I have experimented an intrestin feature.
If I run the engine with very low oil level (5-6mms below min), the smoke gets better. I still have oil pressure, and the head get oil at this level.



Liner-ring incompatibility?...

A drastic step I know but it's beginning to look like the solution may be another engine block.

Just a thought, I know you said you filled it up with the correct amount of oil ... but ...

The A series has a dipstick guide tube in the block, the A+ doesn't.
Although I've never compared them I presume therefore that the A+ dipstick is shorter (from the sealing ring to the bottom end) ?
What I'm suggesting is that if you've put an A+ dipstick in an A block it may sit a lot higher - leading you to grossly overfill the sump ??

Unfortunatly I have conrolled all oil fillups. Approx 4.5-4.8 litres I used each time. Now I have only got 3-3.5 litres in the engine. Which is definiatly abnormal.

BUT! After many hour of running the smoke has got a bit better. I will give the engine a final chance and take it out on the road. Maybe.

If this will not help, I think the only solution would be another engine... unfortunatly. This would be a financial crach.

Thankfully this is not the GTM engine as it costed even more .

Final question:

Is the direction of the AE pistons important? Now the script is facing back.

Nobody knows if the piston is simethric or not?

Yes Pistons Generally Do have an offset and a particular way round. I am Unsure if this applies to the A-series As never built one from scratch.

You need to find out if your pistons do have a particular way round.

Neil

I still not fixed my engine . Although I am after 9 engine "rebuilds" on the same unit.
Now I decided to get some new pistons made by a specialist. Well see.
If it does not work, I will get a new engine and start again.



Still if You have any idea...

Finaly it looks like I could solve my problem.

Thanks for Your help!

You're going to have to be a bit more detailed than that!!!!!!!!!!!!!!!!!!!!!!!!!!! Come on, out with it

To be fully honest, i have not found the exact problem . After many-many hours thinking and trying (I did 15 rebuilds ), I have bought a new block, sent it to a new machinst (who was also unable to do an accurate work ), but this engine is working.

For detailes, feel free to wisit pistonheads here:
http://pistonheads.com/gassing/topic.as ... 0my%20work

I hav made a "public" assembly, and have goz many ideas. I think this is a usefull topic. But no real "solution" yet...

Just recived this message from Pumaracing on pistonheads:

"Well done that man. It's nice to finally achieve a result.

If I understand you correctly this engine that is running fine is back on the EVO pistons that machinist number 1 said were the cause of the problem because the oil ring grooves were not perfectly machined which I refuted and said was not the cause of the problem.

We now therefore apparently have proof that it was indeed the boring and honing at fault as I said from the start and not the pistons, valve guides or any other part of the engine other than the problem in one engine was made worse by the overly high oil pressure.

This has been an excellent learning experience, not just for yourself but hopefully for many others reading the two threads over the months and it goes to show just how important correct boring and honing can be and why I have devoted so much time over the years to trying to perfect it with my own equipment.

I have stated in the past on many occasions that engines are fairly tolerant of nearly all faults including bearing clearances, piston clearances and ring gaps and spending time "blueprinting" these things is nearly always pointless. The only thing you can do to really upset an engine is get the boring and honing wrong and I think your case makes this point very well."

This is the most we can tell.

SOMETHING is not right with the boring/honing. What? I donno...

very expensive learning curve but congratlations all the same

Well done!
At least you can now tell your grandchildren that you can build a A series in your sleep!

Alex

Thanks all!

Unbelivable is, that by pure measurements, this last block is the worst (0.06 piston-bore gap in 3 cylinders, and 0.08 in the fourth, where even the boring marks are visible). i had to shim the trust bearing with 0.4mms(!) and polish one crank journal by hand as it was tight .

The other two blocks were better by measurements, but something was not right in the boring/honing. Nobody knows yet what...