FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: blykins on June 22, 2018, 08:25:42 PM
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(https://farm2.staticflickr.com/1801/42917209541_565b6aef3a_c.jpg)
In case you've ever wanted to know what a factory CJ head flows with a 5/16" stem, 2.080" intake valve and a 7mm stem, 1.650" exhaust valve....well, here you go:
.100 76 67
.200 138 115
.300 204 140
.400 235 157
.500 248 170
.600 250 180
.700 252 189
4.125" bore, no pipe, clay inlet. No bowl work, no porting, no nothing. Just fun with a flow bench.
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Thanks for sharing.
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Is it with the stock 30 deg seats on intake?
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No sir, 50° on the intake, 45° on the exhaust.
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Ok, here are some comparative flow numbers from one of the previous sets of CJ heads that I used:
*Stock head, factory valves, no work.
.100 64 52
.200 124 87
.300 182 118
.400 211 144
.500 224 164
.600 231 174
.700 236 179
*Stock head, Ferrea 3/8" valves, no work, 45° intake/exhaust seats:
.100 80 64
.200 139 100
.300 195 133
.400 230 162
.500 246 181
.600 253 188
At first glance, I thought I had wasted an hour or so of labor, but if you look closely, we did pick up a few cfm on the mid-lift numbers in comparison to the 3/8" Ferreas.
To be honest, I was hoping for a little more, but the main goal of this R&D was to get some valves that were extremely light for an upcoming 390 build. FWIW, the intake valve is titanium and weighs 86g. The exhaust valve is stainless and sits at 88g.
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OK, checked up Edelbrocks own flownumbers they are
close to each others.
I have never seen a Cobrajet head live,The saying around
here was that a early head like a C4-G or such was like a
CJ heads with smaller valve...any Truth in that?
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OK, checked up Edelbrocks own flownumbers they are
close to each others.
I have never seen a Cobrajet head live,The saying around
here was that a early head like a C4-G or such was like a
CJ heads with smaller valve...any Truth in that?
Yes sir, the C4 head is often referred to as the "poor man's CJ head".
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OK thats what i heard, but you hear a lot most of it
not true . But i guess this is one of those times it actualy is
I see you gain 10-20 cfm just with 45 deg seats
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In a table that's easier to read without scrolling up and down...
Intake Flow
Factory 3/8" Ferrea 5/16"-7mm
.1 64 80 76
.2 124 139 138
.3 182 195 204
.4 211 230 235
.5 224 246 248
.6 231 253 250
.7 236 252
Exhaust Flow
.1 52 64 67
.2 87 100 115
.3 118 133 140
.4 144 162 157
.5 164 181 170
.6 174 188 180
.7 179 189
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Thank you sir.
Interesting
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Would have been interesting to do the small stem valves with a good 45* v/j.
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OK, checked up Edelbrocks own flownumbers they are
close to each others.
I have never seen a Cobrajet head live,The saying around
here was that a early head like a C4-G or such was like a
CJ heads with smaller valve...any Truth in that?
Several years ago I sent Les Schmader a pair of C4-G castings with 2.15/1.65 valves. He did ok work for the money. They won a few races on my junky 390.
http://fepower.net/simplemachinesforum/index.php?topic=620.15
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Brent, did you get the finish on these heads from a wheelabrator machine ?
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What is the highest flow numbers ever heard of with highly modified cj heads
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Brent, did you get the finish on these heads from a wheelabrator machine ?
Baked, steel abrated.
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What is the highest flow numbers ever heard of with highly modified cj heads
I've seen some 300 cfm CJ heads before. Blair could probably tell you what some of the older Super Stock heads would do.
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I have ported several sets that flowed 310-315 cfm, and 210 on exhaust. Joe-JDC
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They sure look prettier than when they lived in Omaha :)
Well done for a set of stock heads
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Best I've personally done with a C1 head was 296/19x @0.700 with 2.09/1.65 valves 3/8 stems. I often wondered if the CJ casting was at all any better than the C1's these were flowed on a sf600 on 4.312 bore fixture.
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That's good info, I have some ugly CJ heads here with a weld repair and already been ported, no idea what I am going to do with them but they'd be a candidate for full porting. I need to actually drag them out and see what the difference is in the intake port between CJs and C1s, if any. I've read that the CJ looks like a LR port, but after the opening it ramps up and is more like a MR once you're in the runner. I didn't think an FE has enough runner length for all that transition so we'll see. Have one unported MR head I can compare as well.
In my little spreadsheet of head flows, highest flow for a LR port I have found is 290 @ .700 but it's not a very big sample size
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10+ years ago, I went 9.30's with iron heads in my Super Stock 428. 330-ish intake flow, 250-ish exhaust with brass in the floors. Heads were 155cc intake runner, and 121cc exhaust, mandated 3/8 stem valves, 2.097 and 1.665 diameters. Current rules favor the aluminum heads, even with the weight penalty.
For "no rules" uses, the cost to get really good numbers is prohibitive, compared to several aluminium options these days. Mild OE-appearing stuff, truck towing engines, or CJ restoration stuff are the places to use a CJ head these days, in my opinion. You just can't get anywhere close to the bolt-on aluminum heads from BBM and TFS with OE iron.
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I love this shot...
(https://farm2.staticflickr.com/1830/29433150028_abb71a06cd_c.jpg)
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Little big for a street master isn't it.
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Physically. :)
It's actually a Portosonic.
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I love this shot...
(https://farm2.staticflickr.com/1830/29433150028_abb71a06cd_c.jpg)
Hey Brent, how about a shot of that carb spacer?
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What the heck..... you couldn't fit two dommies :P
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What the heck..... you couldn't fit two dommies :P
Give me an intake adapter, a UR-19 intake, and we'll get on that!
