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Duratec - front crankshaft leaking
black.viper - 16/8/21 at 09:43 AM

Hi all,

I rebuilt std Duratec 2.0HE with 282° camshaft - using R500 Caterham pistons and rods. Max rpm 8000-8500.

The std oil pump was a change to PR7167 (Burton) Pump volume oil pump for Duratec HE - Does anybody know what is difference about pressure and oil capacity - compare with the original oil pump?

I have been three times changing the front crankshaft oil seal, but it is always leaking. Now I have a suspicion of too high oil pressure. Because I am using a high-volume oil pump and when is oil hot (100 °C) the reading is around 3 bars/1000 rpm and 7 bars/8000 rpm.

Is somebody using this kind of pump in Duratec?

Thank you very much for any feedback.

Best regards,

Petr


theconrodkid - 16/8/21 at 10:29 AM

that pressure is far too high, pressure reliefe valve stuck by the sounds of it


black.viper - 16/8/21 at 01:57 PM

We changed the oil pump because the original was about under 1 bar/1000 rpm and 3-4 bars around 7000 rpm. But I don´t have a clue what readings are acceptable for this one - I tried to ask Burton, but they don't know.


theconrodkid - 16/8/21 at 02:17 PM

have you tried asking Ford ?, they would have the blow off pressure, i got rid of my data books when i left the motor trade.
from memory, 1-1.5 bar at idle and 4 bar max sounds about right, no need to have mega pressure as it can cause leaks and pump / filter damage, you got the right oil ?.


Sanzomat - 16/8/21 at 02:25 PM

7 bar at 8k rpm does sound a bit high but not crazy excessive. 7 bar is 101psi in old money. IIRC my pressure relief valve came set at 95psi by default.

However, isn't the crank seal just holding back gravity/crankcase pressure, not the full pressure of the pumped system? I always thought the oil pumped to the main and big end bearings "leaks" out of the journals (rate dependant on how worn the bearing are) and drips back into the sump and the crank seals don't hold back the pump pressure but maybe I'm wrong.

If you are getting a lot of oil leaking from the cranks seal then either 1) the seal is shot or 2) the cranks surface where the seal rubs is rough or 3) the seal and crank aren't matched for size or 4) there is excessive crankcase pressure due to either restricted breather or too much blow by


snapper - 16/8/21 at 08:14 PM

The design of the front cover is such that the seal is not under pressure, it’s likely to be when the seal was fitted or a sharp edge that’s nicking the seal. The seals come with a fitting sleeve and specific instructions so check them.
What breather system have you got? If you’ve blanked the block you may have more crank case pressure or you still have the crank case pressure valve still on and that connected to a catch tank where there is no vacuum to open the valve.


black.viper - 16/8/21 at 08:28 PM

Thank you, it is a good idea... I am using the original Duratec crankcase pressure valve with a catch tank - but when I switch this engine with my spare original Duratec without tune.... there is no problem with a briefing or front oil seal... only on this where were change oil pump for more powerful. But I will try to check the oil catch system. Thank you very much for that idea.

quote:
Originally posted by snapper
The design of the front cover is such that the seal is not under pressure, it’s likely to be when the seal was fitted or a sharp edge that’s nicking the seal. The seals come with a fitting sleeve and specific instructions so check them.
What breather system have you got? If you’ve blanked the block you may have more crank case pressure or you still have the crank case pressure valve still on and that connected to a catch tank where there is no vacuum to open the valve.


black.viper - 16/8/21 at 08:33 PM

Firstly I only changed the front oil seal for the original... still leaking. The next time I tried to solve the problem, the seal was sealed from outside, everything was cleared one more... very carefully and the seal was changed exactly for the measurement of crank.... but the leaking was horrible:-(

quote:
Originally posted by Sanzomat
7 bar at 8k rpm does sound a bit high but not crazy excessive. 7 bar is 101psi in old money. IIRC my pressure relief valve came set at 95psi by default.

However, isn't the crank seal just holding back gravity/crankcase pressure, not the full pressure of the pumped system? I always thought the oil pumped to the main and big end bearings "leaks" out of the journals (rate dependant on how worn the bearing are) and drips back into the sump and the crank seals don't hold back the pump pressure but maybe I'm wrong.

If you are getting a lot of oil leaking from the cranks seal then either 1) the seal is shot or 2) the cranks surface where the seal rubs is rough or 3) the seal and crank aren't matched for size or 4) there is excessive crankcase pressure due to either restricted breather or too much blow by


black.viper - 17/8/21 at 11:37 AM

I found some dates from Raceline 2.0 Duratec

Oil temp 100 - 110 max 84 °C
Oil Pressure 70-80psi (2500 rpm) 65 psi
Coolant Temp 90 degrees max 80 °C

and from Lotus 7 club Lotus

(2.3l duratec csr) is when hot; 2 bar idle and 6 bar at 4k revs. 1 bar~15psi 5w-50 caterham oil


It looks like that problem wouldn´t be the oil pressure but with the breathing of the engine :-(


snapper - 18/8/21 at 07:07 AM

quote:
Originally posted by black.viper
Thank you, it is a good idea... I am using the original Duratec crankcase pressure valve with a catch tank - but when I switch this engine with my spare original Duratec without tune.... there is no problem with a briefing or front oil seal... only on this where were change oil pump for more powerful. But I will try to check the oil catch system. Thank you very much for that idea.

quote:
Originally posted by snapper
The design of the front cover is such that the seal is not under pressure, it’s likely to be when the seal was fitted or a sharp edge that’s nicking the seal. The seals come with a fitting sleeve and specific instructions so check them.
What breather system have you got? If you’ve blanked the block you may have more crank case pressure or you still have the crank case pressure valve still on and that connected to a catch tank where there is no vacuum to open the valve.



There is your problem (I think) the PCR valve needs vacuum to open it, if it connected to a catch tank there is no vacuum, I gutted the valve and have also removed one and replaced with a fitting for a larger diameter hose