Yet another 3B engine rebuild

[audiman]

And here are my old pistons, that have been 'altered'

[audiman]

And the re-conned turbo.....

[audiman]

And the modded pistons on the new rods

[91_S2]

And here are my old pistons, that have been 'altered'

GR8 pics of the before and after pistons. Be interesting to follow you enigne build and see what kind of CR you will get. It will also be interesting to see how your motor will run with the "squish" area removed from the pistons.

[audiman]

It will either run like a bag of rubbish or fine? We will see in the next few weeks. Cant wait to get to it running again

[Pisobiker]

It will either run like a bag of rubbish or fine? We will see in the next few weeks. Cant wait to get to it running again

They look good Tom.

I personally don't think they will run bad. Eventual drawback, if OEM piston was really supposed to use squish effect in any manner, would be not being able to run as much boost as the std design (with same CR) before knock occurs. But this might be a very small difference.

If we really would point out any possible difference, there also is the reduction in height between crown and first ring, which, in very heavy working conditions, might let it work at slightly higher temperatures.

All this is of course purely academical. Differences, as said, might be very negligeble, while saving some significant money for high performance aftermarket pistons.


Marco

[Beetie]

You can tell that they havent took too much off the pistons, (as such) as you can still see the arrow for thrust..

[audiman]

I drew that!!!!

[S2central.net]

Tom - getting excited for you now... looking like a mighty engine spec that should be more than capable of exceeding a reliable 400bhp and I'd guess 600Nm. I'd say your 3B manifold and original MAF will be the limiting factor now, but it should be fun chewing through clutches, gearboxes, somerset hedgerows and small animals with this setup in the meantime

Were you a good boy - weighing everything and buretting the chambers and bores to calculate CR properly (so that we have hard facts for the future) or are you just going on blind faith that everything is OK ?

Start thinking about how you are going to run this baby in. If it was me I would disconnect the WGFV and reduce boost to dull levels of 0.6bar so that you can give it some stick in order to bed in the new rings properly. PS - don't firkin forget to measure the ring gaps on assembly... and double check the thread cleanliness and torque settings on all the critical bolts. Sorry for preaching to the choir, but when all the parts arrive its very tempting to just build it all and throw it back in the engine bay. Do one or more dry builds first and check the crank runs nicely. You know the score !


Paul

[S2central.net]

Here are some pictures for you lot

Std piston(has been cut in half hence the line)

Tom - got any side profile pics - I'd like to know the wall thickness.


Paul

[porkkis]

One vote for duble checking from here too! I took my oil pan off after buidling the engine when I was in doubt if I double checked all the nuts. Well - one big end was not properly tigtened!

[audiman]

I havent buretted them yet. But all the pistons weigh the same now I will remove the cable tie that is holding that cut piston together and take a piccy.

[audiman]

This arrived today, but it has a dent in the top of it Not sure what is gonna happen about it yet.

Took 2 days to come from Hong Kong. Quicker than UK post

[audiman]

this is a close up of the damage. Luckily Dougs is OK

[jubjub]

Took 2 days to come from Hong Kong. Quicker than UK post

......and 2 weeks if you send it back