loony888
i've never read so much dribble in one thread ever, oh and the con rods are CARRILLO, not corrillo. so when do you expect bob to finish it?
paul.
griff851
Blah blah blah, pinkle snort, Ooooo wah didums wibble. Now Miss Paul, you have. And thank you Miss Paul for correcting my spelling. What would I do with out you? 😄
Griff
Ps "i bought mine direct from carillo and paid $775.63 including freight and converted to the aussie banana,err dollar and that was aug 06." Glass houses Paul
griff851
Having a damaged Camshaft, and having been told ages ago why it has to be turfed out( hardness issue), I wanted to know more. So I took the cam to the cam fix it guys and got the gen. The new cams (Not bevel drive) are made of material "X" which they(Ducati) manage, through magic, to get incredibly hard. First problem is the mix of metal they weld on may not stick, and break off due to metal properties not being similar enough. Next is the issue of hardness. While welding on the new blob, the rest of the lobes faces hardness can change due to the heat. If it does, then you have to have the cam spectographed to get the material composition, then get it re heat treaded. So this all ends up costing dollars. And just to top it off a new contour has to be build for the grinding machine. Funnily enough it comes out to near the cost of a new cam. So armed with this new information I see Bob, I threaten to go on another quest and see another cam specialist( A demigod of coarse), who probably would confirm what is now known. Low and behold as if by more magic, Bobs hands contain S4 cams ("Hyper cams" no less, is the name on the box). New, but a bit rusty. A price was negotiated (which contained no actual cash exchange) and agreed upon. Cam problem solved and a little knowledge gained.
Griff
griff851
The rockers and oil pressure:
Well todays exchange of ideas was centered around rocker wear, oil and the 4V head. I won't go into details, as Paul will call me vapid or something.
The gist of it being, are your rockers scuffing? You may need to go up to 15-50wt from a 10-40wt. Or you may not have enough oil coverage above 7000 rpm. So the flow needs to be increased, which means making the restricting elements less restrictive. ie bigger galleries and banjo's and hoses. Or up-ing the oil pressure. The down side to extra flow is a problem associated with too much oil draining onto the rotating crank apparently.
Griff
marvin
griff851 wroteThe rockers and oil pressure:
Well todays exchange of ideas was centered around rocker wear, oil and the 4V head. I won't go into details, as Paul will call me vapid or something.
The gist of it being, are your rockers scuffing? You may need to go up to 15-50wt from a 10-40wt. Or you may not have enough oil coverage above 7000 rpm. So the flow needs to be increased, which means making the restricting elements less restrictive. ie bigger galleries and banjo's and hoses. Or up-ing the oil pressure. The down side to extra flow is a problem associated with too much oil draining onto the rotating crank apparently.
Griff
I didn't know that anyone ever used 10w40 in a Ducati😏 I've always used 20w50, motul, agip. etc. now using RockOil from the UK. At the risk of starting an oil thread, what do you guys know about RockOil?
You can also "flow" your oil pump and passages.
Mr.R
Marvin,
A few years back now it was common to use 5-40 oil in Desmoquatros here in the UK, (It hardly ever get very hot over here!) the theory being that the less drag gave more power and the oil got up to the cams quicker than the thicker oils available.
As time went on and the rockers began to wear out people went away from this idea. 😉
It was found that the thinner oil drains away from the rockers and leaves them un-protected during start up after the bikes been left for a while.
20/50 was thought to be too thick.
At the moment I use a self brewed mix of Fully snyth' Bel Ray 20/50 and Rock Oil 5/40 Synth4 at 50/50% which I think (Hope) gives me a 1/2 way house.
I've used Rock Oil's for many years now in all of my bikes IMHO and that of a lot of highly respected tuners it's top notch kit.
I have two 25 ltr drums of Rock Oil in my work shop, one is TRM for my Classic Bevel Ducati's and the other is 5/40 Synth4 (Yes I too swallowed the thinner is better line, hence the home brew!).
However a good friend has recently become a Motul dealer, so I may well be heading in that direction, as I get whatever I want at the cost to him!
However I'll still be using Rock Oil TRM for my classic Ducs, as I've never found a better oil for roller bearing bottom end motors.
Not totally scientific...
But when I 1st had my 851 I used Silkolene Pro4 and the bike used a fair bit of oil between oil changes, I swapped to Rock Oil and the consumption went down noticably, so much so that I returned to Silkolene to see if the opposite happened and it did!
The oils were the same SAE but the Rock Oil used less between changes, this little personal experiment was good enough for me.
Steve R
marvin
Thanks for the comeback Steve. I have been using the full syn. RO for a while because Rick has been selling it. One of his friends who races Beemers was the distributor for it, decided yo get out if distribution so Rick bought his remaining stock which unfortunately is almost gone. We may go with Spectro then. He has been using the 20w60 in his 748 track bike with good results. I use the 10w40 blend in my DR650 Suzuki.
It gets cold here in NC too but I then just cover the oil cooler, let the engine warm up well before hitting it hard of course, with the 15 or 20w50 wt.
That's interesting about the Silkolene! At one point Rick tried to get a dealership for it, wanted to stock it in barrels but Silkolene would never get back to him so he dropped it
griff851
Good idea for a thread guys. A what oil do you use survey, just for the hell of it.
