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Well, I've already modified my V7C quite a bit from the stock setup. Some of the mods include a LeMans metal tankwith external fuel pump, filter, and regulator. K&N pod filters, Norton peashooter exhaust, Stucchi fairing, stainless steel fenders, and a Power Commander V with Autotune and a ECU flash by Todd at Guzzitech. This bike runs great, but I'm always wanting to mess with something else, so i've decided to fit some four valve heads an see how it runs with a modern fuel injection setup. The main reason for my post is a request for information. I have read a lot about the Larioo heads, and the different valve/spring/cap/ and shim that people have used. I would like to use the updated Moto Guzzi valves, which i have the part number for, but I dont know which springs would work best. Just looking for input from those on the board who have experience with the Lario heads. Thanks in advance!
Interesting upgrade.Is the camshaft still appropriate for a switch to 4 valves?
do you have pix?
It will be fascinating to watch your latest project develop.I stopped in at a fellow Italian Motorcycle Club member's house two weeks ago. He has a lovely V35 Imola that is currently fitted with a V50 motor. On the bench was a beautifully restored V65 Lario motor that is destined for the Imola! He is running Suzuki GN250 valves & springs.Kurt
It was too purty to pass up. The functional difference are the engine characteristics. Jury is out on that one. Better around town, top end comparison is an unknown at this point.
mwrenn, I'm interested in your mods. Like you, I like to work on my V7 as well.Are you going to do a dyno run?
Have you sourced the flat top pistons yet? :+1 on the dyno runs before and after!
It will be fascinating to watch your latest project develop. He is running Suzuki GN250 valves & springs.Kurt
Your tastes for customization run parallel to mine. Any chance you could post or email pics of your bike and LeMans tank fitment ? What LeMans tank did you fit; an original or a steel copy from MG Cycle ? I am very interested in getting rid of the nylon tank for steel.Any info, pictures, contacxts, sharing experience of the fitment would be appreciated.Sincerely,Steve Swan 970.443.2432, mountain std.time
Thats what was in my head. I think Brian (Iceblue) was muttering about Nissan valves of some sort.
With the original Lario valves there was something about them being a two piece, and they were prone to fracture at the join.
Yes, planning on a dyno run, before and after. Kinetic playground in Tulsa has a Dyno, I will use them. How's your V7 running with the Gilardoni cylinder kit?
I have to adjust the fueling, as the big bore kit is too lean with the factory map. However the fueling is taking a backseat, as now I am struggling with left cylinder running much too hot. Right one is normal, approx. 300F (150C). The left cyl is always a little warmer, but at highway speeds it can get very hot, approaching 500F (260C).I knew the left cyl was hot, but I didn't realize the extent until I fitted a pair of cylinder head temp gauges. Now I see it's dangerously hot, and I've got to deal with that. No intake leaks. I had the fuel injectors cleaned + tested, so they are good.Any ideas?
I have not sourced any pistons yet. To be quite frank, I was not 100% sure I would have to change them.
That is quite a common practise. The cost can be reduced as the whole valve doesn't need to be of the same hardened material as the head but the stem can be a material that dissipates and transfers heat better through the valve guides. It can be a win-win.Everything I've compiled on the 4 valve isses is down at the bottom of the article.http://guzzista.wetpaint.com/page/Older+Small+Block+Issues%3FI've posted the link to it before. Its there to be used as a resource.Rod
Maybe swap CHT probes side to side. Make sure the gauge is accurate. Or double check it with an infrared/laser pointer thermometer. My thinking is the heat could be from lack of fuel, intake leak, spark timing, or friction. Or if the piston on that side is a higher compression ratio than the right side.....that would do it. Sheesh, that's a tough one. I have a spare ECU from an 07 Breva I can send you. It made my V7C run better than the factory original one, PM me your address and I'll send it out, might be worth a try...Your problem brings up an interesting point. I am working on a turbocharged Lycoming six cylinder engine right now with the same problem. One cylinder runs 50 degrees F hotter than all the others. The fueling is correct, no intake leaks, with the turbo it runs at 35in/hg manifold pressure, higher than ambient, timing is good. The factory calls for a 7.5 to 1 piston to be in there. When I took the cylinder off for low compression, it had a 8.5 to 1 piston, as did all the other cylinders, from the factory. When I re-assembled it the first time, I put the correct piston in, and it ran hotter! With the 7.5 to one piston! You would think it would be cooler on that cylinder. Anyway, waiting to hear back from the factory rep at this point...its a mystery...
The Lario flat tops are clearanced for the valves.. you'd at least have to do that.