I have pulled out my Rover 3.9 engine as the crankcase pressure was getting rather high. Every thing looked OK bores, slight blow by on a couple of head gasket joins. I bought all new bearings and piston rings and gasket sets. Started putting every thing back together and came to removing old piston rings on No 1 piston and low and behold a chunk of piston between second and oil ring came away (about a third of the way round).
So has any body got a decent set of standard bore low compression pistons for a rover kicking about? I cannot afford to by a new set but will be willing to pay for a decent S/H set.
Perlease help if you can thanks David

Whilst the pistons are out, check the bores are not oval by 5 thou or more. If it is then you will be throwing more money at it later.

They tend to wear oval further down the bore where the most thrust is on the sidewall of the bore.
It may be easier and cheaper in the long run to fix now if its a problem.

I got mine rebored and supplied my own pistons as the rebore company wanted £89 per piston.
Got a full set with rings from v8tuner.com for £170.
No connection with V8tuner except as a satisfied customer.

Just my 2d's worth.

When I rebuilt mine I found that high compression pistons were a lot cheaper for some strange reason - worth investigating?

Curious to know how you knew the crankcase pressure was high? Was it blowing oil out through the seals or something. Sadly for you I have a set of 3.5 V8 Pistons going but there no use to you.

I also second V8tuner, Paul is seems very knowledgeable and is always chatty. His prices are good as well.

If you've got it out it might be a good idea to get it keenly measured for wear and tear.

Thanks for all the suggetsions, the bores are like new can still see the hone marks, so no ovality (not the night time drink), and I need low compression because of the turbo's.
David

I knew the crankcase pressure was high due to advertising (clouds of oily smoke coming out of the breathers, ive got two), I thought it might have been the head gaskets as there was signs of sepage (carbon) from two bores. But as I put in my original, post it wasnt until I took the rings off that the problem surfaced.
David

Had you got the top end breathers done properly, as plumbing them up wrong can give this problem as well.

Still with a broken piston its the probable cause.

As to paul at V8 Tuner, he talked me OUT of spending £200 with him, as I didnt really need it.
Top bloke.

Cheers

Just thought I would post a couple of pictures of my dilemma



Unusual fracture I think, still lucky the whole top did not break free.
David