1973 V7 Sport Cylinder Relining Millennium

[Richiez22908]

Thank you everyone. I can say, the wealth of responses here so far have been amazing and humbling. It's like living in a neighborhood full of Guzzis. I really do appreciate it more than you can imagine. I have a family and work and life so this will take a while but I'll go thru it step by step. My daughter has been enthusiastic and very helpful. So it'll be great for us both... and the bike.

Like I said at the onset... hopefully this thread could become a resource for those that follow. There is already so much great and useful information here.

Going away for the weekend so hopefully next week I'll finish getting the cylinders off, check the piston measurements, and ship them all off to Millennium.

I'll keep the pics and, I'm sure, questions, coming.

Thank you all again!

[s1120]

You know ill jump in here and join the crew. I mean the big money your already spending. Getting those juggs done is a good hit. There is really not a lot to the old Guzzi twins. Having most of my experience in US built V8's there is some fiddley parts to them, but really they are pretty stone simple. If you can follow a manual, and know when to stop and ask questions, anyone thats been into any engine at all should have no major issues. Worse case your labor was for nothing, and you saved yourself from turning it into a big lump of worn out alloy.

[cliffrod]

My almost 19 yr old daughter could care less about my bikes in general, Guzzis included.  She’s btdt and seen enough.    If your daughter finds greater interest, especially in Moto Guzzi, she might like this Moto Guzzi Portraits video about “The Girl by the Lake”-

https://www.youtube.com/watch?v=trX0KdIWR60

[Dave Swanson]

When you have done a proper job bringing the bike back to life after following all the great advice here you will have a truly special motorcycle.  I have always thought the 73  V7 Sport is more desirable than the 73 Ducati 750SS.  For some reason the $$ market fawns on the 750SS and I have no idea why it does to such extreme.  The V7 Sport has rarity, performance, and style!   

[Richiez22908]

When you have done a proper job bringing the bike back to life after following all the great advice here you will have a truly special motorcycle.  I have always thought the 73  V7 Sport is more desirable than the 73 Ducati 750SS.  For some reason the $$ market fawns on the 750SS and I have no idea why it does to such extreme.  The V7 Sport has rarity, performance, and style!   

Wow that's a beauty!!

[Richiez22908]

My almost 19 yr old daughter could care less about my bikes in general, Guzzis included.  She’s btdt and seen enough.    If your daughter finds greater interest, especially in Moto Guzzi, she might like this Moto Guzzi Portraits video about “The Girl by the Lake”-

https://www.youtube.com/watch?v=trX0KdIWR60

That's great! Thanks I'll show her.

[Don G]

I have many years experience in the area of automotive repair, especially in engine rebuilding. If this was my engine I would start out by pulling it completely apart and assessing the total condition of all the components. At the moment you are focusing on only one area that needs attention, sure the cylinders need to be repaired, but how about everything else? You are starting in the middle and that is a mistake, take the engine out and strip it down, you may find that it needs everything or if you are lucky, very little. In any event you should pull the crank and clean the sludge trap, while there measure the journal dimensions etc., inspect the oil pump as well as the cam and followers and be prepared to spend some cash.   DonG

[blackcat]

I have many years experience in the area of automotive repair, especially in engine rebuilding. If this was my engine I would start out by pulling it completely apart and assessing the total condition of all the components. At the moment you are focusing on only one area that needs attention, sure the cylinders need to be repaired, but how about everything else? You are starting in the middle and that is a mistake, take the engine out and strip it down, you may find that it needs everything or if you are lucky, very little. In any event you should pull the crank and clean the sludge trap, while there measure the journal dimensions etc., inspect the oil pump as well as the cam and followers and be prepared to spend some cash.   DonG

This.

I’d install a P3 cam and a pair of 36mm carbs.  Easy to change back for re-sale purposes but a better ride imo.

[czakky82]

I’ve got a gnarly cam and 36mm manifolds.

[Cam3512]

I don’t know, that might be overkill for the Sport’s 750.  Mine does just fine with the stock cam and VHB 30’s.

