Novice Modified 289 Heads

[PRH]

201/160cfm for 1.78/1.45 valves is working pretty well.

The work looks pretty good too........ not that the flow bench knows the difference.

[travis]

Am I reading that right? 159cc?? Stock they are like 124cc iirc.

[Stan Weiss]

David / Phil,
Is the your exhaust valve size the same size for both tests?. There is a thick and thin horizontal red line which shows at .25 D for the exhaust valve. Note the blue lines overlap each other .25 d intake.

Stan

Stock valves were used for both tests, i believe we actually used same exact ones.

Phil,
Could you or David email me the 2 "DAT" files used to produce these graphs?

Thanks,
Stan

[The Iron Icon]

David / Phil,
Is the your exhaust valve size the same size for both tests?. There is a thick and thin horizontal red line which shows at .25 D for the exhaust valve. Note the blue lines overlap each other .25 d intake.

Stan

Stock valves were used for both tests, i believe we actually used same exact ones.

Phil,
Could you or David email me the 2 "DAT" files used to produce these graphs?

Thanks,
Stan

Stan, i will try to get file to you this saturday when im at David's.

[Stan Weiss]

I had to talked with David this morning about the TMC program. So I asked him about this. He found one file had 1.45" and the other had 1.48" for the exhaust valve size. He also said that you / he should maybe remeasure the port (159cc seems high).

Stan

[David Vizard]

I must admit here that I am having a hard time swallowing a 25.6% peak Intake flow gain from just bowl porting work on this one!

Can you atleast tell us what the Valve to Throat percentage is now ?
Can you go into detail on what some sizes where stock and what they are now if you can?

Also why are the Valve lift numbers being given in those increments used in the charts?

The program took the max valve lift and produces 10 evenly spaced lines.

The program also takes the lift points / flow data and generates a "spline curve" which it graphs, rather than straight lines from data point to data point.

Stan

Why does it need a max valve lift? Does that mean if you change the max valve lift by .025" up or down, both H&V axis will have different values again for this same head?

If it will, us who are only seeing a graph here will have a hard time comparing things.

I have a head with the same size intake valve I'm trying to compare with this one...i thought it would be easy.

You pick a round number just above where you are going to lift to and stick with that. The lift for these heads will be about 0.625 so 700 was chosen as the highest measured lift point.

[The Iron Icon]

Well guys i remessured the intake on stock port and one we had ported that we showed results of. Came up 128cc stock and 135cc ported. We will put up the charts to reflect what this changed later on. Sorry for any confusion.

[Carnut1]

Well guys i remessured the intake on stock port and one we had ported that we showed results of. Came up 128cc stock and 135cc ported. We will put up the charts to reflect what this changed later on. Sorry for any confusion.

On my 289 thread my 1.94" port was about 154cc and my 1.85" port was about 146cc fyi.

[gmrocket]

The program took the max valve lift and produces 10 evenly spaced lines.

The program also takes the lift points / flow data and generates a "spline curve" which it graphs, rather than straight lines from data point to data point.

Stan

Why does it need a max valve lift? Does that mean if you change the max valve lift by .025" up or down, both H&V axis will have different values again for this same head?

If it will, us who are only seeing a graph here will have a hard time comparing things.

I have a head with the same size intake valve I'm trying to compare with this one...i thought it would be easy.

You pick a round number just above where you are going to lift to and stick with that. The lift for these heads will be about 0.625 so 700 was chosen as the highest measured lift point.

I understand picking a round number above your max lift. I don't understand using 10% going down as a measuring unit?

Why not start at .700", then next .650" or 600" and on down in .050" or .100" increments?

The graph would still look exactly the same, bit the numbers would make more sense.

Maybe I'm being too simplistic

[Stan Weiss]

Why does it need a max valve lift? Does that mean if you change the max valve lift by .025" up or down, both H&V axis will have different values again for this same head?

If it will, us who are only seeing a graph here will have a hard time comparing things.

I have a head with the same size intake valve I'm trying to compare with this one...i thought it would be easy.

You pick a round number just above where you are going to lift to and stick with that. The lift for these heads will be about 0.625 so 700 was chosen as the highest measured lift point.

I understand picking a round number above your max lift. I don't understand using 10% going down as a measuring unit?

Why not start at .700", then next .650" or 600" and on down in .050" or .100" increments?

The graph would still look exactly the same, bit the numbers would make more sense.

Maybe I'm being too simplistic

So you think that there should be an option to be able to produce the graph like this?

Stan

ab-cfm-flow-100.gif

[GARY C]

Stan, that seems like the way you would want it so one would be able to compare that head to any other published data in the industry.

[gmrocket]

You pick a round number just above where you are going to lift to and stick with that. The lift for these heads will be about 0.625 so 700 was chosen as the highest measured lift point.

I understand picking a round number above your max lift. I don't understand using 10% going down as a measuring unit?

Why not start at .700", then next .650" or 600" and on down in .050" or .100" increments?

The graph would still look exactly the same, bit the numbers would make more sense.

Maybe I'm being too simplistic

So you think that there should be an option to be able to produce the graph like this?

Stan

ab-cfm-flow-100.gif

Absolutely.

Would that work better for your online head flow library?

And everyone else in the world

[Stan Weiss]

I have left the default just the way it always has been at 10 lines on the X-Axis. I have added an option to “Have the Program Automatically Adjust the # of lines for the X-Axis.”. So it is now up to the user how he wants his graphs.

Stan

Adjust-X.gif

[RevTheory]

Well it wasn't bugging me before but it kind of is now I guess it's really not a big deal because, like Stan said, the flow at the lift you personally checked it at is in the printed fields.

IOP.PNG

[Stan Weiss]

Shawn,
This is not for the person that has the program or all of the data but for the person who is just looking at the Graph. If you have the program you can move your mouse pointer to any shot on the graph and the program will show valve lift and cfm for that point. If someone is interested in cfm at lets say 350 lift or 400 lift isn't the above graph easier to see that than this default graph?

Stan

default_x.gif