CCing the cylinder head intake runners...
08-29-2008, 01:19 PM
#1
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Thread Starter
CCing the cylinder head intake runners...
<center><img src="http://pictureposter.audiworld.com/711/headccing.jpg"></center><p>
While the IM is off I decided to go ahead and CC the intake runners. I did this to my low/high RPM runners in both IMs I completed when writing the IM Workshop. But it's an agonizing, fretfully time-consuming effort and I just didn't have the energy til this weekend.
Cylinder head intake runners are finished to the same surface polish as the intake runners but start to get progressively rougher within about 1.5" of the intake valves for more efficient fuel atomization. And my RC Engineering injectors have a MUCH tighter, smaller taper spray pattern then OEM injectors which does an incredible job of keeping my intake valves spotless and free of carbon build-up as the circular spray pattern of the injectors falls squarely on the intake valve head's back-side rather than the runner walls. The back heads of my intake valves are shiney-spotless which is impossible to achieve with OEM spray patters due to fuel contact near 2" before intake valves and on the cylinder head runner walls.
In the above pic the right-most cylinder head intake runner is the one that ALL other 5 head intake ports will be matched to within 1 drop liquid volume of each other. Sealing of valves is acomplished by Vaseline being heated then poured in and allowed to collect around the intake valve as it starts to cool on the cold engine then the engine is cranked over pulling the melted Vaseline into the combustion chamber. Then the remaining Vaseline is removed from the intake runner via carb cleaner and compressed air after crank is rotated so intake valves are closed in one cylinder head bank which effectively seals the valve in that runner port with the Vasoline to further aid in good sealing with no water leakage whatever. Then water is poured in via a calibrated/indexed Pyrex beaker. Then a clear Plexiglass template with a "fill-spout" hole is laid over that intake runner with vaseline to seal it to the intake gasket flange and water is added again via indexed beaker to a certain point. After that water is added one drop at a time and when full that number of drops is added to the beaker numbers for total CC's. Once largest volume runner is known all other intake runners are ported as little as possible then measured til they hold EXACTLY the same amount of water within 1 drop volume. This can take up to 12-20 attempts per runner to nail it dead-on. When finished this will have taken 18-24 hours to do a 6 cylinder car. I started last night at 6pm and worked till 11pm and again this morning from 9am to just now (3pm) and am ready now to move to the opposite bank 3 cylinders. They key is to keep EVERY intake runner ID as small as possible yet still have the greatest flow and identical shape then have them all hold IDENTICAL water volume across-the-board. Not an easy or fun-filled task I assure you!!
Above pic was taken last night after finishing the right-most runner in pic to establish my "standard" for all other runners. The other runners in that cylinder bank now are a virtual carbon copy of the right-most runner in pic. I'll post finish pics before reassembly.
Back-breaking stuff this because of having to be stooped over the engine while doing it and NO WAY to pull up a stool and work from the sitting position.
I'll probably stretch this out until Sunday before cleaning everything up under the IM and putting it all back together.
While the IM is off I decided to go ahead and CC the intake runners. I did this to my low/high RPM runners in both IMs I completed when writing the IM Workshop. But it's an agonizing, fretfully time-consuming effort and I just didn't have the energy til this weekend.
Cylinder head intake runners are finished to the same surface polish as the intake runners but start to get progressively rougher within about 1.5" of the intake valves for more efficient fuel atomization. And my RC Engineering injectors have a MUCH tighter, smaller taper spray pattern then OEM injectors which does an incredible job of keeping my intake valves spotless and free of carbon build-up as the circular spray pattern of the injectors falls squarely on the intake valve head's back-side rather than the runner walls. The back heads of my intake valves are shiney-spotless which is impossible to achieve with OEM spray patters due to fuel contact near 2" before intake valves and on the cylinder head runner walls.
In the above pic the right-most cylinder head intake runner is the one that ALL other 5 head intake ports will be matched to within 1 drop liquid volume of each other. Sealing of valves is acomplished by Vaseline being heated then poured in and allowed to collect around the intake valve as it starts to cool on the cold engine then the engine is cranked over pulling the melted Vaseline into the combustion chamber. