Does this prove David Vizard's 128 lsa formula ?

[Bewy]

It is funny. While I see lots of people taking pot shots at the 128 rule, which determines the LSA, I have yet to see anybody prove that it doesn't work: by grinding a cam using 128 & then using cams with identical parameters except for LSA....& dyno testing/comparing them.
The problem is that the LSA is just seen by many as a number. It is just a number, right?
It is much more than that....
It tells you in crank degrees where max lift occurs. For a 106 LSA, it tells you that the intake valve is at max lift at 106* ATDC & the exh valve at max lift 106* BTDC. Max lift, & either side of it, has to be an important parameter, especially for the intake side, because that is where maximum airflow happens. No air in = no hp.
The other important parameter is piston speed...& that is related to crank position ...which is tied in with LSA. More piston speed, more air 'pulled' into the chamber, all else being equal.

 

[Bewy]

128 rule & the Hemi? DV has repeatedly stated that the 128 rule works for parallel valve heads with a 9 -10.5 CR. Better breathing heads like the 351C, BB Chev, Hemi, etc need to be bigger than 128. I believe he quotes 131.5 for the BB Chev. Similarly if CR is increased the 128 needs to be bigger.

 

[273]

It is funny. While I see lots of people taking pot shots at the 128 rule, which determines the LSA, I have yet to see anybody prove that it doesn't work: by grinding a cam using 128 & then using cams with identical parameters except for LSA....& dyno testing/comparing them.
The problem is that the LSA is just seen by many as a number. It is just a number, right?
It is much more than that....
It tells you in crank degrees where max lift occurs. For a 106 LSA, it tells you that the intake valve is at max lift at 106* ATDC & the exh valve at max lift 106* BTDC. Max lift, & either side of it, has to be an important parameter, especially for the intake side, because that is where maximum airflow happens. No air in = no hp.
The other important parameter is piston speed...& that is related to crank position ...which is tied in with LSA. More piston speed, more air 'pulled' into the chamber, all else being equal.

It's shouldn't be up to others to prove DV right or wrong, he made the claims he should provide the proof apparently he has done 10's of thousands dyno runs, he apparently has done more than just about everyone else (his claim) should be able to provide 100/1000's of examples.

I'm not a DV hater, not even saying he wrong just haven't see any real proof, but I would like to see some test designed to put his formula to the test.

Maybe Eric's cam shootout will give us a glimpse.

 

[Bewy]

273,
I don't know how many examples you need. Watch the Cattle Dog video again. DV has dyno examples in his books & also in tests done for magazine articles. He has consistently said that cams are generally being ground on LSAs that are too wide.
I would say Jon Kaase took his advice, winning the EMC with a cam that had a 98* LSA, 92* ICL. I suspect what made DV think/look at tighter LSAs was the Morris Mini engine, with which he has had a lot of experience. Even the stock low performance cam for those was on 107.5* LSA, & performance versions were even tighter. Those little engines punched above their weight...
Below is a test that was done loooooooooooong before 128 came to be a conversation piece, identical cams, 106,108,110 LSA tested.

 

[273]

273,
I don't know how many examples you need. Watch the Cattle Dog video again. DV has dyno examples in his books & also in tests done for magazine articles. He has consistently said that cams are generally being ground on LSAs that are too wide.
I would say Jon Kaase took his advice, winning the EMC with a cam that had a 98* LSA, 92* ICL. I suspect what made DV think/look at tighter LSAs was the Morris Mini engine, with which he has had a lot of experience. Even the stock low performance cam for those was on 107.5* LSA, & performance versions were even tighter. Those little engines punched above their weight...
Below is a test that was done loooooooooooong before 128 came to be a conversation piece, identical cams, 106,108,110 LSA tested.

View attachment 1716308523

Narrower LSA generally makes more mid range torque, no one in the world is arguing that it doesn't, how does that prove DV's claims that his formula always gives the optimal lsa #, and gonna get huge gains over off the shelf cams and be like him the 1%er of top builders and pick cams that get around 1.4+ lbs-ft per cid. And that narrowing the LSA while maintaining same overlap is gonna be even better gains. That's the proof I'm looking for the ones that prove those claims.

