BigKID

iTrader: (5)

I hurt the engine so as I rebuild it I want to loose the hand ported 241 heads I am currently running for an aftermarket casting for the thicker decks. However, I am in a quandary if the CNC versions from PRC, TFS or AFR are worth the $800+ premium over their as-cast beginnings. As for strictly looking at advertised flow numbers, the TFS 225 CNC outflows the as cast 220 version by quite a bit where as the PRC 227 CNC and 225 as-cast don't differ much at all in cfm.

Here is a snapshot from excel comparing the flow data of the TFS and PRC offerings...


I am just wondering on an as-cast version, when they cnc the combustion chambers and do the valve seats, are the bowls blended as well? Would an as-cast runner be more or less consistent between all runners as a CNC'ed runner? (This is an issue I think I am currently having with my hand ports is #2 is getting significantly more air that the others.) These are the biggest concerns I have with an as-cast in a force induction setup.
Thoughts??

slowec

iTrader: (9)

Pony up for aftermarket castings for thicker deck. Good to see you think like me. Any set back is a set up for a comeback! Good luck man!

TXsilverado

iTrader: (19)

prc 225 as cast looks like an easy decision for F/I. that graph makes me love my CNC TFS225 heads

some of the FI guys on tech are doing awesome with ls3/vic jr setups. not sure i'm ready to jump on the LS3/L92 N/A bandwagon but it's hard to argue their FI results.

WICKEDOWESIX

iTrader: (2)

Just food for though.. its not always about cfm but rather port design and velocity.

03sierraslt

iTrader: (22)

What did you do to your motor?

BigKID

iTrader: (5)

I am not as concerned about intake flow numbers as I am exhaust which is where the CNC TFS really shines above the others.
I have to stick with a cathedral port to keep the KB otherwise I would be looking at some rectangular port heads too.


Which is exactly the reason for the question at hand and why I am wanting to stay with a head in the 220ish cc range.

Not exactly sure yet. I have a knock on the passenger side lots of metal in the oil and filter. Thinking either a bearing or cam/lifter issue considering all the metal is silver, some iron, some aluminum. I will be pulling it this weekend to start going thru it.

BigKID

iTrader: (5)

No other opinions on AS CAST vs CNC for forced induction?

swift700

iTrader: (3)

It looks like the CNC version has a slight flow advantage so why not go with them? I would also think that runner volume is more consistent as well.

TXsilverado

iTrader: (19)

CNC version is a lot more expensive.

Blackpanther99

iTrader: (8)

Cnc...