Imola V75 4V Project

[jacksonracingcomau]

Thanks Martin.

So I slept on it and decided to man up and get with the elephant feet!

Parts I'm planning to use (please confirm if OK/add/change)

Cali 1400 valve springs x 8. Part No. B013517. Stein Dinse take 2-6 weeks, ordered some from Motorcyclesparepart s.eu - seems to be OE parts
x 8 Nevada etc bottom caps
x 8 OE top caps
x 8 OE valves
x 16 collets
x 8 KTM elephant feet Part No. #590362000

Queries:

What collets did you use? OE? Did you use new? I have a ton of used ones to pick from.

Is KTM part No #590362000 correct I can't find it anywhere on the web?
Is it 58036062600 from the 640 LC4 engine like here https://advrider.com/f/threads/ktm-640-lc4-loud-clicking-noise-when-idle.888110/

and here

https://www.motorcyclespareparts.eu/en/ktm-parts/2006-640-lc4-supermoto-blue-06-europe-motorcycles/valve-drive

How did you shorten your pushrods? For example, did you grind a bit off one or both end and then round off or take apart and shorten the rod somehow?

Did you use the early (solid) or late (holes in the arms) rocker arms?



I've 3 weeks on an oil rig to do some reading on cams etc.... :-)

Thinking I might cold build one Cali and one Nevada valve to compare (loose length is 1.6 inches for Cali and 1.7 for Nevada) - what is the perceived advantage of the Cali spring?

Thanks again 
Cheers

ktm part. number in old post sorry just had cataract surgery phone typing hard !
cali springs livhter weight to move and adjustable over wide range / pressure mainly avoiding valve bounce was goal possibly went with more preload than needed but I had no reference number
is all good but more time needed to prove absolute
your numbers are free length it was coil bind (solid) length I was interested in   coil bind was, I. believe, at least part of original problem,  compounded when factory added preload with thicker lower caps, maths says no
pushrods, made tool to tap off one endcap. shorten then press back on

oe collets (old but any doubts use new )
top caps need machining to fit new springs
had to grind rockers for clearance and touch off pedestal
think that was it but lots of checking
guess old rockers did not know different
oh no stem seals on exhausts  poss issue ss and cast iron guide

will pm more detail not ready to post for world yet this engine is test bed
not absolute how to guide,

[Muzz]

Simmoto, Steamdriven on this site has a Monzada where he shoehorned a Nevada engine into his Monza frame.  It was not as straightforward as it sounds.  He was, however, trying to keep it as unmolested as possible and this probably lead to some of the difficulties.

Don't know the differences between the Imola and the Monza frame, but it wouldn't hurt to drop Kev a pm as to problems he faced.

[Simmoto]

ktm part. number in old post sorry just had cataract surgery phone typing hard !
cali springs livhter weight to move and adjustable over wide range / pressure mainly avoiding valve bounce was goal possibly went with more preload than needed but I had no reference number
is all good but more time needed to prove absolute
your numbers are free length it was coil bind (solid) length I was interested in   coil bind was, I. believe, at least part of original problem,  compounded when factory added preload with thicker lower caps, maths says no
pushrods, made tool to tap off one endcap. shorten then press back on

oe collets (old but any doubts use new )
top caps need machining to fit new springs
had to grind rockers for clearance and touch off pedestal
think that was it but lots of checking
guess old rockers did not know different
oh no stem seals on exhausts  poss issue ss and cast iron guide

will pm more detail not ready to post for world yet this engine is test bed
not absolute how to guide,

Great, thanks for getting back to me on those questions mate, much appreciated.
Cheers

[Simmoto]

Simmoto, Steamdriven on this site has a Monzada where he shoehorned a Nevada engine into his Monza frame.  It was not as straightforward as it sounds.  He was, however, trying to keep it as unmolested as possible and this probably lead to some of the difficulties.

Don't know the differences between the Imola and the Monza frame, but it wouldn't hurt to drop Kev a pm as to problems he faced.

Hi Muzz,
Thanks for the info, the Imola and Monza frames are identical, I looked up some of the Monzada posts and yeah, not 100% easy! To retain the quick handling you need to retain the Imola swingarm and probably wheels and forks. There are some differences in the drive splines between models I think so some mods needed there to get it all to fit. Would probs ned a fork brace and other bits too plus, plus plus. Once I get ti the stage of transplantation I'll dig into it more but first the Lario too sort and then the V75 engine to rebuild so willbe a wee while!
Cheers

[Muzz]

Hi Muzz,
 and yeah, not 100% easy! To retain the quick handling you need to retain the Imola swingarm and probably wheels and forks. There are some differences in the drive splines between models I think so some mods needed there to get it all to fit.

Kev is still using the smaller UJ, that area did give him some problems.  He has three spares so he just keeps an eye on them.  That bike is pure eye candy, not restored, just original.

