Author Topic: Goofing off with some CJ heads... (Read 13476 times)

blykins · « **on:** June 22, 2018, 08:25:42 PM »

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.

Joey120373 · « **Reply #1 on:** June 22, 2018, 08:51:21 PM »

Thanks for sharing.

Heo · « **Reply #2 on:** June 23, 2018, 06:47:38 AM »

Is it with the stock 30 deg seats on intake?

blykins · « **Reply #3 on:** June 23, 2018, 07:00:56 AM »

No sir, 50° on the intake, 45° on the exhaust.

blykins · « **Reply #4 on:** June 23, 2018, 07:17:37 AM »

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.

Heo · « **Reply #5 on:** June 23, 2018, 07:18:06 AM »

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?

blykins · « **Reply #6 on:** June 23, 2018, 07:26:32 AM »

Quote from: Heo on June 23, 2018, 07:18:06 AM

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".

Heo · « **Reply #7 on:** June 23, 2018, 07:36:30 AM »

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

blykins · « **Reply #8 on:** June 23, 2018, 07:39:22 AM »

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

Heo · « **Reply #9 on:** June 23, 2018, 07:42:27 AM »

Thank you sir.
Interesting

scott foxwell · « **Reply #10 on:** June 23, 2018, 08:54:00 AM »

Would have been interesting to do the small stem valves with a good 45* v/j.

KMcCullah · « **Reply #11 on:** June 23, 2018, 09:30:31 AM »

Quote from: Heo on June 23, 2018, 07:18:06 AM

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

preaction · « **Reply #12 on:** June 23, 2018, 01:20:23 PM »

Brent, did you get the finish on these heads from a wheelabrator machine ?

fryedaddy · « **Reply #13 on:** June 23, 2018, 01:25:29 PM »

What is the highest flow numbers ever heard of with highly modified cj heads

blykins · « **Reply #14 on:** June 23, 2018, 01:41:25 PM »

Quote from: preaction on June 23, 2018, 01:20:23 PM

Brent, did you get the finish on these heads from a wheelabrator machine ?

Baked, steel abrated.

blykins · « **Reply #15 on:** June 23, 2018, 01:43:02 PM »

Quote from: fryedaddy on June 23, 2018, 01:25:29 PM

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.

Joe-JDC · « **Reply #16 on:** June 23, 2018, 03:35:20 PM »

I have ported several sets that flowed 310-315 cfm, and 210 on exhaust. Joe-JDC

My427stang · « **Reply #17 on:** June 23, 2018, 04:22:06 PM »

They sure look prettier than when they lived in Omaha

Well done for a set of stock heads

bluef100fe · « **Reply #18 on:** June 24, 2018, 10:11:05 PM »

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.

chilly460 · « **Reply #19 on:** June 25, 2018, 07:50:44 AM »

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

CaptCobrajet · « **Reply #20 on:** June 25, 2018, 11:59:03 AM »

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.

blykins · « **Reply #21 on:** July 09, 2018, 12:09:33 PM »

I love this shot...

cattleFEeder · « **Reply #22 on:** July 09, 2018, 12:39:37 PM »

Little big for a street master isn't it.

blykins · « **Reply #23 on:** July 09, 2018, 12:48:29 PM »

Physically.

It's actually a Portosonic.

KMcCullah · « **Reply #24 on:** July 09, 2018, 01:52:12 PM »

Quote from: blykins on July 09, 2018, 12:09:33 PM

I love this shot...

Hey Brent, how about a shot of that carb spacer?

Drew Pojedinec · « **Reply #25 on:** July 09, 2018, 01:59:02 PM »

What the heck..... you couldn't fit two dommies

blykins · « **Reply #26 on:** July 09, 2018, 02:02:08 PM »

Quote from: Drew Pojedinec on July 09, 2018, 01:59:02 PM

What the heck..... you couldn't fit two dommies

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.

