Cross Performance 254 top end

[ZukiRyder400]

What was originally going to be a new piston only turned into needing a top end, heres the end result, the grooves in the cylinder started to transfer onto the piston after only 4 or 5 tanks. Dont mind those lowers...

 

[ZukiRyder400]

Got the new top end and piston in the mail today and I was actually kinda suprised at the quality. Not that its the best but I had my doubts. One of the lowers is kinda rounded on a couple of the corners but Im just gonna send it

 

[ZukiRyder400]

One thing i had noticed is that on the exhaust side of the upper was flatter than flat, I is gonna fix it. Itll be a while before i get more pics

 

[ZukiRyder400]

Whats kinda interesting about this cylinder is that it has a decomp hole but not one on my OeM one

 

[ZukiRyder400]

Piston looks REALLY good casting wise but there were some kinda shard edges that i sanded down the sharp spots a lil bit with 1500 grit,

 

[ZukiRyder400]

One other thing is that the intake on the Cross cylinder is a good amount wider than the OeM one.

 

[huskyboy]

Piston looks REALLY good casting wise but there were some kinda shard edges that i sanded down the sharp spots a lil bit with 1500 grit, View attachment 305459View attachment 305459

How wide are the skirts compared to oem? Almost look narrower but it could be a optical illusion…

 

[ZukiRyder400]

I got it all assembled and the first start was as you would expect, not very easy LOL. But I let it sit an idle for about 30 seconds the first time and about a 5 min break and went up to about 3 minutes. Not sure if there is a term for this method but I do it everytime I put a new piston/ top end on.

 

[ZukiRyder400]

How wide are the skirts compared to oem? Almost look narrower but it could be a optical illusion…

To me it looks the cross piston is a touch narrower but I dont know by how much... dont know where muh calipers went.

 

[ZukiRyder400]

Thats how wide the exhaust window was. Im not going to widen it when I go make port timing adjustments after the base and band cut.
Intake width is staying the same too.

 

[huskyboy]

Thats how wide the exhaust window was. Im not going to widen it when I go make port timing adjustments after the base and band cut.
Intake width is staying the same too.

Stock ports looked tiny. How wide are they? 60%? It looks like you got a little fudge room there to widen them.

 

[ZukiRyder400]

Stock ports looked tiny. How wide are they? 60%? It looks like you got a little fudge room there to widen them.

I dont remember.. ill has to measure tomorrow and they were very small but these things were factory hotrods

 

[ZukiRyder400]

The oem ones were anyways, havent gotten this one into wood yet.