Porting small block 915 j-heads

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polyjohn said:
As you can quite easily see, the pushrod tubes are 'non existant' on these heads.
Intake valves have been re aligned to make way for the Ovalport design.
This means that the intake rockers had to be made to compensate too.

The exhaust ports (always weak on 906 heads) were 'D ported' like the D5 hemi head, so flow would have be much better.

These were NOT designed as 'race heads' but clearly have a 'heat cross over' for passenger car use!
As the 'powers to be' were banning the Aero cars they were also going to ban the hemi in 1970/1971.
This was going to be the answer for the street-440 and the 426 race engines too.

For whatever reason they never got into production and the W2 heads were also to suffer this fate...

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I knew I’ve read about these heads before. From the old SA Design “Mopar Performance” book (1978):

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The heads shown in the pictures from the book have different chambers than the heads you have shown. Any idea what became of these?
 
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Happy New Year 12many!

The heads in your pictures were in the UK for development at 'Weslakes' but went back to Chrylser as duds!
They are in the Chrysler Museum wherever that is lol?
Apparently the 'closed off' chamber design was too radical and hurt the 'flame travel'...
They were highly ported as you can see from the pictures.

The heads I have here are the stock for 68-70 'open' chamber.
A direct replacement to the 906 after the 915 of 1967.
Why they never got into production is a mystery as they are obviously 'passenger car heads'.

Very nicely shaped 'ovalport' intakes with extra cooling passages for heat travel.
This design was used in much later 'Motorhome heads' to overcome 'hotspots'.

These heads I have here un 'unported' as cast and are different port designs as well?
One head has cast in guides like a 906, the other is much more modern looking with the guide sitting in the port...
Plug location slightly towards the intake valve which is 2.250 in diameter!

Ovalport 'Weslake one' intake ports.jpg


Weslake 426 open chamber head with extra water passages.jpg
 
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polyjohn said:
Oceanside sounds wonderful indeed!

Do you know Gary Pavlovich in San Diego?
He has been a wealth of knowledge with our 402ci Poly build.
He supplied us with everything we needed for a 400hp engine.
Just one head casting for a Poly lol...

11/32 stemmed 'cut down' custom valves, 2.02 and 1.60.

Is that what you use in your LA heads 11/32 stems???

Have you done any Poly porting?

Best wishes from the poly porters of Plymouth England...

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I don't really hang out with anyone anymore. I know of Gary and some others.
Most of us aren't the sharing type.. last time I had a head flowed by a guy in escondido who does nitro crackle stuff..when the numbers were in.. he was amazed..especially since he knew i was a no body..it became a couple questions from him..and then when I asked some things... he gave vague responses and then didn't wanna flow nu heads anymore...so i bought my own flow bench ..and here i am.
I use the lighter 11/32 valves ,yes.
Poly stuff I haven't played with much outside of tuning them. Short square ports, low roof. I'd like to see what I could get out of them one day.
 
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WoW MO!

You are a true master of the wizzy wheel and flowbench.

I thought that it was only me that 'doesn't hangout' anymore lol...

When the aluminums came on strong the 'iron-men' were laughed at!

But for folks who have time and skills, a ported IRON head is STILL a work of ART!

I put you up there with the great Bob Mullen the T/A master!

HNY from Limey John

Bob Mullen W2.jpg
 
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SAM of Houston and the Hinkles have done some wonderous things with poly's.

mopar-318-poly-cylinder-head.jpg


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Lot of potential in a Poly head, maybe even more that a 340 LA head?
 
I kinda missed a time period and I think I’m both happy, and sad about it. In the 1970’s early 1980’s I manly street raced because we raced all week. But on weekends I did run a best of 11.82 when at the track with my 340 and ported stock heads. Then I hopped into big blocks. After my wreck in 2010 I jumped into the seat of the black duster I bought but my son was racing. Edelbrock heads were everywhere plus I got one set with my duster. They were so easy (and clean) to work on so I continued to do so. A nicely ported set of stock cast iron heads can be a beautiful thing in the right hands. And run great too. Keep up the great work guys.
 
Everything old is new again...

HNY Pittsburgh-Racer!

Life got tooo easy for the 21st Century folks I believe?
Much more fun when we all sang from the same HYMM sheet.

Iron heads from the factory and purple shaft cams lol...
Too much choice now and everything is STROKER this, STROKER that...
Ali heads and roller cams and roller rockers, roller skates, roller whatever...

I remember in the early 90's going out in my 69 R/T 'all iron' Charger to the local freeway .
Taking a friend or two only for a ride and (conditions OK) running her off the 150 clock and some more...
Most of them never came again lol...

It ran 12's all day long and Gods know what the top end was...

Sold the car and kept the iron heads, they was a work of ART!!!

I'm proud to be the Mid ten second club with and All IRON 452ci/steel street car lol...

