My 422 smallblock build

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Ok. So I’m at the point in this build that I need to order a camshaft. I’ve already reached out to a few cam grinders for their recommendations and have heard back from Jones, Crower, and Oregon. Their respective numbers are pretty close so I kinda know where I wanna be but I thought I’d like to put it out to you all to see what your recommendations are.
For a little background on the application, this is a street/strip build with 75% street and 25%strip. Absolutely zero freeway driving.
72 Duster approx. 3300#s(not verified), 2.66 first gear A833, 3.91 rear, 28” tire.
422” smallblock with long valve W2 race heads (flow stalls at 266cfm @ .550”) 2.08/1.60 valves, 1.5 iron rockers, dual plane Mopar intake, 950 Holley HP, 10.75-1 compression.
I’m looking for a solid roller with a sweet spot of about 2500-6500 rpm that will not need ridiculous amounts of spring pressure. Idle quality is not important, vacuum not important.
Ok guys, give me your thoughts/recommendations/warnings.
 
SSG_Karg said:
Ok. So I’m at the point in this build that I need to order a camshaft. I’ve already reached out to a few cam grinders for their recommendations and have heard back from Jones, Crower, and Oregon. Their respective numbers are pretty close so I kinda know where I wanna be but I thought I’d like to put it out to you all to see what your recommendations are.
For a little background on the application, this is a street/strip build with 75% street and 25%strip. Absolutely zero freeway driving.
72 Duster approx. 3300#s(not verified), 2.66 first gear A833, 3.91 rear, 28” tire.
422” smallblock with long valve W2 race heads (flow stalls at 266cfm @ .550”) 2.08/1.60 valves, 1.5 iron rockers, dual plane Mopar intake, 950 Holley HP, 10.75-1 compression.
I’m looking for a solid roller with a sweet spot of about 2500-6500 rpm that will not need ridiculous amounts of spring pressure. Idle quality is not important, vacuum not important.
Ok guys, give me your thoughts/recommendations/warnings.
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My first suggestion is you need to NET .650 lift. There is no reason to keep the lift down. Let the heads do the work.

Second, you can be in the 244-246 at .050 duration range on a 108, or because you have a stick you can move up to 250-252 at .050 and close up the LSA to 106.

And whatever you do, do NOT let the cam grinder convince you to reduce the intake duration and add exhaust duration and then blow out the LSA to make it pull upstairs. That's a sure fire power killer.

I suggest you get the April 2020 Hot Rod magazine and read from page 73 on. Billy Godbold explains a lot of things I can't do here.
 
Well here is almost the exact cam specs the YR just described
. W2s flowing 297@ .650
408 ci
And my car is damn near the same build as yours.
 
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mbaird said:
Thats 246/250 @ .050 on a 108
.648 lift with 1.6 rockers .
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4 spd manual trans right?
Who ported you’re heads?
Edit... Ryan did right? (IIRC)
 
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SSG_Karg said:
In due time sir. Hoping to hear some unbiased recommendations before spilling the beans on the experts’ numbers.
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Well no matter what us Nuts in the Peanut Gallery say I would follow the recommendations of the pros . Well at least Jones... others may not have much experience with W2.... they love lift !
 
mbaird said:
Well no matter what us Nuts in the Peanut Gallery say I would follow the recommendations of the pros . Well at least Jones... others may not have much experience with W2.... they love lift !
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Well that’s kinda what led me to ask some opinions here. Jones recommended 246/250 @ .050” .562/.520 on a 110LSA. I thought the duration sounded about right but not nearly enough lift. I was thinking closer to 248/248 @ .050” with .620 ish on a 108. I was kinda surprised by the low lift numbers.
 
512Stroker said:
266 cfm
Is that intake or exhaust?
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Intake

547256FF-5D49-4B09-B294-A345EE5DBD2D.jpeg
 
If you told him you dont want high spring rates that may explain the lower lift. I run 610# open 330 on the seat.
 
Oh! The lift stalls and stays, keep lifting the valve if you want to. The recommended duration is fine, the lift I’d go higher. And I’d go to a 108, but....
That’s just me.
 
600 # isnot all that high .
It would be interesting to see how he would change it if you told him spring pressure was not an issue ?
 
512Stroker said:
OK so the intake flow stalls after .500 lift.
What is the advantage to a cam that would have an intake lift that would exceed the flow stall?
Say .600 to .650
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Because it spends more time where the flow is higher.

I never pick lift just because the lift flattens out or backs up a bit. Jones disagrees with me, but he is wrong.

