Porting the Edelbrock Pro Flow XT 7137

[Grumpy]

its looking much improved, youll be amazed at how taking the effort to, think things through,
and then actually do several, seemingly minor improvements, on several sub systems
, can and frequently does tend to add up into significant advantages ,
that might provide a significant advantage over the guys that fail to take the time and effort to research the cars potential,
and result in a total improvement in the engines durability and power curve,
this attention too minor details usually results in the guys who are unwilling to do that research,
too be ignorant of the reason why and wonder why your car handles and runs significantly better than their similar car.

 

[ASE Doc]

Thanks Grumpy. I'm so glad that I'm here with you guys and that you're following along on this project. I am excited today after reviewing the progress so far. Still a long way to go but getting to this stage on the first runner is a big step.

I'll have my calipers soon and then I can map this runner as a guide for the rest, as well mapping an as cast runner for the taper model.

I went back over this runner's taper today and I think it's pretty close. It should work well. Thanks by the way for labelling the before and after photos.

 

[Indycars]

Did your research tell you to keep the same taper?

BTW, looking very nice. Nice to see someone take some time and be concerned about getting-it-right!

 

[ASE Doc]

I'm not sure how, without a flow bench and/or dyno, to be sure if a different taper would be better. The taper will affect the runner's peak torque point, so the ideal taper, like ideal csa, will vary with engine configuration and my peak torque goal. As I said before, I don't know the minimum csa of my heads. Probably somewhere close to Grumpy's ported G2s. I won't know this until the engine is torn down in a few years for a new build. The engine configuration will change then with increased cubic inches. At that point, I can do some calculations to determine how close I am on the intake runners to ideal csa to match the heads and my peak torque goal. I can also take a closer look at taper then. For now, I am retaining the original taper because it was designed this way. The original engineer's design is one thing I have to go on. I decided that it was best at least at this point, to follow the original design as much as is practical.

My goal in this project, with the limited info I have, was to increase the intake's top end flow and shift total average torque northward around 500rpm. Regardless of what I was told by Eddy Tech, it is obvious to me that this intake as cast will not do its best with my ported G2s and the ZZX cam. While I can't say how close I am to ideal with the port work, I can say without question that the performance will be significantly improved. I want to be more mathematical and precise in this work, for now I'll have to settle for my old school experience and gut instinct. I will use measurements and math to be sure the runners are as close to one another as I can get without CNC. I'm also going to be increasing the size of the plenum, partly due to the throttle body adapter and also as part of the port work. I'll determine what percentage I've added to the runners and probably add the same to plenum volume to support the increased flow and shift in the torque curve.

 

[Grumpy]

I would NOT be overly concerned with the increase in plenum volume,being critical to function,
simply because each runner draws from that plenum volume due to the engine firing order ,
spaced out every 90 degrees, not simultaneously,
thus even if the individual cylinder fill reaches lets say 115% of that cylinder volume
(AN ALMOST IMPOSSIBLE EFFICIENCY LEVEL)
the fact that the plenum volume exceeds any pair of cylinders,
and that its that plenum volume the runners draw from, that is constantly being refilled from the throttle body flow,that makes that a minor concern.
or put differently the throttle body flow rate easily exceeds the potential draw or flow of all eight cylinders at peak rpm,
yet only a single cylinder draws from that plenum, every 90 degrees of crank rotation,
so the draw at any instant in time, is far lower than the throttle body plenum combo can easily provide.
your efforts, at modifying and enlarging the runners area, are sure to provide a well matched flow rate if you select the correct size injectors and fuel pump capacity

if we use that 1.6" x 2.10" runner cross sectional area as a rough guide line and do the calcs we have a 3.36 sq inch cross section
that in theory easily supplies a 350 displacement too about 6600 rpm, and a 383 to about 6200 rpm, a 383 spinning 6300 rpm requires about 700 cfm of air flow , thus a single runner consumes about 87.3 cubic feet of air per minute
your runners cross sectional area thus must be able to flow about 3 times that or about 250 cfm to keep up with demand as the intake flow is not constant but intermittent and roughly 1/3rd of the 720 degree cycle is effectively flowing fuel/air into the cylinder.

