Well, the heads arrived yesterday and I thought I'd share some pics of their work with you. Hopefully these things will breathe! :)

Comp Cams dual valve springs


ports


exahust port


combustion chamber

 

They look cool. Wish I had that kind of $$$. I was reading your paper on the first pic, now you have another 1000 state troupers out there coming to get you :eek: watch out now

 

Hey Strick - yep, they're out in full force this weekend. They've even gone so far as to put threats out on the radio...
"If you get caught speeding or without a seat belt, there will be no warnings, you will get a ticket!"
I always did think that the best way to get through to people was to threaten them... :rolleyes:

 

Did they give you a flow sheet with the port job? If so please share it, I would like to include a aif flow profle into my desk top dyno program

 

:withstupid:
:yesnod: Flow sheet

 

No flow sheet was included, but I'm considering taking them to my local speed shop for an independent flowbench session. :)

 

Who did the heads for you?

They look pretty sweet...wonder if the shop you sent them to would do a set of L98 heads? I've got a bare set sitting in my garage...hmmmm...

 

CNC Heads in FL did them up. I would give Pete a call and see what he can do for you! :)

 

I find it interesting that no one seems to have flow data on the CNC Cylinder Heads porting work....

 

I had their heads on my 89 and later sold them to =Jeff=. Very nice work and very nice head.

Jason

 

If don't mind me askin', what did that set ye back "$".

Matt

 

The single valve spring Stage III is $1,500.00 and the double valve springs are $1,750.00. I went with the double valve springs... :)

 

:iagree:
Not to be rude or anything, but my buddy got a set of their stage III heads and they had really rough ridges from the cnc machine. Not getting a flow sheet is :bs IMO
Please get them flow checked locally and post the results.

 

Yes, I would also be very interested to see, because I have seen a number of sets of flow data from people who have had their 128 casting heads CNC'd, and the 128's that I ported flowed ~10% more than ALL of them.....I'm not trying to rain on your parade, I just get very leery of any shop that doesn't provide flow results.

The other question I have is why they are charging $250 more for double valve springs....the difference in cost of the springs is no where near that, and there's no additional labor to install double valve springs.....


[Modified by CorvetteZ51Racer, 6:22 PM 5/23/2003]

 

:thumbs:

 

They are bveautfiul, I whihc I would have had and extra $500 to get those heads but, I got what I got!


BTW, IMHO,,, I agree for that kind of dough, a flow sheet should accompany the heads! But my Darts did not have flow sheet either, but they were not CNC's

Good Luck!

 

Perhaps the following comments will cause the blood pressure to increase for some of you that paid big bucks for CNC heads, but here goes.

Fact: CNC deliveres very repeatable control of the cutting tool, but it does not guarantee the best flowing heads.

Fact: CNC ported heads often are hand ported to eliminate the "corn rows" finished left behind by the CNC cutting heads.

Fact: Most racing heads are hand ported not CNC.

When I had my heads ported to a Stage I level, I asked various shops about CNC ported heads. They all said they saw little reason to pay for CNC ported heads. They all said they could do a better job doing it by hand for the same or less money.

Obviously, since they did not invest in a CNC machine, they wanted to promote hand porting over CNC. However, there is something to be said about skill and experience for the hand porters.




[Modified by Mez, 5:56 AM 5/24/2003]

 

Huh? So you should have your engine hand made, like in 1903, instead of precise computer/robot manufacturing, like in 2003. These are machines - not oil paintings.

I ported my own heads by hand- BUT if I could have hooked-up my Mac to a die-grinder and made a perfect match to every port, I would have a better engine.

Hmm, anyone want to invest in a mac-die-grinder-porting-thingy-company? :D

 

:cool: :cheers:

 

cprgmr: Congrats on the heads. I think you will be impressed with their performance.

CNC vs hand ported is another old discussion kind of like the DynoJet vs the Mustang dyno...! :)

I went with the same folks with my LT4 heads and so far satisfied although I haven't visited the dyno yet. The car definitely picked up and the topend pulls very well.

For those that are tooting their own horn...good for you. If you can port the heads better that is really not a surprise. CNC never guaranteed the best flowing head...and the price reflects it. On the other hand, I paid significant money for their process so do expect a quality job, more so than the local speed shop in Nebraska...no offense to them, that hasn't even seen an LT4 head in person.

I flowed my stock LT4 heads before and after the process (again at the local speed shop), even using the same operator, bench, pressures, and cylinder. No I'm not going to post them, as I don't believe flow numbers are everything. I will say the intake gained ~50 cfm and the exhaust not so much...some have said the exhaust side has a problem...I don't know, haven't visited the dyno and I'm running corks...stock exhaust manifolds...:)

Also I would guess the single valve spring is smaller diameter and may use a less expensive chromoly retainer rather than the dual titanium retainer...

So far quite happy with the CNC experience.

:D


[Modified by No Go, 9:17 AM 5/24/2003]