Imola V75 4V Project

[Simmoto]

I have an Imola project bike; lovely bike but lacks a bit of grunt. Also got a V75 4V which is cosmetically buggered...but has a low mileage engine with intact valves/heads. So I'm planning to restore the V75 4V engine using a modified valvetrain and probably conrods and other bits and put it in the Imola. I have a V65 Lario already and am familiar with and like the 4V Guzzis, aknowledging that they need valvetrain mods to be reliable.

First step was to pull the V75 heads, all good - heads and pistons. Now I'll put em back and check for cam wear with a dial gauge and start sourcing the parts after that.

First question. Will the V75 4V fit OK in the Imola frame? What mods might be needed?

Cheers

[Chuck in Indiana]

cosmetically buggered

I nominate this for understatement of the week. 
I truly don't know, but a small block is a small block. I would think it would fit. (?)

[jacksonracingcomau]

there are different clutch centres, gearbox ratios but asaik no differences in any mounts.
only one frame lug rear of battery that appears on all early sb frames but never seen anything bolted to it.
so easy to do comp running gear swap that would be first test, possible change in footrest position exhaust mount etc etc
mix and match to get what you want
cam and valve tip wear tell whole story, lovely to have one before grenading, I had to start with 2 badly fixed ones only a lucky find of one oe head gave me clues.
will be a hoot interesting to hear 650 v 750 comparo I intend building another, engine size one still to determined

[SED]

I've put a 2-valve V65SP engine in a Monza and really like it, but the carbs are a tight fit with the top frame rail and the fuel taps. 
Here's the link: https://wildguzzi.com/forum/index.php?topic=87045.0

The throttle cables make a tight bend under the top frame rail and fuel taps are very close to the carbs.  These problems will be worse for the V75 because the heads sit higher and wider.  Not sure where the carbs sit on the 4-valve vs 2-valve heads, but Steamdriven on here as put a carbed V75 Nevada engine in a Monza - he dubbed it the Monzada.  He did have to cut the inner edge of the sidecover to clear the carb and substantially modify the V75 airbox.  It looks like his t-cables run all the way under the tank then loop back to the carbs.

The position and angle of the carbs will be really important to making it fit.  Measuring the distance between carbs might tell you where they fit relative the the fuel taps and frame rails.  Another measurement to the carb top might tell you if the throttle cables will run under the tank.  You might be able to run the throttle cables between the heads and the tank outside the frame rails.  I was able to use the stock Monza taps, the V65SP manifolds and airbox. 

Steamdriven said it was a lot of work to convert to the Nevada electronic ignition which must be triggered by the crank?  If the V75 has the Monza/Imola ignition it is an easy swap.

[huub]

nice project!
you will obviously need to swap the gearbox too, to get the gearing about right,
the tank will be a tight fit around the heads.
later on you might consider fitting different front forks,
the imola forks are adequate on a imola, but might be too flimsy for your project.

[Simmoto]

Thanks Guys/Dusty, it's gonna all be a tight fit for sure, was thinking I'd be swapping the engine/box/swinging arm, bevel drive as a unit but lots to check. It was a risk buying the V75 unseen, good heads are rare and can be expensive but the seller had tapped the valves with a hammer before I got it and reckoned they were good. Good point on the carb fit and the suspension too; ignition could be a PITA but the plan is to dump the V75 Motoplatt and swap over the Sachse optical ignition I have on the Imola; it should work I think as same alternator set up (not that I've really thought it through LOL).  Gonna take me a while as the Lario is still going back together but thanks for the ideas and pointers :-) I'll get my tape measure out....

[Simmoto]

I nominate this for understatement of the week. 
I truly don't know, but a small block is a small block. I would think it would fit. (?)

 

Story goes it had a charging issue and was laid up after 16K miles. Left in a shipping container for decades before being bought as a cafe project. Spent some time outside I reckon!

[Chuck in Indiana]

Yeah, I would think so..  The last time I saw one that nasty was one a guy used to power his bbq grill.. 

