assembly weight may be heavier than the original piston assemblies as well. I'd stick to your plan to have the cylinders replated. Have you sourced new rings yet? 

If your pistons don't meet specs on the ring groove widths as Charlie mentions, you could get a set of new pistons with rings to match the Millenium Nikasil job. Maybe other folks who have used those Asso pistons can pitch in with their feedback

https://www.ebay.com/itm/173694313413?hash=item2870fce3c5:g:BlMAAOSwKphcFoKz

Those pistons have a very high dome, higher compression will likely result.

[MTHaas]

I did my 67 V700 a few years ago...twice. I sent my OE pistons and Jugs to Millenium with a quick turn around. While inspecting the finished product I found tiny pits in the coating. I asked about the pits and whoever responded claimed they were OK. Held extra oil for lubrication. I reassembled and ran for several months. All was well except the guy(me) who put it together miss located the O rings in the oil channels.
Popped the heads to discover both pistons and jugs wiped. Yes the ring gap was correct from multi checking on assembly. Lucked into some NOS pistons, sent it all back to Millinium. This time coating was solid through and through. Living happily last few years with the oil passages dutifully weeping. This bike gets out for weekend errands, camping trips and good old fashion tank torching joy rides.

[Richiez22908]

I did my 67 V700 a few years ago...twice. I sent my OE pistons and Jugs to Millenium with a quick turn around. While inspecting the finished product I found tiny pits in the coating. I asked about the pits and whoever responded claimed they were OK. Held extra oil for lubrication. I reassembled and ran for several months. All was well except the guy(me) who put it together miss located the O rings in the oil channels.
Popped the heads to discover both pistons and jugs wiped. Yes the ring gap was correct from multi checking on assembly. Lucked into some NOS pistons, sent it all back to Millinium. This time coating was solid through and through. Living happily last few years with the oil passages dutifully weeping. This bike gets out for weekend errands, camping trips and good old fashion tank torching joy rides.

Thanks for all the info! I may hit you up when I put mine back together to make sure I don’t make the same mistake, if that’s ok?

[Dave Swanson]

+1 with Charlie, as long as you are buying a socket get the correct metric size.

[Cam3512]

At the risk of getting flamed, again.  While the cylinders are out to Millennium, send the heads out to a machinist to be reworked.  It’s already apart.  Your top end will thank you!

Cam

[Richiez22908]

At the risk of getting flamed, again.  While the cylinders are out to Millennium, send the heads out to a machinist to be reworked.  It’s already apart.  Your top end will thank you!

Cam

Lol I’ll look into that!

[Canuck750]

At the risk of getting flamed, again.  While the cylinders are out to Millennium, send the heads out to a machinist to be reworked.  It’s already apart.  Your top end will thank you!

Cam

What Cam said !!!!

[Moparnut72]

It may not apply here but I would like to throw this procedure out for discussion. After I retired I worked for a couple of years for a small business that overhauled radial aircraft engines. We sent cylinders out for chrome plating. Since replacement pistons were not available for most engines due to FAA regulations, but that's another story. So I would measure the pistons we had and send those measurements to the plater. They would grind the chrome to fit the pistons. Is that something that can be done here?
kk

[Richiez22908]

It may not apply here but I would like to throw this procedure out for discussion. After I retired I worked for a couple of years for a small business that overhauled radial aircraft engines. We sent cylinders out for chrome plating. Since replacement pistons were not available for most engines due to FAA regulations, but that's another story. So I would measure the pistons we had and send those measurements to the plater. They would grind the chrome to fit the pistons. Is that something that can be done here?
kk

Interesting! Actually I’m sending the pistons along with the cylinders. As long as they’re ok they will fit I every font for me. I think checking the piston ring grooves etc is to make sure chrome hasn’t screwed the pistons etc too bad if at all.

Also assume I should swap out the rod bearings while they’re off. Right?

[Canuck750]

It may not apply here but I would like to throw this procedure out for discussion. After I retired I worked for a couple of years for a small business that overhauled radial aircraft engines. We sent cylinders out for chrome plating. Since replacement pistons were not available for most engines due to FAA regulations, but that's another story. So I would measure the pistons we had and send those measurements to the plater. They would grind the chrome to fit the pistons. Is that something that can be done here?
kk

Millenium's Canadian liscenced shop ground the nikisill coating to match the pistons I sent them.

[Richiez22908]

Millenium's Canadian liscenced shop ground the nikisill coating to match the pistons I sent them.

Yeah that’s what they said on the phone. That if I sent the pistons with they would fit everything for me.

[Chuck in Indiana]

Yeah that’s what they said on the phone. That if I sent the pistons with they would fit everything for me.

Yep. They are top notch, and I'm happy to see you going this way. I know.. the cold light of reality can be like a slap in the face, but you will be glad you did. 

[Antietam Classic Cycle]

Also assume I should swap out the rod bearings while they’re off. Right?

At that low of miles, it shouldn't be necessary. But, it wouldn't hurt to remove one to check the bearing condition. You could check clearances with Plastigauge as well. Access is a bit of pain though - removing the oil pipe helps, but the oil pickup is still sort of in the way. If the rod bolts are the early type with lock tabs for the nuts it gets a bit more difficult (trying to unbend the old tabs and bend the new ones).

[Richiez22908]

At that low of miles, it shouldn't be necessary. But, it wouldn't hurt to remove one to check the bearing condition. You could check clearances with Plastigauge as well. Access is a bit of pain though - removing the oil pipe helps, but the oil pickup is still sort of in the way. If the rod bolts are the early type with lock tabs for the nuts it gets a bit more difficult (trying to unbend the old tabs and bend the new ones).

I was thinking I’d have to remove the rod bolts to take the pistons out and get the pins out to remove the rods. Pardon my naivety but I can get the pins out and pistons off with the rods still connected to the crank?

And thanks on the heads up on the tabs... I'd have spent hours wondering why I could not find a socket to fit.

Also... without checking the rod bearings and the crank where they reside, what would be my best indication of any damage from chrome off the cylinders. Still advent gotten in them yet to see how the walls look.

[brider]

Was considering Gilardoni first... but can't find them anywhere and no indication of them returning any time soon.

What happened to Gilardoni?

[Tom H]

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.

Your doing great!!!!!

Once over the costs involved, you'll have a bike you can ride for 40+ years of normal use!

Tom

[moto-uno]

  YES , Peter

[Richiez22908]

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.

Your doing great!!!!!

Once over the costs involved, you'll have a bike you can ride for 40+ years of normal use!

Tom

Thanks for the pep talk!!!

Costs aren't the concern(not like I'm loaded but with the numbers this involves we'll be ok). Just want to make sure when we get it back together it works!

In South Florida it's actually the off season(hot as Hades) which is why I bit the bullet now. Just want it back in action and better than ever by the end of summer. But in no rush, just want it right. This is my forever bike(and now my daughter's too).

Thanks again for your encouragement and to everyone for their welcome tips and experience. Hopefully this thread, and everyones valuable contributions, will be a resource for others long after Fabrizio(as my daughter named the bike) is back on the road.

More progress and pics when I get a 1" socket tomorrow!!

[Tom H]

No no, as Charlie said, 26mm. With that said, I use the same as my axle nut size 27mm. Seems to work perfect for both.

And congrats on the family bonding over a bike!

Tom

[Richiez22908]

No no, as Charlie said, 26mm. With that said, I use the same as my axle nut size 27mm. Seems to work perfect for both.

And congrats on the family bonding over a bike!

Tom

That’s right. All metric. Thanks!