http://www.rbracing-rsr.com/runnertorquecalc.html

keep in mind many EFI intakes are updated versions if the basic tunnel-ram intake design offering superior dry air flow and a direct injector shot of a high pressure mist of fuel aimed at the back of the intake valve

Came across this info while doing some research and thought I'd share.

http://www.hobracing.com/tech/tpi_flow.asp
TPI Intakes and runners

The following airflow tests were performed on the University of Northwestern Ohio's SuperFlow SF600 Flow Bench. All CFM values are corrected for airflow at 28 inches of water. Injector flow rates are flowed at 43.5 PSI on an injector flow bench using test fluid with same density as gasoline.

AirFlow

Stock TPI/LT1 48mm Throttle Body w/o airfoil -- 783.0 cfm

Stock TPI/LT1 48mm Throttle Body w/ airfoil -- 821.9 cfm

TPI/LT1 52mm Throttle Body w/o airfoil -- 848.9 cfm

TPI/LT1 52mm Throttle Body w/ airfoil -- 898.8 cfm

Stock 98 Camaro 3800 II Throttle Body -- 554.3 cfm

Stock TPI Bosch MAF sensor w/ screens -- 517.8 cfm

Stock TPI Bosch MAF sensor w/o screens -- 658.4 cfm

Stock 87 GN 3.8L Turbo AC MAF sensor w/ screen -- 584.2 cfm

Stock 86 2.8L AC 5-wire MAF sensor w/ screen -- 576.2 cfm

Stock 96-up AC 3100 V6 MAF sensor w/ screen -- 616.4 cfm

Stock 96-up AC 3100 V6 MAF sensor w/o screen -- 670.7 cfm

Stock 94-up LT1 MAF Sensor w/o screen -- 719.0 cfm

Stock 85-87 Firebird TPI airbox mid piece -- 499.3 cfm

Stock 4.3/5.0/5.7 2bbl TBI complete -- 574.1 cfm (dry)

Stock 4.3/5.0/5.7 2bbl TBI w/o injectors -- 584.7 cfm

Stock 3800 vin L throttle body w/ screen -- 419.1 cfm

Stock 3800 vin L throttle body w/o screen -- 444.8 cfm

4bbl MPFI Holley Throttle Body -- 1287.6 cfm

Another source sent in these flow numbers

Flow and HP ratings for Throttle-bodies:

Flow (cfm) Max. NA HP
Stock 668 300
Stock w/airfoil 710 350
52MM w/airfoil 835 400
54MM (AS&M) 900 450
58MM 1050 500


TPI Intakes and runners flow rates

Stock intake manifold with runner
Stock....................198.72 cfm
ACCEL................213.52 cfm
Extrude/ACCEL....217.11 cfm
Super Ram............220.67 cfm

the stock TPI has a hard time flowing 230cfm even with minor port work, look here
most of this info is right off the accel,holley,edelbrock, and TPIS sites, add a little math and the results become much clearer!!!

Intake....... length ....... port in -- out
Stock GM Base--- 6.375"------ 1.47"- 1.96x1.2
TPiS base------ -6.125"------ 1.75"- 2.09x1.28
Accel base----- -6.125"------ 1.75"- 2.09x1.28
Holley base------- 6” runner 2.3”- 1.9”x 1.23 (2.337 sq inches)
Runners
Stock TPI----- -- 7.250"------1.470" round(1.70 sq inchs)
SLP ----------- - 6.625"------1.600" round (2.01 sq inchs)
Accel LTR------- 6.625"------1.615" round (2.05 sq inchs)
TPiS----------- 7.625"------1.660" round (2.168 sq inchs)
Mini ram -----3.5”
LT1 ----------3”

Runners (measured individually)
Stock....................203.17 cfm
ACCEL................242.02 cfm
Extrude/ACCEL...275.83 cfm
Super Ram............289.18 cfm
Intake manifold with 3/8 inch radiused intlet.............................222.45 cfm
Holley stealth ram ………..275cfm

Stock intake manifold with runner
Stock....................198.72 cfm
ACCEL................213.52 cfm
Extrude/ACCEL....217.11 cfm
Super Ram............220.67 cfm
Holley stealth ram …..275cfm

ACCEL Hi-Flow intake manifold with 3/8 inch radiused inlet.........251.51 cfm

ACCEL Hi-Flow intake manifold with runner
Stock....................215.83 cfm
ACCEL................232.53 cfm
Extrude/ACCEL....243.21 cfm
Super Ram............240.24 cfm

Extrude-Honed ACCEL Hi-Flow intake manifold with 3/8 inch radiused inlet ...............275.83 cfm
Extrude-Honed ACCEL Hi-Flow intake manifold with ACCEL runner ..............266.94 cfm
Edelbrock Performer RPM manifold (Stock)..........286.51 cfm
Edelbrock Victor Jr. ............275.24 cfm

HOLLEY STEALTH RAM
the HOLLEY STEALTH RAM FLOWS at 275cfm out of the box, and has the potential when matched to the correct heads and cam to totally out flow most other intakes available,can easily reach 300cfm with minor port work and costs much less
Stock…………………………… 275cfm
Ported…………………………..300cfm

Runner lengths
Stock tpi manifold 8” runners 11.25”, cylinder head 6” total 25.25”
Accel super ram manifold 8” runners 7” cylinder head 6” total 21”
Holley stealth ram manifold 6.26” ” cylinder head 6” total 12.26”
Edelbrock performer RPM runners 6” ” cylinder head 6” total 12”
Edelbrock vic jr , runner length 5.5” ” ” cylinder head 6” total 11.5”



Also interesting TPI mods. Not so sure I agree with the one on bumping up the initial timing.
http://www.hobracing.com/tech/tpi_mods.asp


Basic TPI modifications
Friday, May 23, 2014

READ THIS

viewtopic.php?f=52&t=10705&p=46582&hilit=there+tuned+port#p46582

Volume (CCs) of Head Gasket
CCs of Head Gasket = Bore x Bore x 12.87 x Thickness of Head Gasket
COMMON SBC INTAKE PORTS
felpro # 1204=Port Size: 1.23" x 1.99"=2.448 sq inches

felpro # 1205=Port Size: 1.28" x 2.09"=2.67 sq inches

felpro # 1206=Port Size: 1.34" x 2.21"=2.96 sq inches

felpro # 1207=Port Size: 1.38" x 2.28"=3.146 sq inches

felpro # 1209=Port Size: 1.38" x 2.38"=3.28 sq inches

felpro # 1255 VORTEC=Port Size: 1.08" x 2.16"-2.33 sq inches

felpro # 1263=Port Size: 1.31" x 2.02"=2.65 sq inches

felpro # 1266=Port Size: 1.34" x 2.21"=2.96 sq inches

felpro # 1284 LT1=Port Size: 1.25 x 2.04''=2.55 sq inches

felpro # 1289 FASTBURN=Port Size: 1.30" x 2.31" 3.00 sq inches
http://users.erols.com/srweiss/calccsa.htm

Your RPM computed from your Cross Sectional Area of 1.95
(the smaller AFR HEADS)
and Bore of 4.03 and Stroke of 3.75 is 5,569.12 .

Your RPM computed from your Cross Sectional Area of 2.05
(the Larger AFR HEADS)
and Bore of 4.03 and Stroke of 3.75 is 5,854.72 .
you,ll barely notice the about 300 rpm shift in the power band on the lower part of rpm range but appreciate it much more on the upper edge of that power curve


heres a chart FROM THE BOOK,HOW TO BUILD BIG-INCH CHEVY SMALL BLOCKS with some common cross sectional port sizes
(measured at the smallest part of the ports)
...........................sq inches........port cc
edelbrock performer rpm ....1.43.............170
vortec......................1.66.............170
tfs195......................1.93.............195
afr 180.....................1.93.............180
afr 195.....................1.98.............195
afr 210.....................2.05.............210
dart pro 200................2.06.............200
dart pro 215................2.14.............215
brodix track 1 .............2.30.............221
dart pro 1 230..............2.40.............230
edelbrock 23 high port .....2.53.............238
edelbrock 18 deg............2.71.............266
tfs 18 deg..................2.80.............250

USE THE CALCULATORS
http://www.rbracing-rsr.com/runnertorquecalc.html
http://www.wallaceracing.com/chokepoint.php
http://www.wallaceracing.com/header_length.php
http://www.superchevy.com/how-to/en...-0902-chevy-engine-port-variations-measuring/
http://www.hotrod.com/articles/choosing-the-right-camshaft/
http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/

Basic TPI Mods: by DEBBIES87

There are a few basic mods that should be done to any TPI car, I call these "entry-level" modifications.

1) Cut the air box open without letting air in the engine without going through the air filter & remove the additional plastic piece below the air box to get more air into the engine.

2) Modify the mass air sensor; remove the screens, & and if your brave cut down the fins.

3) Port the plenum (upper intake). There are two small ridges sticking up in the entry-behind the throttle body, remove these. The throttle body openings are already 52mm, so don't go crazy when porting.

4) While the plenum is off for porting, it is now a good time to get a adjustable fuel pressure regulator & a MAT sensor relocater kit. The Adj. FPR will aid in tuning, and the new MAT sensor will improve throttle response as well. The new LT1 style MAT sensor is placed in the air box instead of the plenum, this allows it to read cooler air and advance the timing accordingly.

5) Advance the base timing to 12-13 degrees. Note: the harmonic balancers on these cars tend to drift with age, adjust timing to where the car still starts good and doesn't detonate.

6) If legal in your area, gut the catalytic converter and remove the smog pump belt (85-87), or run a shorter serpentine belt to bypass the pump (88-92); you will need to remove the smog pump on the 88-92's to reroute the belt properly. Check local smog laws first.

7) On automatic cars, adjust T.V. cable (throttle valve cable), so that the car shifts out between 4200-4500 RPM under wide open throttle. TPI motor power drops off drastically after 4500-4700 RPM, they peak at about 4200-4400 RPM. No need to over-rev these motors.

8) Bypass fan relay to make fans come on manually, or install aftermarket relay to turn on fans sooner.

All together these mods should make the car perform like it should have from the factory, gains should be between .6-.9 tenths of a second from these modifications.




T.V

http://garage.grumpysperformance.co...8mm-throttle-body-on-your-tpi.290/#post-54181

http://garage.grumpysperformance.co...rger-intake-runners-l98-tpi.13785/#post-72483

http://garage.grumpysperformance.com/index.php?threads/tpi-flow-info.10382/#post-42908

http://garage.grumpysperformance.com/index.php?threads/can-you-get-there-with-tpi.10494/#post-44284

http://garage.grumpysperformance.co...rottle-body-size-52mm-vs-58mm.641/#post-26207

http://garage.grumpysperformance.co...-stock-tpi-engine-components.1509/#post-10159

http://garage.grumpysperformance.com/index.php?threads/removing-maf-screen.3352/#post-8823

http://garage.grumpysperformance.co...ting-overlap-and-lsa-or-lca-etc.480/#post-592

http://garage.grumpysperformance.com/index.php?threads/maf-burn-off-relay-info.661/#post-37964

http://garage.grumpysperformance.co...ther-efi-intake-manifold-info.431/#post-32491

http://garage.grumpysperformance.com/index.php?threads/setting-up-your-fuel-system.211/#post-8074

http://garage.grumpysperformance.com/index.php?threads/how-big-a-fuel-pump-do-you-need.1939/

http://garage.grumpysperformance.com/index.php?threads/setting-up-your-fuel-system.211/

http://garage.grumpysperformance.com/index.php?threads/calculate-fuel-injector-size.1200/

 

[Grumpy]

