Chuck Posted December 14, 2011 Posted December 14, 2011 The tappet is case hardened. That means it is hardened only a few thousandths of an inch deep. Once worn through that layer (for whatever reason) wear accelerates geometrically. At any rate, this is calling for new cam, lifters, a look at the oil pump, cleaning the galleries, the whole enchilada. Not fun, but necessary, or you'll be doing it again...
Olivier Posted December 14, 2011 Author Posted December 14, 2011 Thank you again to all of you for your comments and recommendations. Great Forum!! For information, more pictures here. Note that the gasket between the Crankcase and the cylinder was not fitting correctly
luhbo Posted December 14, 2011 Posted December 14, 2011 Your gasket is and was ok. Search other forums or engine shops in your neighbourhood for shops specialised in regrinding cams. I had mine redone after 120.000 km for about 100 USD, incl. hardening and S/H. You need a template, though. Maybe one of your US fellas has one laying around to help you out. Regrinding your tappets is no option unfortunately, as one is crap anyway. I had mine regrinded at the company I work for, just a plain cut of 0,1 mm, without rehardening, and they do well for another 15.000s km in the meantime. Hubert
Mike Stewart Posted December 15, 2011 Posted December 15, 2011 You should be able to have the 3 good lifters refinished, that is only IF they have no pitting. Also, the lifters are NOT refinished flat, they have a very slight convex to them on their face. The way to check for worn lifters is to apply a light coat of engine oil to their face and put two lifters together. While holding one up, the lifters should not stick together, if they do, they are worn and should be replaced or refinished. Mike
luhbo Posted December 15, 2011 Posted December 15, 2011 You should be able to have the 3 good lifters refinished, that is only IF they have no pitting. Also, the lifters are NOT refinished flat, they have a very slight convex to them on their face. ... Some say that is so, some say it's not. So far no one could show me a drawing or the like to proof the first or the latter. In my case, that means in my very special case because I did that on my own bike and not on the net, and important as well, for free, my colleague had to take down rather much material because of the inevitable pitting. For me that is good for 15.000 kms now. The entire experiment was well worth its costs. Anyway, if you had to pay for grinding and on top of that have a set of probably weak tappets anyway, of course you better buy a set of new ones. They shouldn't ruin the budget. Hubert
centeroff Posted December 20, 2011 Posted December 20, 2011 We race a Sprint Car in a spec class that requites a flat tappet cam,after trying every different oil,and getting the same accelerated lobe and lifter wear,I started using GM EOS part #88862586 on top of Valvoline 20/50 Racing with great results.And from a cost stand point it was less than the trick racing synthetics. I used to race Moto Guzzi's a LONG time ago,and after 32 years since my last race/ride on a GUZZI (Ontario 6 hour 1979) I just bought a beautiful 04 V11 Sport with only 5000 mi on the clock,they've come along way since my original 72 V7 Sport. I am using this same lubrication in my GUZZI. You can consider all 4 of your lifters and cam wall art,they're done. Steve
Mike Stewart Posted December 20, 2011 Posted December 20, 2011 Yep, EOS = Engine Oil Supplement. I'm a GM tech of 30 something years and we used the EOS with every engine build, coated the cams and lifters and also used it as assemble lube on the bearings. This stuff is pretty thick, kinda like the old STP oil treatment. Mike EOS ; Engine Oil Supplement ?
centeroff Posted December 21, 2011 Posted December 21, 2011 Thank you again to all of you for your comments and recommendations. Great Forum!! For information, more pictures here. Note that the gasket between the Crankcase and the cylinder was not fitting correctly That looks like an oiling problem,loss of wedge,break down,or just inferior oil,are you going to have a look at your mains?
gstallons Posted December 21, 2011 Posted December 21, 2011 the rest of the engine should be OK. I would change the oil twice after the repairs(within 10 mi or 10km) with a new filter at the second oil change. I think I would use the GM oil supplement with equal amounts added to the oil changes. Do not $kimp on anything going into this bike. It is too good to f**k up.
Olivier Posted February 5, 2012 Author Posted February 5, 2012 As a follow up on my tappet/camshaft failure; I've been struggling to take the timing system out, mainly because of the 32mm nut on the crankshaft. I was finally able to remove the camshaft today. The lobe corresponding to the damaged tappet doesn't look good. Next step, I'll take the camshaft to Moto International, they have proposed to look at the camshaft, if it can be rebuilt (acceptable cost), or if I need a new one :-( Pictures below attachment=11461:Camshaft_1 (Medium).jpg] Olivier
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now