Wildguzzi.com
General Category => General Discussion => Topic started by: czakky82 on May 31, 2022, 07:35:13 PM
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I’m running in my 73’V7 Sport w/fresh cam, followers, guides, valves. Seats were good.
I set this up as normal (for me) by setting valves to .009”, torque heads, re-torque and set clearance a few days later. Ran it up to temp, heat cycled again, re-torque, do valves. I’ve read about running in a fresh cam and flat tappets by keeping steady RPMs at 2k for a few minutes. So I did that. Went for two 15-20mile break-in runs. Then I did my latest torque/valve setting.
Cripes! Clearances were mostly all closed up like I’ve never seen! LH Ex .008”(normal) LH In .004” RH Ex .0025” RH In .006”.
I’ve refreshed atleast three Guzzi top ends and a few others. Never seen them tighten up like that!
Is that normal?
I was hoping to hold off until another few hundred miles like I normally do before checking again. Not sure I’m comfortable going that long now.
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That seems normal, I seen them w/no lash. After the 1st retorque I usually run 300mi or more checking the lash & making it .009". Then one last time on retorque. I also make them tight- 34ftlbs . I only do them twice.
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I just put new piston and cylinders on my 75 T. I did not measure them after running the first couple times but the .009 was not going to get in there.
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Thanks guys, I’ve never seen them close up so much. I’ve never done a cam and followers either.
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Here's my take retorquing the heads with a head gasket and there if it's new will take quite a few times to compress it and will finally find its place and stay set for the torque as far as the valve clearances go in my cases when the valves were put in lap brand new valves cetera are conforming to the seat now the seat is a taper so is the valve it will conform to the seat in the valve together but it will also recessed slightly into the seat and it's closing up your clearances hope that makes some sense and this will also stabilized the clearances for longer periods of time
TOMB
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Took a few times , but I got what you're saying , next time I might suggest saying it
in a few sentences :thumb: . Peter
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Apparently it is common. When I checked my new Norge back in 07 the factory had set them at .014 and .015. Apparently they figured they'd close up before the first service.
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Its better to have the clearance disappear and expect it than to have clearances widening, as this bodes disaster :cry:. Be happy. DonG
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Cripes! Now the clearance is opening up. Both intakes were .002” wider after only 80 miles. I must be doing something wrong.
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Cripes! Now the clearance is opening up. Both intakes were .002” wider after only 80 miles. I must be doing something wrong.
That’s weird.
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Keep a eye on it , getting wider could be caused by some bad things. The worst would be cam& lifter wear on the new cam. Could be collapsed pushrods, especially the aluminum ones. Hopefully it’s a measurement error.
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Yeah, I can't think of anything good to say about clearances opening up. I *assume* you are setting/checking them the same way at the same engine temperature?
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Yeah, I am checking them on a cold engine. I will run them for 50 miles and check again. I’m not too worried yet….
I should add that I did just replace the rocker arm shafts as two of them appeared to have lost some small amount of plating. The new ones appear to be hardened.
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Yeah, I am checking them on a cold engine. I will run them for 50 miles and check again. I’m not too worried yet….
I should add that I did just replace the rocker arm shafts as two of them appeared to have lost some small amount of plating. The new ones appear to be hardened.
FWIW, the old ones were hardened, too.. probably induction case hardening. Not plated. If that case starts to go.. bad things happen. Maybe that is what you are finding. (?)Fingers crossed..
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Yeah, not good…I’ve been checking clearance every 500 miles and it continues to open up.
All four valves had opened up atleast .002” worst was .004”. I set them to 6 and 8 originally.
Rockers and shafts look good. Cam and followers are new and oil looked good, I dropped the pan just to check, I have an external filter setup as well. Compression was 170 both, cold.
My thoughts turn to either pushrods or cam “bearings”.
How do I diagnose bad pushrods, I don’t have accurate enough measurement tools for this length.
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Compare pushrods to each other, check the ends for looseness. Ring test to see if they sound the same, roll them on a piece of glass. If you replace them, get steel ones. Check the valves for stretching or receding.
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Compare pushrods to each other, check the ends for looseness. Ring test to see if they sound the same, roll them on a piece of glass. If you replace them, get steel ones. Check the valves for stretching or receding.
Both of those would cause clearance to close up, not open up.
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Both of those would cause clearance to close up, not open up.
Yep, it was late and brain was running on mt
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I had a thought. It looks like HMB sells a one size cam follower. I didn’t realize that short stroke BBs have different pushrod ends….