IF you have read through this thread (linked below)
where I discussed the engine combo rick eventually built , youll remember that his engine was not built to maximize peak horse power,
but to maximize available torque in the most useful , and potentially used,rpm range
http://garage.grumpysperformance.com/index.php?threads/tbucket-engine-project-dart-shp.3814/
most of the guys I build engines with, going into the project,
have the mistaken idea that they want to build a racing engine combo,
for use in a street/strip performance car,I've yet to have someone feel they did not have enough power to destroy street tires effortlessly ,even from a rolling start,
or scare themselves, if they held the throttle wide open in gear,on the street for very long,
with the engines we build, and several of them win races frequently against even local racers.
this has constantly been proven to be the wrong approach, the steer/strip car spends easily more than 80% -90% of its time operating well below the peak rpm and potential power peak,
thus it makes far more sense to concentrate on building and engine combo that operates in the rpm range the car will be driven in during more than 80% plus of its life,
even if that might require you to potentially sacrifice a couple peak horse power to gain a much more accessible and responsive and more impressive torque curve in the rpm range the car will operate in.
Im reasonably sure RICK will point out that his car is rather responsive and if he held the throttle to the floor while driving for 5-10 seconds or so,
he would have accelerated to a respectable speed that would more than keep up with traffic flow.
Every choice you make is a compromise or trade-off in some area, the key here is making the combo you build match the real world application and not saddling yourself with an engine thats a P.I.T.A. to maintain or drive on the street.
without a doubt, RICK could swap to a longer duration cam and a dual quad tunnel-ram and pick up a significant amount of peak hp, but at the cost of some streetability

 

[Indycars]

Im reasonably sure RICK will point out that his car is rather responsive and if he held the throttle to the floor while driving for 5-10 seconds or so,
he would have accelerated to a respectable speed that would more than keep up with traffic flow.

Yikkeeesss..... 10 seconds is about all I got balls for.

That reminds me, I don't like any sport that requires only ONE ball !!! ( Think about it, golf, baseball, football ......
motorsports) hehehe!!

The fastest so far was during the testing/tuning the the carburetor. The speedometer is GPS so it will tell me
top speed, speed at the 1/4 mile mark and time thru the quarter mile. The TBucket went 12.96, but that was after
reaching 98 mph and coasting back to 80 mph.

http://garage.grumpysperformance.co...-dart-400-cuin-engine.11433/page-7#post-53938

 

[ASE Doc]

Thank you Rick and Grumpy for the information you have given me. I like the tuning system you used on the T-bucket.

One concern of mine, modifying the XT is moving the torque curve too high for practical use on the street. I know what you mean by building for useable torque vs peak power. A big horsepower number sounds cool. A car with a strong wide torque curve is cool to drive. I intend to produce more average torque with the XT than I do with my modified TPI, over a wider curve. This will make my car much cooler to drive.

Tuning the engine around the new intake and injectors will take some time. I have a wide band O2 sensor and the early style ACCEL DFI that I run will record I think up to 3 data pids. Right now, installation and tuning are still a ways off. Have to finish the intake first.

 

[ASE Doc]

BTW Rick. That is a sweet T bucket. I bet it is a blast to drive.

I got some more goodies today and had a chance to play a little more with the XT. I got a bunch of 60 grit rolls, 3/8" diameter. I was afraid they may be too fat for cleaning up around the injector bungs but the size turns out to be just right.

There is a choke point at the bung protrusion where the top of the runner is narrow. I was working that area with a 1/4 inch roll, thinking there wasn't room for much more. Looking closer, there is a lot of material there. I want to have good flow at the upper half of the runner. The injector bungs in that cramped runner roof go against that. I was able to open up around the bung to run the 3/8 roll through on each side. It really opens up the choke point. I'll post photos tomorrow when I'm at the shop.

I also got a pointed tip tree shape carbide 2" length. Wish I also had gotten the 6" length. I used the 2 inch to open up the runner exit a little before going back to the rolls. This tree shaped bit does a nice job. It cuts faster than the rolls and will let me move a little quicker. The pointed tip will be useful too for touching up the corners when the walls of the plenum are welded back on.

