Had my X heads ported - results

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512Stroker said:
Acid porting has fast become a lost art. NHRA engine builders have tight lips and the ones that know how to do head work dont give up their secrets. They produce 500 hp 340's that need to pass an NHRA tare down. The acid ported heads look like factory castings when done correctly. Most builders now use the NHRA approved special Edelbrock alloy heads, which are now becoming very hard to come by.
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Agreed.
 
rmchrgr said:
Not to get too much off topic but stocker combinations are really about sciencing out the entire car. Crazy lightweight tricks, big dollar converters and fully rollerized transmissions, 5.xx rear gear ratios, yada yada. The engine is a big part of the equation for sure and the heads certainly make up a large percentage of what makes power but as you likely know it's he whole combo that makes those cars so impressive. Nothing streetable about them espcially with bigger oil clearances. But to your point successful S/E engine programs are borderline pro level that are put together by guys with a ton of money and/or experience or both.

Like I alluded to, the heads that 512stroker ended up with could very well have been hand-picked out of many individual castings. In my mind stocker engine builders wouldn't just pick a random set of heads and give them the full work up, they try to find particular castings that show the most potential before any real work starts.

But yeah, being able to use aftermarket aluminum heads renders that whole process moot now. All the good factory castings are probably used up or gone now anyway so the switch to aluminum could have been borne out of necessity due to a forever dwindling supply of usable OE parts.

My point being though that your average A Body forum guy using them in a weekend warrior street machine type build up might not achieve the same results employing a similar methodology with a random pair of heads that someone left laying in the dirt for 40 years. And even if they could get them to perform really well, their car still may not work as well as a competitive stocker or an well-planned off the shelf combo with better flowing aftermarket heads.
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I agree, it's much the same in every class of racing. The engine is but a small part. In stock eliminator though, it's a bigger small part, since everything has to meet really strict rules. It all has to work together perhaps even more than any other class. And then the engine and rest of the car must work together perhaps even better than any other class.....at least to be competitive. That's what makes that class so exciting.
 
rmchrgr said:
Not to get too much off topic but stocker combinations are really about sciencing out the entire car. Crazy lightweight tricks, big dollar converters and fully rollerized transmissions, 5.xx rear gear ratios, yada yada. The engine is a big part of the equation for sure and the heads certainly make up a large percentage of what makes power but as you likely know it's he whole combo that makes those cars so impressive. Nothing streetable about them espcially with bigger oil clearances. But to your point successful S/E engine programs are borderline pro level that are put together by guys with a ton of money and/or experience or both.

Like I alluded to, the heads that 512stroker ended up with could very well have been hand-picked out of many individual castings. In my mind stocker engine builders wouldn't just pick a random set of heads and give them the full work up, they try to find particular castings that show the most potential before any real work starts.

But yeah, being able to use aftermarket aluminum heads renders that whole process moot now. All the good factory castings are probably used up or gone now anyway so the switch to aluminum could have been borne out of necessity due to a forever dwindling supply of usable OE parts.

My point being though that your average A Body forum guy using them in a weekend warrior street machine type build up might not achieve the same results employing a similar methodology with a random pair of heads that someone left laying in the dirt for 40 years. And even if they could get them to perform really well, their car still may not work as well as a competitive stocker or an well-planned off the shelf combo with better flowing aftermarket heads.
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You hit the nail on the head, pun intended, it's the entire package that make those Eliminator cars work.
I got lucky the NHRA builder that originally did these heads is a friend of mine.
This set were "spares" after some racers converted to alolly heads.
 
512Stroker said:
You hit the nail on the head, pun intended, it's the entire package that make those Eliminator cars work.
I got lucky the NHRA builder that originally did these heads is a friend of mine.
This set were "spares" after some racers converted to alolly heads.
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There you go. They probably would have worked pretty well before your guy did them up. Starting from a more advanced point is always advantageous.

The exhaust are just about at 70% of the intake flow which is pretty much what you're after. Going by the numbers on the paper, with the 2.02 intake @ .6" lift he has 268.7. 70% of that is about 187 so you're right there at the higher lift with 186.8. Coincidence?