So far, only one person who was not aware of the project has picked up that it has the 750 in it.

[Chuck in Indiana]

So far, only one person who was not aware of the project has picked up that it has the 750 in it.

I was out in New Hampshire/Vermont somewhere a few years ago with the AeroLario. A guy stopped and talked to me for 15 minutes or so, telling me about his Lario back in the day. He never noticed the Aero engine. 

[Muzz]

I was out in New Hampshire/Vermont somewhere a few years ago with the AeroLario. A guy stopped and talked to me for 15 minutes or so, telling me about his Lario back in the day. He never noticed the Aero engine. 

Of course Chuck, he would never have seen a drone motor (a bit thin on the ground I hear ) and probably just expected your bike to still have a Lario engine.

[steamdriven NZ]

Simmoto, Steamdriven on this site has a Monzada where he shoehorned a Nevada engine into his Monza frame.  It was not as straightforward as it sounds.  He was, however, trying to keep it as unmolested as possible and this probably lead to some of the difficulties.

Don't know the differences between the Imola and the Monza frame, but it wouldn't hurt to drop Kev a pm as to problems he faced.

Hi Guys,
Back on the board after some months away.
Simmoto, I can supply many pics and any info you want to help up out. I have a friend in Auckland NZ who put a V75 4V engine and box into a V50 Mk1 that he bought new in 1979 and still has.
Simply put, the big bits are easy to fit, the small bits are not so easy but in many ways we have answers for you rather than you having to dream up the solutions yourself.
The UJ problem Muzz refers to happened early in my ownership (I bought it in 1988)  and hasn't reoccurred, but using a 500 UJ behind a 750 engine works ok. You just have to look after it and it's the only problem left unsolved in that the 750 UJ doesn't seem to have the problems the 500's do/did. I just look after it and keep going.
I did spend a lot of time trying to make the bike look stock, and as Muzz said most people don't notice. That means I've achieved what I wanted so happy days.

Looking forward to seeing yours take shape. A friend of mine has ridden it in both configurations, and pronounced it as now being "the bike he had always hoped it would be", high praise indeed from a long-time Buell rider.

Cheers Kev.

[IceBlue]

So Brian has reliable machines using his set up including Nevada progressive springs, lash caps, Yamaha adjusters and the Chinese valves etc. This is the only durable proven fix I know. I'm not saying there are no other fixes but they are not AFAIK proven durable - yet.

If we forget the valves and assume I use indestrutable ones I don't know of any reasons why the rest of Brian's formula should not work. Have lash caps failed on Larios in the past or is there an issue with the Yamaha adjusters for example? If someone spells out a problem I'm all ears cos I'm a pretty amateur mechanic learning as I go  . I've noted all the stuff that has come up in various posts and it seems to come down to checking before start up there's no interference in the rocker gear and the springs have enough air gap at full compression.

I want a machine that will preserve its cam for the next say 20K miles and not lose a valve head. I'm no racer so only need original RPM red line. Others might be aiming for higher performance goals?

Cheers 

Hi Simmoto!
Just fell over this string doing some wild surfing 
I was just wondering how the project turned out.
In the time away from WG, I have restored a V75/4

I'm not using the Chinese valves any more, although I still have two Lario's with these valves.
As Chuck pointed out, they are not the quality one would want
Just dumped a bucket full of them in the trash.

In my V75/4 restore, I'm using the SD valves, and I'm happy they became available.
Hard tips, no lash caps needed.
Still using the Nevada progressives, and the Yamaha adjusters.
They have never given me a flat cam, so I see no other solution.
I plan to replace the Chinese valves in my Larios with the SD valves.

Please let me know how your project turned out 

Cheers
Brian

[sign216]

Brian,

Good to see you again.  I've used Chinese parts, some are very good quality.  It seems they have improved over what they were years ago.  And of course, there is some trash too.

Joe

[Chuck in Indiana]

Hiya, Brian! 

[jacksonracingcomau]

Good to see some SB 4v talk again
Mine is actually the bike I would choose as my only, despite 45 years and more than half a million miles on my first love, Carcano BB.
Power delivery is superb, a baby under 5K, a (little) rocket to 9
No valve bounce, no rev limiter, power just drops gently.
As with my Bb’s, valve clearances don’t change, uses no oil
The thing is a brilliant design, the original execution pathetic.
Mine is brutally thrashed regularly, after 5 years it just gets better.

Only mechanical work has been two clutches, oil soaked not actually worn out. I simply replaced the pushrod oil seal the first time and dressed the pushrod, cheapskate stuff. The second time I put in a viton seal and new pushrod, fingers crossed it won’t slip again for many years. I’m confident but will fit modern SB clutch if it does.

