Long Stroke full flow oil filter

citroenthusiast

citroenthusiast

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I convinced myself that the long stroke engine could benefit from a modern oil filter. As it turns out, Citroen kindly supplied an external output from the oil pump that could be re-routed. There are three possible places one could install a bulkhead fitting. One would exit under the starter where there is no room. One would exit under the motor mount bracket where it would likely hit the motor mount bracket on the frame. The only reasonable exit is right in front of the crankcase vent, so that's what I did.

I plan to plug the center inlet with a grub screw pressing against a copper disk. Filtered oil will be returned through the oil gallery plug at the firewall.

Keeping my fingers crossed I didn't overlook anything.

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Very interesting! I'll be keen to hear how it shakes down.
 
What if the extra filter becomes clogged? There is a relief spring in the oil pump in this engine, so what steps will you you take to ensure flow resistance doesn't rise enough to open the spring valve, leaving little or no flow of oil to the engine? Will your filter housing have a filter bypass with a lower spring pressure than in the pump?
 
In my experience, this filter is not necessary, and given the risks pointed out by David above, I doubt that it is of any significant net benefit.

The centrifugal separator in the hollow crankpins works very well. And if reasonably regular oil changes are done, the engine life expectancy is very good.
These engines have large relatively lightly loaded bearings, which last very well.

Most important is to clean out the crankpin accumulations during engine overhaul.
 
David S said:
What if the extra filter becomes clogged? There is a relief spring in the oil pump in this engine, so what steps will you you take to ensure flow resistance doesn't rise enough to open the spring valve, leaving little or no flow of oil to the engine? Will your filter housing have a filter bypass with a lower spring pressure than in the pump?
Click to expand...

Hi,
This oil pump has a relief valve just like every other oil pump in existance on any motor ?? What happens to the oil flow in the engine of the car you drive now ! You avoid the problem by changing the filter, DUH.
Just saying !
Jaahn
 
Except that's not always the case. Some pumps are just pumps and the relief/regulation/bypass is done in the filter housing. The ID engine has a fixed spring and plunger in the pump to regulate the pressure. Unlike the Traction, which is very similar except must be adjusted when built, there is no adjustment in the ID, so the spring was obviously chosen to provide sufficient pressure without extra piping and a filter assembly. So, add in extra resistance to flow and what might happen? Maybe not much, but it obviously calls for a little thought about a suitable filter housing and element to use and where any bypassing of the filter will happen. Adding an oil pressure gauge line or sensor at the back of the main gallery plug where John proposed to reintroduce his filtered oil might also be sensible.
 
Good point about the oil pressure relief. I have already made provision for an oil pressure sender.

Oil Pressure Sender.jpg

I had assumed simply using a modern 10W-30 oil and changing the oil filter on a regular basis was an appropriate solution, however I have learned that some oil filters, such as used on early '60's Chevrolets had integral pressure bypass. That may be a solution. If anyone knows of a remote oil filter head with integral bypass, let me know as that would certainly eliminate all doubt.
 
Well, how about that, sometime fortune favors the ignorant. As it happens, the Motorcraft FL400S filter I chose for the application already has an integral pressure bypass valve. At least a plugged oil filter will not be an issue.
 
What's the 10W 30 going to do to the oil pressure vs the specs in the manual. I think I read about 60psi at 4000 rpm is the test spec. for the oil pump. New spring fitted? In the Traction, you would be able to tweak it up a bit if desired, but you'd need to change the spring in the ID.

Does the filter you've selected have some rating on the bypass valve opening? That seems a decent solution if you know a blocked filter will bypass before the pump relief valve opens. I know that's probably an extreme scenario given the care and use the car will receive.

If you can't find something more generic, Jag vendors have a range of spin-on conversion kits to replace the original (messy) element inside a canister on their XK and early V12 engines if that's of any help.
 
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My reason for mentioning a 10W-30 oil is that thin oil, such as a 10W or even 5W will flow easier on startup and therefore will be less likely to cause the oil pump to bypass on start up, which is when the added flow resistance of the extra piping and oil filter media will be the most severe.

