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It's not just upping oil thickness I'm after just increasing pressure. It's a very common mod on competition engines, rough rule is 10psi per 1k revs. So if your engine runs to 8k then 80psi oil pressure should be the target at those revs. Oil change won't get you there. That's what my current engine has and wondering if you can mod the f4r oil pump with washers or new spring.
NorthloopCup
ClioSport Moderator
You can mod the pump to gain higher oil pressure. They also need de-burring internally as there's some nasty castings in the ones I've seen/done
Mine rate 70/80 psi hot with 10/40 millers oil( which matches the 10psi per k revs rule of thumb ) and never leaked bone dry, guess its who built it that makes a difference as the seals will be rated far higher than than. I'm thinking Godneys was running far too low at 3 bar hot using 10/60 oil in a full competition engine. In the f7 build manuals it gives updated pump details but the f4 haven't got anything, sure the must have updated the spring for the group n cars or speced oil pressure for the s1600 f3 stuff with dry sump.
OK but for the works F7 cars/S1600/F3 it was a renault mod with an aim of the 10psi per k rule but nothing for the F4? they must have done it for a reason and surely to the F4 with the likes of Sodemo.
Godneys cars was 3 bar hot with thick oil when the recomendation rule of thumbe is nearly twice that. Can it be done on an F4 oil pump?
clio cup race car
I was actually running 3.5-3.8 bar hot under revs , which I agree in my eye's is not enough , my golf rally engine putting out 250hp is running 85 psi hot , just over 6 bar , most cars I have had run at about this pressure , my GTR road car runs 6 bar hot .
I can't see why the oil pump springs can't be shimmed to up the pressure , this was all they used to do back in the day when we were running Mk 2 Escorts , I believe the Peugeot rally engines just run a harder spring on the relief valve , so shimming it would in effect do the same thing , my engine will be running a higher oil pressure when it goes back in
I can't see why the oil pump springs can't be shimmed to up the pressure , this was all they used to do back in the day when we were running Mk 2 Escorts , I believe the Peugeot rally engines just run a harder spring on the relief valve , so shimming it would in effect do the same thing , my engine will be running a higher oil pressure when it goes back in
clio cup race car
just found this but for the F7 engine
http://www.ebay.co.uk/itm/NEW-Oil-pump-Renault-Clio-F7R-F7P-Williams-16V-1-8-2-0-/140662351630
http://www.ebay.co.uk/itm/NEW-Oil-pump-Renault-Clio-F7R-F7P-Williams-16V-1-8-2-0-/140662351630
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NorthloopCup
ClioSport Moderator
You can retain the original spring and you don't need to shim it either to up the pressure. Just need to be a bit clever about what your doing.
Care to elaborate?
clio cup race car
After speaking to SWR this afternoon , who tell me they used to rebuild a lot of these engines in the Clio cup series say they did used to shim the springs up in the pumps to up the pressure , I'm sure if there was another way he would have told me
Sorry Ian your in car look like 3.0 vs 3.8, I have the uprated spring in my F7 so must be a solution for the F4 without going dry sump. Hope fully a simple solution.
NorthloopCup
ClioSport Moderator
Honestly mate it's quite obvious if you look at the oil pump.
So does that mean i'm wrong then? Unfortunately sometimes even prolific engine builders miss even the most obvious and simplest way of doing things.
clio cup race car
Maybe you could just come out with it instead of keeping us guessing then ??
Just taken photo's of a brand new pump I have had delivered to have a look at it , looks easy enough to shim the spring , I guess i'm missing the obvious part about upping the oil pressure !
I am currently building an engine for my Megane r26. I have a new oil pump in my garage, if it's worth modifying before fitting I would also like to know details.
I am by no means an engine builder so it could be the most obvious obvious thing staring me in the face and I wouldn't know!
I am by no means an engine builder so it could be the most obvious obvious thing staring me in the face and I wouldn't know!
