what are the pros and cons to having an intake port that large?
im running a 222/224 .566/.568 114
exauhst is at 83cc i think and ill be running 10.8-1CR
2.05 1.60 dual springs etc.

WHAT DO YOU THINK????

 

what are the low and mid lift flows? my heads are 215cc int 80 exh 2.02/1.57 with awesome low mid range flow and a peak at 302@600.

 

i have not flowed the heads yet? but will try to before install...
so what are the pros and cons going to be??? no low end, lots of top end????

 

My heads are 237 CCs and they feel really good, This is on a 6 ltr head though and some extra cubes.

 

Most of the aggressive stage 2 heads by vendors here are in the 235cc range on the intake side. I wouldnt worry about it Just match your cam choice to the flow numbers of the heads and take into account the flow with the intake on

 

If I was you I would choose a head with much smaller intake runners. Smaller cams rely on port velocity to fill the cylinders with the air fuel charge as the valve is not held open as long to fill the cylinder. Look at the absolute heads or even better, the AFR 205 head. Absolute uses a 213-215 cc port and gets excellent flow numbers throughout the range.

 

What stage Absolute?

I thought I saw that they had a 235 runner on their really aggressive head?

I have seen so many vendors heads I am probably confused about that though

 

Stage 2. I don't know about his Stage 2.5. I don't think too many stage 2 heads are using that big of a port. I could be wrong though. I do remember the ls6 stage 2 cnc head being really big though.

 

Whats Patriot's runner volume on their 5.3's?

 

The runner volume on the Patriot "LS6" head is 225 cc's, so the 5.3 is probably around 215 cc's.

I think 230 cc's is a little big for such a small cam and stock cubes. I think it'd work ok, but you'd be much better off with a cam that can take advantage of the larger port. But my car still made really good torque/hp with the 225 cc runners and a TR224 cam though.

 

So would an X1 (230/227) cam respond better with 230 cc 5.3 Stage 2E than a SSII (224/220) ???

 

Now this will probably get heated but minus the AFR heads I would be weary myself of a port with 213-215cc runners, After my JPR fiasco and learning about these heads and cc's and seeing the difference between a 215cc head (close to stock) and a 237 cc head (actually ported)I now ask myself just how ported could a set of small runner heads be? and exactly how can they flow alot? at least with the bigger cc heads you know they were ported. Believe me when I say verify everything you buy and verify the flow numbers etc. This is from my own personal experience and I did get screwed pretty bad but I feel I learned a valuable lesson through it all.

 

Sorry to hear that. I think the absolute heads have proven themselves more then once. I deffinately hear what you're saying however.

 

How big are the stock LS6 head runners? Anyone know?

 

oh dont worry mike, i plan to have my heads independently flowed w/ and w/o my ls6 intake on a 3.900" bore. i remember your thread on your JPR head flow , very dissapointing to say the least.

 

Yep exactly, Im not trying to be an *** or point any fingers. Im only saying double check your stuff and that you know with a big runner that it was ported and probably does flow what is advertised where as small runner it would be harder to acheive the same flow number not that it is impossible.

 

you do bring up a good point though. most people just install there heads and take the manufacture's flow without question. be interesting to see the peoples head flow on setups that should be making more power then they are. just another avenue to trouble shoot with. i know jay stands behind the fact that his heads will flow exactly what he states them as though.

 

The PP LS6 Style head checked at 232 cc, I suggested to Terry that he check this and update his info.

 

hahah this is kinda what I am talking about, nobody would ever know if they did not check.



JRP you are right on target about it being interesting if all of us went out and cc'd our chambers and runners. Would the results be astonishing???

 

I'm curious as to how the AFR 225 heads would flow with the 2.02 intake valves? Seeing as most of the big hitters are in this range. The 225 is a worked version of the 205 casting so they should be able to do it.