Yesterday I drove to North Carolina to a friend's shop. He runs a Super Stock program and does all his own machining/assembly. He has a Super Flow 600 flow bench.

http://bellsouthpwp.net/k/_/k_jett/Images/Canfield/sf600.jpg

My goal was to flow my heads, both my intake manifolds (Performer RPM and Dart single plane) and to CC the heads. After a short tutorial on how to use the flow bench I was on my way. All measurements were taken at 28" and we did not use a pipe on the exhaust. The bore fixture was 4.125". I'm not sure what impact the smaller bore fixture had on the intake flow #'s, nor am I sure what not having a pipe on the exhaust hindered. Here is a link to the results:

http://bellsouthpwp.net/k/_/k_jett/Images/Canfield/flownum.mht

I ran out of time and was unable to flow all the cylinders. I did both intake/exhaust on the passenger side head and a few runners on the driver's side head. I'll have to say I was somewhat dissapointed in the results. As you can see the flow fell off quite a bit at .600 lift; at least when compared to the advertised numbers that I got from Canfield's web page. The exhaust numbers were pretty close but the intake flow was off by a considerable amount. After careful examination of the heads I think I've come to the conclusion that they weren't ported to the extent that I originally thought they had been. It doesn't appear that any work has been done to the short turn radius. It appears as if the casting flash was removed in the intake runners and not too much else. That said, the numbers that Canfield advertises on their website are for box stock heads. I'm puzzled as to the difference. Maybe it was something with the manner in which we tested them?

I also tested both of my intake manifolds. We installed studs on either end of the head being tested so that we could easily attach/remove the intake manifold. When each intake valve was at full lift we would attach a manifold to test. It was really interesting to see the impact that the manifold had on the heads at full flow. Some of the intake runners on the manifold read different by just rotaing the manifold 180 degrees on the head. I'll have to say I was impressed with the way the little Edelbrock Dual Plane intake flowed. It flowed nearly as well as the Dart despite having a smaller runner. The #4 and #5 intake runners on the Dart were dragging down the max flow by ~25CFM. We ported the Dart intake in small increments taking it back to the flow bench at each stage to measure the changes. When all was said and done the Dart was flowing at FULL capacity on each and every port. I'll try and post some pics of the changes we made to the manifold. The biggest gain on the intake was made by raising the roof area in the plenum where the air coming in from the carburetor transitions into the runner.

I'll have to say that other than having to do a ton of driving (340miles each way, same day) that this was a very rewarding learning experience. I now understand why head flow is such a black art :D

We should all have friends with flow benches. smile.gif That's an incredible asset.

Thanks for sharing.

Rod

Originally posted by Rmchevelle:
We should all have friends with flow benches. smile.gif That's an incredible asset.

Thanks for sharing.

Rod I'd think what would be more important is having a friend with a flowbench that actually knows how to use it effectively ;) :D .

Sounds like you had a very educational day Ken. Good data is one thing that can only help improve your combinations performance.

It's a guess, but it wouldn't surprise me to see maybe 15-25 cfm difference between the 4.125" bore fixture and a 4.310 fixture...expecially if the smaller bore fixture puts the cylinder wall real close to an intake valve and shrouds it severely. As with anything, the only way to know is to try and dig up a 4.310 bore fixture for a direct comparison.

The thing I see is many heads manufactures are advertising flow numbers for 4.500" or even 4.600" bores which means the numbers are useless for anyone putting them on a 4.250" bore 454 style block.

Todd,

I agree on all accounts. We were able to manipulate the flow numbers by slightly moving the head around on top of the bore fixture, so there is little doubt that a larger fixture would have changed the flow characteristics. Roy showed me quite a number of tricks that he uses to determine what needs to be done to the cylinder head/intake runner. It was very interesting to watch. I took a ton of notes :D

As I recall you had some flow numbers on your 049s. Can you send them to me? I would like to see how a factory open chamber casting flows compared to the Canfields.