Ford Specs the bypass in the filter at 11-17 psi. That pressure differential is likely to be seen only if the filter is not changed or on cold start when the oil is very thick.

I have not looked yet, but is it not possible to add shims under the spring in a DS oil pump? It looks like the cover plate can be removed but I haven't disassembled it yet. I have replaced the badly scored pump gears with new, so as to restore the pressure and flow capability.
 
Sorry, I was thinking older car, thicker oil as in 20W50 per later engines, but the UK ID19 handbook stipulates SAE20 or 10W30 oil. SAE 20 is even printed on the filler. It's easy to forget it's close to a vintage engine. There's also the issue of reduced anti-wear zinc compounds in oils intended for cars with a catalytic converter, if you are using something 'modern'.

I doubt cold weather is a big issue for you though ... Phoenix Weather Forecast and General Information

Oil pump overhaul instructions are in operation ID100-3 of manual 472, paragraph 24. It provides for a bench test of the pump similar to the Traction test, but just suggests replacing the spring if it fails. There's a required clearance between the end if the gears and the end plate if the pump is to work well. It's meant to make 50psi at 1,000 rpm on test, so the relief valve pressure is obviously way above the filter's internal bypass rating.
 
Hello, how about a remote electric scavenge pump and remote filter head. One short and one long pipe along the length of the sump and then complete the circuit via the scavenge pump and filter head. A bit like a dry sump, could even place the pump and filter in the boot.

I like spending other people's money

Peter
 
One has to ask, why are we trying to fix something that ain't broke ?

Engine longevity has not been a significant issue in my (more than) half million km of long stroke D motoring.
 
A lot depends on the type of use with engine longevity. If Buttercups half-million clicks has all been done on long trips I'm not too surprised, but if the cars on multiple shortish runs a filters a good idea. There's no modern engine without a filter to my knowledge.
Adding a filter to my Light 15 was on my 'to do' list but never got round to it. My only mod. Was a big magnet on the outside of the sump near the drain plug
 
badabec said:
Hello, how about a remote electric scavenge pump and remote filter head. One short and one long pipe along the length of the sump and then complete the circuit via the scavenge pump and filter head. A bit like a dry sump, could even place the pump and filter in the boot.

I like spending other people's money

Peter
Click to expand...

Perhaps, a hand pump rather than electric? Gives the passengers something to do on those long trips.
 
jaahn said:
Hi,
This oil pump has a relief valve just like every other oil pump in existance on any motor ?? What happens to the oil flow in the engine of the car you drive now ! You avoid the problem by changing the filter, DUH.
Just saying !
Jaahn
Click to expand...

Jaahn. There still needs to be a by pass valve in the filter attachment body. I am sure that a CX unit could be modified for this purpose.
 
baldrick56 said:
A lot depends on the type of use with engine longevity. If Buttercups half-million clicks has all been done on long trips I'm not too surprised, but if the cars on multiple shortish runs a filters a good idea. There's no modern engine without a filter to my knowledge.
Adding a filter to my Light 15 was on my 'to do' list but never got round to it. My only mod. Was a big magnet on the outside of the sump near the drain plug
Click to expand...

Why did you not just simply add a magnet to the drain plug itself? Easier to clean the magnet as it all comes out with the drain plug!
 
citroenthusiast said:
Not the first time someone has told me I just can't seem to leave well enough alone. :)
Click to expand...

Don't get me wrong, I'm one of most prolific modifiers around.

But I usually only try to fix things that are actually demonstrably deficient.

Right now I'm building my own car, 'cos I can't find one that ticks all the boxes.

Requirements are:
No computer! (points ignition, human foot on brake pedal, manual gears)
No active hydraulics (master cylinder brakes only, but discs all round)
The best looking body ever (1st front DS)
The best chassis/suspension system ever (2CV)
The best engine ever (GS1220.... if you can tolerate oil leaks)
Removable hard top.
Convertible boot/load space (DS bootlid OR Ute tray back interchangeable)

Pics and performance report in a few weeks.......
 
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