My guess is if the OP puts his head on a bench and put the intake on it, the flow numbers would drop but the flow curve would change and it wouldn't lay down like that at higher lifts.

And even if it does lay down, use lift.

BTW, I seriously doubt any head pulls 28 inches at max lift. In fact, I've seen CFD stuff that says it's nowhere close.

That means if you reduce the test pressure to say 10 inches and test again you won't see that port lay down.

I always test at 28 for a base line, then go as high as the bench will go, and then drop down to 10 or so and then start looking at what to do.
 
SSG_Karg said:
Well that’s kinda what led me to ask some opinions here. Jones recommended 246/250 @ .050” .562/.520 on a 110LSA. I thought the duration sounded about right but not nearly enough lift. I was thinking closer to 248/248 @ .050” with .620 ish on a 108. I was kinda surprised by the low lift numbers.
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I'd call Mike back and ask him WTF? I don't like the split (no reason for it) and I certainly think the lift is horrible. And why the 110? You are just killing the middle to get a bit more over rev after peak HP.

If you can find that Hot Rod article on line it would be well worth your time to download it and read it.
 
yellow rose said:
Because it spends more time where the flow is higher.

I never pick lift just because the lift flattens out or backs up a bit. Jones disagrees with me, but he is wrong.

My guess is if the OP puts his head on a bench and put the intake on it, the flow numbers would drop but the flow curve would change and it wouldn't lay down like that at higher lifts.

And even if it does lay down, use lift.

BTW, I seriously doubt any head pulls 28 inches at max lift. In fact, I've seen CFD stuff that says it's nowhere close.

That means if you reduce the test pressure to say 10 inches and test again you won't see that port lay down.

I always test at 28 for a base line, then go as high as the bench will go, and then drop down to 10 or so and then start looking at what to do.
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OK thanks I get it.
Is there a general rule of thumb that can be used to determine net lift based upon maximum flow? I know that there a other factors involved, just looking for a starting point.
 
The reality of a head having that much pressure drop (28) is —- and correct me if I’m wrong but I don’t think so—— ) impossible.

A head flowed @10 is much more reasonably accurate or closer to real world operations. The world is just used to the rags flowing everything at 28. And then we base our understandings in that.

@SSG_Karg , lifting the valve passed peak, even more so since your flow rates don’t tank, allows the valve more time (coupled with duration) at the max flow area allowing more air and fuel into the cylinder.

If you stop lifting the valve at max lift, it spends a very short time there and flow decreases rapidly. This is also why a roller is better. The cam lifts the game up, let’s it sit there, then brings it down. With a roller, when making big power, the larger the cam is, the better it makes power with hanging the valve open longer.
 
512Stroker said:
OK thanks I get it.
Is there a general rule of thumb that can be used to determine net lift based upon maximum flow? I know that there a other factors involved, just looking for a starting point.
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I try and get as much lift as the valve gear and cam lobe (solid flat tappet) as I can. For a solid roller I use as much lift as I can get reliably, which with W2/5 stuff is about .770-.800 and you better have your crap wired tight for .800 lift. I said net .650 for Karg because it's a street deal and the springs for much more lift than that get expensive and life starts going down. At .650 net with good springs it should be stone reliable. I wouldn't use less than 260 on the seat, maybe 240 if the spring rate got me to 675ish or a bit more at max lift.
 
rumblefish360 said:
The reality of a head having that much pressure drop (28) is —- and correct me if I’m wrong but I don’t think so—— ) impossible.

A head flowed @10 is much more reasonably accurate or closer to real world operations. The world is just used to the rags flowing everything at 28. And then we base our understandings in that.

@SSG_Karg , lifting the valve passed peak, even more so since your flow rates don’t tank, allows the valve more time (coupled with duration) at the max flow area allowing more air and fuel into the cylinder.

If you stop lifting the valve at max lift, it spends a very short time there and flow decreases rapidly. This is also why a roller is better. The cam lifts the game up, let’s it sit there, then brings it down. With a roller, when making big power, the larger the cam is, the better it makes power with hanging the valve open longer.
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Actually, at valve opening the depression can go as high as 100 inches.

It's worth testing at different pressure because the higher depressions will find flaws you can't find at say 10 inches.

But like I said, if a head backs up at 28 and you bolt the intake on it probably won't. The intake slows the air speed down, and that's what causes the stall.

If on the other hand it's backing up because of a junk valve job, that's a whole different issue and you need to fix that.
 
Maybe at the valve just as it opens, but as a in general across the board of averages....
:lol:
 
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