Here are the flow #'s of various cleveland heads.


Head Casting I / E Valve
Size Lift Port Config Source
0.100 0.200 0.300 0.400 0.500 0.600 0.700
Cleveland 2V I 2.03 68.5 142.2 189.0 199.5 196.5 198.0 - Stock Mustang & Fords - Dec. 1999
Cleveland 2V E 1.67 57.2 89.7 120.2 143.5 159.6 162.7 - Stock Mustang & Fords - Dec. 1999
Cleveland 2V I 2.05 59 114 177 202 204 210 - Stage 3 Walden’s Pond Website
Cleveland 2V E 1.65 45 83 117 150 170 179 - Stage 3 Walden’s Pond Website
Cleveland 2V I 2.05 - - - - 220 - - Stage 3 Tom Moranna
Cleveland 2V E 1.65 - - - - 180 - - Stage 3 Tom Moranna
2V 2.19 / 1.71 I 2.19 70 139 197 216 216 218 216 Stage 3 Walden’s Pond Website
2V 2.19 / 1.71 E 1.71 54 102 142 166 178 181 181 Stage 3 Walden’s Pond Website

Aussie Cleveland 2V I 2.19 62 119 165 189 198 - - Stock www.powerheads.com
Aussie Cleveland 2V E 1.71 47 84 114 138 162 - - Stock www.powerheads.com
Aussie Cleveland 2V I 2.19 84 163 218 232 252 - - CNC Ported www.powerheads.com
Aussie Cleveland 2V E 1.71 79 116 165 190 212 - - CNC Ported www.powerheads.com

Cleveland 4V I 2.19 64.3 115.8 163.5 210.0 246.0 273.6 - Stock Mustang & Fords - Dec. 1999
Cleveland 4V E 1.67 66.7 103.7 133.8 154.4 169.0 178.4 - Stock Mustang & Fords - Dec. 1999
Cleveland 4V I 2.19 65 107 162 208 245 267 - Stock Walden’s Pond Website
Cleveland 4V E 1.71 50 85 122 145 160 167 - Stock Walden’s Pond Website

C302B I 2.15 - 156 224 278 306 335 358 Pro Porter Super Ford - Sept. 1991
C302B E 1.65 - 129 169 200 223 245 256 Pro Porter Super Ford - Sept. 1991

The cnc machined Aussie's do out flow the 4V until you get to the highest lift which is where most cams spend the least amount of time! They also kill the 2V!

 

So, FX4ALL, where exactly are you getting your numbers. The numbers you posted for PowerHeads are higher than PowerHead's own web site, and way higher than other measures of PowerHeads.

I have reformatted the data and used better sources here;

0.100 0.200 0.300 0.400 0.500 Lift
68.50 142.2 189.0 199.5 196.5 Stock 351C/2V Intake 2.03 (Mustang & Fords)
59.00 114.0 177.0 202.0 204.0 Stage 3 351C/2V Intake 2.05 (Walden’s Pond)
70.00 139.0 197.0 216.0 216.0 Stage 3 351C/2V Intake 2.19 (Walden’s Pond)
79.10 153.9 205.7 231.4 243.7 PowerHeads from their web site
65.70 124.0 178.9 211.0 226.4 PowerHeads (another source)
64.30 115.8 163.5 210.0 246.0 Stock 351C/4V Intake 2.19 (Mustang & Fords)
65.00 107.0 162.0 208.0 245.0 Stock 351C/4V Intake 2.19 (Walden’s Pond)
nn.nn 156.0 224.0 278.0 306.0 Boss 302 Intake 2.15 Pro Porter (Super Ford)

0.100 0.200 0.300 0.400 0.500 Lift
57.20 89.70 120.2 143.5 159.6 Stock 351C/2V Ex 1.76 (Mustang & Fords)
45.00 83.00 117.0 150.0 170.0 Stage 3 351C/2V Exhaust 1.64 Walden’s Pond Website
54.00 102.0 142.0 166.0 178.0 Stage 3 351C/2V Exhaust 1.71 Walden’s Pond Website
74.50 109.1 155.9 179.5 200.0 PowerHeads from their web site
54.60 87.30 124.2 155.1 168.5 PowerHeads (another source)
66.70 103.7 133.8 154.4 169.0 Stock Cleveland 4V E 1.67 (Mustang & Fords)
50.00 85.00 122.0 145.0 160.0 Stock Cleveland 4V E 1.71 Walden’s Pond Website
nn.nn 129.0 169.0 200.0 223.0 Boss 302 Exhaust 1.65 Pro Porter (Super Ford)

Considering the low cost of Aussie heads and their naturally good flow, it's hard to beat them. PowerHeads cost $1100, Aussie heads cost less than $300. PowerHeads have never been worth the money.

 

Thanks for the good numbers Paul!

I have saved them in my files. I did add headings for Intake and Exhaust when I saved them.

 

Not all flow benches are created equal. For some reason the numbers from Walden’s Pond are lower than other sources.

The numbers from Powerheads site are going to make their porting job look like there are big improvements. We don't know if the numbers provided are the average of many ports or just one.

If I were selling heads, I'd list the worst port tested and the best port tested. It's not lying, it's just marketing.

 

Paul M mentioned the striking difference between 2V and 4V intake flow numbers at low-mid lift. The reason for that is shrouding.

If you look at how much room that 4V valve head takes up in the chamber, you can see how it has to get to 0.4" or more lift just to clear the side of the chamber/cylinder. The 4V exhaust valve has the same problem, though less severe because the heads are not as big.

That low-mid lift flow is why the 2V heads work so well on a 400 with a longer duration cam (say 20-25 degrees more than stock) with moderate lift (say 0.550" or so). That and getting the compression up to 9-9.5:1 makes an honest 400hp (and 500 ft lb torque) feasible, without high-dollar heads or exotic machine work.

 

This is the site I got the chart from. I didn't mean to step on anybodies toes. I was just offering my two cents.

http://www.jason.fletcher.net/tech/f.../cleveland.htm

Brain your right, not all flow benches are created equal.

 

FX4ALL, I hope I wasn't jumping on your case but those numbers were so high I had to check it out.

Here's another swipe at PowerHeads; they tested the stock 2V heads but with 4V valves. That caused a net loss of flow. They then compared their ported heads to those stock 2V heads that they've screwed up.

If they would compare their heads to some mildly worked Oz 2V heads they wouldn't look so good.

BTW, elsewhere on this forum someone described how to take 4V intake valves, cut them down to a smaller diameter, give them a 30^ valve job instead of a 45^ valve job, and produce some awesome flows.

I believe that this would work great with US Cleveland 2V heads; the open chambers would help with low-lift flow. My Oz heads are definitely shrouded and might work better with the standard 45^. I don't know this, I'm just sitting here thinking this crap up.