SR2 Crank Case pressure

[BODs SR2]

My SR2 started to blow oil from the D rings between the Head and the opening for the rods/ fuel pipes etc. I disassembled and reassembled the head making sure the seals were in good order and clamped everything back down accordingly. Starting is good. A small oil patch is still weeping out in the same area on both head joints. Talking to the helpful chap from Lister spares.co.uk he said it might be pressure in the crank case caused by warn piston rings. When I take one of the caps off that expose the decompression arm I can feel air blowing out. Do any of you gurus have a take on this. Cheers.

[Morris ute]

Hi, we have just had a similar problem on our LPWS4, in our case the dipstick was being blown out. The breathers in the rocker covers were blocked. 
Trevor. 

[Peugeot 106]

The Lister Petter LPW/LPWS Alpha workshop manual shows you how to do a Crankcase Vacuum test on the engines.

 

“In engines in good condition the vacuum increases eases slightly with engine speed but not proportionally. A fluctuating vacuum may indicate faulty oils seals, valves or piston blow-by troubles”.

 

It is very simple to carry out the test with a length of clear tube and vacuum figures for an engine in good condition are included. For the Alpha LPW/LPWS engines running above 1800rpm minimum vacuum is 20 Average 35 mm WG

 

I don’t know if this test is included in the SR2 manual along with the figures. It could tell you something

 

Hope this is of some help. I think that most engineers just test the vacuum by holding their finger over the dipstick tube! Not being experienced and having the manual I just followed it for reassurance 

[john.k]

Blowby from worn rings will be lots of  smoke coming out of an open oil filler cap on the rocker covers...........however.....worn rings and easy starting dont go together....if the motor has "bouncy "compression,I would doubt worn rings.

[john.k]

I would also add ,every Lister LR or SR I have ever fitted/.sold has had complaints of oil leaks around the pushrod /injector pump housing on the side of the motor.....Its just the way they are......they are like GMs ....if the oil leaks stop,you re run out of oil.

[john.k]

I once rebuilt a 6cyl Caterpillar,and it was so oiltight ,the outside of the motor went rusty......and the owner came back and complained about that.;

[Peugeot 106]

When I pulled my Narrowboat out of a barn after a rebuild  the Fordson tractor I used blew the dipstick out and oil poured out all over the yard. The owner said carry on just keep topping the oil up and he would fit new rings sometime. We had an awful job cleaning up the concrete but got the boat out and onto the lorry........

[BODs SR2]

Hi thanks to everyone for replying. 
 

I’ve checked the breathers I think one may have been blocked however both clear now. No smoke coming out internally. Waiting for new cover gaskets to arrive then I’ll check the pressure from the dipstick outlet. I like the comment that no leak means run out of oil. Maybe I’ll use a drip tray and every now and then just pour it back in!

 

Let you know. Cheers.