|
|
| Author |
Message |
Bayliss Thomas
Joined: 25 Sep 2009
Posts: 557
Location: SUFFOLK
|
 Posted: Sat Oct 23, 2010 5:12 pm Post subject: Running in - what oil? |
 |
|
As most on here are aware, my 1928 vauxhall OHV engine is going to have an top end rebuild + new piston rings. My normal engine oil is Commer SAE 40, however in cold weather I would run with Commer SAE 30. Both detergent free oils which I prefer to use. Would the Commer SAE 30 be OK for running in period for the engine after the rebuild?
Also I am having an Flexolite oil filter system in place of the original by pass filter for which the filters are impossible to obtain. I will use the existing arrangements on the block therefore minimizing 'damage' to the original fittings. The old oil filter cannister I will be keeping for any future owner who may wish to re-instate the original equipment. I am assuming that the modern 'spin on/off oil filter cannisters are OK for use on by pass systems with the lower pressure? |
|
| Back to top |
|
 |
Penman
Joined: 23 Nov 2007
Posts: 4880
Location: Swindon, Wilts.
|
| Posted: Sat Oct 23, 2010 8:14 pm Post subject: |
|
|
Hi
Check for direction of oil flow.
For instance Bristols have a different direction (inside to outside) compared with a lot of other engines (outside to inside) and consequently you have to find a specific spin on canister which is designed to flow the correct way.
_________________
Bristols should always come in pairs.
Any 2 from:-
Straight 6
V8 V10 |
|
| Back to top |
|
|
Jim.Walker
Joined: 27 Dec 2008
Posts: 1229
Location: Chesterfield
|
| Posted: Sun Oct 24, 2010 3:49 pm Post subject: |
|
|
By-pass oil filters do not operate at a lower pressure in general. The oil feed pumped to the engine is split. Unfiltered oil going to the bearings etc. while the "by-passing oil" follows a different path to the filter from whence it is returned to the sump (on O.H.V. engines some is sometimes used to feed the rockers).
The low pressure output from a by-pass filter is because the element gives much finer filtration and there is a significant pressure drop across it. Using a full-flow filter (element) could well drop engine oil pressure dangerously by providing a low resistance path back to the sump without lubricating the engine.
Neither type of element should ever be replaced by the other.
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then! |
|
| Back to top |
|
|
Bayliss Thomas
Joined: 25 Sep 2009
Posts: 557
Location: SUFFOLK
|
| Posted: Sun Oct 24, 2010 7:18 pm Post subject: |
|
|
| Jim.Walker wrote: | By-pass oil filters do not operate at a lower pressure in general. The oil feed pumped to the engine is split. Unfiltered oil going to the bearings etc. while the "by-passing oil" follows a different path to the filter from whence it is returned to the sump (on O.H.V. engines some is sometimes used to feed the rockers).
The low pressure output from a by-pass filter is because the element gives much finer filtration and there is a significant pressure drop across it. Using a full-flow filter (element) could well drop engine oil pressure dangerously by providing a low resistance path back to the sump without lubricating the engine.
Neither type of element should ever be replaced by the other.
Jim. |
Thanks for input Jim, I am puzzled though with reference to not being able to change my old by pass filter to an modern 'Flexolite' spin on/off cartridge filter. I have worked out the engine oil is pumped from the sump up through the filter to the rockers whereby it drains back to the sump. The filter in my current oil filter system is now passed its usefulness and needs changing, but the filters are unobtainable. Thats why I thought best to change the filter unit complete. Are you suggesting this is not the best idea? |
|
| Back to top |
|
|
Jim.Walker
Joined: 27 Dec 2008
Posts: 1229
Location: Chesterfield
|
| Posted: Sun Oct 24, 2010 9:29 pm Post subject: |
|
|
| Bayliss Thomas wrote: | | Jim.Walker wrote: | By-pass oil filters do not operate at a lower pressure in general. The oil feed pumped to the engine is split. Unfiltered oil going to the bearings etc. while the "by-passing oil" follows a different path to the filter from whence it is returned to the sump (on O.H.V. engines some is sometimes used to feed the rockers).
The low pressure output from a by-pass filter is because the element gives much finer filtration and there is a significant pressure drop across it. Using a full-flow filter (element) could well drop engine oil pressure dangerously by providing a low resistance path back to the sump without lubricating the engine.
Neither type of element should ever be replaced by the other.
Jim. |
Thanks for input Jim, I am puzzled though with reference to not being able to change my old by pass filter to an modern 'Flexolite' spin on/off cartridge filter. I have worked out the engine oil is pumped from the sump up through the filter to the rockers whereby it drains back to the sump. The filter in my current oil filter system is now passed its usefulness and needs changing, but the filters are unobtainable. Thats why I thought best to change the filter unit complete. Are you suggesting this is not the best idea? |
If you put a full flow filter into the by-pass system it will allow a greater oil flow because it is less restrictive (it does not filter the oil so finely). That will have two possible results.
First: Oil pressure (and hence oil flow) to the crankshaft and associated bearings will most likely be reduced.
Secondly: The rockers will be swamped with oil, probably causing oil to bleed down the valve guides increasing oil consumption.
Full-flow filters have a pressure relief flow system built in to maintain oil flow if the filter becomes clogged. Putting a finer by-pass element in a full-flow canister would possibly operate that flow system allowing unfiltered oil to the bearings and no filtration at all would then occur.
Fram used to make an after market by-pass filter which could be mounted on the bulkhead or other convenient place. I don't know whether any such filter is now available, but I have seen unused ones on sale at auto jumbles etc.
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then! |
|
| Back to top |
|
|
Bayliss Thomas
Joined: 25 Sep 2009
Posts: 557
Location: SUFFOLK
|
| Posted: Sun Oct 24, 2010 10:28 pm Post subject: |
|
|
| Thanks Jim, your advise is appreciated. |
|
| Back to top |
|
|
Jim.Walker
Joined: 27 Dec 2008
Posts: 1229
Location: Chesterfield
|
| Posted: Sun Oct 24, 2010 10:57 pm Post subject: |
|
|
A further thought on this.
I THINK the last Standard 8s and 10s and probably early Triumph Heralds had a spin off by-pass filter. If so that might solve your problem.
Rick should know more about that than me. He has a Standard Companion.
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then! |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Profile
Log in to check your private messages
Log in
