Thread:

bb2 x-tra

Originally Posted by steele211

What does everyone think of these heads in the Cnc version? Any good for blown alky?

I guess that would depend if they were for a blown alky 396, or a 632

Originally Posted by steele211

500" 8-71 15# 11:1 want to be able to push the boost into the 20# plus range without problems. Going in a shovelnose for lake and drag use

That head would be on my list of considerations.

Originally Posted by steele211

What does everyone think of these heads in the Cnc version? Any good for blown alky?

Originally Posted by steele211

Short list? Top or bottom? Other considerations? The price seems right on these bare castings at 660 or so per from summit

really?

I prefer Dart myself.

We use the 345's on a little engine, 427 + .060, now everybody gonna say they are WAY to big !!!!!

Originally Posted by wizbang

I prefer Dart myself.

We use the 345's on a little engine, 427 + .060, now everybody gonna say they are WAY to big !!!!!

Not as oversized as that manifold you were running on the SS.

They're a littel down on flow for a CNC 355 cc head (especially on the exhaust), but they are also about the strongest castings going.
The PB BB2 Xtra (CNC) is a 355cc, the as-cast non-CNC BB2 Xtra is a 365cc. The one Summit has for that price is the 356cc non-cnc. I'd stay away from that.
I think the 355 is a little on the big side for what you're describing, but I wouldn't lose any sleep over it. I think as 355cc runners go, they have a relatively small cross section which I tend to like.

Originally Posted by steelcomp

They're a littel down on flow for a CNC 355 cc head (especially on the exhaust), but they are also about the strongest castings going.
The PB BB2 Xtra (CNC) is a 355cc, the as-cast non-CNC BB2 Xtra is a 365cc. The one Summit has for that price is the 356cc non-cnc. I'd stay away from that.
I think the 355 is a little on the big side for what you're describing, but I wouldn't lose any sleep over it. I think as 355cc runners go, they have a relatively small cross section which I tend to like.

You bring up a couple interesting things here. First the Brodix is one strong casting.
But on the flow thing. ALL Brodix heads with the possible exception of the Head Hunter series seem to be low on flow for the size of the port ACCORDING TO THEIR FLOW NUMBERS, vs others. Are Brodix numbers more realistic than some others, or more conservative, or do the heads actually not have the flow that some others have for relatively similar port size, or is it due to, like you say, a small cross secton for the port size? Always wondered about this.

Originally Posted by steele211

My bad they were actually 675 per they are the 2020003. Yes, no, maybe?

I know that Summit's website shows that head as being CNC'c on the spec page, but if you go to Brodix's website you will find out it is not.
Not the first time that Summit has had their specs wrong.
The part number for a Brodix 2xtra CNC head is 2028000 and the price is more like 1400.00.
Thats why I question it when you posted them in the 600.00 range. I was ready to order 3 pair.

LINK: Brodix BP BB-2xtra

Originally Posted by steele211

Short list? Top or bottom? Other considerations? The price seems right on these bare castings at 660 or so per from summit

Originally Posted by steele211

Damn summit!

To answer this question. At the price you first posted, they were WAAAAAY up on my list.