 

[ASE Doc]

BTW Rick. That is a sweet T bucket. I bet it is s blast to drive.

I got some more goodies today and had a chance to play a little more with the XT. I got a bunch of 60 grit rolls, 3/8" diameter. I was afraid the may be too fat for cleaning up around the injector bungs but the size turns out to be just right. There is a choke point at the bung protrusion where the top of the runner is narrow. I was working that area with a 1/4 inch roll, thinking there wasn't room for much more. Looking closer, there is a lot of material there. I want to have good flow at the upper half of the runner. The injector bungs in that cramped runner roof go against that. I was able to open up around the bung to run the 3/8 roll through on each side. I really opens up the choke point. I'll post photos tomorrow when I'm at the shop.

I also got a pointed tip tree shape carbide 2" length. Wish I also had gotten the 6" length. I used the 2 inch to open up the runner exit a little before going back to the rolls. This tree shaped bit does a nice job. It cuts faster than the rolls and will let me move a little quicker. The pointed top will be useful for cleaning up the corners when the walls of the plenum are welded back on.

 

[ASE Doc]

3 replies in a row. I feel like I'm hogging the mike here. I wanted to say, the injectors I'm planning to use are 35lb/hr, rated of course at 3 bar, or 43.5psi. Using an injector size calculator, this size injector fits 450hp. I was planning on 33 lb Bosch IIIs and increasing pressure as needed to serve the 355 now and the larger engine later. I have a very strong fuel supply system with a Fuelabs variable speed pump capable of much more than this engine needs.

I like to run smaller nozzles at higher pressure to improve atomization. However, I'm also trying to be practical and buy just one set of nozzles that will work in the 355 and can then be adapted to the 383 or 406 in a few years. I'm thinking the 35lb units will do this for me. As long as I don't get the injector pulse to short on the small motor trying to tune idle fuel, it should work.

 

[Grumpy]

don,t worry too much about the use of 35 lb vs 33 lb, or similar concerns there is a wide tolerance as the pulse duration compensates very easily and the sensors will feed the required data to the system controls, remember the injectors are pulsing dozens of times a second and its not overly precise in that the cloud of misted fuel droplets from each pulse is not the exact amount required, its more of an average, in that at lower rpms intake runner reversion pulse waves tends to allow some small percentage of the mass of fuel/air to be shared between the runners in the plenum, and at higher rpms the injectors basically have a very low percentage of the time they are not flowing at least some fuel no mater the rated flow as they will be open more than 50% of the time even though the intake valves will be open less than 1/3rd of the 720 degree cycle.
remember

if we use that 1.6" x 2.10" runner cross sectional area as a rough guide line and do the calcs we have a 3.36 sq inch cross section
that in theory easily supplies a 350 displacement too about 6600 rpm, and a 383 to about 6200 rpm, a 383 spinning 6300 rpm requires about 700 cfm of air flow , thus a single runner consumes about 87.3 cubic feet of air per minute
your runners cross sectional area thus must be able to flow about 3 times that or about 250 cfm to keep up with demand as the intake flow is not constant but intermittent and roughly 1/3rd of the 720 degree cycle is effectively flowing fuel/air into the cylinder.

your injector provides the fuel required to keep the oxygen sensors in the exhaust showing a certain level of remaining oxygen in the burnt air, mat/maf sensors, temp sensors, etc. calculate the required engine rpm, load, and air flow mass and speed data too determine how much more fuel must be added, or how much the injector pulse duration should be shortened, the control software ,adds or reduces the injector pulse duration based on the exhaust gases content , its an average base line , not a precise cylinder to cylinder , and power stroke to power stroke method of control and compensation or adjustment, injectors should not be pushed past about 80% pulse duration limits but less duration is fine. if you've ever noticed the cloud of fuel/air mist over the top of an open carburetor due to reversion pulses in the intake runners you'll realize that there's never a steady single directional flow of air in that engines plenum.
its almost always preferable to error in selecting any injector size on the larger vs the smaller end of the required or preferred,size range, as a larger injector just reduces the pulse duration but a smaller than required injector won,t keep up with demand, resulting in a lean/hot mix and frequently detonation, that can result in rapid catastrophic engine damage

related

http://garage.grumpysperformance.co...-and-brand-of-injectors-bsfc.5503/#post-16537

http://garage.grumpysperformance.com/index.php?threads/calculate-fuel-injector-size.1200/#post-2506

http://garage.grumpysperformance.co...ing-c-4-or-tpi-fuel-injectors.1378/#post-9085

 

[Indycars]

BTW Rick. That is a sweet T bucket. I bet it is s blast to drive.