Hi Todd graemlins/waving.gif You already have these ;)

Ken,
I didn't look at your numbers yet but here are the differences on a 315 full CNC AFR

Tested at 28" , Radius intake & no pipe.

4.530" --------------- 4.310"
..050 - 40/34 ---------- 43.4
.100 - 78/69 ---------- 78.1
.200 - 164/142.5 ------ 162.3
.300 - 247/198 -------- 239.5
.400 - 309/240 -------- 290
.500 - 350/267 -------- 334.4
.600 - 375/280 -------- 358.3
.700 - 383/283 -------- 374
.800 - 381/286 -------- 377

++++++++++EDIT++++++++++++
Forgot to mention, these are not advertised numbers they are measured on my bench.

Originally posted by Wolfplace:
Hi Todd graemlins/waving.gif You already have these ;)

Ken,
I didn't look at your numbers yet but here are the differences on a 315 full CNC AFR

Tested at 28" , Radius intake & no pipe.

4.530" --------------- 4.310"
..050 - 40/34 ---------- 43.4
.100 - 78/69 ---------- 78.1
.200 - 164/142.5 ------ 162.3
.300 - 247/198 -------- 239.5
.400 - 309/240 -------- 290
.500 - 350/267 -------- 334.4
.600 - 375/280 -------- 358.3
.700 - 383/283 -------- 374
.800 - 381/286 -------- 377

++++++++++EDIT++++++++++++
Forgot to mention, these are not advertised numbers they are measured on my bench. Thanks for the info, Mike. It looks like the larger bore fixture made an appreciable difference at .500+ lift. That is where my numbers were surprisingly low. I noticed the smaller bore fixture you used was 4.310. Have you ever used a 4.125" fixture on BBC heads and if so what was the outcome?

Thanks.

Here are a couple of pictures of the modified intake runners on the Dart:

http://bellsouthpwp.net/k/_/k_jett/Images/Canfield/dart001.jpg

http://bellsouthpwp.net/k/_/k_jett/Images/Canfield/dart002.jpg

Ken,
Never tried a 4.125 bore.
I would expect it to make a reduction from the 4.310 but probably not as dramatic as the big bore does as you already have the sharp edge of the bore stuck into the airflow with the 4.310.
If you "roll" your bore at the intake it really seems to help with the smaller bores as it gets rid of the sharp edge that really upsets flow.
If I had a head here I'd test it just for giggles.
AFR's are noted for the mid lift flow as the port is very efficient & Tony designed the head with a big bore in mind.
This is why they drop off so much in the .3-.6 area.
The Canfields are going to drop but probably not quite as much but I would expect them to follow the same trends.
BTW, the AFR has 2.25 X 1.88 in the 315's for info.

Did you have the head centered on the bore for all your tests?
Reason I ask is there is usually a pretty substantial difference between the "good" & "bad" ports that I didn't see with yours??

+++++++++EDIT+++++++++++
Just saw the intake,, very nice.
Glad to see some bright spark didn't grind the leading edges of the runners to a sharp edge to "improve" the flow
You would not believe the number I have seen that have been ruined by some self professed pro's :mad:

Maybe my flow results aren't as bad as I originally thought. I was looking at the cylinder head database on Chevy Hi-Performance:

http://chevyhiperformance.com/techarticles/41598/index9.html

They have Canfield and other head stats. Considering I used a way too small bore fixture, no radius, exhaust pipe or tulipped valve I guess I did ok smile.gif

Mike, the numbers on the AFR head are incredible. My friend Roy (guy with the flow bench) said that he flowed a set of the 357cc AFRs for a RED. He said that was the best flowing head he's ever had on his bench. If I were in the market for a new set of heads I would strongly consider the AFRs. Having said that, I'm tickled to death with how the Canfields have performed and I hope to get a little more out of them when the new combo comes together.

Originally posted by kjett:
Maybe my flow results aren't as bad as I originally thought. I was looking at the cylinder head database on Chevy Hi-Performance:

http://chevyhiperformance.com/techarticles/41598/index9.html

They have Canfield and other head stats. Considering I used a way too small bore fixture, no radius, exhaust pipe or tulipped valve I guess I did ok smile.gif =
Ken,
If you don't use either an intake manifold or a radius on the inlet it will kill your high lift numbers & the test is pretty much meaningless.
The shearing effect & turbulence will essentially make the port become smaller at the inlet is the best way I can describe it.

The more volume you try to put through the port the worse it gets.
You would probably get better results testing at say 10" & converting the numbers ;)

A Tulip exhaust does not belong in most smaller intake port heads.
It seems to works very well in some good ex ports as long as the intake can flow enough.
Seems to work in AFR's from 325 & up & in the 315's with a straight pattern cam.
It would probably work well in very well ported 320+cc Canfields with their raised exhaust but might end up flowing too much with a 310cc intake.
If you ever get a chance to flow them again, you can make a radius out of clay.
You want about a half inch radius if you are wanting to compare to other tests which is not the best idea unless you have good data supporting both benches with the same head.
For info, most of the CHP tests seem very real from what I have seen.

I took a pair of oval port iron BBC heads to a guy who has been building circle track engines for 14 years and had him flow them. I think it was a Super Flow 1000, although it looked like your picture. Coulda been 600, I dunno. It did have a digital readout option. Anyway, he tested them for $30 (two intakes and one exhaust). I was there for an hour and a half and he talked about engines the whole time. It was great.

He used a wooden "trumpet" (for lack of a better term)and a little clay on the intakes. He had a variety of them for different engines. He did the exhaust without a pipe, except at .500" lift where he compared both ways. Flow didn't increase much with the pipe which he said was good; a sign of smooth flow.

I had a great time. Everybody should try it. I learned a bunch. It was my first try at pocket porting and the numbers came out good, he said.

In case anybody's wondering, here are the numbers:
Intake, CFM
Lift Cylinder 4 Cylinder 6 Average
0.1 91.5 92.3 91.9
0.2 161.4 162.2 161.8
0.3 219.0 215.8 217.4
0.4 264.2 261.8 263.0
0.5 300.2 283.8 292.0
0.6 311.0 287.0 299.0
0.7 302.0 290.6 296.3

Exhaust, CFM
Lift Cylinder 4 Cylinder 4 with tube
0.1 82.9
0.2 119.4
0.3 146.1
0.4 189.4
0.5 210.0 218.0
0.6 226.8
0.7 230.3

Thanks for sharing your info Ken. Looks like you've got a nice flowing set of heads there. And I agree, running that flow bench was a blast and I learned a ton graemlins/thumbsup.gif

I bought a pair of the 310 not ported,running 11:085 if i spent the money and have them full ported,what kind of extra hp or et would you think id have

Originally posted by 69blkrat:
I bought a pair of the 310 not ported,running 11:085 if i spent the money and have them full ported,what kind of extra hp or et would you think id have Well, each cfm is worth 2.2 hp (potential).So if you can increase the airflow 10 cfm accross the usable range (not just peak), then you have the potential to pick up 22 hp.

For a 10/11 second car, it takes approx 20-25 hp to pick up a tenth.

These are all basic generalizations, but should give you a small idea of what kind of power is on tap if you can gain X amount of cfm head flow (again, usable range across the board, not just peak). Low/mid lift numbers are the most important. The valve see's these lift points twice as long compared to when the valve is peaking at max lift.

just my uneducated .02

Kjett , I ported a set of old Merlin cast heads Rectangular port 320cc runners combustion chambers ended up @ 121 cc which I'm running now. This was my first experience w/ cleaning up a set of heads but here are the #'s @ 28" of H2O. I don't know which machine was used as I didn't witness the testing.
ACTUAL
LIFT Intake Exhaust
.3 223.1 151.8
.4 266.9 192.6
.5 297.6 206.8
.6 316.7 214.4
.7 321.8 230.2

My exhaust #'s aren't near what your getting. I was disappointed w/ what little improvement I got over advertised however we didn't flow them before we did the work so maybe the stock #'s are alittle over stated.