I have a set of carbs and carb spacers to try out on my 390 project. Went ahead and had a 4150/4500 HVH adapter matched to it. I had good results from trying a skirted booster Dommie on a 354C with a Strip Dominator intake, so I always try one when I can on the higher rpm stuff.
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Cool, gonna be super cool when all done.
I honestly don't know much at all about 4500's, kinda outside my realm of interest.
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I honestly don't know much at all about 4500's, kinda outside my realm of interest.
You would like them.
You would like them a lot... 8)
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Man, at first I thought that was an Edelbrock P2S2 ( think that’s what it’s called...)
Thought it was a joke.....
Now I’m kinda interested in how that combo might shake out....
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Sent heads off to be ported. I think it will shake out pretty well for an old 390.
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Are port-o-sonics cast with Dominator flanges hard to find?
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Mike, I'm using a Super Sucker 4150/4500 adapter. No Porto's were made with Dommie flanges (to my knowledge anyway).
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There's one in the mezzanine of the shop, used to run it on my uncles drag car. Just wondering why I don't see people using them, like you in this situation.
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It's really a Port-o-sonic with a cast in Dominator flange? Or is it a 360?
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It's a port-o-sonic, cast in dominator flange. Or else somebody did a ridiculously good job modifying it and making it look right haha
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As you can see, I'm a big Molnar rod fan...
(https://farm1.staticflickr.com/836/42655454494_db8f67ea5b_c.jpg)
Two sets of those are Molnar 6.488" FE rods. One set is destined for my 390.
(https://farm2.staticflickr.com/1810/42655454374_2c92f390d0_c.jpg)
These rods only weigh 758g. Most Scat rods that I've seen come in somewhere around 830g. Quite a savings!
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pictures are good , the old saying , pictures are worth etc. thanks , to see what the pros use makes a difference to me .
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Heads are finished......added another column to the table:
In a table that's easier to read without scrolling up and down...
Intake Flow
Factory 3/8" Ferrea 5/16"-7mm Ported 5/16"-7mm, 2.080/1.650
.1 64 80 76 62
.2 124 139 138 126
.3 182 195 204 197
.4 211 230 235 260
.5 224 246 248 279
.6 231 253 250 281
.7 236 252 289
Exhaust Flow
.1 52 64 67 54
.2 87 100 115 107
.3 118 133 140 134
.4 144 162 157 156
.5 164 181 170 171
.6 174 188 180 183
.7 179 189 191
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Really nice numbers for iron heads, imagine the 5/16" are fairly light? No idea on reliability concerns of 5/16", or cost difference, but could help out the hydraulic roller guys if they work out.
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Every valve weighs about 85g. Incredibly light.
No issues with the smaller stem valves, it's almost common place to see 7mm and 5/16" valves on SBF and SBC heads these days.
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Hmmm - got to really lift that intake to get the full benefit but it does really start to wake up over .3. Interesting how it took a real hit coming off the seat. Exhaust didn't seem to make much difference, pretty decent out of the box.
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Did you happen to cc the ports before and/or after?
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Did you happen to cc the ports before and/or after?
I will cc them before assembly. I didn't check them before.
I'm going to set aside some time to work on them this coming weekend. They need to be milled and I need to see how much they need to be cut. I'll check a port too.
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Posted by: mbrunson427
« on: July 10, 2018, 10:35:28 AM »
Insert Quote
It's a port-o-sonic, cast in dominator flange. Or else somebody did a ridiculously good job modifying it and making it look right haha
it is most likely an Offenhauser Equa-Flow intake. I guess it is possible that there are some FE Super-Sonic intakes out there, but to my recollection I am only aware of that intake being available in sbc,bbc and big block Olds.
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Intake port volume is 162.2.
Increase of 7cc.
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I honestly don't know much at all about 4500's, kinda outside my realm of interest.
You would like them.
You would like them a lot... 8)
I have used 2 circuit dominators on aggressive street/strip big blocks a few times, the ifr's generally need to be reduced, and if the carb you use doesn't have a primary side power valve, you will want to add one, once you have done that, they work very well indeed..
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Heads are assembled and set up for my 390 dyno mule.
Very pleased with how they have turned out. 280-290 cfm from a 2.080" intake valve sitting in a 162cc port isn't shabby.
Assembled with Comp conical valve springs and PAC titanium retainers.
(https://farm2.staticflickr.com/1942/43970645850_f5c6467414_c.jpg)
(https://farm5.staticflickr.com/4847/44875006595_60e8c287b3_c.jpg)
(https://farm5.staticflickr.com/4865/44875006725_4da6530953_c.jpg)
And a shot of the mule......factory crankshaft, with Molnar rods and Racetec dome pistons.
(https://farm5.staticflickr.com/4834/45809902671_d989f116d2_c.jpg)
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Night and day difference between those heads and the ones I boxed up and sent out this summer! Nice work, they should do well, especially with your ability to keep the port volume under control
I cannot wait to hear the mule at full song!
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Just curious, what's the difference between the intake and exhaust valve seals?
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My "leftover pile" consisted of some 5/16" stem valves and some 7mm stem valves. A regular Viton seal for a 5/16" stem .530" guide is readily available, but I had to scrounge up some Viton seals for the 7mm stems. The 7mm exhaust valves got the orange seals.
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Broncos fan is my guess....
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My "leftover pile" consisted of some 5/16" stem valves and some 7mm stem valves. A regular Viton seal for a 5/16" stem .530" guide is readily available, but I had to scrounge up some Viton seals for the 7mm stems. The 7mm exhaust valves got the orange seals.
And I was guessing there was something special about the orange seals. Sometimes a round peg is just a round peg..lol
Ross, not gonna lie, I'd be disappointed if he was a Broncos fan ;D