Brian
When you change your valves, look for the tell tale signs, hammering on tips, adjusters , pushrods and followers.
You say your cam is not flat, put a degree wheel on it and graph lift over crank angle (all 4 lobes), report back.
Others on here have reported second valve drops with these springs, not at all surprising, the cause has not been addressed.
I realise you do not thrash or abuse, perhaps you can baby it forever.
If you put it on a dyno when first built, give it another run after refresh. Any cam wear will be obvious by figures if it doesn’t go bang on the dyno

Best of luck but your Chinese valves were never the issue, only a symptom. I had Chuck’s heads with these, another set with Suzuki valves and one head with oe valves. All hammered to hell.

I’ve since bought another Lario, same story. My fkd camshaft collection grew.
When you truly fix the camshaft problem, you fix the whole thing, rev to the moon, safely.

We should have an SB 4 valve convention with a day on racetrack to prove to the world how good they really are, sadly there may be very very few takers, I’ve yet to see another one that goes as designed.

[IceBlue]

When you truly fix the camshaft problem, you fix the whole thing, rev to the moon, safely.

We should have an SB 4 valve convention with a day on racetrack to prove to the world how good they really are, sadly there may be very very few takers, I’ve yet to see another one that goes as designed.

Sounds like a dream - one I want!
You are right, I don't abuse my 4V's (max 8.000rpm only for a moment), knowing that the Chinese valves weren't top quality stuff.
My newly restored V75/4 rev's to 8.000 in a split second. It has the 14mm cams, SD racing valves, Yamaha adjusters, no caps, and there is very quiet at the top end. No valve rattle. SWF ignition.

Could you let me in on the "camshaft fix", please. I have six 4V engines sitting around the shop with my solution. Could be nice implementing the final solution.
I was convinced the progressive springs and good valves were the golden egg, as they were for the 2V's back in the days.

Cheers
Brian

[jacksonracingcomau]

It is and it isn’t that simple
I use the ABC method when modifying

At risk of repeating what I wrote 5 years ago
When choosing valve springs, basically
1/They must fit
2/ valve seat pressure must be appropriate for application, as must valve fully open pressure
3/ there must be adequate clearance from coil bound

I’m not sure where the idea of using Nevada valve springs came from, possibly Pete Roper .?
Under my tests they pass # 1, it is possible to install them.

Most important is never ever to reuse a cam that has suffered from incorrect valve springs. Both of the engines I was working with had Suzuki springs fitted , which may have been satisfactory but the damage was already done, once a cam has lost it’s hardening it’s all over , red rover.

I never got to see the valve springs stein dinse sell under original part number, it wouldn’t surprise me to find they are perfectly made but please, anyone trying them, measure first, #2 and #3 are crucial.

[IceBlue]

It is and it isn’t that simple
I use the ABC method when modifying

At risk of repeating what I wrote 5 years ago
When choosing valve springs, basically
1/They must fit
2/ valve seat pressure must be appropriate for application, as must valve fully open pressure
3/ there must be adequate clearance from coil bound

I’m not sure where the idea of using Nevada valve springs came from, possibly Pete Roper .?
Under my tests they pass # 1, it is possible to install them.

Most important is never ever to reuse a cam that has suffered from incorrect valve springs. Both of the engines I was working with had Suzuki springs fitted , which may have been satisfactory but the damage was already done, once a cam has lost it’s hardening it’s all over , red rover.

I never got to see the valve springs stein dinse sell under original part number, it wouldn’t surprise me to find they are perfectly made but please, anyone trying them, measure first, #2 and #3 are crucial.

If you PM me your email, I can send you a very detailed spread sheet on the Nevada springs. The idea of using the Nevada/V7C springs came from Germany after some cam pressure measurements done with some guys there.

[jacksonracingcomau]

If you PM me your email, I can send you a very detailed spread sheet on the Nevada springs. The idea of using the Nevada/V7C springs came from Germany after some cam pressure measurements done with some guys there.

Very kind of you but I test metal, not spreadsheets, I bought, tested, rejected, chucked. Absolutely incapable of what I need them to do, period.
There is a reason why my one is safe to 9krpm .
Next will be stronger still and need a little more spring, I got Chuck’s Aero cam reground for a bit more whizz.
Will probably run the Aero timing chest too, just to be different
He’s got the only Aerolario , I can have the only Larioaero !

[dguzzi]

  Don't pick on Chuck.

[IceBlue]

Well - so far the original Nevada/V7C progressives springs sold by SD has served me very well - now they have the 4V valves again, hard tipped in great quality.
No need for Chinese knock offs.
Springs will fit with the appropriate top/bottom retainers.
They were originally replacing the double spring config on the early 80's SB's to protect the cams and avoid valve drop.
At the same time the 12mm cam shaft was replaced with a 14mm - that happed too on the late 4V's.
That turned out to be a success on the 2V's - 4V's still grinded down the 14mm cams with the very hard OEM springs which remained.
I have a few sitting in the trash here.
Hence the idea sprung also to use the updated progressive spring config on the 4V's.
The springs came out after Guzzi ditched the 4V's
- The "dog" had a bad name - so it was put down.

