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Canfield Head Porting (Updated)

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kjett

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Discussion starter · #1 ·
The shop that's porting my heads (Champion Racing Heads) contacted me today. The port work is done on the heads. The chambers were at 120cc when they arrived. They measured max flow of 330cfm on the intake side which is very close to what I recorded on my friend's flowbench before sending the heads out. Both benches are SF600. Champion felt like the intake runners were TOO big making the port lazy. They epoxied the floor of the runner and raised it ~.280". They then ported the chamber, worked the short turn radius and raised the roof area (among other things). I also sent them my manifold so that they could make sure the alignment was correct. They ended up epoxying the intake runner of the manifold too in order to get the port alignment correct. He gave me the flow numbers for the #6 port. Below are the original flow numbers that I recorded on my friends SF600 as well as the numbers Champion provided me today:

Intake
======
lift original New
.200 158.3 186.5
.300 222.9 260.7
.400 272.7 312.7
.500 299.0 347.6
.600 312.2 357.2
.700 316.6 366

Exhaust
=======
lift original New
.200 134.3 143
.300 179.2 199.2
.400 194.9 246
.500 235.8 275.6
.600 251.6 292.5
.700 264.1 299

Just looking at the raw numbers this shows about a 14% increase on average. After the port work the chamber ended up at 122cc. I'm having the heads cut down to 119cc. I ordered new pistons yesterday. The new pistons are Wiseco with a 48.4cc dome. This should put the compression just a tick under 13:1. I also ordered a new cam .726 254/260@.050 108lsa. Installing new Crower I-Beam rods and a crank scraper. The rotating/reciprocating weight will be down a good bit as well. Planning to spin the new engine to 7k. This thing should be making HUGE torque for a 460ci engine. The port cross sectional area is a good bit smaller than before and the flow is significantly improved. I should have the heads back early next week. The block is being machined right now. I hope to be able to start assembly in the next two weeks. Once assembled it will be put on the dyno. I'm shooting for 750hp/650tq. I'm not sure if I'll get there but that's the goal
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I'll post some pictures of the heads after I get them back.
 
#2 ·
Wow thats a killer port job. The midrange flow numbers are exceptional. Correct me if I'm wrong, but didnt you have the heads originally flowed with a test pressure of 25"? Do you know what bore fixture the heads were flowed with, before and after? And do you know what the port volume is now?
 
Discussion starter · #3 ·
Originally posted by -SS454-:
Wow thats a killer port job. The midrange flow numbers are exceptional. Correct me if I'm wrong, but didnt you have the heads originally flowed with a test pressure of 25"? Do you know what bore fixture the heads were flowed with, before and after? And do you know what the port volume is now?
Click to expand...
Yes, I'm pretty pleased mathematically speaking ;) As always, the proof is in the pudding. Both sets of measurements were taken at 28". The flow numbers that I recorded on my friends flow bench were done with a 4.125" bore fixture. I believe Champion used a 4.310" fixture. I'll ask to be sure. Not sure about the port volume, but I'll ask
Image
 
#4 ·
maybe i am totally wrong, but i thought i read somewhere that epoxy can fail, and isn't a good idea, but it seems plenty of people use it? The numbers are outstanding!
 
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Discussion starter · #6 ·
Ok. I got a clarification from Champion. They used a 4.400 bore fixture to flow the heads. I asked about port volume, they said that isn't important to them. They said they're more concerned about crossectional area. The port is ~2.9 square inches at the pushrod.

Cody, I had heard the same thing about epoxy. I think that is from the old days when nobody really knew how to use it and/or the composition of the chemicals wasn't as good. Champion builds heads for a lot of off shore boat stuff. He has expoxied heads that have been in service for nearly 10 years in those applications and there isn't an issue. The surface has to be knurled or roughed up a little for the epoxy to bond correctly. He assured me it wouldn't be an issue. Good question, though.

Mike, I think a chassis certification is also required. However, even if the engine will be making enough power to push the car into the 9's there is no way that my suspension/tire combination would be able to stand it. Maybe a mini-tub on the horizon
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I'll wait and see what it runs first. Hell, it may slow down
Image
 
#9 ·
Wow!! That's what you can get using a professional shop. Impressive!!
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You'll see low 10's for sure!!! Mine did 10.3 spinning like crazy off the line so with your dialed suspension it's going to be great. Take another look @ that cam. With the flow #'s you now have you might be able to use alittle more duration. With the new found power and 10" tires you can sacrifice some torque down low for some on top. just a thought.Keep us posted.
 