Griff
griff851
Well inlet ports are finished, inlet manifold is matched. I just forgot to wipe them out before the pic. 120 grit used for the surface finish. A couple of hours work.
Griff
griff851
A brief explanation of the porting. Basically the port from the factory were a rough as guts. The machining left the walls of the throat extremely uneven with depressions somewhere between ½- 1 mm deep and a lot of fine ridges. As smooth is fast, I just cleaned them up with a rod with a bit of rubber on it and 120 grit abrasive paper glued to it. This I stuck in a drill and honed the 2 throats, being careful not to change any angles as the throat diminishes in size. The rest was done manually using the same home made tool, and at times just abrasive paper and my finger. Al is too soft to use a rotary burr as you would if it was steel. The manifold to port had mismatches so I just cleaned them up as well.
I remember reading years ago that the cfm of a 4 barrel Rodchester carb could be increased by 50-100 cfm just by removing the mismatch of the parts down the throats.
Griff
Ps I used inside dividers to ensure as symmetry as close as possible, by comparing certain points in each throat and on each head. Each round throat hole is 27.94mm giving 613.11 area x 2 = 1226.23mm total inlet area. Standard 851 inlet port is 27.43 giving 1181.87 total area. A difference of 44.36 sqmm Going up valve size from 33 to 34 mm gives an increase in 105 sqmm.
got2dv8
Griff,
You read my mind!😯 I was going to post an query on what tool(s) you were using to clean up the ports. Thanks for the descriptions. There are those who quietly read about your work.
Robert
...it has begun
griff851
The rubber is that stuff that builders use, it has sticky on one side and comes in a roll for filling joins. Sort of soft spongy stuff. I just super glued the abrasive paper on.
At the moment I am wrestling with the figures about the throat size, this is because its a venturi and if you make it too big you loose velocity, too small and there is not enough flow. I think I need to find a new friend who does porting and have a chat. Although I do like the almost 2:1 valve area/throat area increase, it has a natural feel to it somehow. Stay tuned.
Griff
PS Thanks for reading. At least if I stuff it up, you'll know where and why and won't make the same mistake.
griff851
Here is the complete home porting kit (It doesn't get any cheaper than this folks). The roll of rubber I found on the side of the road, but its available from industrial rubber supply shops for a couple of dollars. Please note: the brown shafted tool, it is a genuine "Ducati" pencil! 😁 I tried it in the drill but wood is just not as tough as steel. 😄 I did use it with a reduced diameter for the smaller radius bits.
The big stick is what I started out with to really give it some, it was not used in a rotating mode more an in out sexual thrusting sort of way!😄
Griff
griff851
I've read this.
http://www.gofastnews.com/board/tech...ort-areas.html
As far as I can calculate I have gone from 69% valve area to port size to 67.5% This should give me increased velocity, which in turn means increase dynamic cylinder pressure increase and thus more torque. Can anyone verify this please. I have brain failure now.
Griff
loony888
griff851 wroteI have brain failure now.
Griff
what? just now?😏
paul.
griff851
Brain back on line. Today the 748 drop cam style head was put up next to a 748r head, a ST4S head, and a 996 flowed and ported head. Inside dividers were going everywhere.
The flowed and ported head had a taper expanding to the valve guide then a loverly wide open chamber before the seat insert. The seat insert had been widened and was flush with the seat insert
The 748R head had a clean neat chamber flush with seat insert.
The ST4S had blobby bits like in the pic of mine. So now the chamber section has to be smoothed out and a nice bowl shape. More grinding.
A discussion was had about numbers and stuff, and my calculations are wrong basically because my calipers are shot by at least 0.5mm (which would explain a lot of things generally.) If you do the port area/valve area % My heads with 34mm valves give 65%. Standard 851 would be 66%. The flowed heads with 34mm valves gave 66-68% (Tapered). Which makes sense as they had been on a flow bench and had work done to increase flow.The work has effectively widened the bowl on the sides. Where as on a standard head you can't do that with out boring out the seat insert to bring it flush with the depression in the bowl as marked in the lower bit of the pic, and I'm not going down that road.
So I'm just going to clean up the yukky bits in the bowl next, as marked, and leave it at that. It will be better than it was thats for sure.
Griff
WolfManSpecial
very interesting post,
question:¿is the same for two valves heads???
griff851
It should be I guess, I have not looked into 2 valve heads.
Attached is a pic of what I was trying to describe. Hope that makes it easier.
Griff
griff851
crankshaft preload
Hi a new problem among many. Changing from a crankcase gasket to using 3 bond does have it problems. I need 2 shims/washers (pt No 85210611A) which are 0.15mm thick. They are non orderable, (this is because they shattered apparently). However 0.2mm are readily available, but will give me a preload of what the book says. I'd like a little less. Looks like its the oil stone and grinding down to 0.17 for me.
griff851
Porting chamber
Its really difficult to show in a photo, but I think these give the general idea. The yellow drawing above doesn't really show what I was trying to (Blue bit) I hope these do. Image 1252 I just ran abrasive paper over hoping to high light the un-eveness of the surface.
Griff
