Why would low lift head flow hurt power?

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I think its time to move on from this discussion.......

How much power do Nascar engines make with just a 390 cfm carb.........
 
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Let’s just put it this way. I’m not book smart. I Just believe in keeping things simple. I have the books, I just Dont read them.

I could lose my hearing (it’s pretty bad right now) and I’d be bummed but if I lose my eyesight and couldn’t read I’d whip out my tool and end it.

I try and read no less than an hour a day. I’ve spent an entire weeks vacation locked away reading, taking notes and learning.
 
I think its time to move on from this discussion.......

How much power do Nascar engines make with just a 390 cfm carb.........
Yes it's impressive, airs compressible, but they do it to kill power not cause it's optimal.
 
I could lose my hearing (it’s pretty bad right now) and I’d be bummed but if I lose my eyesight and couldn’t read I’d whip out my tool and end it.

I try and read no less than an hour a day. I’ve spent an entire weeks vacation locked away reading, taking notes and learning.


Forty years ago we had to read to learn anything. You know yourself once you get to a point you want to just do it and test. I shared all those Darren Morgan porting videos and never watch a single one. But yet I’ve done 20 plus flow tests in a day, made port molds, taken a notebook and pen to bed. I sleep like crap because I think all night about crap. I retired 13 years ago and I’m still doing millwright work in my sleep. Now if I question myself on a job I’ll watch a few YouTube videos and do it. Heck I take notes at church and rarely go back to them. I should but Dont. I bought a book on porting LS heads and read 1/3 if it to find out which ones to buy, and why.
 
Yep! Sounds like my youth days. I got tired of asking questions on how to ……. And started experimenting myself. Learned more than those that I thought knew something.
 
Forty years ago we had to read to learn anything. You know yourself once you get to a point you want to just do it and test. I shared all those Darren Morgan porting videos and never watch a single one. But yet I’ve done 20 plus flow tests in a day, made port molds, taken a notebook and pen to bed. I sleep like crap because I think all night about crap. I retired 13 years ago and I’m still doing millwright work in my sleep. Now if I question myself on a job I’ll watch a few YouTube videos and do it. Heck I take notes at church and rarely go back to them. I should but Dont. I bought a book on porting LS heads and read 1/3 if it to find out which ones to buy, and why.

I agree, you have to read and then do. And, you can’t just take everything you read and accept it. You have to test it and then do other things.

Thats why I flowed everything at as high a test pressure as I could. I flowed everything in reverse. I have tested probably 6, maybe 7 different 50 degree seats, probably 20 different 45’s and several 55’s. And I developed 3 or 4 (I forget if I actually had the 4th one made) seats that I couldn’t find, but only one actually worked and it has a very limited use.

Running a full set of tests on every seat is time consuming plus it generates huge amounts of data that you have to look through and analyze.

I spend more time looking at the data coming off the dyno than I do making pulls. Especially when looking at the fuel curve. And timing. Timing is a real PITA to do.
 
I think its time to move on from this discussion.......

How much power do Nascar engines make with just a 390 cfm carb.........
An embarrassingly inferior amount compared to running unrestricted, not to mention an ill-mannered time bomb that had to be subdued by NAPCAR to prevent routine explosions oiling down the track, and leaves the drivers helplessly hanging on praying the suspension & aero won't get them killed....and looking for friends that won't send them 20 fooking spots back in 1/2 a lap. That cover it for You?
 
Wait.......are you saying the throttle bore size and venturi diameter no matter what size are in no way affected by reversion? Guess the port size and valve curtain area don't either because reversion doesn'r exist?
 
Wait.......are you saying the throttle bore size and venturi diameter no matter what size are in no way affected by reversion? Guess the port size and valve curtain area don't either because reversion doesn'r exist?
All your statements, questions are vague it all depends on what engine, goals, preferences, uses what you got, money, whims etc... Money being the biggest hurdle unless we're talking a highly competitive race class it's cheaper to build larger less efficient engine.

Like carbs you might have to try a few, same with cams gears converters etc... depends how dialed in you want your combo.
 
