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Daimler 15 Cam bearing

Posted: Thu Jan 24, 2019 8:16 pm
by bop
While assembling my 2003cc engine I noticed the two end cam bearings are pressure lubricated from oil from the oil pump that is first feed through the main bearings and then on to the cam bearings. The three center ones appear to be splash feed? I do not want to drive out these three bearing shells just to see if there is any holes covered. Below is a photo of 2 of these bearings.
100.JPG
So does anyone know if these three are pressure feed or not?
thanks
Bob

Re: Daimler 15 Cam bearing

Posted: Tue Jan 29, 2019 2:56 am
by qantasqf1
Bob, I did some research on this issue because it intrigued me! First of all I had a look at the DB18 arrangement and that showed all 4 camshaft bearings are force fed from drillings leading from the main bearings to the camshaft bearings. However, the DB18 has one camshaft bearing less than yours so it’s a simple matter to drill a straight hole to each camshaft bearing from each main bearing because they line up. However, as you say, you have 5 camshaft bearings and that makes it complicated because of non-alignment of the 3 intermediate camshaft bearings with the main bearings. That would mean either the hole taking a bend or drilling 3 connected holes and blanking off the ends of the middle hole. Tricky! Unless Daimler actually did this - which I strongly doubt - then the 3 intermediate bearings must have relied on splash. As an afterthought is there a drilling in the crankcase casting immediately above the bearing locations to allow oil to find its way to the bearings? This is all conjecture, Bob, but maybe of some help.
Cheers
Steve

Re: Daimler 15 Cam bearing

Posted: Tue Jan 29, 2019 8:44 am
by ranald
These cam bearings in my Lanchester engine sit in an oil bath with a hole drilled to allow oil to enter.

Re: Daimler 15 Cam bearing

Posted: Tue Jan 29, 2019 3:58 pm
by Rolf B.
Hi Bob,

the chain driven camshaft in the 1.805 cc engine of my very early 1933 Daimler 15 is running in an oil bath within the block below. This means the three center bearings are oil fed by the bore holes in the engine block, where the bearings are located. And the two outer bearings of the camshaft are pressure lubricated bearings, fed by the hollow bore in the camshaft.

Rolf B.

Re: Daimler 15 Cam bearing

Posted: Tue Jan 29, 2019 5:16 pm
by bop
Thank you all for your replies.

The other day I spun the oil pump (cam shaft was not installed) and watch as oil came out of the front and rear cam bearings. These two bearings are of the replaceable Babbitt shell type. The 3 center cam bearings are also of the replaceable Babbitt shell type and were dry. I decided I would probably do more damage then good trying to remove these shells to investigate further, plus I assume the engine had run for many years as the bearings are. I also read an article which mentioned the camshaft gallery floods with oil and this is how those bearings are lubricated. Makes sense because the drain hole to the sump for this gallery is part way up the gallery and not at the bottom.

This is a photo of drain hole (arrow) at rear of camshaft gallery to sump
2.jpg
And this photo is of the only other place for oil to drain (arrow) from camshaft gallery (into timing gear housing and then to sump)
3.jpg


Also the holes in these 3 cam bearings are below the flood level allowing oil to the Babbitt surface. My original photo shows the location of lubrication holes in the cam bearing support castings.

So the consensus appears to these 3 cam bearings are not pressure fed.
thanks again Steve, Ranald and Rolf for taking the time to reply

Bob