Header Design Using Dynomation 6 & PipeMax 4.7

ICE mock-up kits are very expensive to get enough to complete both sides .... unless you can
design and build ONE side at a time.

Each piece is 1 inch and the Summit kits contain 40 pieces for $180, that's enough to do ONE
primary tube. Times 8 in my case (Both Sides), that's $1440 and then there is the collectors.
But those are for 3 inch radius, we need some to go straight. Oh, and then sometimes you want
a 4 inch radius, now you need another kit, they come in 2 inch, 3 inch and 4 inch radius.

What if you want 1.75 inch primaries or a 1.875 inch, well those are both another set of kits. It's
certainly possible to use one diameter and then build from that mock-up, I'm guessing that most
companies or the individual could work from that.

https://www.summitracing.com/search...ending&keyword=ICEngineworks&kr=ICEngineworks
.
 
Rick, what would you have done back in my day when we used coat hangers to form headers and entire exhaust systems. Bend hangers and carry to muffler shop (1 in town) and he would bend the pipe he furnished at $00.25 a foot and no labor. Headers usually worked out but sometimes had to tweak the rest to fit under whatever car/truck we were working on. I miss the old days of hot rodding when it was more about the win than the money. Not many had much money and we all built jalopies from junk cars until we could do better.
 
Needed to know the Exhaust Runner Volume for Pipemax 4.5, so I had to break out the
100cc Buret. Came up with a value of 71.4 cc.

FP06_ExhaustRunnerVolume71.4cc_01582.jpg
FP06_ExhaustRunnerVolume71.4cc_01589.jpg
.
 
I have measured the intake port volume and it's 203.4 cc. The 3.4 cc over 200cc is probably
from port matching.

I found a procedure for measuring port length by Larry Meaux, author of Pipemax, so I will
be trying that in the next few days.

Below are the first calcs I ran, probably need to add the port length for the intake manifold to
the 5 inches shown in the input window. Still reading and learning alot about using Pipemax.

The two Blue parameters are linked together, so when I set the first one under "Intake Data", it sets the
other one under "Exhaust Data" to the same value.

FP07_PipeMaxParameters_HeaderDesign01.jpg

The graphic below is the output using the parameters above.

FP07_PipeMaxOutput_HeaderDesign01.jpg
 
I don’t understand how they come up with the formulas to do all this so I’ll call it FM! I’m getting excited for you and looking forward to seeing the progress.
 
I don’t understand how they come up with the formulas to do all this so I’ll call it FM!


very short version on header design
exhaust gases have a known mass, temp range,expanded volume and velocity,
the engines cylinder volume, effective dynamic compression, cam lift and duration and lsa,
rocker ratios , ignition timing, combustion burn times, connecting rod lengths, combustion chamber volume, valve sizes, should all be known factors
and fuel/air mixture are variables, everything is always a compromise in some area.
but the calcs are generally assumed all those to be close to optimal
at the generally accepted power band for a 383 sbc thats from about 4300 rpm to about 6300 rpm with an average performance street engine build
remember piston speeds must remain under critical stress levels (think red-line)
the max negative pressure at the exhaust valve in that rpm range and its timing can be calculated.
factors like drive train gearing, transmission gearing and fuel octane all affect potential calculations

tubingsizeversusarea.png

volumetric.gif

exhaustpressure.jpg

EXFLOWZ4.jpg

pistonposition2a.jpg

read the links it should help


http://garage.grumpysperformance.com/index.php?threads/calculating-header-design.185/

http://garage.grumpysperformance.com/index.php?threads/calculating-required-exhaust-pipe-size.11552/

http://garage.grumpysperformance.com/index.php?threads/x-or-h-pipe.1503/

http://www.wallaceracing.com/header_length.php

http://www.bgsoflex.com/bestheader.html

https://www.musclecardiy.com/perfor...t-system-math-build-high-performance-engines/

https://www.centuryperformance.com/exhaust-header-tube-sizing-and-length.html

https://www.sandersonheaders.com/lets-get-technical.html

https://www.hotrod.com/articles/proper-exhaust-header-collector-volume-vs-engine-size/
116_0312_02_z+header_tech+graph.jpg


http://www.headerdesign.com/extras/engine.asp
 
Last edited:
Does a blown motor change the theory of this stuff? Seems like boost would really mess with scavenge waves at valve overlap. Does that make primary size not important?
 
while boost changes things it also makes primary size restrictions even more pronounced,
if you go a bit too large in port size for a naturally aspirated engine you tend to lose a bit of off idle torque,
with a super charger equiped engine, this is rarely the case,
but with a super charger equiped engine, in most cases the larger port has a significant and measurable effect on increased power in the mid and upper rpm,s
 
I mentioned above a procedure for measuring port centerline length by Larry Meaux the author
of Pipemax, below is that procedure. First you will need some 1/8 inch pin stripping tape. The
photos a pretty much explain themselves.

It takes two runs of tape along the short side radius and the long side radius. Mark the tape at both
ends. Remove the tape and place in a straight line on a flat surface to be measured. After you get both
measurements, add them together and divide by 2 to get the Centerline length.