All those test prove that tightening the lsa makes more midrange torque and again who's really arguing it don't. It's like saying more duration generally gains hp, no ****.

 

[Dan the man]

273,
I don't know how many examples you need. Watch the Cattle Dog video again. DV has dyno examples in his books & also in tests done for magazine articles. He has consistently said that cams are generally being ground on LSAs that are too wide.
I would say Jon Kaase took his advice, winning the EMC with a cam that had a 98* LSA, 92* ICL. I suspect what made DV think/look at tighter LSAs was the Morris Mini engine, with which he has had a lot of experience. Even the stock low performance cam for those was on 107.5* LSA, & performance versions were even tighter. Those little engines punched above their weight...
Below is a test that was done loooooooooooong before 128 came to be a conversation piece, identical cams, 106,108,110 LSA tested.

View attachment 1716308523

I've read on this website and other places as well that a tighter LSA improves the low to midrange torque, so say a cam has a 108* LSA and duration of 204* / 214* would the idle be smooth, noticeable or rough? I'm just asking.

 

[273]

I've read on this website and other places as well that a tighter LSA improves the low to midrange torque, so say a cam has a 108* LSA and duration of 204* / 214* would the idle be smooth, noticeable or rough? I'm just asking.

Haven't seen your name pop up in while.

It's the overlap mainly responsible for idle, overlap is duration and lsa, a 204°/214° cam isn't gonna have huge overlap even with a 108 lsa.

 

[Newbomb Turk]

It is funny. While I see lots of people taking pot shots at the 128 rule, which determines the LSA, I have yet to see anybody prove that it doesn't work: by grinding a cam using 128 & then using cams with identical parameters except for LSA....& dyno testing/comparing them.
The problem is that the LSA is just seen by many as a number. It is just a number, right?
It is much more than that....
It tells you in crank degrees where max lift occurs. For a 106 LSA, it tells you that the intake valve is at max lift at 106* ATDC & the exh valve at max lift 106* BTDC. Max lift, & either side of it, has to be an important parameter, especially for the intake side, because that is where maximum airflow happens. No air in = no hp.
The other important parameter is piston speed...& that is related to crank position ...which is tied in with LSA. More piston speed, more air 'pulled' into the chamber, all else being equal.

You pay for the cam and dyno time and I’ll test it.

But I’m not taking one cent out of my pocket to do it.

 

[273]

You pay for the cam and dyno time and I’ll test it.

But I’m not taking one cent out of my pocket to do it.

To me the only way to test it is say DV say a 260° @ 0.050" on a 107 lsa with 75 overlap is the cam for whatever build, someone would need to test it with cams probably at least from 102-112 lsa in 1 degree increments while maintaining the 75 overlap (of whatever it works out to be in the made up cam above).
And really you would need to do similar test with at least a dozen or so different type, sizes and levels of engine builds to see if it holds up overall.

All the test people are talking about just prove tighter lsa generally gains mid range torque.

 

[RustyRatRod]

It's shouldn't be up to others to prove DV right or wrong, he made the claims he should provide the proof apparently he has done 10's of thousands dyno runs, he apparently has done more than just about everyone else (his claim) should be able to provide 100/1000's of examples.

I'm not a DV hater, not even saying he wrong just haven't see any real proof, but I would like to see some test designed to put his formula to the test.

Maybe Eric's cam shootout will give us a glimpse.

All I've ever read he's actually DONE is raced a few Pinto motors. Or was it Vega? Gremlin?

 

[273]

All I've ever read he's actually DONE is raced a few Pinto motors. Or was it Vega? Gremlin?

Think he's raced Mini's.

I think his books are a good first step, overall if you follow his advice you generally gonna have decent results, problem is some take it as the final word in performance theory.

 

[RustyRatRod]

Think he's raced Mini's.

I think his books are a good first step, overall if you follow his advice you generally gonna have decent results, problem is some take it as the final word in performance theory.

