5 GT Turbo Oil Filter; which one for the 5GTT C1J engine?

[LowiePete]

Hello Folks,

This topic is a subject that I've long been researching an answer to, particularly as
some of the "popular" marques are seemingly no longer manufactured and are
fetching quite spectacular and stupid prices. The price of oil filters is going so far
north it's becoming a cheque-book sport. For what is nominally a simple service
item, that's just daft. The whole point of these parts is that they are changed
properly and frequently.

So, as the owner of a 2L petrol turbo Renault I was rather surprised to find that
the oil filters for the F4R engine have more or less identical dimensions as those
fitted to the smaller, historical C1J engine. I've broached this subject here before,
only to find objections because of presumed "oil pressure loss". To be honest, I
didn't buy those arguments then and, having done more research since, I certainly
don't buy them now.

If it means that I can replace the oil filter at frequencies of at least twice or more by
using one that has been developed for the modern era, that is for engines (and oil)
developed long after the C1J went out of production, then so be it. The idea that we
be tempted to "stretch" the life of filters that were previously specified because of
cost or rarity just becomes daft. So, with this overlap in mind, what should we look for?

Well, it's very simple, although finding the evidence for this simplicity has not been
at all easy. The first bit of research is in oil pressure measurements. The absolute
critical measurement is that the by-pass valve is not forced to open and let through
unfiltered oil until it's absolutely necessary. Next comes the flow statistics, that is
the filter not interfering with the oil pressure on the exit side. That can fairly easily be
answered by the physical dimensions. In other words, if the enclosure dimensions are
similar, then the flow will also be well within tolerances. Indeed, it could be argued
that flow, at a non-diminishing pressure, will be as good or better with modern filters.

So, it comes down to getting accurate statistics regarding oil pressures at critical
moments and making comparisons. Trying to track these down has not been an easy
job. They are, thankfully, available in tech publications from Renault. For the C1J it
came down to researching period publications. For the F4R they're found deep in the
Dialogys system. So, to the figures...

C1J Turbo

Revs @ 750 rpm (idle) 1.3 bar
Revs @ 4,000 rpm (turbo active) 3.2 bar

F4R Turbo

Revs @ idle 0.4 bar
Revs @ 4,000 rpm 2 ~ 4 bar

What the figures show is that the tolerances of the 8200 768 913 oil filter for the
later Renault engine will happily cope with the C1J engine. So that should make the
market for paying well over the odds collapse. I've discussed this at length with Karl,
my Renault mechanic of many years, and it's quite clear that he won't be screwing-up
his nose at me for substituting them. I'm not inclined to ignore his advices at the
best of times.

Like me, he's far happier that the filter gets a regular change, rather than sticking to
what is likely to be old technology at what is becoming stupid pricing. This especially
as the specs of the oil have not stood still in the intervening years either.

Regards,
Steve

 

[gtmatt]

I only had 5 minutes to check things at work this morning but my findings at present is that C405 oil filter 7700727482 has a Motrio alternative 8671002274 which is also the Motrio alternative for 7700873583 & 7700274177 filters, all within the £5-£8.50 range.
IF I get time during the week I'll try to do some more checking.

they all look like the talk 172 type

 

[Norwich Nick]

Bored watching Saturday night tv and this appeared on my Facebook, thought of this thread, its of hardly any relevance or use but if you're bored something to kill a few minutes

 

[Big Steve - Raider]

A great little threat @LowiePete!! I'm all for keeping the GTT's on the road and not being held to ransom for expensive spare parts!!

I bought a glut of the MANN filters from Dale Jarvis a few years ago but have yet to fit one.. everytime I go to do an oil change on the Raider my guts push me to pick another OE one out of stock..

 

[Chris H]

they were all substituted/superseded for the the small filters about 10 millions years ago.

Also as to the return valve, the last dinosaur used the only existing non return filter.

The return valve is the one in the wee holes around the periphery. The big spring in the middle is the pressure relief valve.

You can get larger filters which I use on the f engines sometimes but usually its the small one.

 

[Steve Swan]

Oil and filters is always a polarising subject. Years ago my local Renault dealer had a genuine OE Purflux filter cut in half on the parts counter, along with a cheaper brand item, also sectioned. It was obvious that the purflux filter had twice as much filter paper in it and therefore twice the filtering capacity. The point being made that it was worth an extra couple of quid for a quality item. In essence if a filter is the correct thread and the sealing ring is the correct diameter then that filter will work, also the bigger the better as there will be more filter in the bigger can. When you look at the threaded end if you can see a rubber flap over the outer holes this is the anti-drain valve, some poor quality filters do not have these. The spring you see up the far end is the bypass valve which will open in the event of the filter paper becoming choked. GT Turbo's are difficult to cater for as there is not much room in there, so it makes sense to use a top quality filter with as much filter as can be crammed in the little can. If you prefer, blank it off and use a remote filter which you can fit hanging down so it wont drain back. With a cherished car it always makes more sense to change the oil and filter frequently as the car's use is more infrequent, nothing like a bit of fuel and water contamination in your oil to reduce its effectiveness
Happy Motoring

 

[DaveL485]

When you look at the threaded end if you can see a rubber flap over the outer holes this is the anti-drain valve

...and if you're looking for a bigger filter off the shelf make sure the anti-drain runs the right way!

 

[Steve Swan]

@Brigsy . One thing is for sure if you get different oil pressures for different filters change it again . The oil filter should play no part in determining oil pressure, the clearances in the engine determine oil pressure. A weak point in hot C1J Atmo motors is the cam, the loads on the parts at high rpm are huge. When I finally line bored my block to take 3 white metal cambushes plus the std one at the flywheel end we found more oilpressure hot at tickover on the Dyno than we has seen before, also it stopped sounding like a Renault (no tappieness) As we had tightened up the clearances the oilpressure had improved. For what it's worth I tend to use Purflux if I can get them or Mann , never had an issue (yet)

 

[Brigsy]

@Steve Swan agreed cam journal tolerance and clearances in spec makes a massive difference to oil pressure. Im currently using a low mileage c3j block with cat cams camshaft, no oil cooler and purflux ls218, 20/50 valvoline vr1 mineral oil and i see 60psi oil pressure when hot (90deg) at 7600rpm.