Another 1100 Sporti Valve Question

[Old Jock]

Not that I'm expecting much luck as most of my previous posts have failed to illicit much response (although I'm very grateful to those who did go to the trouble)

Not only are the barrels away for recoating, the cylinders were out of spec and oval, but I decided to get the valve guides replaced. When my head guy inspects them he tells me that the valves are also shot into the bargain. You just would not believe this on a bike with under 10k on the clock, anyway I digress.

To the point of the question, I was informed by the vendor that I'm planning to purchase the valves from that I'm better getting valves from an LM 1000 than trying to source 1100 Sport valves (apparently rare and expensive if I find any).

It surprised me to learn that the valves on the Sport are actually 0.5mm smaller in diameter than the LM 1000 apart from that the valves are identical. I spoke to the guy doing the heads and he does not seem to think it would represent much of a problem.

Prior to making a decision though I'd like a second opinion and wondered if anybody like Andy Medic or Pete or whoever has been in the position of messing with a Sport's heads have heard of this tried or simply have an opinion

John 

[yogidozer]

That's .019 difference. If there is a big difference in replacement costs, I'd go with the least expensive. JMO

[RinkRat II]

   It would seem that the new valve being that much larger may be enough of a weight difference to matter to the springs your using. Can they tell you the weight versus the stock valve? My $.02
        Paul B

[Howard R]

I believe it was either Guzziology or Greg Field in his Big Twins book explained the difference in valves, Dr. John at the factory did that for a reason.  The "full size" LeMans valves would tend to get a bit too well acquainted with each other on overlap with the cam they came up with on the Sport 1100s so they whittled the valves down just enough to work. 

Howard

[rocker59]

I believe it was either Guzziology or Greg Field in his Big Twins book explained the difference in valves, Dr. John at the factory did that for a reason.  The "full size" LeMans valves would tend to get a bit too well acquainted with each other on overlap with the cam they came up with on the Sport 1100s so they whittled the valves down just enough to work. 

Howard

That is what I recall.

[Kristian]

The heads on my Sport are off for the 2nd time. First time four months ago for a checkup at 4.5K miles, when it was found both valves and guides were wearing with several just outside spec. It is a common problem on old Guzzis and Ducatis, even much Italian machinery going back to the '60s, including Ferraris--per my machine shop. I only put it back together because I wanted to ride and have something to fiddle with when the weather turned sour.

I have new Sport 1100 valves on order from MG Cycle, which are non-OE and sourced from Germany, as far as I can tell; I did not want to go with bigger valves for the noted reasons. There were good engineering reasons for why Wittner et al did what they did, as noted above, plus intake velocity and port/head design. I'm guessing your supplier didn't want to pay for two batches of valves made up, in LM and Sport sizes. Just offering one valve size would save a dealer a lot.

I tried to buy valves and guides from Mike Rich; I spoke with him, sent him an email as prescribed with my order, and followed up with a voicemail a week later. No response. Forget that, and the excuse that he's busy. Hire staff.

I got new valve guides from Kibblewhite; no reason to chance using stock guides as we don't know whether the formula has been changed. You might also want to check your valve springs. They will be less springy by now. Kibblewhite also makes springs.

Ta,

Kristian

[Old Jock]

That's great info and convinced me not to follow his advice, I was a little skeptical when he said it

I checked and the LM 1000 different part numbers for springs and the last thing I need is to put it together and end up with the valves locked into a deadly embrace.

Stein Dinse do non OE valve replacements & there may be a possibility of sourcing a OE set from Giovanni Moto but I'm awaiting a reply from them on availability

I'll probably get the stems from HMB and either the valves from Giovanni Moto if I can get OE if not then I'll go down the Stein Dinse route using the non OE, being in the UK.

I'd love to get better quality valves and guides but there does not seem anywhere in Europe that caries that sort of stuff

Valve springs have been checked and are within spec

Thank You everybody

[Frenchfrog]

Amadeo at Raceco uk used to sell stainless valves when he was still doing Guzzi suff...i'd be surprised if he got them from outside the UK and may it be worth contacting him to see where they came from and if they are still available.He's on face book and did a run of cams last year due to interest.According to HMB the SD valves are not good quality so if that's true it won't help matters.I'd be inclined to k line the guides...did it on my T3 with no issues but can't find anyone who does it on this side of the channel.

[pete roper]

As long as the guides are still firm in the heads I'd always suggest K-lines rather than re-guiding. As for the valves? Get the larger ones, grind 'em down and be happy. You'll also get a slightly deeper margin which will help combat any potential preignition problems.