If I understand correctly, coil bound means the springs is compressed to its maximum?!

The picture shows the original 4V spring to the right compressed 100% - hence coil bound to my understanding...
The left shows the Nevada/V7C progressive spring - it still has air in the coil.




 

[jacksonracingcomau]

  Don't pick on Chuck.

Whoa, no-ones picking on Chuck, au contraire, he gave me aero cam and cover as he wasn’t using them
Converstaion may be hard to follow

Well - so far the original Nevada/V7C progressives springs sold by SD has served me very well - now they have the 4V valves again, hard tipped in great quality.
No need for Chinese knock offs.
Springs will fit with the appropriate top/bottom retainers.
They were originally replacing the double spring config on the early 80's SB's to protect the cams and avoid valve drop.
At the same time the 12mm cam shaft was replaced with a 14mm - that happed too on the late 4V's.
That turned out to be a success on the 2V's - 4V's still grinded down the 14mm cams with the very hard OEM springs which remained.
I have a few sitting in the trash here.
Hence the idea sprung also to use the updated progressive spring config on the 4V's.
The springs came out after Guzzi ditched the 4V's
- The "dog" had a bad name - so it was put down.

If I understand correctly, coil bound means the springs is compressed to its maximum?!

The picture shows the original 4V spring to the right compressed 100% - hence coil bound to my understanding...
The left shows the Nevada/V7C progressive spring - it still has air in the coil.




 

Yes, you understand #1 and #3 perfectly
#2 is pressure at seat and full lift
This controls the valve, major differences to 2v heron heads and rockers
4v makes power at much higher rpm, correct pressure is vital for performance, when valve cannot follow cam we have a problem. Perhaps safe if you baby it, perhaps not, read up on spring pressure, measure yours
Correct spring will rev to moon, try it, I run original spec pressure without coil bind, late Guzzi 4vpc valve springs, only because Pete sent me a set to try. Caps needed machining + new bottom seats + shims
Fixed, problem was never valves themselves, nor camshaft, both symptoms NOT CAUSE
Collateral damage was pushrod tips, valve stem tips, adjusters and followers, all symptoms

[IceBlue]

Whoa, no-ones picking on Chuck, au contraire, he gave me aero cam and cover as he wasn’t using them
Converstaion may be hard to followYes, you understand #1 and #3 perfectly
#2 is pressure at seat and full lift
This controls the valve, major differences to 2v heron heads and rockers
4v makes power at much higher rpm, correct pressure is vital for performance, when valve cannot follow cam we have a problem. Perhaps safe if you baby it, perhaps not, read up on spring pressure, measure yours
Correct spring will rev to moon, try it, I run original spec pressure without coil bind, late Guzzi 4vpc valve springs, only because Pete sent me a set to try. Caps needed machining + new bottom seats + shims
Fixed, problem was never valves themselves, nor camshaft, both symptoms NOT CAUSE
Collateral damage was pushrod tips, valve stem tips, adjusters and followers, all symptoms

Thank you for spelling it out to me.  Can you define what the Guzzi 4vpc valve are - in which engine they originally reside, please.
I'll try to find a way to scale the the pressure at seat and full lift on the Nevada springs.
I actually think they are in the excel sheet I mentioned.
Yup here it is:




Cheers Brian

[jacksonracingcomau]

About the size of it, as I said, not possible for me to use.
It appears that you have changed the original springs that became coil bound, wore out cam etc, creating a situation where valve couldn’t follow cam for springs that cannot  follow cam at high revs.
The result is identical but for an entirely different cause.
The springs I used (Griso or 1400 Cali) will work but are a lot of faffing about, measuring, machining and shimming etc.
May I suggest you buy one stein dinse replacement Lario spring , measure pressure as per your spreadsheet but also measure crushed (coil bound).
Then measure (all 8 to be sure) between seat and cap where springs go.
Then measure valve lift (dial gauge on top collar), in and ex
Post or send to me (I’ve never seen the new replacement 14mm cam, I used a later V7 EFI cam)
From this we can deduce if they work, we know the factory did fix the 8v for the Dakar bikes, none dropped valves, I know of one still running.
This will be simpler, cheaper and quicker than what I did and be repeatable for anybody else, happy to help but my way , no shortcuts.
If they are not right, I’ll help you spec aftermarket (or possibly V85) springs that drop in.
Not rocket science but not entirely simple either, worth every minute and dollar IMHO, these things need saving not destroying.