causes more "blow by" pressurizing the cases and blows oil into the carb.

This needs a little more explanation for my simple mind... Could you please elaborate a bit more?

Theres not much to explain. An advanced engine has excess pressure in the chamber so more gas leaks past the rings than normal. This can carry oil through the breather to the induction or cause leaks from the seals.

I would love to here Ken's opinion about this, in my mind this is rubbish sorry.. Offcourse if your oilrings are gone already then you would have a slightly chance but not on a good engine...

Isn't it all about the MBT?
( Maximum Brake Torque (MBT) is defined as the smallest amount of ignition advance that
achieves 99 % of the maximum power. )

http://download-v2.springer.com/static/ ... b0d6e956df

Fig.2 on page 3 and Fig.3 on page 4.
Notice the increase in peak cylinder pressure without an equivalent increase in torque and bhp when the ignition timing was advanced beyond the optimum of 31* BTDC...

yeah probably is

Broken link Ken.

Sean,
This may be another link that gets to the place directed above?
http://link.springer.com/content/pdf/10.1007%2Fs12544-013-0099-8.pdf

So I took the engine apart and had a go at replacing the oil stem seals on the O/S of the engine. It turned out to be a little more tricky then I first anticipated as the stem seals that I had appeared to be all the same size. Also the exhaust guide was a pig to fit and as soon as you pushed the valve back in, was pushed off. The exhaust guide also appeared ever so slightly oval compared to the inlet valve - normal!?

Anyway glossing over that - and the slight oil leak from the push rod seals and cylinder head oil feed tube which meant taking off the head again to rectify - it has made... no difference. It still consumes oil by the bottle, it's noisy, thirsty and the drivers side mirror - a part that is, as far as I can tell, completely independent of the engine, now folds itself in when you go above 40mph. I don't know whether its trying to slipstream itself Herbie style to try and take a bit of strain off its crap engine but only set to annoy me further particularly as if I tighten the screws up anymore they'll likely snap. But anyway by the by.

I've decided to use a little bit of intelligence before I strip the car down again so I've taken advice and bought a compression tester. When I took the top end of the O/S apart, I looked down the cylinder and apart from a oily looking piston, the barrel looked as new, with no scoring and its honing marks.



O/S



N/S

I think the ideal for a 9.0:1 is about 175 psi this is obviously under that and just above the red so pretty appalling...

you cant usually see worn barrels - i give any barrel a quick spin with a hone, it soon higlights the worn parts which remain shiny and the good bits are a mat grey

warm engine wide open throttle? if so thats a pretty terminal reading

as for valve seals yes they do kook the same the trick is to have a loose inlet valve - the seal that slips over the inlet in an easy fashion is the exhaust seal

I've taken the engine to bits as far back as I did originally and taken pictures... I don't know whether this makes things any clearer.

The O/S rocker



N/S which looked like it had a tiny bit more oil in it.




O/S










The rings haven't rotated round...



I then rotated the rings round.



Ditto with N/S...









So that's where I've left it. I don't really know what to do next! confused:

I can only assume that the problem is only with the rings or the heads. The barrels, pistons and rings were part of this set. http://www.ecas2cvparts.co.uk/barrel-piston-barrels-pistons-rings-gudgeon-pins-circlips-good-quality-p-511.html