SBM Edelbrock/Speedmaster Head Data

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rumblefish360 said:
Then why do you get behind it so much and defend it so hard?
You swore up and down and fought really hard for what…. Years that an engine that calculates to consume 600 cfm should only use that since a larger carb won’t produce any meaningful amount of extra HP but only give a worse throttle response, lower mileage and a crappier pedal feel on the road?
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Never once have I ever argued that position, I've said over and over the carb formula is junk as a carb formula, It tells the approximate displacement of a running engine that's it.
rumblefish360 said:
Dozens here argued against you but you stood proud until engine masters showed you wrong.

The applied science is in the program. What’s to argue about there! LOL!

So the formula over valves carbs?
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People over value what that formula predicts is needed when choosing a carb.

Eg. A 360 @ 5500 rpm that formula says 450-500 cfm is the ideal carb I definitely don't agree with that outcome, never have/would.
rumblefish360 said:
Is 1.5hg the optimal goal point? For you personally that is.
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Nope, it just what basically the formula results would be.


I think your thinking of Hysteric he's the small carb/head guy :)
 
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273 said:
Never once have I ever argued that position, I've said over and over the carb formula is junk as a carb formula, It tells the approximate displacement of a running engine that's it.
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Yeaaaaa - Uh Huhhhhhhh
273 said:
People over value what that formula predicts is needed when choosing a carb.
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I find 99% laugh at it.
 
pittsburghracer said:
I always say one port is easy, but the work starts porting the other 7 to match. That my simple way of saying it. My buddy won’t even port a head without it being cnc’d first. Who’s the smart one him or me. Lol. He’s done porting work longer than me and went to Joe Mondello’s hands one class. When I told him Joe died I think he felt like crying. He had questions he put off asking him. I’ve usually pick up 10-20 on most cnc’d heads I’ve touched minimum. Just remember a cnc program can’t get every port the same (case in point my TrickFlow heads) so you average out a great port with a good port as that’s what the engine does.
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Eight ports! Forget that. Us R&D types wear pocket protectors, use calculators and work on 1 port at a time.
 
Here's the latest tests. Still curious about the 35 deg top angle so that's what I'm working on.

Test 350 is with a new 90/75/60/45/30/15 valve job and Ferrea 30/45 valve.

Test 351 is sinking the intake valve (not the exhaust) around 0.080" and recutting the valve job at 75/60/45/35. A 4mm radius was cut at the top of the 35 deg angle where the 35 meets the shrouded side of the chamber. Same valve.

Test 352 is extending the 35 degree top cut as far as possible with clay. Again, this covers up the spark plug and extends the 35 degree angle more than actually practical - but this is a test. Things can be modified later. Same valve.

Initially, this looks like a bad move for low lift flow, but there are a few things to consider. First, since the exhaust valve has not been sunk, it is very much in the way of intake flow. Also, I think there is a good bit of shrouding in the spark plug area that needs to be addressed.

The flow past 0.25d has increased dramatically. May not be usable for the street or translate to horsepower, but all of this is usable for education.

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IMO, you need to put the spark plug in and adjust the clay around the plug.
 
273 said:
When you 1st posted it I tried for a few minutes to figure where 0.0009875 comes from, part of of it must convert cubic inch to cubic feet, per revolution (every other stroke) 1 cubic in = .0005787 cubic feet / 2, so 360 x 6000 x .0005787/ 8 /2 = 78 actual cfm vs the 266 cfm of need head flow. That's far as I got, problem with head flow is the depends on a depression, there's not a direct translation between the two. Why the carb formula doesn't work unless the goal is to have 1.5 hg at WOT.
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Finally found an explanation for the 0.0009875 number.

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Good find, should of known it's based from Pipemax.
 
Problem with formulas like that not saying it wrong but more for building a certain type of engine, an average guy that puts together a 360 or 408 with compression and around a 235-245 cam only got a few head choices basically stock, speedmaster/edlebrock or trick flow, so around 400 hp or 450 hp or 500+hp.
 
Here's another guy's channel you might want to check out, I just finished watching his latest video, Dyno Test: Compression vs Flow

 
A bunch of that video was covered by @IQ52. Jim showed a few results from his dyno tests. More information is always good.
 
273 said:
Here's another guy's channel you might want to check out, I just finished watching his latest video, Dyno Test: Compression vs Flow

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I watched that. I need to watch it again. What he credits to compression increase I say is something else. He’s just missing it because he is stuck in a rut with his testing methods.
 
Newbomb Turk said:
I watched that. I need to watch it again. What he credits to compression increase I say is something else. He’s just missing it because he is stuck in a rut with his testing methods.
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What was he over looking?
 
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