Hey thanks for the comment! Yes it does put you back in the seat pretty good.

Just an idea, but it would be lots of work thou. Probably more trouble than it's worth, but ......

Since it will be hard to measure with the inside calipers around the bung how much you are removing.
You could could use volume to keep track of your progress. Like measuring the total port volume, you
would measure volume by taking two measurements about 3/4" apart where the bung is located. Then
subtract the two measurements giving the volume around the bung. Compare that to the next port and
you can keep track of the removal process and keep the ports closer to identical.

 

[ASE Doc]

That's not a bad idea. I still don't have my calipers. Amazon delivery is having a tough time finding me I guess. Say they've made 3 attempts. They might have called me to ask for directions. If I don't have them by tonight, I'm getting my money back and I'll go somewhere else. Here is a photo of the runner after opening up around the bung. I still have some smoothing to do, but you can really see the difference from the as cast next to it.

 

[ASE Doc]

Wow. Between lack of skill and this cheap phone, I take really crappy photos. I think you can see what I'm trying to illustrate.

 

[Grumpy]

its always a learning process, and it looks like your making progress

 

[ASE Doc]

I started on the second runner today. I still don't have my calipers and Amazon isn't responding to my email. Very disappointing. I've had good luck with them in the past. May have to make trip to Harbor Freight this weekend and see what they have. Mealtime, I'm trying to keep moving on the project as much as I can. I'll post more photos tomorrow.

 

[ASE Doc]

Finally had a satisfying conversation today with a very nice Amazon rep. My calipers are on their way via one day express and the initial shipping charge I paid has been refunded. So, should have my calipers Friday. I can take measurements and see where I am for taper on the first runner and finish the second runner. Then continue on.

 

[ASE Doc]

Calipers are here. They look like they'll do fine. I got the 8" size. The inside calipers are the ones I'll probably use most, but the outside will be handy too for measuring thickness. I'm looking forward to trying them out tomorrow.

 

[ASE Doc]

Went through the initial ported runner with the inside calipers. I'm happy with the taper. Even better, the second runner, that I jumped ahead and started on without having the calipers to measure it, appears to be about a perfect match. I'll spend a little more time going over these two runners with the calipers to be sure. I can see where I need to work a little more in the upper corners of the second runner, around the injector bung, to match the initial runner. I also dug a hair too deep on the bottom at the exit. Overall though, the dimensions look to match right up. I was unsure about where the taper was turning out on the ported runner. After opening up the runner exit and entrance, and of course carrying the porting through the runner, I was concerned that I may have created a choke point midway through. Checking with the calipers, I see that the taper is very good. I will go over an unported runner to be sure that my ported runners' taper follows along with the original design. So far though, it looks good.

I did get a little deep on the second runner, across the bottom. Too much focus on removing material and not enough on taking care. Won't do that again. I was following my gasket marks and not thinking that I had left about 1/16" of margin in this area of the initial port for alignment purposes. The picture without the gasket shows what looks like a pretty big difference. The photo with the gasket in place shows that the difference isn't that huge. Be aware of course the second runner isn't finished out yet. That's still a 60 grit surface, yet to be finished up to 120. Still need to clean up the rough edges a little as well. I was thinking I might take the rest of the runners out to this point so they match. I think instead I'll leave the first runner where it is and do the rest the same. The one I screwed up, I'll either leave or I could fill the floor with epoxy and bring it back to match the first runner. Then again, I'm thinking it really shouldn't have that much affect. Tell me what you think.