[Simmoto]

2 steps back already! My Lario was nearly buttoned up but inlet springs on one side are coilbound when turned by hand. Reason is the head is not standard, has car valves machined to fit Suzuki GN250 and when you swap the springs for Nevada (2V progressive) and keep the valves it doesn't add up, even with extra grooves machined higher up - some error in the machining of the collet grooves or enlarged inlet valve seat. So for the mo' the V75 heads are off and stripped and go to be soda blasted then they get new valves from somewhere, probs new guides plus the Nevada spring package and then go on the Lario. SO the Imola will get the Lario modded heads that have oversize inlet valves (28mm vs 27 stock). The idea is the Lario will do the miles so needs the most reliable bits...we shall see.

Interesting that when I stripped the V75 heads the top of the valves were mushroomed and had to be filed to get the valves out of the guides in 5 of 8 valves. Also it still had the original dual springs and in 2 cases the inner spring had snapped and left half a coil inside the bigger spring.

V75 heads off to the cleaners after stripping after getting some of the worst crap off





Cheers

[jacksonracingcomau]

déjà vu
posted similar a few months back
Herbert who ‘ built” mine used suzuki valves, didn’t  stop there but ground away rocker arms for cap clearance, still hit
opposite to you his had no preload on springs, suzuki too
every mod I saw had a knock on effect that was worse than oe
valve tip and adjuster wear on every valve, had 28 valves all in bin
imho they are proven fixed only after a serious year thrashing then showing no cam/ tappet wear, adjusters and tips still virgin
good luck, I’ll be watching ( and trying to break mine)

[Simmoto]

Interesting, my Suzuki valve job also had rocker arms ground away underneath but i stock form I don't know if it was coilbound - only when I changed to Nevada springs. To find out I put all the Suzuki stuff back on these heads and bolted them onto the V75 to measure but then found the engine's seized....

Meanwhile back at the Lario, I'm going the whole Iceman route (Nevada progressive springs, top and bottom caps, collets) plus lash caps and Yamaha screws. Will add a new set of his Chinese OE replica valves.  This is proven by Iceman (Brian) on his three 4 valves over tens of thousands of km so the best option I can see. Still need to measure, check etc before I start her up - that 14mm cam and new followers were expensive.

More new to me info - didn't know the 4Vs updated their rockers - early ones without the hole in the arms (below). Live n learn...

[Chuck in Indiana]

I suggest you very carefully measure those Chinese valves..

[huub]

current stainless guzzi valves seem to survive pretty well,
i think i have 45.000 km on them in three years ( with the later springs)
right now i am more worried about the durability of the camshaft than the valves.
the next camshaft i fit i want to have it nitrided ,

[jacksonracingcomau]

current stainless guzzi valves seem to survive pretty well,
i think i have 45.000 km on them in three years ( with the later springs)
right now i am more worried about the durability of the camshaft than the valves.
the next camshaft i fit i want to have it nitrided ,

yes thanks to your post before I. bought oe cheap too
only ex is ss but all have hard tip no need for caps
Agree re cam, all we can do is use old spec hi zddp oil
sacrificial in my one, intention is still roller tappet mad cam
but I. need to prove top end to my satisfaction first
All good so far, love the elephant feet, that was another idea from here, they just look right
hindsight says I should never have ridden mine,  clue was there when checking clearances, adjusters right out, so obviously wrong

[Simmoto]

I'd like the Guzzi valves but can't find new ones at a good price. The Chinese valves have proven to be fine within their limits and they're affordable. 

[sign216]

I'd like the Guzzi valves but can't find new ones at a good price. The Chinese valves have proven to be fine within their limits and they're affordable.

I share the other's doubts about Chinese products.  Some are top rate, others...

But a good price is nice too.

Please keep us posted w your progress.

Joe

[huub]

you tried stein dinse for the valves?

did you end up using the elefant feet adjusters from guzzi?
was looking at vespa adjusters, they seem affordable

[Antietam Classic Cycle]

https://www.stein-dinse.biz/product_info.php?products_id=8677
https://www.stein-dinse.biz/product_info.php?products_id=8676

[jacksonracingcomau]

you tried stein dinse for the valves?

did you end up using the elefant feet adjusters from guzzi?
was looking at vespa adjusters, they seem affordable

I bought from sd  cheapest valves i bought for a while, just that you have to buy 8 so adds up.
no dissing but Chuck had the tiddly valves, came to aus went in my bin. not near oe quality even free I would pass
ktm el feet not cheap bout same price as valves each
but well spent I think they just make sense to me
vespa may well be exact same thing but I was in red mist mode,
had to get it running, test my build, took long enough as it was
just remembered pete sent me early griso ones too they are same but threads were all mullered so I couldn’t use them
i thought then overtightened now i think too loose, we’ll see if my new ones do it

[Simmoto]

I bought from sd  cheapest valves i bought for a while, just that you have to buy 8 so adds up.