I don't knock his knowledge. At ALL. ....and I'm not taking pot shots. I'm just not suckin his balls. I know how to design and build an engine and I know how to tune. That's all I really need. My own mind is a dangerous enough place for me. I don't need to get into someone else's.

 

[RustyRatRod]

Oh and his "128 rule" works out to a 108 LSA for any of my slant six builds. That's what I would choose anyway.....either that or a 106. So even without him, I was right. Funny how that works.

 

[mgoblue9798]

No, from my understanding 350 Chevy only.

Not according to his youtube videos. He specifically says works with inline wedge heads from ford and chrysler as well. Canted valve heads have a different formula.

 

[273]

I thought mission impossible was his first mopar, pretty sure when picking the cam he used the ford or chevy formula saying it should be close enough for a mopar.

 

[Newbomb Turk]

It is funny. While I see lots of people taking pot shots at the 128 rule, which determines the LSA, I have yet to see anybody prove that it doesn't work: by grinding a cam using 128 & then using cams with identical parameters except for LSA....& dyno testing/comparing them.
The problem is that the LSA is just seen by many as a number. It is just a number, right?
It is much more than that....
It tells you in crank degrees where max lift occurs. For a 106 LSA, it tells you that the intake valve is at max lift at 106* ATDC & the exh valve at max lift 106* BTDC. Max lift, & either side of it, has to be an important parameter, especially for the intake side, because that is where maximum airflow happens. No air in = no hp.
The other important parameter is piston speed...& that is related to crank position ...which is tied in with LSA. More piston speed, more air 'pulled' into the chamber, all else being equal.

It depends on what you are doing. A tight LSA will limit high(er) rpm or you have to use a bunch of duration.

 

[RustyRatRod]

I thought mission impossible was his first mopar, pretty sure when picking the cam he used the ford or chevy formula saying it should be close enough for a mopar.

So in other words, he has nothing specific for Mopar, even though they have larger lifter diameters and different valve train angles. Got it.

 

[273]

It depends on what you are doing. A tight LSA will limit high(er) rpm or you have to use a bunch of duration.

There might be another issue here with DV way of picking cam, for him it's all about lsa and overlap and get the duration from those specs, a tighter lsa with same overlap would be less duration so probably lowering top end even more. Also he really don't give much info on how to pick overlap therefore duration, so it really ain't a cam formula just an lsa formula.

 

[replicaracer43]

Just remember, those who dont "DO" .......they "teach" Go to ANY motorsports event ANYWHERE and you will not find a engine built by DV.....

 

[RustyRatRod]

Just remember, those who dont "DO" .......they "teach" Go to ANY motorsports event ANYWHERE and you will not find a engine built by DV.....

Exactly. Reminds me of a member here who writes books for posts but you never see **** he's built.

 

[AJ/FormS]

Exactly. Reminds me of a member here who writes books for posts but you never see **** he's built.

Are you barking at me again?
You preach this;
"Smart men don't tell you how smart they are. Rich men don't tell you how rich they are. Tough men don't tell you how tough they are. Honest men don't tell you how honest they are. Christian men don't tell you how righteous they are. Con men do."

But here you are again pointing out how smart you are. Jumping to conclusions, and over and over and over, stomping on those you consider of lesser intellect.

Look man, I'm not attacking you, nor your character, nor your intellect, nor even your Faith. and if your meds make you run around the house naked, well so be it. I don't care about that. All I ever wanted, was tell you that I was interested in the health of your spirit, and your Soul, and those of your wife. All I ever showed you was love.

Look man, IDK what I ever said to offend you, you've never said. But you keep taking potshots at me, and sometimes at my kind, and sometimes at newbe's, for no good reason. So out with it already. Get it off your chest, so I can say sorry, so you can forgive me, so you can get your health back, and so the meds won't make you cranky all the time.

Look man, I'm trying to be polite.

 

[Newbomb Turk]

Are you barking at me again?
You preach this;
"Smart men don't tell you how smart they are. Rich men don't tell you how rich they are. Tough men don't tell you how tough they are. Honest men don't tell you how honest they are. Christian men don't tell you how righteous they are. Con men do."

