guzziriders.org - moto guzzi forum Homepage
Forum Home Forum Home > Technical > Loop Frames
  New Posts New Posts RSS Feed - Chrome bore replacement. V7 850 GT
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Chrome bore replacement. V7 850 GT

 Post Reply Post Reply Page  <1234>
Author
Message
v7john View Drop Down
Senior Member
Senior Member
Avatar

Joined: 14 May 2014
Location: West Wales, UK.
Status: Offline
Points: 587
Post Options Post Options   Thanks (0) Thanks(0)   Quote v7john Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jan 2017 at 14:11
I think it's always the safest option to fit nikasil barrels if you can afford it. Having said that, my V7 700 is still running the chrome ones. I've now examined the RH one and it's good with no sign of deterioration. The LH one should be coming off this afternoon.  The intention is to have the chrome removed and nikasil applied but I don't have the cash at the moment.

If you find bits of chrome in the oil, it's too late. From experience I can say that those hard chrome flakes can find their way around the whole engine causing damage as they go.

My bike has 4 rings per piston. There's one below the gudgeon pin. I've found it easy enough to fit barrels over the piston and rings when already fitted to the con-rod. There's a very short chamfer on the inside of the base of the barrel. I just work my fingers around each ring in turn until it's in the chamfer and then push the barrel down to the next ring. I've not used a ring clamp or broken a ring (yet). With the extra bottom ring this is really the only option.
1972 V7Sport "The Racing Rhino".
1972 V7 700cc "The Fire Bike".

Read my blog https://racingrhino.wordpress.com/
Back to Top
jmee54 View Drop Down
Senior Member
Senior Member
Avatar

Joined: 28 Nov 2014
Location: Cornwall
Status: Online
Points: 477
Post Options Post Options   Thanks (0) Thanks(0)   Quote jmee54 Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jan 2017 at 16:09
I did exactly the same with both of mine, just dropped the cylinder down the piston and squeezed with my fingers. I did forget to align the gaps and had to take it to bits again first time though, doh!
There is nothing at all dificult in any top end work. Just stick a rag or something in the hole when you are replacing the piston in case you drop a circlip into the crank case.
Back to Top
Dave P. View Drop Down
Senior Member
Senior Member


Joined: 12 Jan 2015
Location: Northants
Status: Offline
Points: 2058
Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 27 Jan 2017 at 16:37
The only reason that I do it as I described is to remove the risk of broken rings.You can, of course do it either way.I started using this method on Laverda twins where the finger method is more fiddly being a 360-degree vertical twin.

TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
Back to Top
Normski View Drop Down
Falcone
Falcone


Joined: 28 Jan 2015
Location: Devon
Status: Offline
Points: 64
Post Options Post Options   Thanks (0) Thanks(0)   Quote Normski Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2017 at 11:00
Originally posted by Lemsteraak Lemsteraak wrote:

do I need any special tools ?,sorry if this sounds dumb, rings clamps for instance etc.I ve the online download for Chilterns but will wait until Johns hard copy is with me.

Not sure about loops but on the T3 the nearest thing to a special tool required was a long 10mm hex key adaptor for one of the stud nuts. I cut a c. 2" piece off an Allen key and fitted it into a socket but you can get the proper job.
Back to Top
v7john View Drop Down
Senior Member
Senior Member
Avatar

Joined: 14 May 2014
Location: West Wales, UK.
Status: Offline
Points: 587
Post Options Post Options   Thanks (0) Thanks(0)   Quote v7john Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2017 at 11:31
Originally posted by Normski Normski wrote:

Originally posted by Lemsteraak Lemsteraak wrote:

do I need any special tools ?,sorry if this sounds dumb, rings clamps for instance etc.I ve the online download for Chilterns but will wait until Johns hard copy is with me.

Not sure about loops but on the T3 the nearest thing to a special tool required was a long 10mm hex key adaptor for one of the stud nuts. I cut a c. 2" piece off an Allen key and fitted it into a socket but you can get the proper job.
Yes, this is needed on the loops as well.

Also a C-spanner to get the exhaust nut undone. Just taken the LH head off mine and it was a proper - insert expletive here -  to get off. No exhaust gasket, already bent out of shape, stuck in with "gun gum" or the like and with most of the notches rounded off. Lifted the barrel - chrome again but in good nick.


