Direct Connection ( Mullen LA ) heads

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Garrett Ellison said:
Correct! While the numbers aren't huge (about the same as properly worked J heads), they fit the class requirements well and allow enough of a weight break to put the car in the middle of the field. They should still feed 321 inches with a 1.94:1 rod ratio to just shy of 8000 rpm.
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I like how u think it will certainly make some nice ( Ear **** ) up above 7500 !
 
1Badcolt said:
Thank you keep in mind my model heads are simply 1975 smoger castings that were ported at Mullen and company !!!!
They are 5 years after the TA heads were campaigned and 1 year before the W2 was revealed my castings are mentioned as
(W1) in several 1975 publications.
Mullen offered a heavily modified (360 casting - same as mine but special welding needed etc for Pro-Stock class I wish I had some of those and my numbers would be more impressive nevertheless for class I want to race in these will work until I desire something else. I have a alot of money in these and many will question my direction versus other routes but These heads are Super rare to me and im honored to have um .

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Nevemind, I think you just answered my porting question. lol
 
RustyRatRod said:
Nevemind, I think you just answered my porting question. lol
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He did the Rpm intake and its beautiful ! All his work is exceptional

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So if I miss something here tell me what post that I can find it, my question is why so much lift on a style of head that typically begins to stall around 550 or so, I realize it will get to maximum flow quicker but it seems extreme to me. It seems like an extreme amount of spring pressure to accommodate questionable gain?
 
K.O. SWINGER said:
So if I miss something here tell me what post that I can find it, my question is why so much lift on a style of head that typically begins to stall around 550 or so, I realize it will get to maximum flow quicker but it seems extreme to me. It seems like an extreme amount of spring pressure to accommodate questionable gain?
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I’ve answered this before but I’ll do it again. You can make almost any port back up on a flow bench. Especially with the intake manifold not on the head when it’s flowed.

So let’s say at .450 lift you are flowing...I’ll pull a number out of my hat...220 CFM and at .500 you are flowing 205 and it stays there. If we assume that the port is actually backing up while it’s running with the intake manifold on, if you lift average you’ll see that more lift still gives a higher average. And that matters.

Like compression ratio, most guys don’t use enough lift. Just because a head does something at a certain lift at a certain test pressure doesn’t mean it actually does that when it’s running.
 
yellow rose said:
I’ve answered this before but I’ll do it again. You can make almost any port back up on a flow bench. Especially with the intake manifold not on the head when it’s flowed.

So let’s say at .450 lift you are flowing...I’ll pull a number out of my hat...220 CFM and at .500 you are flowing 205 and it stays there. If we assume that the port is actually backing up while it’s running with the intake manifold on, if you lift average you’ll see that more lift still gives a higher average. And that matters.

Like compression ratio, most guys don’t use enough lift. Just because a head does something at a certain lift at a certain test pressure doesn’t mean it actually does that when it’s running.
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Okay that all is legit but at what point is beating the hell out of the valve train for questionable gain? I'm asking because I don't know I just like things to last. Maximum performance for a few hard runs is not an approach that I would take.
 
"Why Lift beyond the peak flow of a head"
Its area.
Lets picture a cam lobe ..'a soft triangle' for the purpose of this example. Open close...the higher the lift-the wider apart each side= the more time in peak flow and just a blip at peak lift where it may or may not back up or saturate..or even momentarily dip and come back.

"Why beat the **** outa the valvetrain"
Who says you have to?
Thats on the lobe profile/designer of the cam.
Classic magazine 'everyone knows example' -- Hughes engines.
High velocity lobes .
 
K.O. SWINGER said:
Okay that all is legit but at what point is beating the hell out of the valve train for questionable gain? I'm asking because I don't know I just like things to last. Maximum performance for a few hard runs is not an approach that I would take.
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This engine is for a Vintage Super Stock class also and not a street vessel !
 
K.O. SWINGER said:
Okay that all is legit but at what point is beating the hell out of the valve train for questionable gain? I'm asking because I don't know I just like things to last. Maximum performance for a few hard runs is not an approach that I would take.
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I’m saying (and MO a explained it in more depth than I’m going to do here) is that you leave way more on the table than you think by using low lift.

As for hard on the valve train...that’s crazy. It’s 2021. The springs are better than ever. So are pushrods. And anyone with a smattering of gumption can correct their rocker geometry, which is where most valve train failures happen.

The GM guys are running .750 lift on the street and do it very reliably. Why should the Chrysler guys not benefit from higher lifts? You let the port do the work. You can run less seat timing, keep the same @.200 timing and make more power.

It’s the same with RPM. Chrysler guys are stuck at 6000 or maybe 6500. With a good oil pan and some careful prep work 7500 is easily doable. And that’s more horsepower. The gain from 6500 to 7000 is pretty good. You can also use a bit more gear with RPM and a loser converter, which BTW converter technology has gone through the roof.

So when you start adding up the gains from more lift, some RPM, gear and converter you are talking about some really big improvements.

For some, the minimal effort isn’t worth it. For me, it always is because the few extra dollars spent upfront pays big dividends in the end.
 
yellow rose said:
I’m saying (and MO a explained it in more depth than I’m going to do here) is that you leave way more on the table than you think by using low lift.

