16V Lysholm

If the there is sufficient resistance to airflow on the engine side and the charger is spun at the charger speed that matches it's mapped characteristic then yes 21 psi is possible in theory.
This would differ in your engine as it may have areas where pumping efficiency actually starts to catch up with the air supplied charger and reduce manifold boost ( resistance to airflow).

Yes please keep us posted on your developments.

 

Well I have just done a leak down test on my engine.
All 4 cylinders showed just under 20% cold and hot - which was not really a surprise as very little is blown out of the breather. So it looks like the rings and valves are sealing well, so where is the oil going ?

Could it just be that my oil scraper rings are not fitted properly ?

So to recap:
(1) The engine does not smoke either on startup or running, so that pretty much rules out valve stem oil seals.
(2) There is not much leakage around the valves or rings, about 20%.
(3) Boost is lower than expected, 10psi instead of 17psi. It is a man in the shed ported head and a 1.9l overbore with 83mm pistons that have 0.006" of clearance. I did read that a ported head may show less boost, and kind of fits in with Toyotecs last post.
(4) It is polishing off 1 litre of oil every 250 miles :-(
(5) There is no oil leakage anywhere else.
(6) The breather does not fill with oil.
(7) The plugs are a good colour.
(8) It runs and pulls really well with no flat spots at all.
(9) The exhaust pipe is sooty, hence the oil must be going on the combustion stroke and being burnt with the petrol.

Any further ideas from experience ?

 

So I have been looking around the net and it appears 20% is way too high.
The test kit said up to 20% is ok, but I am beginning to doubt this !!
At 20% the leaked air was coming out the breather, so that is past the rings.

I am beginning to think that the overbore to 83mm was not a good one...
Winter strip down to sort that one out.

 

Did you do a hot compression test? Post up numbers if you can. Also put some oil down to see if it improves.

 

No I couldn't find my tester today - I have put it away safely or leant it out and forgotten who to !!

Will hopefully find it in the week and get some numbers up. Not expecting to see them low with how the power is delivered though.

 

I know diddly squat about superchargers. Is your type of charger lubricated by the engine oil system? If so then it could be the cause of the oil consumption.
VWs do run a reasonably high oil pressure which may cause issues with charger seals.

If the piston rings were not sealing correctly then the engine would be breathing heavily.

 

Yes the Lysholm is lubricated from and engine oil feed. It is the same feed that fed the G60 charger.
If the charger oil seals had gone then the oil would have to go somewhere, there is no leakage or oil in the boost pipes. The charger was brand new and has only covered about 1000 miles so I would be very disappointed if the seals had gone !!

Thanks for your thought though mate.

As a side issue, are we always going to have to login every time we access the site now - it is driving me nuts !!