Thoughts on Rods and Pistons

[momento1]

Obviously we are spoilt for choice with rods and pistons..

its all about how much someone is willing to spend.
Currently i am booked for a standalone ecu install and tune for E85 ethanol blend fuel.
Now i am only running a GT3071 turbo but will eventually for a 3076 or even a 35 tubro in the future.
For now i am tuning for the 3071.
Now im going to need to do rods and bearings and studs pretty soon. Im not sure if i need to do pistons though

Which brings me to me question:
Im considering using FCP x beam rods but i dont know if i really need to do the pistons at the moment.
What power levels are the stock pistons capable of?
If im doing rods i may as well refresh piston rings? if so should i just do the pistons at the same time?

If i do the pistons what should i go for? Stock compression? FCP offer pistons at 8.5;1

Thoughts?

[Quattronaut]

IMHO stock pistons are within the best. They are good for at least 500hp. If you got them out, measure them, and if they are not worn due to 300 000km, they should be fine. I would change rings and rods. You can machine the stock pistons for lower CR, when going over 400hp; or use a thicker head sealing. Piston change I only would do, when I go really over 500hp. Or, that is clear, when you bore the block.

[vti2]

You can put 1000hp on stock pistons without problems.

[Thuppu]

Higher CR stock pistons is better than low 8.5:1 CR aftermarket pistons when you run e85 at low power tagets. I run stock pistons 600+hp, no problems so far. New rings and light cylinder honing and your oil consumption should be close to zero.

[Thuppu]

You can put 1000hp on stock pistons without problems.

Experience with this? First thing that fails is the stock piston pinns. Risk to brake them is quite high at 800hp level, maybe earlier.

[GazzaG60]

when i removed my stock pistons they showed a little sign of det. slight pitting.

i fitted scats and skimmed the entire surface of the piston down. i know its not the best but it worked and worked well. i ran the original rings to save honing the block.

my turbo is basically an non bb 35. my solution was cheap like under 500 uk for rods, piston skim and weight match. and worked well. i ran 2 bar on that. the skim helps get some timing in up top.

[Albert]

Experience with this? First thing that fails is the stock piston pinns. Risk to brake them is quite high at 800hp level, maybe earlier.

My friend in PL has 980HP with stock pistons on E85.

[vti2]

You can Upgrade the pin's and kipp the Pistons

[igor136]

Experience with this? First thing that fails is the stock piston pinns. Risk to brake them is quite high at 800hp level, maybe earlier.

Is that because replacement rods dont have hole for oil?

[rst]

Is that because replacement rods dont have hole for oil?

No.

Stock wrist pins just break at 750-800hp. With uprated wrist pins you can push a little more, how much i dont know. Usually at this power range it is easier to upgrade pistons and use 22mm wrist pins.

[Rusty]

Problem with stock pistons is that they require the bores to all be in good order, which on an old engine, they tend to be a little oval or have wear which requires a rebore.

I too have gone for the FCP kit, with the X beam rods and 81.5mm pistons. Combined with new bearings, I got change from £1000 delivered for the lot...

[momento1]

Problem with stock pistons is that they require the bores to all be in good order, which on an old engine, they tend to be a little oval or have wear which requires a rebore.

I too have gone for the FCP kit, with the X beam rods and 81.5mm pistons. Combined with new bearings, I got change from £1000 delivered for the lot...

Cheers Andy.
good point you make. Im hoping that my cylinders are all good. A compression test was done only 15,000km ago and all were well within tolerance which is great for 200k +km so im hoping mine are still great.

did you go the FCP pistons? 81.5mm is same a stock is it not?
Have you installed as yet? What size wrist pins?

[Kieron20V]

Stock bore for 20vt engines is 81mm.

[Rusty]

Stock wrist pins, not sure what that is but they'll custom make what you want.

I bought a low mileage engine and one piston bore was 2/3 worn, so we bored it. Just plan to bore it, go 82mm and have done with it

[momento1]

hmmm i may just hold off and see what the cyl look like.

what do you guys reckon the capacity would increase to if i was to bore out to 81.5 or 82mm?? 2.3L??

and what is stock compression? 8:1? or 8.5:1