Vito's rip

[Chariot Performance]

I can accept that vito's pistons are a bad choice for some engine setups but a great choice for others. I am a true believer in information and this site is great for that.

[Woolfman]

they are made by wiseco to vitos specs which sadly are fairly dangerous given they design them with extra large intake windows that crack and shatter on the bridge prematurely. they have a long histroy of this and youll find in a search on here that this is the main reason people wont run them also they will screw up your exhaust duration and blowdown timing on a port job with the pie cutting over the exhaust area .slighlty better response and 1-2 hp arent worth a new topend and possibly crank and cases too.ive dug them out of too many lower ends to think they are a good option over a standard prolite design .. my 2 cents

I was just wondering if it would jack up a port job on the exhaust side cause of that thing they do on the exhaust side. Thats what mine did shattered sucked ass. Isn't that little cut out a way of cheating getting a port job on stock jugs? If so that would be bad with a port job.

[AKheathen]

i don't like how they change the shape againstr the chamber, but it is a reversable porting, if ylou are on the fence about the exhaust timing

[shanYE west]

I was just wondering if it would jack up a port job on the exhaust side cause of that thing they do on the exhaust side. Thats what mine did shattered sucked ass. Isn't that little cut out a way of cheating getting a port job on stock jugs? If so that would be bad with a port job.

 

 

That piston would be a bad choice for ported engines because it would mess up port timings. Thats what that cut away does is change the exhaust port timing. So in theory... its a cheater port job. I'm pretty sure they say on their site not to use it if the motor was ported. For ported motors they suggest the power pistons. IMO.... if the motor was already ported then you'll probably see minimal gains if any. They're might be some good gains with the superstock pistons, But I'd like to see some dyno's before I say its 100% worth it. I know my cousin swears by them in his stock ported bike. At the drag strip in the stock class.. only person he lost too was a CRF450. He was running pretty close times to my well modded YFZ450.

[flotek]

if a guy wanted the same performance effect as a power piston without the potential intake problems you would simply raise your exhaust ports .040 and run standard wiseco prolites

[shanYE west]

Simple for some.. but not for most. I think your refering to the superstock pistons though.. The power pistons dont have the exhaust cutaway on the crown.

[flotek]

i see your point but to my understanding according to vitos the only forged pistons they sell are the super duper modifed ones with their pie cut .. now the other design like standard is the cheap cast versions that have "made in china" right on the bottom of the piston boxes

[shanYE west]

i see your point but to my understanding according to vitos the only forged pistons they sell are the super duper modifed ones with their pie cut .. now the other design like standard is the cheap cast versions that have "made in china" right on the bottom of the piston boxes

 

Nope.. they sell 2 different forged pistons.. The superstock pistons have the cut crown while the power pistons dont... They also sell some forged pistons in the same style but made by someone other then wiseco. I'm assuming a over seas company as it doesn't say USA after the part description and they're cheaper.... So thats atleast 4 different forged pistons they offer. They do offer casted OEM pistons also..

 

Forged power pistons

 

Forged superstock pistons

[Ieat4strokes]

Isn't that little cut out a way of cheating getting a port job on stock jugs? If so that would be bad with a port job.

 

Thats EXACTLY what they are designed for, a lil ooomph on a non-ported motor by changing the timing, they are not designed to work with a ported motor im sure it will jack up ya timings. There was actually a nice write-up about them on the web somewhere, where they tested them against stock pistons on stock jugs and noticed a good improvement in power over stock.

 

[mopar1rules]

here's the review:

 

http://www.atvsource.com/articles/product_...ock_pistons.htm

[flotek]

ahh,my bad...i apologize i was thinking of the 72mm blaster big bore pistons they sell like that ,had to get alot of these setup lately for spring

Edited May 2, 2009 by flotek

[Ieat4strokes]

thats the write-up.......thanks mopar

[Toomey Banshee]

thats the write-up.......thanks mopar

 

 

Thats a very interesting article. Vitos recommends 35 pilots? What size mains, anybody know? I think I read this is with an open air box with I assume a K& N. It's about time I did my sons 99, maybe I'll go this route.