Looks like both side totals were averaged out on the bottom so not all the readings conform to the rule exactly but close enough for horseshoes and hand grenades.
 
rmchrgr said:
I would like to know what the acid porting did! Always been curious about that process. Did the ports look a certain way? What was the valve job like?

A S/E valve job has a LOT of science and skill behind it so these castings must have made the cut. If someone went to the trouble of acid porting those particular castings they must have showed better potential than the other 900 sets that were gone though before those were chosen.
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Exactly Correct!!

I have 200 sets of the part # Heads we have use our various Stock/SS cars and have disposed of at least another 100+ Sets.

You would be surprise how much the same # heads vary on a flow bench = Also true on the intake manifolds!!

Often there are as many a 10 cars in each of our classes - all within a .1 of a second.
In Denver @ Nationals some year back - I won a class race against a 340 Cuda
heads up by .0001 of a second true margin of victory. You could not see who won
with a naked eye! For every second we are on the Track = Ther is a Week's work in the shop!!
 
GTX JOHN said:
Exactly Correct!!

I have 200 sets of the part # Heads we have use our various Stock/SS cars and have disposed of at least another 100+ Sets.

You would be surprise how much the same # heads vary on a flow bench = Also true on the intake manifolds!!

Often there are as many a 10 cars in each of our classes - all within a .1 of a second.
In Denver @ Nationals some year back - I won a class race against a 340 Cuda
heads up by .0001 of a second true margin of victory. You could not see who won
with a naked eye! For every second we are on the Track = Ther is a Week's work in the shop!!
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I bet the argument ensued there, didn't it? lol
 
I have a 273 with 302 and intake that the heads and intake are acid ported. The car ran in stock eliminator. The ports look factory. The motor was in a 66 Valuant
 
I was racing Earl Blake and he is a friend. Most everyone that runs a Mopar Stock/SS
in the Western US is a pretty good friend of mine. we check fuel and weigh after the run.
My car weight exactly to the pound the minimum it could legal weigh and Earl's Cuda was 5 lbs
over his minimum. I told him "You would have beaten me by about .0004 if you had been 5 lbs lighter.
However, if my car had been a scant one pound lighter = I would have been disqualified. I was glad to weigh -
so I could visit the bathroom (Would not of made weight and I knew I was very close). Actually the timing system will
determine a winner if it is a dead heat on the clocks! Street Racing (How I used to make my living) is a different story
of racing if it is that close!
 
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davescuda said:
I have a 273 with 302 and intake that the heads and intake are acid ported. The car ran in stock eliminator. The ports look factory. The motor was in a 66 Valuant
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Shush!!!!!!!!!!!!!


PS: I could tell!

Hint: look at the short turn radius.
 
GTX JOHN said:
I was racing Earl Blake and he is a friend. Most everyone that runs a Mopar Stock/SS
in the Western US is a pretty good friend of mine. we check fuel and weigh after the runf it is a.
My car weight exactly to the pound the minimum it could legal weigh and Earl's Cuda was 5 lbs
over his minimum. I told him "You would have beaten me by about .0004 if you had been 5 lbs lighter.
However, if my car had been a scant one pound lighter = I would have been disqualified. I was glad to weigh -
so I could visit the bathroom (Would not of made weight and I knew I was very close). Actually the timing system will
determine a winner if it is a dead heat on the clocks! Street Racing (How I used to make my living) is a different story
of racing is that close!
Click to expand...
Years ago I sometimes would help out on a Trans Am team. To make weight they used a big steel donut that looked like a roll of Duct Tape. It was not in the car during the race but would magical appear in the car before it got to the scales.
 
Nice thread indeed!

In Stock classes it’s all about the best castings you can find!
All eight intakes and exhausts must flow identical and if possible outflow the best ‘of the best’ available...

Every casting has issues and some are terrible.
Flow benching a 100 identical heads would be mind numbing.

If you are lucky to get a pair of those ‘best of bunch’ heads, what a great starting point indeed...

I have ported about a dozen pairs of ‘J heads’ on the whole, they are all OK.
Picked up some cutaways from Weslake Eng. they are so helpful...
 
