Piston help

[mike 850]

I am needing to change the rings on my 850 t5, I heard some rings aren't available depending on what Pistons I may have, question is are there better standard t5 pistons available eg v70 ones? That rings are available for?

[mike 850]

Anyone with piston experience?

[t5 pete]

For the 850 block your best bet will be to get the mayle oversized pistons and rings to match these are more than good enough for decent power.

[mike 850]

Thanks Pete. Do you know where I get these from?

[t5 pete]

I believe volvo still sell them but when I did mine the machine shop got them and they were better priced than volvo aswell

[mike 850]

Awesome, in the middle of pulling the block out so when I take it to the engineer I'll see what he says, thanks for your help. Out of curiosity are you running higher power? I'm looking at about 400bhp so don't want inferior pistons if they can't cope, did you manage to get good quality ones? Cheers

[t5 pete]

They will be good for 400 I'm currently running some where between 300 and 350.
Other options is wiseco forged pistons but the general rule of thumb is the standard pistons are pretty good

[Sweep]

I was going to say, I thought the stock stuff is more than capable at that power, it's the rods that struggle.

[mike 850]

I was going to say, I thought the stock stuff is more than capable at that power, it's the rods that struggle.

I have forged rods, it's not to handle but I have low compression so need to sort the rings out, if I need oversized or if I have to change the pistons due to rings not being available I might go forged as it probably isn't going to cost much more, I need to see how worn the block is first.

[t5 pete]

The mayle pistons runs about 100 each with pins and rings

[mike 850]

The oversize ones? Forged ones look about £550 plus postage from states, emailed a couple of places to get a price, customs on top, not really sure which way to go yet, guess I need to wait and see what wear there is first

[t5 pete]

Yes that's for over size search on part box they wil have wiseco and uk supplier so no charges

[t5 pete]

Wiseco
http://www.part-box.com/product_info.php?products_id=18706

[mike 850]

https://re-volvparts.com/store/home/64-wiseco-forged-pistons-for-850-s70-v70-c70-set-of-5-ke155m81.html

That converts roughly to 560, no idea on postage and customs, probably wait a month for not much saving I think? I think I'll stick to the mahle ones, do you know where you get them for 100 each? From Volvo?

[t5 pete]

Y machine shop sourced them ask the guys who's doing your re bore to get a price on pistons and shells also take your crank in to match shells

[mike 850]

The rods were fitted last year, that side is ok I was stupid and didn't do a compression test done or check that out so its my fault, rods, crank etc are all good.

[t5 pete]

Ah that's good news then just a case of a re bore and a new set of pistons I would imagine

[mike 850]

Yeah, fingers crossed :)

[oblark]

I'm running 22 psi at 353 bhp on stock internals.

30046

http://i1067.photobucket.com/albums/u433/oblark/volvo%20850%20t5/M4%204%20flashing/20150905_162554.jpg (http://s1067.photobucket.com/user/oblark/media/volvo%20850%20t5/M4%204%20flashing/20150905_162554.jpg.html)

[mike 850]

I bent rods at about 320bhp, are you not running me7 or was that just the top half?