Wiseco +3mm piston kit for Royal star

[adamax]

Here we go again.... there is a wiseco +3mm big bore kit with a 10.5 compression that will yield a 1394 cc. Has anyone done it? what do you people think about it if I am going to use an older Royal star Block with Vmax heads.
Any ideas? shave the block? shave the heads? nothing radical, but I have a vmax that has no crankshaft so I am thinking about fitting a seasoned engine...

 

[adamax]

here is the link:
http://www.ebay.com/itm/96-99-XVZ13...Parts_Accessories&vxp=mtr&hash=item5648285c50

bearing in mind the new and the old royal star use the same gudgeon pin and the same piston rings by part number as the newer one, I assume the big bore kit could be installed on the older royal star block and mounted in a vmax frame, no?
C'mon fellow vmaxers wrenchers, shout me your thoughts....

 

[one2dmax]

I could sell you a new set of Arias for that too. BUT, I would not bore the block out that much on the stock sleeves. I would install new sleeves at the same time.

Sean

 

[adamax]

Sean, thank you for chiming in....
Arias kit for the Venture block? What is the cost ? What is the cost of the sleeves and how complicated is the process? What are the drawbacks on boring 3 mm bearing in mind a fun riding bike not a dedicated daily driver... so can I skip the sleeves and get away with a little warmer engine...

 

[one2dmax]

You can get the arias for ANY engine! Some engines we may need a stock piston to get specs from. The 86-93 venture blocks are the same as the early vmax blocks.

Anything more then 1.5mm overbore on the Venture block or 2.5mm on the stock vmax block is pushing your luck.

So, when you want to go big you have to resleeve the block. Basically the process involves removing the old sleeves, bore the bare block, install the new sleeves, bore the new sleeves.

So, you have double the machine work. It's also more difficult to get the new sleeves to be fully seated so it's been a problem with some engines to have a blown head gasket in a short period of time. Thankfully we haven't had that happen yet.

Sean

 

[adamax]

now another question: can I resleeve the Vmax block to accomodate 82-ish mm pistons on the vmax block? and do I need to change other parts and call it a day? just to get it become worthy but not necessarily extracting every tiny bit of HP...

 

[one2dmax]

The vmax block can be resleeved and bore to get as big as 87mm.

Sean

 

[adamax]

Sean, a couple more questions:
"Anything more then 1.5mm overbore on the Venture block or 2.5mm on the stock vmax block is pushing your luck." why not 2.5 mm on the venture block too?

Also, if I want to re-sleeve and install bigger pistons only, what is the largest bore I can go without changing anything else in the basic engine ?

 

[one2dmax]

If you get too thin a wall thickness on the sleeve you'll have durability problems as well as heating problems. I am not sure what amount of sleeve thickness can be tried sucessfully. If you want to try and report back you are more then welcome to. It can be an expensive experiment though.

We've done the 1.5"" on the 1300 blocks (which makes it 80.5mm bore) and 2.5mm on the vmax blocks (which makes it 78.5mm bore). Stock Venture bore is 79mm and stock Vmax bore is 76mm.

We have actually bored out the Vmax block 3mm to match the venture bore but that engine is running Methanol so heating is not a problem.

PCW suggest no larger then a 1428cc engine which is 83mm bore. To do this you still must remove the stock liners, bore the block, then install new liners and bore again. The reasoning behind that size and not the 1500 or 1570 is to save extra work required to the cylinder heads. Beyond the 83mm bore you need to unshroud the combustion chamber to get proper filling of the engine.

Sean