NorthloopCup
ClioSport Moderator
SBD use a nylon valve not nylon shims mate. The original one on the xe used to stick.
clio cup race car
Aren't the standard valves in a vauxhall engine nylon ?? They have issues with them sticking and losing oil pressure , happened to me before which took a bottom end out.
so what are the mods you say can be done to a standard pump , I can't see after looking inside the pump
so what are the mods you say can be done to a standard pump , I can't see after looking inside the pump
NorthloopCup
ClioSport Moderator
No the standard prv on an xe is made of aluminium. Tbqh it was very much luck of the draw as to if the original would stick or not and the same can be said for the nylon ones. I've seen both stick!! I've ran the original aluminium valve in my vauxhall turbo motor without issue for years. The only mod I made to that o/p was the addition of the steel gear as the original one could shatter.
The mod to up the pressure is just a simple and easy one that requires no faffing. Look for the R clip in the pump. The piece that the R clip secures is the bit you modify. Measure how deep the recess is in the original item and then turn it through 90 degrees. Make another groove that R clip can locate into. You just make it look like a hot cross bun. If the original groove is 4mm deep, make the new one around 3mm deep. You'll immediately see an improvement in o/p. It also gives you the opportunity to adjust the pressure to suit if you don't go lairy with the groove depth. You can take out but you can't put back in.
Yes you could very easily just shim the spring with penny washers to get the same result, but if the pressures to high you have to machine it down to suit - this method requires the use of a round file. I've done it and it works.
Your hot idle o/p issue is unresolvable unless you go to a dry sump imo.
Hot oil pressure at idle is an issue if it drops to the level I have seen which has been data logged, especially as the oil temperature was not excessive.
Steve
Correct, a poorly designed oil pump.
The low hot oil pressure has always been a problem, the people I have spoken to data logged everything, new crate engines, high and low milage engines all had the same problem.
No need to up the spring pressure on the PRV as it will be closed at that pressure unless there is a problem.
have you data logged your engine's oil pressure ?
Steve
clio cup race car
Can you tighten up the tolerance between the pump body and gears ? this will surely reduce the amount of pressure you're loosing , perhaps its worth looking to see what clearance is there on a standard pump , and if that clearance can be improved on.
What about running a thicker oil , I always run Castrol Edge 10/60 in my rally cars and I have never noticed the oil pressure low when its hot on tick over
I mentioned this earlier on but the reply was this doesn't work...
As you make the oil thinner you reduce the pressure by making it less resitant to flowing.
So if you increase the hot viscosity you can increase the pressure. You don't necessarily need a 60 weight oil, a 50 might do but you need to look at what the hot viscosity is.
Also an oil cooler will help, a decent sized one too.
Then to avoide surge issues a baffled sump should be all that's required.
If idle pressure is an issue then a slightly raised idle will help a little. Wouldn't be an issue on a race car.
Given that at 3 bar or whatever you are seeing that you consider low the spring will still be holding the release valve shut anyway, what do you hope to gain with a stronger spring?
The problem is a lack of flow through the pump means that on hot (hence thinner and leaking out of all the bearings etc more) oil it cant generate enough pressure even when the relief valve is shut, so changing the spring isnt going to effect that, if its shut, its shut!
If you want more pressure you need either more flow through the pump, or less haemorraging from the egnine, so either a better pump or a thicker oil, or tighter tolerances, not a stronger spring, that will just make you run far far too much pressure when cold and knacker all the seals.
The problem is a lack of flow through the pump means that on hot (hence thinner and leaking out of all the bearings etc more) oil it cant generate enough pressure even when the relief valve is shut, so changing the spring isnt going to effect that, if its shut, its shut!
If you want more pressure you need either more flow through the pump, or less haemorraging from the egnine, so either a better pump or a thicker oil, or tighter tolerances, not a stronger spring, that will just make you run far far too much pressure when cold and knacker all the seals.
clio cup race car
Are you saying the pump can't physically make more than 50 psi of pressure ? have you tested this , and tested shimming the spring to see what difference this makes , it works on all other cars so I fail to see why it wouldn't work on the 172 engine , it works on the Williams engine as you can buy an uprated spring ??.