Cooky's Dodge.jpg
 
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polyjohn said:
Nice work Moparofficial!

Happy New Year from a porting Limey lol.

I read on another site that the 'X' head is better than the 'J'?
They prefer them to the 'J' for Superstock (back in the day)

Whenever I do the port floor I get all nervous and anxious about a break through!

This is the template I use for max flow lol...

The curve is actually 2.02" drawn around an intake valve approx 1.00" high...

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I will post pics of x heads I ported and 308 heads i also ported....magnum heads too...and 906...and slant and 915 bb....
Done most of the regular stuff and w2. I have not had any max wedge, p7,w9,w8...yet.
The 1970 j heads in the pic touch 280's and are 186cc port...like a w2.
587's 260's cfm and 173cc

You have to love it, pride it and embrace the potential...at the same time staying grounded. There are better heads and cores are not the same....gotta be a gambler.
 
12many said:
I knew I’ve read about these heads before. From the old SA Design “Mopar Performance” book (1978):

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The heads shown in the pictures from the book have different chambers than the heads you have shown. Any idea what became of these?
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I have that book.
Pic 3. "The chamber is the reason for the disappointing flow"
Not just with that head...think 302
 
Much thanks for posting so much information, learning a lot here. I’ve got a set of 1975-1985 production HD 360 475A heads Ive been comparing to a set 974 heads. So far the exhaust ports are nearly identical and the intakes appear to be, too. I’ll know after I get them baked and blasted how closely related they are.
 
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Garrett Ellison said:
Much thanks for posting the video link. Learning a lot there as well as here. I’ve got a set of 1975-1985 production HD 360 475A heads Ive been comparing to a set 974 heads. So far the exhaust ports are nearly identical and the intakes appear to be, too. I’ll know after I get them baked and blasted how closely related they are.
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Anytime.
Imo 1.94 valves are the way to make short work for 250 cfm in that head.
The 2.02 is great..but more material need removed to get the shape .
 
MOPAROFFICIAL said:
Anytime.
Imo 1.94 valves are the way to make short work for 250 cfm in that head.
The 2.02 is great..but more material need removed to get the shape .
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Thanks again! That is exactly the pre existing plan on the intake side with some 5/16 stem valves. I’m debating if I should have hardened seats installed to bring the exhaust valve height back up or if if should go with a larger exhaust valve, I haven’t got to talk to my machinist about that detail yet, but I’m thinking a 1.65 would probably do it. I’ll be cheating a little leaded fuel into the mix to help the seats live, anyway. I’m going to be running a .533 lift with [email protected] solid. FWIW, they’ve been running a lot of four angle valve jobs on the performance stuff.
 
Garrett Ellison said:
Thanks again! That is exactly the pre existing plan on the intake side with some 5/16 stem valves. I’m debating if I should have hardened seats installed to bring the exhaust valve height back up or if if should go with a larger exhaust valve, I haven’t got to talk to my machinist about that detail yet, but I’m thinking a 1.65 would probably do it. I’ll be cheating a little leaded fuel into the mix to help the seats live, anyway. I’m going to be running a .533 lift with [email protected] solid. FWIW, they’ve been running a lot of four angle valve jobs on the performance stuff.
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That's only .025 wider, go with a hard seat instead is my advice.
 
Okay, I was afraid that was going to be the case at less than 1/32. I imagine 1.60 exhaust valves would be adequate, but what are your thoughts? With the single pattern cam on a 103, would a larger exhaust valve be of any benefit? Using standard 1-5/8 A body headers.
 
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MOPAROFFICIAL said:
I have that book.
Pic 3. "The chamber is the reason for the disappointing flow"
Not just with that head...think 302
Click to expand...

Better go tell all the race head manufacturers they need open chamber heads because they flow more.....
 
Garrett Ellison said:
Much thanks for posting the video link. Learning a lot there as well as here. I’ve got a set of 1975-1985 production HD 360 475A heads Ive been comparing to a set 974 heads. So far the exhaust ports are nearly identical and the intakes appear to be, too. I’ll know after I get them baked and blasted how closely related they are.
Click to expand...
What video link, i don't see it?
 
You are so right MO!

Steve Dulcich is also a very clever guy indeed has done wonderful work with iron heads too!
He has said in the past that the Small-block 340 head far 'outflows' and Big-block head in stock form.

But I have seen Pro-Porters getting 300 cfm with a 906 and close to that with a 452 especially Koffel.
They also say a badly ported head will put you down in the LOW 200's if you mess up the flow.

This is where the Flow bench tells you when 'enough is enough' and dimishing returns and/or breakthrough occurs!

I am a great admirer of 'Ovalport heads' and love what the Hinkles did with their 550hp POLY build...

Ovalport poly Hinkles 426ci.jpg
 
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