Updated Oil Pump Spring

[Mart Pug 0]

Cant see any previous topics in the search on uprated oil springs.

 

There's a few on eBay at the moment, just wondering if anyone runs a track day car with one?

 

They appear to increase the oil pressure.. What would be the benefit of that?

 

Thanks

[JRL 14 1 Cars]

welshpug will tell you that they are a couple of quid from peugeot main dealer and the ebay ones are the same but marketed as grp A or uprated apparently they are just a 306 gti6 spring hopefuly someone can confirm this.

I have one on my mi16 and it does keep the pressure up higher which is more reasuring. on an 8v surge is not such a problem.

[Atari Boy 11]

As above, available from a main dealer.

I fitted one to my 8v, there is a noticeable difference on the pressure gauge.

[Mart Pug 0]

So more pressure means less surge risk? Or some other benefit? Sorry if that's a daft question!

[welshpug 1,662]

no, a dry sump means less surge risk.

[Henry Yorke 269 3 Cars]

It is a good question. Obviously no oil getting to a part is a problem, but as long as it is there, how does the pressure it is at make a difference? I had one to fit to my turbo whilst the sump was off but was advised by Turbo Technics not to do it as you increase the chances of blowing the turbo seals. Low pressure can apparently also mean it is flowing faster and potentially better cooling properties. I never have a problem with oil temp on mine and don't even run an oil cooler and just a finned alloy sump. Can anyone confirm the logic?

[unariciflocos 49 1 Cars]

It's not that simple. From what I know you need pressure in the crank oil ways to keep metals from touching. Oil is injected at high pressure between bearings and crank to form a film of oil and keep the bearing from ever touching the crank. If that pressure should drop and stress between the rod and crank increase, that film will get thinner or even disappear.

 

A higher pressure does mean more stress on the seals so I;m not arguing that they may give up faster. Also higher pressure means a higher temperature. Same principle as in diesel engines, but I don't think 1 bar will make that much of a difference in temperature.

 

Pressure does decrease if there are less restrictions and flow is increased, but in the engine the conditions are the same, flow will stay roughly the same as the oil ways don't change size.

 

Just my thoughts from what I can remember from school physics, may be wrong though.

[welshpug 1,662]

I disaggree that the higher pressure will affect the seals, I can't think of any instances in an XU engine where pressurised oil is against a seal?

[JRL 14 1 Cars]

So more pressure means less surge risk? Or some other benefit? Sorry if that's a daft question!

Mart pug to keep it simple:personally if you are taking off your sump/ fitting a new oil pump etc i would put one in and see a bit more pressure on your gauge I did this when i took the sump off to fit a baffle but I wouldnt have bothered if i wasnt doing this job.

[Mart Pug 0]

Mart pug to keep it simple:personally if you are taking off your sump/ fitting a new oil pump etc i would put one in and see a bit more pressure on your gauge I did this when i took the sump off to fit a baffle but I wouldnt have bothered if i wasnt doing this job.

 

Thanks for all the replies guys. Very helpful, as usual!

 

JRL: yes mate, I was planning to fit a baffle, so will follow your advice and stick an uprated spring in the pump whilst it's off.

 

Mart

[Henry Yorke 269 3 Cars]

I disaggree that the higher pressure will affect the seals, I can't think of any instances in an XU engine where pressurised oil is against a seal?

Turbo seals. You need a decent drain or to restrict the flow or both.

[pug_ham 244 3 Cars]

As above, they are under £3 from Peugeot so don't belive (or pay) the ebay hyped prices.

 

I'm tempted to try some testing on these uprated springs" because I bought one during my rebuiild & found (like Tom Fenton did iirc) the spring was the same length etc as the spring I removed (even had the same paint stripes on) but compared to the original PTS spring that's in the pump in my old engine there is about an inch differnce in length iirc.

 

The later XU engines have different sized oil pump crank pinions so they spin at a different speed making the difference in pressure more apparant.

 

Graham.