512Stroker said:
Just got my old LA 340 X heads back from a local retired engine builder.
I left the heads with him for some economy street performance porting as this is not a track engine. I had to remove the heads to swap out some bogus hyd roller lifters so I thought what the hell I'll have them cleaned up. These heads were prior used on a NHRA stock Eliminator LA 340 and had been acid ported. I also provided a new in the box Edelbrock AirGap intake that he touched up. The flow numbers shown below are through the intake and the head.
I would have liked to seen a little better exhaust numbers, but for $200 I'm not going to *****.
The Gent that did the work told me, which I agree, that its not so much the numbers but the shape of the port that really makes them work. Maybe when I get my back in better shape I'll post some pic's of the heads.
Jim K

View attachment 1715833116

View attachment 1715833117
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Looks pretty good numbers even compared to some aftermarket.
The fellow is correct, exhaust flow at 28" depression is not a big deal. Remember in a NA engine, the intake only has atmospheric pressure to push the air into the cylinder. When the exhaust valve opens, the cylinder pressure is still about 70 to 100PSI. This causes supersonic velocity exhaust gases passing out the barely open valve. This is important for pulse tuning of the exhaust, to get the high velocity colume of exhaust in the head pipe. When tuned correctly this arrives at the collector and transmits a negative pressure back up the exhaust which should arrive at the almost closed exhaust valve, just about the time the intake valve is opening. The negative exhaust pressure at the valve helps vacate the combustion chamber. Whatever atmospheric pressure is at the port side of the intake valve at valve opening is aided in initiating intake flow by the negative pressure in the cylinder, while the piston is still approaching TDC.
 
So I have a numbers matching 72 340 duster... It is early enough 72 the motor came with the big valve j heads however I believe it's still had the 8:5/1 compression ratio... My intention, I'm going to keep all of my numbers matching parts however this motor will be built to the spec of a 1970 340 4 speed car... I am looking for a set of X heads that aren't into terrible shape, if anyone could help me out with that I would greatly appreciate it!
 
ParDaddy said:
So I have a numbers matching 72 340 duster... It is early enough 72 the motor came with the big valve j heads however I believe it's still had the 8:5/1 compression ratio... My intention, I'm going to keep all of my numbers matching parts however this motor will be built to the spec of a 1970 340 4 speed car... I am looking for a set of exits that aren't into terrible shape, if anyone could help me out with that I would greatly appreciate it!
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"exits"? Do you mean X heads?
 
ParDaddy said:
Yes, my humble apologies... Missed some of that fancy book learning early on
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That may be a tall order.
I would start with perhaps contacting GTX JOHN an FABO member in CO
And posting a Parts Wanted ad in the FABO classified's
 
Dale Davies said:
Looks pretty good numbers even compared to some aftermarket.
The fellow is correct, exhaust flow at 28" depression is not a big deal. Remember in a NA engine, the intake only has atmospheric pressure to push the air into the cylinder. When the exhaust valve opens, the cylinder pressure is still about 70 to 100PSI. This causes supersonic velocity exhaust gases passing out the barely open valve. This is important for pulse tuning of the exhaust, to get the high velocity colume of exhaust in the head pipe. When tuned correctly this arrives at the collector and transmits a negative pressure back up the exhaust which should arrive at the almost closed exhaust valve, just about the time the intake valve is opening. The negative exhaust pressure at the valve helps vacate the combustion chamber. Whatever atmospheric pressure is at the port side of the intake valve at valve opening is aided in initiating intake flow by the negative pressure in the cylinder, while the piston is still approaching TDC.
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The only time exhaust goes sonic is under detonation.
 
I have a nice virgin unmodified set of X Heads left:
$500.00 plus Freight

If Pistons are about .050(Approx.) down in the bore and 4 Valve Notches
they are 72 or 73

If Pistons are about .050 (Approx.) above and have only 2 valve notches
they are 68 to 71
 
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GTX JOHN said:
I have a nice virgin unmodified set of X Heads left:
$500.00 plus Freight

If Pistons are about .050(Approx.) down in the bore and 4 Valve Notches
they are 72 or 73

If Pistons are about .050 (Approx.) and have only 2 valve notches
they are 68 to 71
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Little things like that 2-4 valve notch is why I'm a member of this group!
...and the commentary
Interested in the heads also, be after Christmas tho...
 
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