LOL yeah like you say the price is OK but multiply by 8 and it starts to get costly. I'll see how the Chinese valves size up and will go the SD route if I don't like them.
Cheers 

[Simmoto]

you tried stein dinse for the valves?

did you end up using the elefant feet adjusters from guzzi?
was looking at vespa adjusters, they seem affordable

I'm not going the elephant foot adjuster route just now; don't have the skill to do the machining apart from anything else. I have a set of lash caps and will use them first on either the Chinese or SD valves and see how it all lines up once assembled.
Cheers

[Chuck in Indiana]

I am *not* bashing Brian's work.. he went to a lot of trouble getting those valves made. When I received them, I did some checking and pinged him saying the manufacturing was really not up to standard. He offered to refund my money immediately. I made the decision to just put them in, see what happened, and watch the lash like a hawk. It didn't take long..wiped a cam lobe in about 5K miles.
I wasn't really concerned, because by that time I had found a new Aero engine. I knew I wouldn't have to worry about valves with it, and the rest is history.
If I were building another 4V, I'd look very closely at what Martin is doing.

[Simmoto]

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 

[Chuck in Indiana]

These are from the "Lario rehab" thread in the finished projects area.. starting at the end of page 17
Lash caps

 

[Simmoto]

Thanks for that Chuck, I thought i'd read all there was to read but no! The lash caps I have are OE Guzzi so should be a bit tougher than the RDs but maybe not tough enough for a long life and based on that post I now have reservations about the Chinese valves.

So currently thinking I'll try Guzzi OE valves from SD and the Guzzi OE lash caps and keep an eye on them or give the elephant feet a go if I can get some advice on exactly what's needed.

The elephant feet Martin (?) fitted needed pushrods shortened and springs (I think) shimming. What make were the elephant feet used in the end, must have missed this KTM I think? This is into proper engineering, that's my problem - it may be good but it needs a lot of skill to implement that I'm not sure I have  .

Cheers
 

[Chuck in Indiana]

I *think* KTM. They are pretty pricey. Martin made a pretty long (for him)  post on what he's done within the last 6 months or so. Maybe a search will find it, or you can ping him with a PM.
The only "stock" valve train Larios I know of that have higher mileage have been limited to a 7K red line. What's the fun in that? 
Martin is trying for even higher than 8K reliability. If his proves to be reliable, I would say the 4V issue can finally be put to rest.
It will be worth it. The 4V small block engine is a hoot.

[Simmoto]

Yeah thanks Chuck, I'll leave it to the strong-wristed trailblazers for now

I'm just not that hard a rider, in all honesty 7K RPM would do me 95% of the time.

So I'm gonna go with SD valves and the Guzzi lash caps with close monitoring...when Martin nails it I can update later..at least this way I can get a few miles on the bike and see if it's a keeper...:-)

Thanks for all the help 

[jacksonracingcomau]

Yeah thanks Chuck, I'll leave it to the strong-wristed trailblazers for now

I'm just not that hard a rider, in all honesty 7K RPM would do me 95% of the time.

So I'm gonna go with SD valves and the Guzzi lash caps with close monitoring...when Martin nails it I can update later..at least this way I can get a few miles on the bike and see if it's a keeper...:-)

Thanks for all the help 

with oe. valves you won’t need caps they have hard tips on stems
but if you do use, same checks as elephant feet for clearance
as on all rockers you are looking for perfect angle/ contact halfway through valve stroke, read some tuning books or google rockers angle hot cam etc
also do measure installed spring height as well as check for coil bind
failure is expensive , measure 3 times cut once
ask on here if something looks or feels wrong

[Simmoto]

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

[huub]

you might check these out, just not sure about the thread pattern
https://www.scooterwest.com/adjuster-screw-for-valve-tappet-vespa-gts-484654.html