Edited by v7john - 28 Jan 2017 at 11:36
1972 V7Sport "The Racing Rhino".
1972 V7 700cc "The Fire Bike".

Read my blog https://racingrhino.wordpress.com/
Back to Top
Amboman View Drop Down
Falcone
Falcone


Joined: 05 Dec 2015
Location: Maryland, USA
Status: Offline
Points: 70
Post Options Post Options   Thanks (0) Thanks(0)   Quote Amboman Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2017 at 14:24
Originally posted by ranton_rambler ranton_rambler wrote:

I think mine has still got it's original chrome bores. Some people are paranoid about it but I'm not going to do anything about it until something goes wrong. No bits in the sump last time I dropped it, and I'll be doing it again shortly.

Quote from a movie: "you're not paranoid if they really are out to get you". In this case, it's not paranoia if it really does happen. If you wait until "something goes wrong" then it will be too late and the cost to fix it will be four times the cost of new Gilardonis. It's a bit like playing Russian Roulette with your engine... 
Charlie
'69 V700, '69 Ambassador, '72 Ambassador "mongrel", '76 Convert, '85 Morini 350 K2
http://www.AntietamClassicCycle.com
Back to Top
Vin0bim View Drop Down
Guzzino
Guzzino


Joined: 27 Sep 2015
Location: Cornwall
Status: Offline
Points: 9
Post Options Post Options   Thanks (0) Thanks(0)   Quote Vin0bim Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jan 2017 at 11:43
Bender reckons for the amount of faffing around it is easier to get the kit and not much more expensive
Back to Top
Lemsteraak View Drop Down
Falcone
Falcone
Avatar

Joined: 12 Jan 2017
Location: Tiverton ,Devon
Status: Offline
Points: 76
Post Options Post Options   Thanks (0) Thanks(0)   Quote Lemsteraak Quote  Post ReplyReply Direct Link To This Post Posted: 31 Jan 2017 at 18:07
Kits on their way.
Moto Guzzi 1970 V7 Special
Laverda 1973 GT750
Laverda 1970 SF750
Laverda 1986 RGA1000 Sprint
Back to Top
kateguy View Drop Down
Senior Member
Senior Member
Avatar

Joined: 24 Nov 2014
Location: uk
Status: Offline
Points: 957
Post Options Post Options   Thanks (0) Thanks(0)   Quote kateguy Quote  Post ReplyReply Direct Link To This Post Posted: 02 Feb 2017 at 18:37
Well we've got 4 of the buggers...all on chrome bores....all go well, have frequent oil changes and we check the strainers.....its different if its comin off in strips of course....my black loop had wear of the chrome at the top and a 5 ish cm pit in one bore where the piston had stopped and remained for some years, the plug was out when we aquired it. Thing is...we didnt know that when we got it going.....it ran fine, the strainer stayed clean...and the bike didnt smoke.
One day at work I left it out during a particularly long storm....when I came home I did the last 10 miles on 1 cylinder cos water had got in the dizzy. When we got it on 2 it was smokin like a good un....methinx due to excess fuel having washed a lot of carbon deposits away. I carried on using it and it began to smoke less n less till it stopped. I ran it till me n Guy did a swap...and he decided to take a look inside...which was when we discovered the pit in the bore.
Guzzi chromed these bores for a reason.....
Moto Guzzi Club GB.....
850 LE MANS...1 & 2....V7 Loop Frame..V7 Sport replica...Guzzi Daytona...Ducati 900ss Bevel not belt.....Laverda 3C ....and an MZ...
Back to Top
Lemsteraak View Drop Down
Falcone
Falcone
Avatar

Joined: 12 Jan 2017
Location: Tiverton ,Devon
Status: Offline
Points: 76
Post Options Post Options   Thanks (0) Thanks(0)   Quote Lemsteraak Quote  Post ReplyReply Direct Link To This Post Posted: 02 Feb 2017 at 18:46
Hi Kate n Guy another " face" from the Laverda world,

 I expect the bores will be fine,but with no history of it"s past in Italy except it was ASI historic registered and it"s condition is good,only 47Kms but  I d rather have the piece of mind.