As for hard on the valve train...that’s crazy. It’s 2021. The springs are better than ever. So are pushrods. And anyone with a smattering of gumption can correct their rocker geometry, which is where most valve train failures happen.

The GM guys are running .750 lift on the street and do it very reliably. Why should the Chrysler guys not benefit from higher lifts? You let the port do the work. You can run less seat timing, keep the same @.200 timing and make more power.

It’s the same with RPM. Chrysler guys are stuck at 6000 or maybe 6500. With a good oil pan and some careful prep work 7500 is easily doable. And that’s more horsepower. The gain from 6500 to 7000 is pretty good. You can also use a bit more gear with RPM and a loser converter, which BTW converter technology has gone through the roof.

So when you start adding up the gains from more lift, some RPM, gear and converter you are talking about some really big improvements.

For some, the minimal effort isn’t worth it. For me, it always is because the few extra dollars spent upfront pays big dividends in the end.
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This information confirm my knowledge type of casting or design it is very strong at low lift numbers and benefit from more duration. I realizing compression is a consideration but it would help you extend the RPM range while decreasing un desirable angles and possibly unstable valve train. If we were talking about Apache heads or ls'cathedrals I would say yes and jam those valves to the Moon but we're not? 6,500 or 7,000 is one thing 8,500 or more it's night and day.
1Badcolt said:
This engine is for a Vintage Super Stock class also and not a street vessel !
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K.O. SWINGER said:
This information confirm my knowledge type of casting or design it is very strong at low lift numbers and benefit from more duration. I realizing compression is a consideration but it would help you extend the RPM range while decreasing un desirable angles and possibly unstable valve train. If we were talking about Apache heads or ls'cathedrals I would say yes and jam those valves to the Moon but we're not? 6,500 or 7,000 is one thing 8,500 or more it's night and day.
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Who said 8500? .600 lift is nothing. I do it on the street with heads that break over at .500 without an intake manifold and at 28 inches. I know the limits of the flow bench which is why I ignored the flow numbers.

I guess this won’t make sense to you until you get a flow bench and start testing. It appears you are still in love with flow numbers and that is not a good thing.

Look at the shape of the curve. Forget about much under .150 lift because it doesn’t matter. Ever. If you stop and plot out the lift curve against piston movement you’ll see why I can say that.

Then spend some time looking very close at overlap and the heads we are discussing. Overlap is looked at as a bad thing, but IMO if overlap is done correctly, and you shape the valve seat correctly you can lose quite a few CFM at .100 or even .200 lift and make way more power.

And then there is reverse flow...as a general rule when I see big low lift numbers (compared to valve size) I can say with almost 100% accuracy that the head will flow in reverse almost what it flows forward and that is not only pissing away power in the middle it kills driveability.

Edit: seat to seat duration is a bad way to make up for not running enough lift. That right there is a sure fire way to kill the middle and make driveability go to hell. Lift averaging proves this out. Add to that guys love to drop the intake duration (or add exhaust duration depending on your philosophy) and then blow the LSA out to get the RPM they want is another sure fire way to kill the middle of the power curve. Again, this relates to overlap, the overlap triangle and header design and function. If you use junk headers the engine becomes almost oblivious to changes in LSA.
 
K.O. SWINGER said:
This information confirm my knowledge type of casting or design it is very strong at low lift numbers and benefit from more duration. I realizing compression is a consideration but it would help you extend the RPM range while decreasing un desirable angles and possibly unstable valve train. If we were talking about Apache heads or ls'cathedrals I would say yes and jam those valves to the Moon but we're not? 6,500 or 7,000 is one thing 8,500 or more it's night and day.
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Chryslers do great without monster lifts for the very reasons you stated... thats why they can dominate stock class racing.
When it comes to stock head castings...there are so many cookie cutters copying chevys... and they end up running like ****. ..dogs...
Once you get a well modified or better design usage of the same constraints..then you can do that and see positive results. They're all animals...right... just different species that like different things... and until you make them clones... they will have different appetites.
Anyone who wants to buzz 7500 with a 360 and live...all they have to do... is full groove mains, proper oil clearance, deep baffled pan ...and a good balance job.
Extra aside from that would be to make sure the galleys are sized and not stepped down as some are.
340s need bearing mods, period.
Narrow up the lsa, decrease the int cl ...easy rpm
 
1Badcolt said:
2.02 now
Yes basically hate to alter some of the Last true Chrysler speed parts like these so I will proceed with that fact in mind but if they need work I will spend the money and try to improve them in general flow numbers stock and after final assembly will be gathered seems to be a mystery about the flow numbers .
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Was 2.02 originally and still 2.02 but lite weight 11/32 TF valves
 
MOPAROFFICIAL said:
I'm just going to say I really was hoping to see like... 300 CFM out of these things or something legendary.. from a legendary name , that's all.

I had high hopes that were crushed. Lol
I think i shed a tear when i saw the numbers, needed a hug.. lmao
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The Prostock versions with monster valves and some needed brazing would have maybe reached your expectations.
 
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