240 BBK Pistons

[Blaner]

I have questions regarding pistons for a BBK,

I recently got myself a used vitos kit off ebay for a good price, its still on original bore. It came with a Piston, but i dont want to use it again. It looks like a Vitos commissioned Wiseco Superstock

Such as, :PISTON-FORGED BIG BORE-USA...

Now what are my options?

I am weary of the Superstock as i want to run it with a 3+ stroker and a nice port job, so the exhaust cut out on the piston is confusing me somewhat, can i still use this? it would surely mean some sums need to be made with regard to porting including this step?

The Vitos cast piston: CAST BIG BORE PISTON WITH... looks good and i like the idea of the transfer/triples short cicuiting prevention. but its CAST!! with that said, its a normal piston, so porting is straight forward.

Following that, i know Wossner make forged stock design pistons. although they are very expensive.

what do you guys use and what are the conditions of using a Superstock Wiseco?

BBK's are scarce here, in fact i am the only person ive ever heard of in SA with one! I:I -fastest blaster in Africa? we will have to see! hence my lack of knowledge about them!

 

[sicivicdude]

If you are willing to keep your tolerances tight and a good healthy check on it, a cast piston will work. They run just like a forged piston as long as they don't slap around...

When you have the BBK cylinder and piston in hand, check the cylinder to piston clearance and see if you can run the piston that comes with it. If so, you can buy new rings for it and rock out. The superstock piston just "raised" the exhaust blowdown time by having that 1mm pie cut on the exhaust port side. They ran fine like that.

Wossner was a backorder for the BBK pistons but they JUST got a batch in (a very small batch mind you). ONce you measure the cylinder to make sure what size you need, you can order one (they're about $150 retail BTW).

 

[blaster hybrid]

ill but it off u if u dont want it , but some nice clean porting will fix that exhaust up

 

[Blaner]

ok, i take it the idea with the superstock is to fully uncover the exhaust port at BDC as well as let it close later, now are the transfers still partially covered by the piston in the vitos setup?

If so, if i use a spacer plate on a stock crank to correct the tansfer port timing, i would in doing so increase the exhaust timing even more so-probably out of functional range?! so the superstock only gives me half a solution by way of the exhast only, while a spacer would give me both transfers and exhaust.---this is basically my predicament!

But regardless, i want to only run it with a +3 stroker which i have not yet got or ordered. it will be a while still before i can afford one. how then would the superstock relate to porting with a spacer made to work with the stroker? you see there are so many changes with that piston its really confusing!

 

[Blaner]

ill but it off u if u dont want it , but some nice clean porting will fix that exhaust up

of course i want it! why do you think im paying more for customs than i did for the whole kit??- just a matter of doing my sums right

 

[sicivicdude]

That piston will work regardless, even if the "pie cut" drops below the exhaust port floor.
You would have to set it up and look at the port heights to determine if the pie shape cut is going to be too low, anyway.

 

[Blaner]

are there any other changes to the superstock? i think the intake windows are larger on the skirt but that shouldnt be a problem at all. i think its best for me to set it up like you say and do some measuring, i just need a spare motor and a bbk to do it on. i will soon have both!

i could run the cast pistons, and be careful with tolerances. but id like to find out if the superstock will work