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Discussion starter · #10 ·
Mike,

No more pump gas. This a bracket race only car effective immediately
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(like I was driving it on the street much this past year anyway).

Thanks, Todd. I'm pretty excited as well.

TWC,

I too am anxious to see wht it will run. I had the chassis working pretty good the last time out, but I was also on a damn good track. My home track isn't always prepared so well. I'm sure I'll have more work to do on the suspension. As for running more duration... You're right, and several others have pointed that out as well. However, my design for this rebuild from the start was to have an upper limit of 7,000RPMs. I feel the engine can go longer between refresh as opposed to running say 7,400 every pass. Depending on the outcome of the dyno testing I may be shifting at 6,800. A little smaller duration at .050 as well as the relatively small LSA will make for some honking torque and that's what it takes to get nearly 3,800lbs down the track.
 
#13 ·
If you mapped the ports which you paid for, you would own the programme, no? Then, you take the head to Canfield and say hi, my name is Ken and have I got a deal for you.....
 
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#14 ·
How much difference does the bore fixture make using two different sizes for comparison? How do the intake port sizes compare to an iron oval port? Are they still quite a bit larger? My 781's were gasket matched and polished up pretty good and he also opened up and reshaped the exhaust ports too. I had the option to have them flowed,but I didnt feel it was necessary as I'm going to keep the shift point below 6500.
 
Discussion starter · #15 ·
Originally posted by ejrempel:
If you mapped the ports which you paid for, you would own the programme, no? Then, you take the head to Canfield and say hi, my name is Ken and have I got a deal for you.....
Click to expand...
I wish
Image
Canfield has a CNC program they run on their newer heads. The CNC program is no doubt the product of many hours spent working on those heads.
 
Discussion starter · #16 ·
Originally posted by Rapid Robert:
How much difference does the bore fixture make using two different sizes for comparison? How do the intake port sizes compare to an iron oval port? Are they still quite a bit larger? My 781's were gasket matched and polished up pretty good and he also opened up and reshaped the exhaust ports too. I had the option to have them flowed,but I didnt feel it was necessary as I'm going to keep the shift point below 6500.
Click to expand...
Bob, there seems to be some conflicting opinions on the subject of bore fixture size. Champion recorded a max flow of 330CFM on my heads when they received them, although I didn't ask on which port. I measured 329cfm on my friends flow bench so that's pretty close even though we were using two different fixture sizes. I think it depends on the size bore in question, head chamber size and shape, how the head is positioned on the bench, how you're measuring valve lift, how a particular port is shaped/flows, etc... IOW, there are too many variables to say with any certainty how the two different fixtures would affect flow. As for how my heads compare in port cross-section area to an oval/iron head, I'm not sure. I've never measured the later. I now have a good set of mics (inside and outside). If you like I'll measure my heads when they come back to give you something to compare to yours. The reason I had the heads flowed before and after is to try and measure a change. I will be flowing these heads again myself after I get them back as each flow bench (along with the variables listed above) can produce different readings. It will be interesting to see what sort of power the new engine will make.

Superflow has a formula to calculate theoretical HP. The formula is CFM x .265 x # of cylinders. With mine that works out to 366 x 265 x8 = 775.92. That's pretty close to the 750hp I'm hoping for. This of course assumes that the engine is capable of pushing that much air ;)
 
Discussion starter · #18 ·
Originally posted by -SS454-:
The bore fixture no doubt makes a big difference on flow numbers. A 4.50" fixture can be worth 25-30 cfm (depending on head), over a 4.25" fixture.
Click to expand...
May I ask what you're basing that information on? What lift, runner, head? Have you done back to back testing on a flow bench? From what I've seen I'm not 100% sure that's a universal truth (read the variables I mentioned earlier). I know that all the major manufacturers are testing witha larger bore fixture (usually 4.60) and I'm sure there is a reason for it. Just curious what you might know about the effects of different size bore fixtures on different applications. As per my comment above it didn't seem to make much difference in my case.
 
#20 ·
[qoute]The bore fixture no doubt makes a big difference on flow numbers. A 4.50" fixture can be worth 25-30 cfm (depending on head), over a 4.25" fixture.[/quote]

Yep, it sure can, I'll bet if their measured
on a 4.125 those numbers will drop.

Question, how much ( if you don't mind me
asking ) did those Canfield heads cost you.

One thing to remember thro, it's the port
shape and cross section that really matters,
not saying flow isn't important, cuz it is.
I'd be interested in knowing what the port
volume is.
 
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