Advertised:

.3 216 141
.4 258 175
.5 292 193
.6 313 207
.7 325 213

The worst part is when my hexadjust let go I pulled one of the rocker stud bosses off the head. My builder says he can weld it back on and use a longer rocker stud, otherwise all my hours of porting are in the trash :( :(

Well, I got the scoop on me heads. I first purchased these heads as part of a turn key engine build from a local machinist/builder. I called the builder and got the invoice number for the heads. The heads were prepared by Champion Racing Heads in Palm Coast, FL. I called and spoke to Tom at Champion and he pulled the paper work on my heads. They had done what is called an "economy port job." This included some unshrouding of the chambers, cleaning up the openings, competition valve job and surfacing. After a lengthy discussion with Tom I've decided to send my heads back to them for a full port job smile.gif I'm really anxious to see what this combination will have in store for next year. Should be a terror graemlins/thumbsup.gif

TWC,

Thanks for sharing your flow numbers. They look pretty darn good especially considering you did them yourself. I'll post new flow numbers for my heads in a few weeks after they come back from Champion.

Ken, thats great. Not to muddy the waters but you might want to also call TEA or CFE. Both have excellent reputations for getting the most from the Canfield 310. You can check out some flow #'s from TEA on their website. TEA did a pair of TFS heads for me and the flow #'s they gave were right on the money when I had them flowed locally on a sf600. Their exhaust #'s tend to read high due to testing methods and bench design. Champion may be excellent also, just trying to offer some options.

http://www.totalengineairflow.com/


You'll notice the TEA Canf has an excellent exhaust (due in part to .600 raised port) and very strong intake mid-flow. Even better mid-flow than an AFR.

Good Luck!

Thanks for the info, John. I'm pretty set on using Champion but I will give TEA a call and see what they say, too.

Great post Ken, I look forward to actually reading all of it in a few days when I can actually "think".. Yes, I am that busy with everything right now......as you know I have these same heads and mine are box stock as well as my intake manifold(s).

Tom

i believe if you pay enough CFM can get you almost 400 CFM out of a 310 canfield head!!!!obviously they won't be 310 anymore

The Canfield Big Block Head flows reasonably well but suffers some cracking if ported heavily so be careful how much is done to these. A fellow on Mike Stark's board was promoting the 350 cc Heads that flowed somewhere in the neighborhood of 430 CFM after porting but cracked into one or more ports.

Originally posted by Harold Sutton:
The Canfield Big Block Head flows reasonably well but suffers some cracking if ported heavily so be careful how much is done to these. A fellow on Mike Stark's board was promoting the 350 cc Heads that flowed somewhere in the neighborhood of 430 CFM after porting but cracked into one or more ports. Yeah, Harold. That's what concerns me. I spoke with one head porter who has a CNC program for the head and claims he can get the intake to flow nearly 400cfm. There was some ambiguity about how much material had to be removed in order to achieve that flow, though. The two other porters that I spoke with thought that 370-375 was a realistic goal without sacrificing the structure of the head. I'm also a little uneasy about having a CNC mill done on used heads. My heads have been surfaced a couple times. I'm sure they could shim/measure to get the alignment right, but I'm gonna pass. I'm using my first pick, Champion Racing Heads. Their going to do a full port job on the heads. I'll keep everyone posted as this project progresses. Thanks for all the comments and suggestions.

Ken, graemlins/thumbsup.gif

Harold, my understanding is that the problem with thin spring pockets cracking through the port is only with the 350cc head. :confused:

I can't wait to see what happens, mine are more or less bone stock other than a dingleberry job I did myself.I kinda wish I would have gone for at least the cnc chambers,but all in all quite satisfied so far.Keep us updated.

what kind of bucks should i expect to pay for full ported heads, 800 to 1200$ and are the canfield 310 worth spending that much on.69 chevelle 454 12to1 666 full roller ,1000 demon victor 454r ,running 11:10,would that get me in the 10s