FP08_PortRunnerMeasurements01_01593.jpg

FP08_PortRunnerMeasurements02_01597.jpg

FP08_PortRunnerMeasurements03_01599.jpg

FP08_PortRunnerMeasurements04_01603.jpg

These measurements will be used to make a calculation that is Critical to Pipemax. The calculated
values below will be input into Pipemax in the Yellow fields. First are the measurements input into
the Excel table. I took lots of extra measurements.

FP08_PortRunnerMeasurements06_ExcelTable.jpg

Now the calculations. The yellow values go directly into Pipemax.

Copied from Pipemax is the formula used in the Excel table below.
Calculate the CSA Velocity FPS by measuring the Head's Intake Port CenterLine Length , then measure the Intake Port Volume CC's,
****** CSA Velocity FPS = ( Intake Port CFM * Intake Port CenterLine Length * 39.3289536 ) / Intake Port Volume CC

FP08_PortRunnerCalculations07_ExcelTable.jpg

BTW I took more measurement than what's needed for Pipemax, didn't want to find out I needed
something later and then couldn't get to it to measure. Since the exhaust port exit is not square or
round, I traced it onto graph paper to get the port cross sectional area.

FP08_PortRunnerMeasurements05_01609.jpg
.
 
Do you do this for each cylinder? Would that mean you don’t necessarily want equal length primaries but equal flow lengths to the collector? Talk about space age!
 
impressive detail work for sure, but I'm rather interested in what you see in real world results,
after you build the headers vs what the current headers provided.
Id point out that the best headers in the world won,t do much to reach their full potential,
if the exhaust system behind the collectors is even marginally exhaust gas flow restrictive.
I at one time built a killer set of custom side exhaust headers for a 1968 BBC corvette I owned,
commercial side exhaust systems without the inserts work rather well.
but theres issues with noise, burnt calves, melted socks and less than happy female riders as a result

corvsider1.jpg


and compared the results to the off the shelf hooker side pipe header that they replaced,
both sets of headers lost significant/very noticeable power if the exhaust muffler inserts were in place
with open side pipes the result in lower et, times with the custom spec, headers were marginally better ,
but considering the cost to build the custom headers the hooker side exhaust was a darn good value. I could run in the high 10.30s with hooker side exhaust and no inserts
, the custom headers added about 1.4 mph and about 1 tenth lower ,
or less to the better E.T,
but cost about 3 times what the hookers cost,
now admittedly that was back in the 1970s-1980s when my tuning and diagnostic skills were marginal compared to now ,
but it was a damn good learning experience and helped build welding skills

related threads
http://garage.grumpysperformance.co...-exhaust-system-for-your-car.1166/#post-30424

http://garage.grumpysperformance.co...impressed-with-dougs-headers.7831/#post-33125

http://garage.grumpysperformance.com/index.php?threads/building-custom-headers.961/#post-1716

http://garage.grumpysperformance.co...-just-slap-on-factory-headers.3155/#post-8423

http://garage.grumpysperformance.co...haust-system-design-is-critical.260/#post-315
 
Last edited:
Do you do this for each cylinder? Would that mean you don’t necessarily want equal length primaries but equal flow lengths to the collector? Talk about space age!
You certainly could, but I don't think it's necessary. There is enough unknown variables that the
accuracy would not be effected appreciably. Testing is the only way to know for sure.

The length determines the when the negative pressure wave will return to the exhaust valve, the
pressure wave travels at the speed of sound. The speed of sound is dependent of temperature, which
varies as the exhaust travel down the tube. Diameter determines how much (volume) can flow thru
the tube, that's why you see bigger engines usually have bigger dia tubes. Equal length tubes will help
the peak HP, but it won't be as wide of a rpm band. I'm wanting to build unequal length headers to
broaden the TQ/HP band.
 
Last edited:
Do you plan on buying some dyno time when you are done? Will any of your software combine your info for a power/ prediction?
 
No, I'm not looking to use the dyno at this time. Pipemax's primary purpose is to help with header
dimensions. I can take those dimensions and input that to Dynomation to get a prediction on TQ/HP.
 
I'm wondering if I have a problem with the copper head gaskets. As you can see, every cylinder
has some carbon coloring/buildup in some places.

At first I thought they might be extending into the cylinder slightly, but that's not the case.

FP09_HeadGasketCarbon04_01641.jpg
FP09_HeadGasketCarbon01_01632.jpg
FP09_HeadGasketCarbon02_01634.jpg
FP09_HeadGasketCarbon03_01638.jpg
.
 
thats common and no issue, simply carefully re-clean the copper gasket on both surfaces and spray both sides sticky/tacky before you re-install
the key to use is simply a clean gasket coated with a consistent thick tacky coat of copper coat gasket spray
copperspray1.jpg

http://garage.grumpysperformance.com/index.php?threads/sbc-head-gasket-choice.11070/#post-71671

http://garage.grumpysperformance.com/index.php?threads/head-gasket-related.1859/#post-50617

http://garage.grumpysperformance.com/index.php?threads/head-gasket-related.1859/#post-50617
 
Back
Top