Is there any resale on good chrome barrels i(f they are)?Smile
Moto Guzzi 1970 V7 Special
Laverda 1973 GT750
Laverda 1970 SF750
Laverda 1986 RGA1000 Sprint
Back to Top
italianmotor View Drop Down
Senior Member
Senior Member
Avatar

Joined: 14 May 2014
Location: UK
Status: Offline
Points: 1960
Post Options Post Options   Thanks (0) Thanks(0)   Quote italianmotor Quote  Post ReplyReply Direct Link To This Post Posted: 02 Feb 2017 at 19:02
Here's a pic of a peeled chrome barrel - I believe it was from my S3 about 20 years ago, or from one of my loops, can't remember. Anyway, I am running an early ('75) T3 Cali still on chrome bores, and as Kate says, it's just a case of keeping an eye out on oil changes and so on. I'm waiting for the next euro value drop to buy a Gilardoni kit to keep for the day that I'll need it..




Guzzi lover doing my own thing: http://www.italianmotormagazine.com
Back to Top
kateguy View Drop Down
Senior Member
Senior Member
Avatar

Joined: 24 Nov 2014
Location: uk
Status: Offline
Points: 957
Post Options Post Options   Thanks (0) Thanks(0)   Quote kateguy Quote  Post ReplyReply Direct Link To This Post Posted: 05 Feb 2017 at 17:50
Originally posted by Lemsteraak Lemsteraak wrote:

Hi Kate n Guy another " face" from the Laverda world,

 I expect the bores will be fine,but with no history of it"s past in Italy except it was ASI historic registered and it"s condition is good,only 47Kms but  I d rather have the piece of mind.

Is there any resale on good chrome barrels i(f they are)?Smile

Mite well be hon...tho the last pair we aquired were a swap for a loop head ! Xx

Incidentally...goin slightly off topic...the foto is of Red and the Beetle...the Beetle came with the fat tank....but no vestiges of chrome.....I wanted to try and ressurect some of the appearance without the expense...the 'chrome' you can see is a roll of stick on which came from the Range...the pinstripes are me....amateur....
Sorry about the foto res....Guy says you wouldnt know...

Edited by kateguy - 05 Feb 2017 at 17:57
Moto Guzzi Club GB.....
850 LE MANS...1 & 2....V7 Loop Frame..V7 Sport replica...Guzzi Daytona...Ducati 900ss Bevel not belt.....Laverda 3C ....and an MZ...
Back to Top
Lee Davis View Drop Down
Falcone
Falcone


Joined: 25 Apr 2017
Location: New Mexico
Status: Offline
Points: 17
Post Options Post Options   Thanks (0) Thanks(0)   Quote Lee Davis Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 2017 at 15:41
Just a note on the cylinder wall treatments. Nikasil is the name of the Mahle originated coating that was developed for Mercedes and Porshe engines. The Gilardoni cylinders developed by Moto Guzzi are named Nigusil, and are different in subtle ways. Nigusil was new in the late '70s in response to the problems with chrome bores (also developed by Moto Guzzi). The new Gilardoni piston/cylinder sets for retrofitting on old loop frames are a major improvement, to say the least, and seemingly last forever. I have 6 loopframes in the lineup for restoration and I would not consider using anything else but new Nigusil.
Lee Davis
Back to Top
Lemsteraak View Drop Down
Falcone
Falcone
Avatar

Joined: 12 Jan 2017
Location: Tiverton ,Devon
Status: Offline
Points: 76
Post Options Post Options   Thanks (0) Thanks(0)   Quote Lemsteraak Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 2017 at 16:11
well i m riding it and keeping an eye on the oil, until Dave can fit the new barrels, nice pic Kate, I ve ditched those horrible plastic puffy grips for Verlicchi  rubber ones ,no more hand cramp .

Moto Guzzi 1970 V7 Special
Laverda 1973 GT750
Laverda 1970 SF750
Laverda 1986 RGA1000 Sprint
Back to Top
Vin0bim View Drop Down
Guzzino
Guzzino


Joined: 27 Sep 2015
Location: Cornwall
Status: Offline
Points: 9
Post Options Post Options   Thanks (0) Thanks(0)   Quote Vin0bim Quote  Post ReplyReply Direct Link To This Post Posted: 21 Jun 2017 at 16:23
so what is the difference: Nigusil vs Nikasil. Is one better than the other or is it trade name stuff? i.e. the same thing?
Hayden
Back to Top
 Post Reply Post Reply Page  <1234>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.10
Copyright ©2001-2017 Web Wiz Ltd.

This page was generated in 0.047 seconds.