Blue smoke take two...help

[paulanthony]

Any advice re this puzzle;
Previously smokeless 1098 moggie has a head gasket problem - forces out oil - son drives car ... no oil or very little. Head gasket replaced, valves lapped in. original small circular valve gide oil seals impossible to fit because they were too small and inflexible, so shroud type ones used instead. No discernable bore wear at all - was on a rebore - had 2 stamped on block beside pistons. Car then had compression of 145psi per cylinder without oil in the bores but...
On starting = blue smoke
On any acceleration at all will put out blue smoke esp 2 and 3 gears- OK on overrun and just pootling along.
Is this a ring problem or a valve guide problem?
Would anyone lend me a 1098 head just to test out which it is?
Any advice welcomed

[bmcecosse]

Well - hard to see how 'head gasket' problem forced out th oil - but if the car was driven without oil(!!!) then it's safe to assume the crank bearings and the piston rings will have suffered. Although you have 145 psi compression - which is 'ok ish' - the oil rings on the pistons may be damaged. You have fitted the later oil seals to the guides - so it's not going to be that! Better pop the head - and pull the pistons for inspection of big-ends and rings.

[PSL184]

I'm going to stick my neck out and say big ends worn. What oil pressure have you got - a wet line gauge is the most useful accessory you can fit to your car.... 145 is not perfect. I would be expecting to so 160+ on a healthy engine....

[MarkyB]

When you say "forces out oil " where from?
I don't think the 2 denotes a rebore especially if the 2 was in a diamond shape.
I the thing that alerted your son was that the pressure light came on it's time to strip the whole thing down and see how bad it is

[eastona]

sounds like rings. a 2 in a diamond isn't an overbore.

How did you measure bore wear? An internal micrometer or fealer gauge and rings?

theoretically it could be valve stem oil seals, but I doubt it after a rebuild like that.

When you say forcing oil out, is it of the breathers/oil cap? if so, it's the rings because you're getting blow by which is pressurising the crank case. Pop the oil cap off while it's running. You should be able to tell if there's loads of pressure in there.

Andrew