Engine lubrication modification

Post your general FAQs, comments & questions regarding all Ducati engine & transmission restoration here. [Specific engine FAQs should go in the 'BevelHeaven Garage' section.]
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Per Garbos
Diana
Posts: 55
Joined: Sat Feb 03, 2007 11:41 am
Location: Denmark

Engine lubrication modification

Post by Per Garbos »

I have been told that the oil filter only works as a by-pass filter which means that not all the oil are passing though the filter.

Now my bevel is split a part because of a big-end break down, and i would like to do some improvements regarding the oilsystem

I have seen some bevels with an external tube going from primary drive side to the top of the oilfilter house.

Where do i find futher information regarding this modification


Best regards Per
cafe*racer
SSD900 Darmah
Posts: 364
Joined: Tue Nov 16, 2004 1:49 am
Location: Castro Valley, CA

Post by cafe*racer »

Per, I am curious if you ever sorted this out? I am planning on improving my GT with an external cooler any filter system similar to the prototype built in 1973. Jordan
MartinMille BANNED
BANNED
Posts: 766
Joined: Fri Sep 21, 2007 8:15 pm

Post by MartinMille BANNED »

The SD that I have coming, it has been taken out to 92mm and it uses an external oil cooler, the work was done by an engineer and the oil feed was take from under,near the oil filter and the return was run back through the rear cam cover ,I dont have any pictures at this point to show you
Lumpy
SD900 Darmah
Posts: 329
Joined: Sun Mar 25, 2007 5:49 am

Bevel oil system

Post by Lumpy »

Per,
I`m so glad your out there. I saw this system, line from the filter housing to the primary drive side, once on a Darmah but could not work out what it was all about. The bike was parked at some bike races and I was just walking past and noticed it. I since told a few bevelheaded friends about it and they claimed I was dreaming. There was no other modification, no cooler or the like. Is it possible that this line takes only filtered oil to the big end?? I`d be interested to know if anyone has any further info on this modification. If it is dedicated big end oil, does the original oil feed to the big end need to be pluged??
baddean
Parallel Twin
Posts: 148
Joined: Sun Jun 17, 2007 7:11 pm
Location: Cincinnati Ohio

Post by baddean »

Hey All,
A dear friend of mine who was an incredible machinist (he is missed by many of us in the area) past away last year and left another friend and me several of his bikes. I got a 900SS and the other fellow got his bevels. Two 1974 750GTs both bored to 860.
I'm getting to the subject here!!
On one of the bevels he had tapped into an oil galley to run an external cooler and, I think, a filter and his system works very well.
I'will get more info and some photos to post here.
I know that he ran lines to the cam covers to get more oil to the heads as well.
It might be a while before I can get to it because my friend is out in Moab Utah dirt biking and before he gets back I am going to Spain on an Edelweiss tour so it may be three weeks before I can get to this. I'll call his wife and see if the bike is at their house or their offsite storage. If it is at their house I might get photos before I go to Spain.
Dean
Faster, faster until the thrill of speed overcomes the fear of death.
Hunter S Thompson RIP
wdietz186
Cagiva Alazzura
Posts: 707
Joined: Sun Sep 10, 2006 5:40 pm

Post by wdietz186 »

The external oil lines have a few different purposes. The oil feed from the pump runs to a tube cast into the timing side case. It feeds the cylinders and on the square case models the oil filter. The filter is a partial bypass type as it is fed from an orfice in the filter housing. If you look closely at the case in front and below the housing you will see a flat area. On some 750's this was drilled and tapped at the factory. This is where cyl feed tube is located. It provides the oil for the cams. The crank oil feed goes across the case behind the oil pump. A popular modification was to block off the holes in the case and run external lines directly to the cam blocks on the heads. The reasoning behind this was to be able to restrict the oil flow to the cams and provide more oil to the crank. A further reason was to allow cooler oil to feed the heads as it didn't pick up heat travelling up the cyl and through the head before feeding the cams. With modern oils and the fact nobody really runs the crap out of these engines anymore these mods aren't really needed anymore. But the plumbing does look cool!
Per Garbos
Diana
Posts: 55
Joined: Sat Feb 03, 2007 11:41 am
Location: Denmark

Post by Per Garbos »

Thanks for the reply
I actually did the modification, but I also made it so I very easy could go back to the original design. At the same time I replaced the standard oil pump with a high capacity oil pump.
My only reason for the modification, was because I wanted to have filtered oil to the big end. During my last rebuild I saw how much dirt there was in the slugde trap.
Anyway, it seemed like a good idea, but during start up test (rotating the rear wheel by hand) I found that it took the oil around 3-4 times longer to reach the big end.
The oil had first to fill up the filter and the filterhouse before it could reach the big end.
Then I tried to make some modification so I could keep the Oil level in the filter house when the engine was not running. See picture
It never really worked, so i went back to the original system with by pass filter.

All this above was only done as a test, but because i could not accept the longer flow to the big end during start up, I went back to the original setup, but still with the high capacity pump.
Now I change the oil each 2000 km instead.

Best regards Per

Modified filterhouse:
Image
Lumpy
SD900 Darmah
Posts: 329
Joined: Sun Mar 25, 2007 5:49 am

Oil feed

Post by Lumpy »

I know what you mean by the oil taking a while to get moving. I have bevel gear windows on both my GTS and SS and the oil comes up quite quick when it`s cold but takes ages when hot. I do oil changes every 1000 k`s on mine. I beleive it`s cheap insurance. By the way, who did you buy your high volume pump from?
Per Garbos
Diana
Posts: 55
Joined: Sat Feb 03, 2007 11:41 am
Location: Denmark

Post by Per Garbos »

I bougth the high capacity from kaemna in Germany (www.kaemna.de) but i have also seen Ducati specialist Brancato in GB have it.

Best regards Per
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