Drew Pojedinec · « **Reply #27 on:** July 09, 2018, 02:15:39 PM »

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.

Barry_R · « **Reply #28 on:** July 09, 2018, 02:25:54 PM »

Quote from: Drew Pojedinec on July 09, 2018, 02:15:39 PM

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...

Joey120373 · « **Reply #29 on:** July 09, 2018, 03:06:15 PM »

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....

blykins · « **Reply #30 on:** July 09, 2018, 03:21:52 PM »

Sent heads off to be ported. I think it will shake out pretty well for an old 390.

mbrunson427 · « **Reply #31 on:** July 09, 2018, 04:25:22 PM »

Are port-o-sonics cast with Dominator flanges hard to find?

blykins · « **Reply #32 on:** July 09, 2018, 04:31:27 PM »

Mike, I'm using a Super Sucker 4150/4500 adapter. No Porto's were made with Dommie flanges (to my knowledge anyway).

mbrunson427 · « **Reply #33 on:** July 09, 2018, 04:47:17 PM »

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.

blykins · « **Reply #34 on:** July 09, 2018, 04:57:55 PM »

It's really a Port-o-sonic with a cast in Dominator flange? Or is it a 360?

mbrunson427 · « **Reply #35 on:** July 10, 2018, 10:35:28 AM »

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

blykins · « **Reply #36 on:** July 12, 2018, 06:34:54 PM »

As you can see, I'm a big Molnar rod fan...

Two sets of those are Molnar 6.488" FE rods. One set is destined for my 390.

These rods only weigh 758g. Most Scat rods that I've seen come in somewhere around 830g. Quite a savings!

gdaddy01 · « **Reply #37 on:** July 13, 2018, 04:07:06 AM »

pictures are good , the old saying , pictures are worth etc. thanks , to see what the pros use makes a difference to me .

blykins · « **Reply #38 on:** September 30, 2018, 06:26:47 PM »

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

chilly460 · « **Reply #39 on:** October 01, 2018, 05:13:39 AM »

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.

blykins · « **Reply #40 on:** October 01, 2018, 05:25:01 AM »

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.

Falcon67 · « **Reply #41 on:** October 01, 2018, 09:09:03 AM »

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.

matt souders · « **Reply #42 on:** October 06, 2018, 03:21:34 PM »

Did you happen to cc the ports before and/or after?

blykins · « **Reply #43 on:** October 07, 2018, 06:06:50 AM »

Quote from: matt souders on October 06, 2018, 03:21:34 PM

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.

FErocious · « **Reply #44 on:** October 07, 2018, 12:28:43 PM »

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.

blykins · « **Reply #45 on:** November 08, 2018, 07:45:38 PM »

Intake port volume is 162.2.

Increase of 7cc.

falcongeorge · « **Reply #46 on:** November 09, 2018, 11:33:34 AM »

Quote from: Barry_R on July 09, 2018, 02:25:54 PM

Quote from: Drew Pojedinec on July 09, 2018, 02:15:39 PM
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...

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..

blykins · « **Reply #47 on:** November 10, 2018, 07:47:46 AM »

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.

And a shot of the mule......factory crankshaft, with Molnar rods and Racetec dome pistons.

My427stang · « **Reply #48 on:** November 10, 2018, 08:37:05 AM »

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!

cjshaker · « **Reply #49 on:** November 12, 2018, 01:02:46 PM »

Just curious, what's the difference between the intake and exhaust valve seals?

blykins · « **Reply #50 on:** November 12, 2018, 01:06:30 PM »

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.

My427stang · « **Reply #51 on:** November 12, 2018, 02:24:43 PM »

Broncos fan is my guess....

cjshaker · « **Reply #52 on:** November 12, 2018, 10:34:07 PM »

Quote from: blykins on November 12, 2018, 01:06:30 PM

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

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Author Topic: Goofing off with some CJ heads... (Read 13476 times)

scott foxwell

FErocious