Uprated pistons

Hi guys have question not really that good when it comes engine internals, I have seen some second cp pistons on eBay
Iteam number: 251382136579
Am sure some of you will be watching them or bidding on them what I would like to no is are the a straight swap over what I mean by this is my engine has standard pistons which I believe are 86mm I asked the guy on eBay what size his were and he said 86mm so will these go straight into mine or do I need some sort of spec sheet incase the bores might want adjusting or something

Thanks guys

I'm having a set of 86mm CP pistons going in my engine mate, It will just need honing to suit.



Rob

As the pistons are second hand you should really be getting a new set of rings as well.

Also if using the arp bottom end bolts you should really get the line bore checked.

It says in the advert the pistons have only done around 2200 miles from new would you still say they the piston rings need replacing

What do you mean by get the line bore checked sorry for the noob question

No doubt about it... Never use second hand rings, common sence

Yes,the rings and bores need to bed in together really.

I am not saying it cant be done but imo it will never bed in correctly or be as good the second time around, especially in a completely different bore/engine.

Scooby_killer wrote:It says in the advert the pistons have only done around 2200 miles from new would you still say they the piston rings need replacing

What do you mean by get the line bore checked sorry for the noob question

I'd never fit second hand rings mate they would of bedded in to the old engine you need new rings the pistons should be fine though, If you're fitting ARP main studs you should really have the bottom end line bored or at least checked to make sure their is no binding issues with the crank.

If you where on about ARP rod bolts that's a different matter.

As above really,using different studs/bolt with more than likely higher clamping loads than the stock bolts can I think pull the mains out of round or out of line with each other where everything distorts differently.

Thanks for the info guys would I need to buy standard pulsar piston rings or do I have to buy percific cp piston rings or would any aftermarket ones do as long as the are for standard size pistons

you will also need your cylinders checked for ovality with a dial bore gauge to make sure they are within spec
if you fit new rings and cylinders are ovalled (which they will be to some degree) then they wont provide a good seal and youll be wasting your time and money.

if you do buy them and your cylinders are out of spec then I have good blocks which are within spec for cylinder runout which we have checked so not the end of the world as there not that expensive.

hks are extremely good pistons so if there all ok I would snap them up if I were you.
but don't forget as rob said above cp are also extremely good and you can buy a brand new set for around £400 with rings and everything so really need to take this into account when buying secondhand