New guy with questions

[aerojack7654]

Ducati 350.JPG

Hello all, Jack here, with his new 73 350 widecase , recently bought on ebay (a lot of you probably saw it). It’s has a fully built for racing engine, with balanced reworked bottom end, carrillo rod, borgo 10.5:1 piston, twin plugs, Mega 564-390 cam, Norris racing valves, springs and valve guides, head polished and ported to a 34mm intake and exhaust port. It’s got a Rita electronic ignition, dyna coil, Amal 34 mm smooth bore, Syd’s race megaphone Grimeca double leading 4 shoe brake, and a bunch more high end stuff, all brand new. All this work was done in ’92 – ’93 and then put on a shelf – never run! - until it was recently put up for sale.
I’ve been rebuilding older Hondas for the last several years but I’ve been hankering for an old single cylinder to go with my 916. I recently sold a nice Black Bomber to open a slot in my wife’s four bike limit, so I’ve been looking for the right bike to play with when I saw this one and was enticed by the build list and the pristine condition of the engine, but a little nervous about the long hiatus. I have many questions that I’ll eventually be asking for help/opinions, but I’ll start with these:
1. I’m fighting the urge to just hook up the Rita and hang a remote tank on the thing and see what the engine does. My more conservative self says open the thing up and make sure everything like the cylinder bore to the valves are all ok. What I can see from the outside is very impressive and super sano. According to the PO, it was kicked over regularly (not easily done with the 10.5:1 compression), and its full or very clean oil. Any suggestions as to what I should look at before seeing what the thing will do?
2. I’ve been vacillating over whether to try and make this thing streetable or keep it in its racing form and see what kind of track/AHRMA bike it could be. Should I want to try and use this thing on the street, is its current configuration at all capable as a hot street application, or do I need to go to a more reasonable cam, carb, etc. to get any bottom end. Mega and Jim’s cam document both say that the 564 390 cam is essentially a copy of a Norris race cam. I’m assuming that this configuration will be stumblin’ until the revs are up there. My optimal configuration would be something that would have enough bottom end to make it at least useable on the street, but still have enough higher up to make it fun on the track. Any comments/suggestions are very welcome.
Thanks for all your help!

Jack

[Eldert]

Hi Jack

did you check the cam timing figures yourself ? that cam is indeed a Norris profile made by Megacycle after they bought out Norris . the camtiming is 51 / 77 and 77 / 51 i thought .
the lobes could be way out . on my 564 N390 cam the lobecentres are way of and around 90 degrees instead of the 103 degrees as per specs

Eldert

[Jordan]

You may not know yet how amazingly easy it is to dismantle the top end of Ducati OHC singles.
If you want to check the bore, you will likely move the piston and hence the timing gears. These work on the hunting tooth principle, so re-timing is a little more involved, but the information can be had for this to be a painless procedure too. If the crankshaft position is not disturbed (to ensure, remove kickstarter after moving piston to TDC of compression stroke), then it's just a matter of putting the head back and bolting it on, with a little sealant on the bottom of the bevel tunnel.

[aerojack7654]

Thanks for the suggestions guys,
No Eldert,I have not checked the cam at all, just going by the info from Mega and from the cam document that was posted on the site (very useful!). The timing difference is significantly different from spec, did you try that cam, and if so, how was it? Did you ever contact Mega about that?
Thanks for the encouragement Jordan, I'm just now receiving my new collection of manuals and books on these things - Mick Walker (expensive!), Haynes, and my Ducati shop manual from Guzzino (waiting for their return from vacation!), got lots of studying to do to get up to speed mechanically on these things. They do look like they have some simpler procedures, and a few more complex than the 60s Hondas that I've been working on. This is my favorite part though, getting to know the machina!

I have been in contact with Barbara at Mega (wife of proprietor), she says that they are thinking about doing a milder grind cam than what they advertise right now (the 564 390 is not on there any more, the lower spec 564-00 is still listed, same as on Jim's cam listing), but I don't know if that's still too much for a street application. Apparently they have been getting multiple requests for something more streetable for this engine.

Thanks for the help!
Jack

[double diamond]

Webcam will grind any profile you want on a hardwelded core. They have many, many profiles in their template inventory and Steve, the owner, is very knowledgeable and enthusiastic about his products. There is a lot of information on cam specs on this forum if you do some searching. But if the intake has already been opened up to 34mm, along with the other components you mention, you're limited as far as how much you can detune it and end up with something that performs as you would like. Matt

[Bevel bob]

I run a 250 with similar problems on the road. I have no experience with your cam. I would remove the valve covers and oil the cam and give it a run to assess the situation. If you have to encounter much traffic then it could be hard work. Much may depend on what you intend to do about silencing ,a restrictive silencer may cause too much reversion to be acceptable, also the CR will need high octane fuel and if a total loss ignition fitted you will be restricted in running time. Any problems getting legally on the road?.It does not look like it has been tried at all as there is still fair bit to do.Fiberglass tank? ,don't put any eth fuel in it.

[aerojack7654]

Thanks for the input guys,
Yeah I figure that the opened up port will limit the torque out of the bottom I do have a racing pipe set up from Syd's Cycles - a really ugly piece of kit, so it shouldn't be limited in that regard. It's interesting, I've been reading "Ducati Singles - First Person" by Tom Bailey (good read) and he points out repeatedly that the single is limited by it's intake being restricted to 29mm, particularly for the Desmo heads since they cant take advantage of their higher RPM capability because of the restricted intake. We'll see what this one does, I suppose that the upgraded valve gear and the bigger intake and exhaust will let this thing rev higher.
I hear your comments Bob, my guess is this won't be a city bike by any means, between the power up higher and the racing clutch as well as the tough kickstarting. BTW, whats the story with a valve lifter on the 350 and 450s? Nothing on mine, is this something that was added later?
The bike is in a partially assembled state, having come in pieces. I'm still rounding up some parts for the rear brake drum, new shocks (the ones shown are something that let me just sit the bike up). I'm also trying to figure out the electrical system (there is none), I was told that a "12 volt conversion" has been applied, but there is nothing on the bike that would indicate what that conversion is (the alternator is dangling 2 yellow, one red and one green wire). I can probably start the bike with a remote battery and gas tank (yeah, the damn fiberglass tank - I'm looking for a nice alloy one but lots of $$), but I won't be able to ride for awhile while I finish up assembly of brakes, etc. I was going to strip everything including the frame and start painting and finishing, but as you suggest Bob, I think I'll try a drive before I decide how I want to finish this thing - it might end up a track/AHRMA bike.

Thanks,
Jack

[Bevel bob]

Hi , Jack, A valve lifter would be considered as too wimpy for a racer, thats why you don't have one!, The Ducati head is crippled by its poor port shape and not its diameter. You will find that with the porting you have you will be able to rev high enough to cause mechanical problems anyway. Kickstarting can be an art form, and takes a while to learn what works on your bike. You don't want to be kicking it over compression ,more like towards compression. You have to get flywheel momentum working for you.My bike now starts first kick much of the time but needs lots of fuel ,an open throttle and plenty of throttle twisting to keep going and to clear the excess fuel. It won't give you an easy time, but who needs that?.