All your statements, questions are vague
Here it is again because you're too simple to grasp the implications:

"Remember that there are also a lot of inert contaminates in reversion too, and they amount to wasted mixture volume because they don't burn."
Larry Widmer.


If you can't grasp how the different elements like Carb, Intake port, and valve contribute to this then sorry I can't help you. Maybe start with what an inert contaminate is........

Here's a hint: What's all that black **** on the underside of the air cleaner lid and how dose it get there........
 
Here it is again because you're too simple to grasp the implications:

"Remember that there are also a lot of inert contaminates in reversion too, and they amount to wasted mixture volume because they don't burn."
Larry Widmer.


If you can't grasp how the different elements like Carb, Intake port, and valve contribute to this then sorry I can't help you. Maybe start with what an inert contaminate is........

Here's a hint: What's all that black **** on the underside of the air cleaner lid and how dose it get there........
I'm seeing every post as a bread crumb to start a debate with anyone cause it's a bait n switch you really want to prove everything needs to small.More power to you but nothing here really to debate about so far maybe another time.
 
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I'm seeing every post as a bread crumb to start a debate with anyone cause it's a bait n switch you really want to prove everything needs to small. Which more power to you but nothing here really to debate about so far maybe another time.
That's funny some one else gets it.......It just isn't what you think it is.

You kill it and you see that in VE.
This
 
That's funny some one else gets it.......It just isn't what you think it is.


This
Your acting like I'm overly disagreeing with you, if noticed most everything I've said is against your ultimate conclusion not what your saying now.
 
I agree, you have to read and then do. And, you can’t just take everything you read and accept it. You have to test it and then do other things.

Thats why I flowed everything at as high a test pressure as I could. I flowed everything in reverse. I have tested probably 6, maybe 7 different 50 degree seats, probably 20 different 45’s and several 55’s. And I developed 3 or 4 (I forget if I actually had the 4th one made) seats that I couldn’t find, but only one actually worked and it has a very limited use.

Running a full set of tests on every seat is time consuming plus it generates huge amounts of data that you have to look through and analyze.

I spend more time looking at the data coming off the dyno than I do making pulls. Especially when looking at the fuel curve. And timing. Timing is a real PITA to do.
Can you please go into detail about your process for timing on the dyno and what makes it a pain? Thank you.
 
Can you please go into detail about your process for timing on the dyno and what makes it a pain? Thank you.


If you want to find out what curve the engine wants (they ALL want a curve and that curve is almost never all in by 2500 as Jenkins proved back in the 1970’s and for that particular combustion chamber/rod to stroke ratio/compression ratio/gearing/chassis etc that curve is still the same) you need to load the engine at different throttle openings and RPM, let the engine stabilize and then move the timing until you find peak torque. You write that down and move to the next throttle opening/load/RPM and do the same.

Once that’s done you have to put the distributor on the test bench and make it match what you found while testing.

I think many people would be surprised at how much timing an engine will want above and below peak torque and that most engines want LESS timing at peak torque than it does at peak power.

You can spend a TON of time sorting it out.
 
If you want to find out what curve the engine wants (they ALL want a curve and that curve is almost never all in by 2500 as Jenkins proved back in the 1970’s and for that particular combustion chamber/rod to stroke ratio/compression ratio/gearing/chassis etc that curve is still the same) you need to load the engine at different throttle openings and RPM, let the engine stabilize and then move the timing until you find peak torque. You write that down and move to the next throttle opening/load/RPM and do the same.

Once that’s done you have to put the distributor on the test bench and make it match what you found while testing.

I think many people would be surprised at how much timing an engine will want above and below peak torque and that most engines want LESS timing at peak torque than it does at peak power.

You can spend a TON of time sorting it out.
How do you measure throttle opening so that it can be repeated accurately during testing? Thank you.
 
He talks about exhaust and reversion

 
A thing you have to be aware of and avoid if you can?
Is it possible?


LMAO
 
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Echoing why I don't use/don't prefer a back cut on the intake valve. Also reiterating the necessity for exh port speed/velocity.
I just watched his valve shootout @ .200 there something like a 129 to 151 cfm

 
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