Hopefully my new followers aren’t too beat up. I might try to use some of the later pushrods I have here, although they might be too short.
Wish me luck! :boozing:
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Well that sucks!
I now have the correct pushrods. Lash still opened up after only 200miles!….
I double checked to verify correct rockers and these dont match what Guzziology describes as correct. The adjuster screw boss measures 11mm (guzziology says they should be 14mm) but they appear to be what is in other early BBs just going off pics.
Even if my lifters were wearing would they wear that fast?
I never did check cam runout, but there was no noticeable play.
What am I missing before tearing off the top end?
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Full lift on exhaust and intake. Does the rocker angle look extreme?
(https://i.ibb.co/0trbdG4/2-E156-A61-2021-46-E1-987-D-F304-EDAC3097.jpg) (https://ibb.co/0trbdG4)
(https://i.ibb.co/tJywHw7/15714668-F5-EC-4-DA1-8578-CEDF2-ECB1-E92.jpg) (https://ibb.co/tJywHw7)
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All the big blocks I’ve done have 11mm adjuster lock nuts. Strange spec. Just thoughts, but are the small head bolt oil seal rings in their correct position? Is TDC accurate on your flywheel? I would take the heads off, check the base gasket and oil rings, check TDC and start over.
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I'm not sure I'd be too concerned just yet.
Check 'em every 500 miles or so and see if they stabilize
after 2K to 3K. If things are still changing lots after 3K, then
you've maybe got some trouble. Run some more heat cycles
so that everything can find it's happy place. YMMV.
New cams and pushrods - there's lots to change there, especially if all is
not factory.
Good Luck!
-Stretch
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@scout, early BBs have 13mm lock nuts made of the finest Italian hard cheese (soft). I made my own TDC marks on the bench, with a piston stop. Good point, will check again though. Thanks for the input.
@stretch, thanks for putting my mind at ease a little.
Here’s where my head goes. If it was bad lifter(s) I’d only likely see one or two. Same with collapsed pushrods. Cam bearings I’d be losing oil pressure and timing would be sloppy. It squirts oil when I rotate the wheel in 5th gear and timing is as stable as any ignition I’ve seen.
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My 98 EV wore like that the first 1500 miles. 10 thousands larger at 1500 than where they were set at the 600 first set. Settled down after that and quit completely at 20000 when I changed to full synthetic oil.
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You have no idea how much better I feel! I will keep an eye on it.
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So much for feeling better…
(https://i.ibb.co/9TSNC0p/65-E23-AEA-54-AE-4098-88-C9-6240-A5-F6-B4-D3.jpg) (https://ibb.co/9TSNC0p)
(https://i.ibb.co/PhFK8wp/7-EE9-A2-AD-9-E62-4833-B5-F9-1717-F14977-F2.jpg) (https://ibb.co/PhFK8wp)
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So much for feeling better…
(https://i.ibb.co/9TSNC0p/65-E23-AEA-54-AE-4098-88-C9-6240-A5-F6-B4-D3.jpg) (https://ibb.co/9TSNC0p)
(https://i.ibb.co/PhFK8wp/7-EE9-A2-AD-9-E62-4833-B5-F9-1717-F14977-F2.jpg) (https://ibb.co/PhFK8wp)
Are those the "V7 Sport" Gilardonis you got from GTM? Look like plain old Ambassador pistons without the valve relief to me. V7 Sport pistons will have the relief for this very reason...
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Sure are… measured at 82.5mm and I read somewhere that there were v7 pistons without an intake pocket. So I went with it… :violent1:
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Crap. That definitely looks like a warranty claim to me.. as we say in Indiana.. "that ain't rat."
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Just for the heck of it I did a leak down test and it was close to perfect. Maybe a 4% loss on the right and less than that on the left. The right seems to have loss through exhaust valve of which there is no evidence of of the exhaust valve making contact.
What are the odds I can put the correct pistons in and be okay?
I’ll of course have the heads and guides examined.
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Just for the heck of it I did a leak down test and it was close to perfect. Maybe a 4% loss on the right and less than that on the left. The right seems to have loss through exhaust valve of which there is no evidence of of the exhaust valve making contact.
What are the odds I can put the correct pistons in and be okay?
I’ll of course have the heads and guides examined.
You could just have the relief machined into your current pistons. Definitely look at the intake valves to make sure they're straight.
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You could just have the relief machined into your current pistons. Definitely look at the intake valves to make sure they're straight.
That’s what I was thinking too , and you have perfect locating marks!
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And pushrods to the above.