[cliffrod]

The two World Record bikes (each approx 750 cc displacement) had SS1-38 carbs, with only intent to run WOT top speed.  The 850 LeMans have bigger valves and more to fully exploit 36mm carbs. I would expect 36 carbs on a relatively stock small valve 750cc V7 Sport street bike to be overkill and more trouble than benefit in regular traffic situations. 

The VHB 30 carbs do hit the wall, but not until you get into 100+mph range. 

[Richiez22908]

While I’m managing to get these things off and haven’t sent to Millenium, if anyone has a source or suggestion on how to get a Gilardoni set I’d appreciate it. It would be easier and less to worry about and measure as far as the old pistons.

I have many years experience in the area of automotive repair, especially in engine rebuilding. If this was my engine I would start out by pulling it completely apart and assessing the total condition of all the components. At the moment you are focusing on only one area that needs attention, sure the cylinders need to be repaired, but how about everything else? You are starting in the middle and that is a mistake, take the engine out and strip it down, you may find that it needs everything or if you are lucky, very little. In any event you should pull the crank and clean the sludge trap, while there measure the journal dimensions etc., inspect the oil pump as well as the cam and followers and be prepared to spend some cash.   DonG

Very low miles and almost none since it was brought back to life after sitting… so hoping for the former. And I may reach out to you if that’s ok once I get it apart to see what I should be measuring and what those dimensions should be. Thanks

[Antietam Classic Cycle]

Do you have a shop manual? https://www.thisoldtractor.com/mg_manuals/workshop_manual_v7sport_750s_850t.pdf
Piston specs are on (pdf) page 21 of 135, paper manual page 19. The drawings of how to measure and dimensions is on 98 & 99 of 135.

[Don G]

As for specs and dimensions, the factory work shop manual can be found online or purchased in book form yet, take your components to a reputable engine shop and have them looked at, supply the specs with the parts. As for hoping that the internals are mint due to low miles is only hoping, I have seen my own 1974 Eldorado with 5000 original miles on it needing crank bearings, wrist pin bushings, couple of followers and of course cylinders. By the look of your cylinders it will likely have some oil pump wear, only way to tell is take it down and inspect, because of the chrome being hard and the bearings and crankcase soft,(no oil filter) the chrome and dirt particles imbed themselves in the soft surfaces and wear the shite out of the crank, cam journals, oil pump etc. I have had a fair number of these apart and seen the carnage.... DonG

[Richiez22908]

Do you have a shop manual? https://www.thisoldtractor.com/mg_manuals/workshop_manual_v7sport_750s_850t.pdf
Piston specs are on (pdf) page 21 of 135, paper manual page 19. The drawings of how to measure and dimensions is on 98 & 99 of 135.

Yup... I actually have the paper one(and owners manual) from the original owner and did download the pdf as well. Thanks for the pages to find the info.

I make, like suggested later, take the parts to a shop and pay them to check them.

Thank you again!

[huub]

The two World Record bikes (each approx 750 cc displacement) had SS1-38 carbs, with only intent to run WOT top speed.  The 850 LeMans have bigger valves and more to fully exploit 36mm carbs. I would expect 36 carbs on a relatively stock small valve 750cc V7 Sport street bike to be overkill and more trouble than benefit in regular traffic situations. 

The VHB 30 carbs do hit the wall, but not until you get into 100+mph range.

i had 36 mm PHF on a basically stock V7sport , and it did not improve over the stock carbs.
at medium revs it would struggle to accept full throttle. even after a couple of dyno runs we could not get them to fuel cleanly
( according to the dyno operator simply not enough air going through to let the 36 mm work properly)
I swapped them for PHF 32 mm, which are great and are a improvement over stock.

[Richiez22908]

Thanks for the suggestions... but I'll be leaving it stock. No need or want for more power(I'd have kept the Ducati if I had).

Also the local shop said I can bring any parts over there for testing and inspection... so that is a huge help.

But I'll post pics here for your opinions as well.

Thanks again so much everyone.

[guzzisteve]

While I’m managing to get these things off and haven’t sent to Millenium, if anyone has a source or suggestion on how to get a Gilardoni set I’d appreciate it. It would be easier and less to worry about and measure as far as the old pistons.