I like the idea of running an oil cooler , but would you lose more oil pressure again as its got to got through the rad ?
Im saying that if it cant flow enough oil relative to the amount that the engine is losing then it cant make more pressure.
I have seen tests done but not on this specific engine.
Like I said, there is a point where the valve is shut, once that happens more spring pressure makes no difference.
So you might find a higher spring raises it slightly, but up the spring and nothing more happens, there is a VERY finite amount of increase available, once the valve is properly shut, thats it, no more increase from spring pressure is possible. And if you are as low as the 3 bar the OP is talking about, I would wager that valve is shut fully on the standard F4R spring anyway.
Not once the bypass is shut it doesnt, when you are no longer bleeding off oil anyway how can a harder spring help?
You lose pressure a little from pushing through the cooler but its generally not a lot, and if it drops oil temps you will gain pressure from it resulting in less hemorrhage, its a case of trial and error to get it right.
I dont know of anyone with issues with cold oil pressure on an F4R (it goes over 100psi IME if revved when cold) so getting the oil to be cooler is a good plan.
That is the exact problem with upping the spring pressure, the cold oil pressure will be off the dial.
As you said it is the poor tolerances with the oil pump which appears to be the problem, something I am trying to address with Porkie's engine.
Steve
clio cup race car
Well no if the pump can only make 50 psi then no shimming of the valve would change that , but i'm sure all car oil pumps are designed to run a lot more pressure than they actually do and just bleed the rest off via the valve , so I think shimming the spring will make a difference on all engines , but it will be trial and error getting the right amount on this one as no one offers one ready to go , I know too much oil is no good as is not enough.
If Fred has not already done it , i'll be shimming the pump spring , and might have to do it a few times to get it where I want it , and I will be fitting a baffle into the sump to help , I personally don't thing I'm getting surge issues the use my car see's as is will not generate the cornering forces a track day car see's.
Having said that , i'm also hoping to go dry sumped on the Sodemo engine which will do away with these issue , just got to worry about the dry sump pump belt coming off then lol
If Fred has not already done it , i'll be shimming the pump spring , and might have to do it a few times to get it where I want it , and I will be fitting a baffle into the sump to help , I personally don't thing I'm getting surge issues the use my car see's as is will not generate the cornering forces a track day car see's.
Having said that , i'm also hoping to go dry sumped on the Sodemo engine which will do away with these issue , just got to worry about the dry sump pump belt coming off then lol
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Then you just have to get it up to temp before driving it , which is what I do anyway
That is EXACTLY what they are designed to do, and they are designed to do so with oil that does not get excessively hot.
Let us know how you get on when you shim the pump, personally if you are getting oil pressure as low as the OP mentions (3 bar) then I think that the spring is already strong enough to hold the valve shut against that and hence a firmer spring wont effect hot pressures, but I would expect it to up the cold pressure.
To get decent data what we really need is a datalog with and without a shim on the spring for the same engine, dont suppose you fancy doing both? (bit of a ball ache taking the sump off and swapping it in and out I realise)
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I don't think they are designed to run exactly a certain amount of oil pressure , otherwise they wouldn't need a pressure relief valve , personally I think they will run more pressure , and is capped on the valve , we'll soon see
Something worth mentioning which many people overlook, is oil cooler hose size. IF you run cooler hoses of too small a bore, they cause a localised increase of pressure, which causes the PRV to open earlier than it should. The PRV sees a higher pressure than the rest of the engine is actually getting. 5/8th ID hose is the minimum you should run IMO
And even more important than the hose diameter is the type of bends used on the fittings, on Porkies old oil cooler setup that was fitted by jamsport it had bends on the lines that were not constant radius and hence nipped into a smaller diameter at the middle of the bend, so we replaced them with better ones that didnt do so.
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