Are CNC Ported head really that great when compare to hand ported head??

Just saw in Dsport mag a company called Performance CNC (www.cncport.com) doing CNC porting on the head. Anyone had experience with them??

Is there any other CNC porter that are good in their job??

Thanks.

 

A cnc ported head is only a copy of a hand ported head.If the original porting is good then the cnc ported head will be good.Its a way of repeating a good job over and over.

 

The CNC ported head is only as good as the original. If the original head was junk, the CNC copy will be junk. Import Builders also offers CNC ported heads-I personally flowed my IB head and it flowed 300 CFM on the intake side. The head made good power too. 10 hp more peak than a competitor's full race head that flowed significanly less.

 

Todd, do you think the IB C&C head is a lot better than Portflow's heads?

 

My Portflow head is very close to my IB head at peak lift. Within a couple of CFM. The Portflow head is actually slightly better at .200"-.350". I highly recommend them both.

 

Hi

So how do we get more details of the CNC head from Import Builders and Portflow?

How much do they cost and the turn around time?

Thanks

 

http://www.importbuilders.com/
http://www.portflow.com/frame.htm

 

exactly guys a cnc machine is just a very big zerox copier for metal thats all.

 

we also have a CNC program for head porting.... Tom can vouch for me on this(portflow) our CNC head with a valvejob from tom flows 311 on the intake side and i believe 228 or 224 on exhaust side... quote from tom "this is the highest flowing B series head that has ever come across my flowbench"

 

Nice numbers Whitfield.

What lift was that 311cfm taken at?

Any pitot tube measurements?

 

pics are key

 

If you are getting 300+ CFM with stock sized valves that is un-godly good.

I've only seen high 280's/ low 290 cfm on raced out heads with stock sized valves. These were developed by a good friend of mine.

Cosworth

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Don Lackey &raquo;</TD></TR><TR><TD CLASS="quote">If you are getting 300+ CFM with stock sized valves that is un-godly good. </TD></TR></TABLE>
Both my IB head and Portflow head run stock ITR valves. And judging by the power that they make, they are pretty darn good

 

I know porting heads is like a art form for some professional engine builders, but do these 300 CFM numbers really mean anything? Realistically can't you just port the hell out of the head and make it flow 300-300 CFM and head will flow like crap onces its on the block. I know people are real big on high CFM, but what does it really mean if they did a terrible job on the head.

 

damn those are really good numbers....
but when it comes down to it I just wanna see HP numbers....Better yet show me some track times!

 

A cylinder heads job is to flow well, seal well, and mix fuel well. It's job is not to be responsible for HP, that is the engine builder/tuner's job. And it's not HP's job to make the car go fast down the track. That is the responsibility of the driver/crew cheif.

So looking at the heads on the fastest cars is not the end-all piece of information that can be used to conclusively compare one cylinder head shop agaisnt another but it does provide some insight on the choices made by fast people.

 

i will post pics when i get a chance ... and yes these are stock 33mm valves

 

Looks like I'm going with PortFlow when I decide to get my head ported.