Porting small block 915 j-heads

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Is it bad ??

I don't think so....
I've got to do a set of BBM heads this week.. I will make a point to epoxy guide to a point, like that, so see if the bench likes it or not.
 
I would say the most scienced out heads I’ve worked on were the SBC 18* heads that came off the Busch motors.

No sharp edges.

I don’t put sharp edges on the leading edges....... but not for concerns of air flow(although, I don’t think a pointed leading edge is fundamentally correct from an aerodynamic standpoint).
 
I don't think so....
I've got to do a set of BBM heads this week.. I will make a point to epoxy guide to a point, like that, so see if the bench likes it or not.

Please let me know
I would say the most scienced out heads I’ve worked on were the SBC 18* heads that came off the Busch motors.

No sharp edges.

I don’t put sharp edges on the leading edges....... but not for concerns of air flow(although, I don’t think a pointed leading edge is fundamentally correct from an aerodynamic standpoint).

Maybe it’s not too late to make them less sharp if it turns out 63GT:s bench doesn’t like it.
From what I’ve learned so far is that experience and equipment is a VERY good thing to have.
Shape , flow test , reshape , flowtest again , pitot tubes , flowballs , the sound of a port and so on and on and on.
Everything is experience and testing.
 
Please let me know


Maybe it’s not too late to make them less sharp if it turns out 63GT:s bench doesn’t like it.
From what I’ve learned so far is that experience and equipment is a VERY good thing to have.
Shape , flow test , reshape , flowtest again , pitot tubes , flowballs , the sound of a port and so on and on and on.
Everything is experience and testing.

I have seen that sort of thing in some Super Stock Hemi heads 20 yrs ago... the details are a little foggy, but they abandoned it cause they didn't want any of the epoxy coming loose at 8000 rpm.:eek:
 
So , I made a provisional "flow bench".

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Just a U tube manometer with water to see what happens
My readings on the ruler was


Stock port

,050" 890 mm 35”
,100" 635
,150" 528
,200" 472
,250" 433
,300" 425
,350" 418
,400" 415
,450" 413
,500" 413 mm 16”

,550" 415
,600" 418

Ported

,050" 890 mm 35”
,100" 570
,150" 470
,200" 413
,250" 395
,300" 383
,350" 377
,400" 372
,450" 370
,500" 368
,550" 364
,600" 364 mm 14”

As I can see it and understand this the stock port stalls at ,450" and backs up.
I also see and understand that something has happened in comparison between the ports and as I can see it´s good so far. Still haven´t done the valve job with bigger valves and angles.

Thoughts ??? (are welcome)
 
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I am assuming the numbers next to 'lift' is corresponding millimetres in the made up manometer? 890 mm = 35" H20 , 364 mm = 14" h2o ?
Although those numbers can't be converted into CFM, we can see your baseline max flow of 413 mm @ .450" is now at .200" on the ported version. Given no valve job has been done, I would call that a success!
 
That was a good read.......I think I will just port match my camel humps!
You guys are way more patient than I. I don’t need to destroy a set of heads. I was pondering it though!
Knowledge and skill come with time and practice. Sharing information is like giving away trade secrets.

Kudos gentlemen. This is helping keep real talent around.
 
That's how i made my first bench, as the hole get bigger the inch of water go down as you only have a set volume.
It will get you hook and cause you to make the next step when you realize it short comings.
don't get me wrong you can lean a lot. A lot more then if you had no measuring stick.:)
If you count that one i have had 3 flow benched. but i consider that one as just a get your feet well exercise.
quick simple and most important vary inexpensive to build.:thumbsup::thumbsup:
 
:)
I am assuming the numbers next to 'lift' is corresponding millimetres in the made up manometer? 890 mm = 35" H20 , 364 mm = 14" h2o ?
Although those numbers can't be converted into CFM, we can see your baseline max flow of 413 mm @ .450" is now at .200" on the ported version. Given no valve job has been done, I would call that a success!

You are right there. Forgot to add millimeter after the numbers. I assumed you guys would understand and you did.

Where will the bigger valve and valve job show?
Valve job from ,200” and down?
Bigger valve all over the readings?

