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Sometimes I get a little obsessive & compulsive. The change in the ports to the 06 heads was one of those things that I was curious about. So I decided to compare a few today. Test heads were 02 and 06 to keep things fair I disassembled both sets and blasted them clean then reassembled for testing. Both sets are completely “stock” with 1” radius inlets installed. Upload restrictions on file types and sizes make this a little tough.
This one is Both intake and exhaust, 2002 and 2006 TC heads
The intake flow is about the same on both up to .350" lift and then the 06's kept climing and the 02's levelled off. By .500" the 06 intakes beat the 02's by around 14 CFM. On the exhaust side the 06 heads dominate the early heads hands down.
It looks like if you can score a set cheap (ebay) that the 06 heads may make a worthy upgrade for the buck. To bad for the guys with 06's that just blindly replace there heads. You do have to use the 06 flanges on your intake. Next for this project may take a little time due to the holidays. I plan to clean up the throats and blend the bowls, and then retest them. The final step would be to bore the seats, replace the valves and retest one last time. I may add a set of 05's into the test for another Data point. The 05's have the same port as the 99-04 but the valves, springs and guides from the 06. I know we all tend to stay with what works and resist change but the beehive spring are progressive and resist harmonics plus the smaller stem and retainer size reduces reciprocating weight in the valve train.
Also, how do these number compare with other heads? For example, how would a set of mildy ported '02 heads flow? Would it be easy to make the '02 heads flow more than the stock '06 heads? Your numbers are really interesting, and I'm glad somebody finally did the testing. But I'm not knowledgable enough to put the numbers in context. To me, the graphs show a remarkable improvement in not only performance, but front to rear stability and performance potential. I think.
How do the stock '06 heads compare to aftermarket heads - like S&S or Edelbrock - for a mild high torque street engine?
And (finally) what about SE or HTCC heads? How do they compare? I was considering holding off on any engine upgrades until the '06 HTCC heads are available (whenever that might be); would it be worth it? Or would the small amount of gain not be worth the wait and expense?
I guess what I'm asking you is to help me put this in context for a Harley engine. All my new research and info on Harley heads is giving me a Headache.
As for the valve springs, I agree with you. Bee hives are the bees knees. I'll be putting a set on my small block Ford stroker this winter.
I will be anxiously awaiting your next round of tests.
__________________
.boB
'06 FXDI
95", High compression, 204's, SEII slip ons, SERT
And a bunch of other cool stuff
There is allot of head dyno charts in the 2006 Screamin Eagle performance catalog, (including HTCC heads) you can pick one up at your dealer for free. I have been doing some reading and thinking about adding a 50mm throttle body/ manifold kit from it.
Yes I have seen the SE 06 Catalog but at this time I just wanted to compare some heads only. Dyno numbers like flow bench numbers tend to be a little happy depending on if your selling a product or not and who is running the equipment. I have nothing to sell or service to offer and doing this just for my own interest. I ran the tests on a SF110 Bench with FlowCom and Performance trends Port Flow Analyzer software to collect the Data.
As for the 06 heads, this is the only info I found printed from HD.
Redesigned Cylinder Heads
• New intake and exhaust ports
• Intake port requires new symmetrical flange
• Existing intake seals to be used with new flange
• Redesigned valve seals. Running change in 2005
So the first part of this test was to see very simply, Do the 06 heads flow better than the early Fat Heads Yes/No? Answer Yes
I will most likely flow all four heads again Monday just for grins before disassembling them again.
The dyno charts in the SE catalog are intersting, but difficult to compare. It includes lots of differant combos with lots of differant parts. There are significan cam, head, and piston changes between each chart.
IMO, the head flow data presented here is a lot more valuable when comparing heads and head work.
__________________
.boB
'06 FXDI
95", High compression, 204's, SEII slip ons, SERT
And a bunch of other cool stuff
06 Heads on flow bench