Very low miles and almost none since it was brought back to life after sitting… so hoping for the former. And I may reach out to you if that’s ok once I get it apart to see what I should be measuring and what those dimensions should be. Thanks

You may want to check w/Todd over at GT or in his store. I thought I saw a set there.

Yes
https://gtmotocycles.com/products/gilardoni-piston-cylinder-set-82-5mm?_pos=1&_psq=Cylinder&_ss=e&_v=1.0

Maybe it was above on this thread.

This is the very reason I used LA Sleeve & cast bores matched to my pistons. A process used for many years. Don't need Nik just cause others say so. The 1st V7 motor is perfect, been riding that one for 17yrs. Getting another I had done at same time put together now for another V7 of mine to run. Got 3
I had 2 sets done w/sleeves for less than 1 set of Nik.

[Antietam Classic Cycle]

As I posted previously, the photo of the Gilardoni kits on Guzzitech show Ambassador pistons - no relief for the intake valve. Likely 83 mm bore and slightly lower compression as well.

Nikasil allows tighter clearances for cooler running and less noise. When I priced buying LA Sleeves, having the cylinders bored, sleeves installed, bored to the correct i.d. and honed, it was nearly the same cost as Nikasil at Millennium.

[Richiez22908]

Millennium, including fitting the pistons, rings, etc is only charging $600 for both. Obviously Shipping is additional $100 or so total for both ways.

Seems perfectly reasonable to me. Just hope the pistons are still usable.

We'll see.

[guzzisteve]

That's what I paid for 2 sets done in 04 from a friend w/engine remanufacturing shop. Your deal sounds good for stuff now.

[Canuck750]

I have many years experience in the area of automotive repair, especially in engine rebuilding. If this was my engine I would start out by pulling it completely apart and assessing the total condition of all the components. At the moment you are focusing on only one area that needs attention, sure the cylinders need to be repaired, but how about everything else? You are starting in the middle and that is a mistake, take the engine out and strip it down, you may find that it needs everything or if you are lucky, very little. In any event you should pull the crank and clean the sludge trap, while there measure the journal dimensions etc., inspect the oil pump as well as the cam and followers and be prepared to spend some cash.   DonG

Don is 100% on this advice,

just replacing the cylinders / pistons does not solve the problem(s). If the crank journals, main or shell bearings and/or the oil pump are worn the cylinder replacement will not forestall a failure.

[Frenchfrog]

On the same page too. Not hard to check all of this for an experienced mechanic. Parts availability for the bearings is excellent too......

[Dave Swanson]

I will pile on with all the others.  I assumed you were in for a total engine strip, and inspection when deciding to plate the cylinders.  If that wasn't your plan, please listen to the sage advice given. 

[Richiez22908]

I will pile on with all the others.  I assumed you were in for a total engine strip, and inspection when deciding to plate the cylinders.  If that wasn't your plan, please listen to the sage advice given.

Yeah a while up on the thread I mentioned definitely taking it all apart.

The local shop agreed to inspect, measured etc everything and I'll also post pics and measurements here and will replace, refinish what is needed.

[Frenchfrog]

Great ...it's probably disappointing to have to do this but at the end you won't be plagued by nasty surprises.

[Richiez22908]

Sorry deleted previous post when I remembered I could just turn the rear wheel and get it where I needed everything.

Ok finally got back in town. My daughter and I got the right cylinder off this morning. Thankfully it looks fine, better than the left. So fingers crossed the rebuild will find little to no damage. But we'll deal with whatever is found. Next will get the pistons off(bought a heat gun to help with he pins), verify they're in spec... and get the whole set off to Millennium.

Thanks again for all the help!

[Richiez22908]

Before I go to get the piston ring out... are these smaller on one side the the other or can they be removed in either direction?

Thank you!!

[Antietam Classic Cycle]

Before I go to get the piston ring out... are these smaller on one side the the other or can they be removed in either direction?

Thank you!!

The pin bore? Same diameter the whole way through. Can be removed either direction.

[Richiez22908]

The pin bore? Same diameter the whole way through. Can be removed either direction.

Thank you!! Very rarely I've heard of ones that were not... and people finding out after they've lost their minds trying to get them out the wrong side.

Thank you again!