Big valve motors are murder on both valves and guides. It's one of the reasons I'm not fond of them.

Pete

[Chuck in Indiana]

Big valve motors are murder on both valves and guides. It's one of the reasons I'm not fond of them.

Long live the medium valve Guzzi.. (that's as close as I could come to a toast.)

[MedicAndy]

Hi John,

I wish that I could be of some help here, but "Knock on wood", I so far had no cylinder or valve issues to deal with. But you got some great responses so far, so please keep us informed on what you end up doing, and from where you purchased parts from.


Andy

[Old Jock]

Thanks Again

I never realized this was going to pose such a problem

Right now my thinking is to purchase guides and inlet valves specifically for the sport from HMB and the larger exhaust valves for the LM 1000, as the Exhaust valves for the 1100 aren't available

I spoke to the guy doing my heads and he said that he could turn the larger valves for the LM 1000 down by the 0.5mm required on the diameter to match the correct size for the Sport

It's not ideal but otherwise I'm going to end up in  a world of pain and that seems the easiest and fastest way to get a satisfactory solution to the problem

Any other comments on this course of action would of course be welcomed

John

[little750]

Have a look here http://cylinderheadshop.com/

[rocker59]

Thanks Again

I never realized this was going to pose such a problem

Right now my thinking is to purchase guides and inlet valves specifically for the sport from HMB and the larger exhaust valves for the LM 1000, as the Exhaust valves for the 1100 aren't available

I spoke to the guy doing my heads and he said that he could turn the larger valves for the LM 1000 down by the 0.5mm required on the diameter to match the correct size for the Sport

It's not ideal but otherwise I'm going to end up in  a world of pain and that seems the easiest and fastest way to get a satisfactory solution to the problem

Any other comments on this course of action would of course be welcomed

John

I was thinking the same thing.  Turn down the LM1000 valves. 

People I know used to do that, back when we were younger and into "hotrodding".

[Kristian]

I was thinking the same thing.  Turn down the LM1000 valves. 

People I know used to do that, back when we were younger and into "hotrodding".

LM valves are .3-.5 mm shorter, though that can be taken up by the adjusters.

[Kristian]

Thanks Again

I never realized this was going to pose such a problem

Right now my thinking is to purchase guides and inlet valves specifically for the sport from HMB and the larger exhaust valves for the LM 1000, as the Exhaust valves for the 1100 aren't available

I spoke to the guy doing my heads and he said that he could turn the larger valves for the LM 1000 down by the 0.5mm required on the diameter to match the correct size for the Sport

John

John, SD has them: https://www.stein-dinse.biz/product_info.php?products_id=195118 Hard to speculate about quality, especially when the criticism comes from another vendor. SD isn't usually in the business of selling poor-quality merch.

Kibblewhite would be happy to send you guides from sunny California; terrific guides. http://shop.kpmivalvetrain.com/c/sport_moto-guzzi_all-2-valve-big-blocks-1971-2012

Kristian

[Old Jock]

Yeah I noticed the SD non OE valves & thought about them, then had second thoughts when I got the post about HMBs opinion

I PM'd you Kristian to ask about info & you are reading my mind as I was also thinking of getting the Kibblewhite guides

If you don't have valve dimensions that I could use to get a set of valves made at the Cylinder Head Shop, my backstop will be to hell with it all and getting the SD valves and Kibblewhite guides

You've all been a very big help and it's appreciated

John

[Kristian]

Yeah I noticed the SD non OE valves & thought about them, then had second thoughts when I got the post about HMBs opinion

I PM'd you Kristian to ask about info & you are reading my mind as I was also thinking of getting the Kibblewhite guides

If you don't have valve dimensions that I could use to get a set of valves made at the Cylinder Head Shop, my backstop will be to hell with it all and getting the SD valves and Kibblewhite guides

John

John, will send you a PM tonight with the relevant pages from the shop manual and valve lengths from Guzziology. Problem is you'll still need to send your valves in to have the notches measured; those specs aren't anywhere.

Custom sounds expensive. Me, I'd trust SD and just get the valves there. The primary problem with big-valve heads is simply too much rocking force on valve stems + the whole geometry of it. There's only so much you can do to alleviate the problem of big-valve head valve/guide wear. Negative reports of something on the web can be very misleading.

Ta,

Kristian

[Old Jock]

Many Thanks for all the help from everybody

I must single out Kristian who has been through this & given me some brilliant advice

John

[Kristian]

Thanks, Jock-BTW, per Guzziology, the Sport 1100 intake valves are 104 mm long; exhaust are 102.3 mm.

Kristian