But here you are again pointing out how smart you are. Jumping to conclusions, and over and over and over, stomping on those you consider of lesser intellect.

Look man, I'm not attacking you, nor your character, nor your intellect, nor even your Faith. and if your meds make you run around the house naked, well so be it. I don't care about that. All I ever wanted, was tell you that I was interested in the health of your spirit, and your Soul, and those of your wife. All I ever showed you was love.

Look man, IDK what I ever said to offend you, you've never said. But you keep taking potshots at me, and sometimes at my kind, and sometimes at newbe's, for no good reason. So out with it already. Get it off your chest, so I can say sorry, so you can forgive me, so you can get your health back, and so the meds won't make you cranky all the time.

Look man, I'm trying to be polite.

All right, I’m not getting into this but how do you know he’s running around the house naked?

If he’s doing that I can promise you his wife would be sending out here to live with us.

And yes, I just asked the wife and she says Rob can live here any time he wants.

He just has to have his clothes on.

 

[AJ/FormS]

I said;

if your meds make you run around the house naked, well so be it. I don't care about that.

cuz I heard that some meds make you do crazy stuff.
I don't know anything about meds. Not much about vitamins either.
********************************************************
I don't do drugs unless it's to take a shot of morphine when passing a kidney stone. Daymn that hurts.

 

[RustyRatRod]

Are you barking at me again?
You preach this;
"Smart men don't tell you how smart they are. Rich men don't tell you how rich they are. Tough men don't tell you how tough they are. Honest men don't tell you how honest they are. Christian men don't tell you how righteous they are. Con men do."

But here you are again pointing out how smart you are. Jumping to conclusions, and over and over and over, stomping on those you consider of lesser intellect.

Look man, I'm not attacking you, nor your character, nor your intellect, nor even your Faith. and if your meds make you run around the house naked, well so be it. I don't care about that. All I ever wanted, was tell you that I was interested in the health of your spirit, and your Soul, and those of your wife. All I ever showed you was love.

Look man, IDK what I ever said to offend you, you've never said. But you keep taking potshots at me, and sometimes at my kind, and sometimes at newbe's, for no good reason. So out with it already. Get it off your chest, so I can say sorry, so you can forgive me, so you can get your health back, and so the meds won't make you cranky all the time.

Look man, I'm trying to be polite.

I've not said a thing about "how smart I am" because I constantly humble myself here. What I know won't fill up the head of a pin. I'm not the braggart here. I can post pictures of what I have built date stamped current with me standing beside it. I've never seen one single picture of anything you have. The only thing you talk about is your 367 and how you power slide and do burnouts on your Goodrich tires you put on your car in 2001, spin your engine regularly past 7k and powershift all the time. Anyone with any sense can figure out you're full of crap. All they have to do is read. You have so little experience and it's glaringly obvious. You have to depend on formulas and calculators to come up with answers so you can make yourself look like the smart one. So who is the braggart? It's certainly not me. You don't know the meaning of the word humility, but it sure needs to slap you upside the head.

 

[AJ/FormS]

See, there you you go again, blinded by your own rage.
Humble people do not profess their humility.

I'm sorry that your heart cannot accept any truth but your own date-stamped pictures.
My job is not to prove my innocence.
Your job is to prove me a liar.
Your opinion is not a truth.
Everything you quoted about me is true.
Except I have no need to be the smart one. If it happens so what. If you pay attention, you will see that when I have been wrong, I have apologized.
I offer help, without condemnation. I am a helper, an assistant, a coworker, a fellow worker, a workmate, teammate, helpmate.
I tell what I have done, what worked, what didn't, and so on; Twenty five years with the same combo.. If you do not agree with it, then it's on you to say so at the time you read it., and then we can talk it out. Since I already did it, what I have said cannot be argued with. But I can give you a step-by-step, and then you can go do it, and afterwards you can come back to the table and tell me who is full of crap.
Stop your mud-slinging. It's unbecoming to a man of your age and history.

I think I know what's bugging you but you won't say it here; and I won't press the point.
My intention was never to make you feel something that you didn't want to feel. That happened for lack of understanding, and I already apologized for it. Forgive me and move on.