Stiff pistons! not sure what i've done wrong.
Turbo Mini Forums

WHAT?

You oil rings... they are design to run with oil!

That document you have quoted advises using an assemblty lubricant!

By the same toke you would not lube a new cam so that the followers bed in quickly!!!!!

Alex

AlexF

and more...

oil is what seals the bore... there should be no metal to metal contact. That is why you hone - the pattern is ciritical as it holds oil in place on the bore.

WD40 is more solvant than lubricant :(

AlexF

I'm in Grays right near the dartford crossing.

Also in my first attempts at getting them in i managed to break a few of the rings. (Hadn't quite got the hang of using the compressor.). Anyways can someone point my in the direction of a good set of piston rings for a standard size metro turbo piston. The ons i have are the AE ones from minispares. Just wondering if theres a better set than the ones i'm trying to use.

WWW.TURBO-MINI.COM

WD40 - Totalseals words, Not mine. In absence of their dry film Assembly lubricant. They make the rings so i trust them.

Also note the Haynes book does not mention oiling rings.

But then im a pure amature self taught who knows nowt

run your rings how you wish

is there a difference between n/a rings and turbo rings? if so have you got the right ones?

also when checking the the ring end gap in the bore put the ring in the bore and use an upside down piston to push the ring into the bore so the ring goes in straight, if you just push it in by hand it can be crookedd(sp?) and you may not get the correct reading. also check the ring gap at the top, middle and bottom of the bore.

oh and rings need to be oild when fitting them.

no longer a series, but still 1.3 turbo.

Yeah these were rings for a metro turbo. Anyway after that stressfull situation i decided to leave the block alone for the moment and concentrate on putting my gearbox back together. This is the only job that scared me but when i got into it everything went together nice and easily. Feeling a lot better today now that something went together right. lol! Only issue was one of the gears i got to calibrate the speedo was a bit big for the speedo housing. Other than that was all good.

With the block now i'm strongly leaning towards forking out for some forged pistons with a larger dish and taking the block down my local machine shop to be bored and honed properly.

just dish the ones youve got and try again :)

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Have also just read "my first turbo's" thread bout there being two different turbo pistons and hence two different types of ring. Could be my problem!

i think its just the hone but then what do i know

Remove the pistons and check that you can 'pull' the rings to one side of the groove - and that they are not proud of the piston. Basically - make sure the diameter of the groove in the piston isn't too large - or the internal diameter of the ring too small.

That is a pretty easy check - but it needs to be done on all the rings.

Do you have your original piston rings as a reference?

Incidentally - the rods are the last things that go in an engine I build - in that I put the crank alone in the block, and slowly nip down on the mains - using plastigauge if neccesary.

Once all is good - Remove the crank and put each rod onto the crank and check that - again - plastigauge as required.

I THEN drop each piston into the block in turn - and after stroking it up and down the bore a few times; I use a fishing scale to measure and compare all four bores...

All the above - and everything before and after - is why it takes me many hours to build my own engines. I know it's way more than many builders will even put into a miglia engine, but it's just the way I do things....

I advise the original poster to purchase a few books on engine building / blueprinting... OR to learn from a trusted individual who has built many accredited engines. They don't have to be A-series engines - lessons learnt in blue-printing apply accross the board...

:)