I for sure will have to take the heads to a real flow bench to get a receipt on the results





That's how i made my first bench, as the hole get bigger the inch of water go down as you only have a set volume.
It will get you hook and cause you to make the next step when you realize it short comings.
don't get me wrong you can lean a lot. A lot more then if you had no measuring stick.:)
If you count that one i have had 3 flow benched. but i consider that one as just a get your feet well exercise.
quick simple and most important vary inexpensive to build.:thumbsup::thumbsup:
Cheap but yet taking some time to do.
Mostly done on working time :):thumbsup:
 
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Nice workmanship KMA.
Seen a few guys have made their own flowbenches, thats well cool!
I have a friend in California who is from Finland, he used to live and work in Sweden and now in the US of A.
He has incredible skills when doing sheetmetal and has restored many Mopars, to the top level.
Not only can he do wonderful work he also speaks three languages too.
What is it with you Scandanavians, blonde hair, looks to die for and very talented...
Me, I can port heads, look awful and speak English very badly , ''so my wife says''...:lol:

From what I can gather, the airflow should NOT be promoted around the 'long side' of the port as it can 'bump into' the main flow and it can stall it. (Hotrod Dulcich)
So I would always keep the guide 'knife edge' straight or even biased away from the inner wall.
STR

340 J port floor to wall modification.jpg


Guide edge.jpg
 
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Ohh. Never reflected over that it was straight. Hmmm.

How did you know I was blonde? Ha ha

Ready for guides
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Hi guys and Gals,

Short Side Radius, what's the LOWDOWN on 'how far to go'?

Anyone got some flow bench info as I don't want to wreck a good set of J's by 'going to hard' at IT!

340 J floor waterway SSR info.jpg


This is a 'Weslake' J-head cutaway I found here in the UK.
As you can see the floor is limited by the waterway, but how far should you 'pull the seat' BACK???
 
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Been studying my ‘Weslake’ J head ‘cutaways’ and they are very interesting indeed.
We all know about ‘Bob Mullen and Keith Black’s work’ on the famous 70 T/A heads for the “lunchbox 305” cube NASCAR engine, but was there work on the stock J heads being done at Weslake UK too?
Harry Weslake was ‘all for’ smallport heads...
This was more about a good ‘range’ of power for street driven cars!
When it comes to ‘high speed ovals’ then big is best...

I have been reading the wonderful Sox and Martin, most famous team in racing book.
They ran a F/stock Duster 1972 with a S/b 340 into the twelves. (11.70 best)
Maybe if they didn’t have 700hp hemi’s to play with, they would have done a lot more J head work lol...
 
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Hi guys and Gals,

Short Side Radius, what's the LOWDOWN on 'how far to go'?

Anyone got some flow bench info as I don't want to wreck a good set of J's by 'going to hard' at IT!

View attachment 1715716439


As you can see the floor is limited by the waterway, but how far should you 'pull the seat' BACK???
You don't really... you do like the cutaway.
 
Thanx for the reply Mopar official.

There are limitations with all cast iron head as we all know.
The T/A head had the best modification with the un-drilled pushrod tube!
The other side of this cutaway has been ported with a tube inserted down the pushrod hole.
You can then widen the port up to over an 'inch' wide and this straightens it up nicely too.

The 'Weslake W1' Big Block heads I have are unique, as they are bigger versions of the infamous W2 heads.
Ovalport intake and 'D' port exhausts.
Even more amazing is one head has 'cast in' guide bosses and the other has bronze 'race type guides that are prominent in the port.
But still a pair of very unusual heads indeed.
2.250 intake valves and 1.80 exhausts.

Weslake 426 heads .jpg


Weslake 426 open chamber head with  extra water passages.jpg


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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...

Ovalport Weslake intake ports.jpg


D-port exhaust Weslake 426 D5ish.jpg


Ovalport 426 hemihead D5 Weslake.jpg
 
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Heres conservative. This is a 251 cfm @.500 flowing intake port. Small bowl. 2.02/1.60 974 j
.300 194cfm
.400 222 cfm
.450 242 cfm

I'll dig up some other pics.

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How much short side work do you have on them?
How to gauge that... some to a decent amount? It goes beyond. Its entirety is the floor hump from the floor to the valve job. You work the wall somewhat and the hump off it... keeping it tall though. If you lay it back and keep it stock heigh...you'd leave a lip at the top to pull mid/roof air and get the same flow or so.
Funny how the bowl is touchy..but the turn could be a range of shape/length.
Your low lift can be great with a small bowl but just croak at 230cfm and in the .400s..or you can make it bigger and get the full range...then bigger and watch the low lift fade. You can gain stable high lift and just wipe the .300 into the 170's..from 190's. When looking at a head..bowl shape can tell you things.
 
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...

340 J head cutaway with template.jpg
 
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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...

Roosta Poly heads.jpg
 
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