Just recieved CNC 5.3l heads (63cc) and am wondering how these #'s sound. I was a little suprised at the drop off at .600, but I am going with the TR 224/114 and it won't see that high anyway. These will be going on a stock bottom end LS1. Any input would be appreciated.

Intake
.100 67.4
.200 149.1
.300 210.1
.400 259.1
.500 288.5
.550 297.7
.600 267.7
Exhaust
.100 50.9
.200 113.8
.300 158.8
.400 192.5
.500 241.9
.550 251.8
.600 258.3

 

Those #'s look awesome.. Your exhaust is really up there.. I personally have not seen exhaust that high.. You are over 30cfm higher on the exhaust than my heads.., but our Intake looks about the same except mine continues going up past 600 lift..

 

What size bore did they use? 3.9 or 4.0?

 

You should be in the 11's for sure on street tires if you are already running 12.3's at 114mph..

 

Numbers look great, exhaust numbers might be TOO good. You might have setup where one of the reverse split cams work very well.

 

I keep seeing this hi flow on exhaust, these #'s are too high to be realistic, the testers flow bench needs to be calibration tested. I own one so i no what im talking about, there is a flow plate orifice that is used for this, if numbers dont jive with oem calibration #'s than bench is leaking somewhere. If you cant pinpoint leak, than you have to flow at pressure that gives correct calib. numbers. In my case i flow exhaust at 25" to relate to 28"flow rate numbers.Dont fall for false #'s.

 

I agree with LS1derfull - one point though - the flow number may be realistic - they are probably with a nice pipe on the exhaust side - they still seam a bit high, but with the proper shaped pipe, etc. it's could be possible.

On general they look good though!

Chris

 

Chris b, i dont disagree about how good they are, but we need to be able to compare oranges to oranges when it comes to port flow comparisons or the info is useless. As far as header tube on port i have found that short tube on port raises flow #'s about 10 or more over no tube testing, but if you put actual header to be used on head for testing, flow goes back down to basically same #'s as no tube on exh. testing. I think people should know this, tube testing is important because sometimes it changes turbulence and smoothness of flow at different lifts.

 

Thanks for the input.
These heads are from TEA (Total Engine Airflow).
I would hope that they are realistic numbers. The heads have Ferrea Valves 2.02 and 1.55. The one thing that I did notice on the heads, very little port work was done on the intake runners, it seems like the bowl area and the combustion chamber is where the major work was done. The floor of the intake ports do seem to have been ported a bit. The exhaust is fully ported and looks sweet, it's obvious that a lot of work was done there. What's nice about the CNC work is that all the ports look identical (they better <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> ) and the combustion chamber looks great.
If Thunder wants to send me their reverse split cam I would be more than happy to test it out <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
I will try to post some pics on Thursday.

 

Where exactly has intake port floor been ported?
TIA, Ls1derfull.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by LS1derfull:
<strong>Where exactly has intake port floor been ported?
TIA, Ls1derfull.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I don't really know if it has been "ported", but if you look at the walls, you can still see most of the original casting, the floor (closest to pistons) show no original casting marks. I hope that answers your question. I have the pics up at http://01vette.5u.com/cylheads/ls1.html
<img src="http://01vette.5u.com/cylheads/cylinderhead06.jpg" alt="" />

 

And for those who wanted to know the exhaust flow method, I received this e-mail from Brandon at TEA
Anyhow, the exhaust was flowed @28"H2O with 1.75" round pipe approx. 4"
long. We flow all of our ex. ports with pipes. It is true that the use as
well as shape of the pipe will affect the flow characteristics of the port.
It is also true that the port will flow less without the pipe: even so
probably more than most. We have been very successful with that head,
particularly the exhaust. In fact, some of the prototype stuff has gone
270cfm+!

 

Is the pricing reasonable? Would be a nice SC setup. How much to lower the C/R with the chamber cc size?

 

Pkmoose, thanks for the detailed pictures and exh. flow info. since i am porting LS1 heads, and im new to doing this style of heads these pictures teach me alot about shapes and approaches to doing them.When you take exh. valve size into consideration it really makes those flow numbers hard to believe but anything is possible. Good luck and let us know how this combo runs!