Comet Oil Filter Woes
- Thread starter Martyn Goodwin
- Start date
Furthur research informs me that of the 2 makes of filter, VSOC and the Australian item now differ in the size of the bore. The latter has a larger bore which fits over most if not all Comet filter bosses, so it seals at the base
of the housing below the boss properly, It is also metal lined to resist the crushing force of the cold oil at start up. I have just fitted one in my bitsa Comet with no problems, whereas before it was not wide enough to pass over the boss, the original was Australian as was the new one. Thus the design has been changed. Ken
of the housing below the boss properly, It is also metal lined to resist the crushing force of the cold oil at start up. I have just fitted one in my bitsa Comet with no problems, whereas before it was not wide enough to pass over the boss, the original was Australian as was the new one. Thus the design has been changed. Ken
OK, I am waiting for all engineers in the club to to start shaking and weeping. My solution to this problem was thus, get yourself 2 x hole saws, good quality ones, you want one hole saw with the internal diameter a very small amount under the diameter of the filter chamber, just a running clearance, the other hole saw with the internal diameter a shade smaller than the internal diameter of the hole in the filter, use the large hole saw to make a circular disc out of a decent piece of fairly thick plywood, good quality, say marine ply 15mm thick, now follow through the centering drill hole with the smaller hole saw, now Araldite the disc that you have made onto the small hole saw, that will ensure that when the hole saw is used to remove the excess casting from the filter housing spigot that the spigot remains concentric with the filter chamber, hold your heads in horror, but it worked for me, you could make a positive stop depth gauge by packing out the internal of the hole saw but I find that unlike twist drills, hole saws do not have a tendency to pull themselves through so not really necessary, you can do the job in very little stages until you happy with the result, clean any swarf out, job done. There you are Clever Trevor, what do you think of that!
Have now found that I have the same problem, at some point in the past a Spares Co. filter has been fitted and it is obvious from the way the end is bent inwards and the marks on the sealing rubber that it has not been seated properly. For the filter to sit over the crankcase boss it needs to have a 30mm bore on that end, the new one I have just ordered has a 20mm bore and a sticker stating that I may need to open the bore up.
I am a Diesel generator engineer by trade so I will track down an oil filter which will fit, and require NO alterations (not ideal to risk getting swarf in a new filter) when I have a part No. I will post it on here.
I am a Diesel generator engineer by trade so I will track down an oil filter which will fit, and require NO alterations (not ideal to risk getting swarf in a new filter) when I have a part No. I will post it on here.
You confirm the experience of some other Comet owners. The Spares company seems to be supplying a filter element that is genarally not fit for purpose. I also ame now searching for a suitable alternative supply.
Can anyone confirm for me the INTERNAL diameter of the oil filter chamber itself??[
QUOTE=aldeburgh;39350]Have now found that I have the same problem, at some point in the past a Spares Co. filter has been fitted and it is obvious from the way the end is bent inwards and the marks on the sealing rubber that it has not been seated properly. For the filter to sit over the crankcase boss it needs to have a 30mm bore on that end, the new one I have just ordered has a 20mm bore and a sticker stating that I may need to open the bore up.
I am a Diesel generator engineer by trade so I will track down an oil filter which will fit, and require NO alterations (not ideal to risk getting swarf in a new filter) when I have a part No. I will post it on here.[/QUOTE]
Can anyone confirm for me the INTERNAL diameter of the oil filter chamber itself??[
QUOTE=aldeburgh;39350]Have now found that I have the same problem, at some point in the past a Spares Co. filter has been fitted and it is obvious from the way the end is bent inwards and the marks on the sealing rubber that it has not been seated properly. For the filter to sit over the crankcase boss it needs to have a 30mm bore on that end, the new one I have just ordered has a 20mm bore and a sticker stating that I may need to open the bore up.
I am a Diesel generator engineer by trade so I will track down an oil filter which will fit, and require NO alterations (not ideal to risk getting swarf in a new filter) when I have a part No. I will post it on here.[/QUOTE]
2 1/16"........................
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Thanks to all for the input. Today I had a meeting with the owner of V3 products (advert in MPH) who also has paper element filters available for both twins and singles - these ARE NOT the same as the VOC filters. V3 filters have the metal screen on both the outside and the inside, and the size of the central bore opening is 24mm. The ID of the sealing rubbers is approx 30mm. The overall length of the single filter, including the sealing rubbers is 3.18 inches - however as a consequence of this thread I understand, that once his current stock of singles filters are gone, the replacements will be closer to 3.0 inches long, thus accomidating bikes like mine where there is absolutly no sign of any machining having been performed within the oil filter chamber.
I also had the chance to examine the engine cases of another Comet and with that, the interior of the oil filter chamber had the end of the chamber machined flat and the central spigot also machined so that its sides are at 90 degrees to the base with no bevel what so ever, thus allowing the filter to sit flush and seal on the chamber base.
When (if ever) I have the need to strip down the bottom end of my motor I will be having that machining performed - All I can assume is that some how a machining step was missed out during the initial build back in 1951.
Till then I have laid in a supply of felt filters that should see me thru till V3 has their new (sized) filters available.
I also had the chance to examine the engine cases of another Comet and with that, the interior of the oil filter chamber had the end of the chamber machined flat and the central spigot also machined so that its sides are at 90 degrees to the base with no bevel what so ever, thus allowing the filter to sit flush and seal on the chamber base.
When (if ever) I have the need to strip down the bottom end of my motor I will be having that machining performed - All I can assume is that some how a machining step was missed out during the initial build back in 1951.
Till then I have laid in a supply of felt filters that should see me thru till V3 has their new (sized) filters available.
I certainly hope that VOCS are informed of this development. I had been hoping that the days of supplying parts not fit for purpose were history but if they (the VOCS) are not told of problems then they cannot fix them. Having said that, there should now be a quality control protocol in place to check. Over to you Ian and Arthur.
I think that the VOCS oil filter is OK but not for all Comets! There seems to be various shapes of centre boss on this model and the VOCS filter does NOT fit all correctly , yes it will go in and the brass cap will screw in tight but check what is actually happening inside the housing.
On mine the centre boss can only be described as "random shape" i.e. not machined on its outside edge at all, at its maximum diameter it is approx 30mm therefore the filter opening on that end also needs to be 30mm to allow it to sit over the boss onto a seal against the end of the housing. The "original" felt type filter was practically a 2'' tube with a seal each end this would easily accomodate any weird shapes of centre boss and provide full flow filtration . The VOSC filter which I removed from mine was NOT sealing over the centre boss thus allowing oil to "short circuit" and avoid going through the filter ,I hope there are no other Stevenage Steeds running around with this "undetectable" fault.
On mine the centre boss can only be described as "random shape" i.e. not machined on its outside edge at all, at its maximum diameter it is approx 30mm therefore the filter opening on that end also needs to be 30mm to allow it to sit over the boss onto a seal against the end of the housing. The "original" felt type filter was practically a 2'' tube with a seal each end this would easily accomodate any weird shapes of centre boss and provide full flow filtration . The VOSC filter which I removed from mine was NOT sealing over the centre boss thus allowing oil to "short circuit" and avoid going through the filter ,I hope there are no other Stevenage Steeds running around with this "undetectable" fault.
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