Top end work

[Tom M]

Tom,

 

Thanks for the update. What kind of valves?

 

Hi Doc,

 

I bought some FBF stainless valves off of ebay a while back when they were clearing them out for $20 each. I was planning on pulling the heads this winter, and given the number of folks here who have found a lot of valve stem and guide wear I knew there was a pretty good chance I'd need them.

 

It looks like they're still selling the valves on ebay. They might be a good investment for anyone planning on keeping their V11 for a long time since the factory valve stems aren't known for their longevity.

http://cgi.ebay.com/ebaymotors/Moto-Guzzi-V11-Valves-Stainless-Steel_W0QQitemZ360198567588QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item53dd81f6a4

[Slavomir Musilek (R.I.P.)]

back to my top end troubles, I was told that best valves are non-magnetic, have you heard anything about it?

 

Slavek

[GuzziMoto]

Stainless valves are non-magnetic, but I would not call them the best. They do work reasonably well, but stainless is neither light weight nor especially hard. But as the stock valves are made of old cheese they would be an improvement me thinks. Just be sure to replace the guides at the same time.

[docc]

I should probably buy those FBF valves, but how would I know if I'll need the oversize? I'm trying to hold out for the 100,000 mile tear down (30,000 to go).

[raz]

I should probably buy those FBF valves, but how would I know if I'll need the oversize? I'm trying to hold out for the 100,000 mile tear down (30,000 to go).

Someone actually having the knowledge please correct me but I don't think you'll ever need oversize valves due to wear. It's more of an option for tuning. I read somewhere (possibly Guzziology) that the 1100's got the 0.5 mm smaller valve sizes because their hotter cam would make the larger valves come too close at overlap.

[Tom M]

I took my first ride with the refreshed top end today and it seems like mission accomplished: NO MORE PINGING!

I went full throttle in 4th gear right through the area where it used to ping a few times and it pulled cleanly with no pinging at all. I can't say for sure the problem is 100% gone yet, but based on the 75 miles I rode today it sure seems like it is.

 

I got a PM from another forum member a while back who said he too installed MR pistons and had a valve job done and his bike didn't ping at first but the problem did return later. I'm hoping I have better luck than he did.

 

In the end my problem may have been caused by the worn valve stems and guides allowing too much oil into the combustion chamber and the resulting carbon may have been causing the ping. I probably could have just done the valve job then had my stock pistons recoated with fresh anti-friction coating on the skirts and have the thermal barrier applied to the crowns, and gotten the same results as I did with the MR pistons. Time will tell I guess bit for now I'm very happy with the results of my top end work.

[Greg Field]

Congratulations!

[Tom M]

Congratulations!

 

Thanks for that and thanks again for the deal on the valve springs.

 

I put a hundred miles on it today and took it through the ping zone at full throttle in 3rd, 4th & 5th gears at different times during the ride and again no pinging whatsoever. It's really looking to me like it's fixed and I'm thrilled that all that work and expense seems to have paid off!

[Skeeve]

I put a hundred miles on it today and took it through the ping zone at full throttle in 3rd, 4th & 5th gears at different times during the ride and again no pinging whatsoever. It's really looking to me like it's fixed and I'm thrilled that all that work and expense seems to have paid off!

 

Great news, Tom; happy to hear that all your work paid off & you're happy with the results!

[Slavomir Musilek (R.I.P.)]

meanwhile...

 

I found one of my valve guide is gone, as well as one ventil, so these needs to be replaced.

 

Friend of mine played a bit with my heads:

 

[Slavomir Musilek (R.I.P.)]

and some numbers:

 

flow 1 - both heads together before porting

flow 2 - one head before porting

flow 3 - both heads after porting

flow 4 - one head after porting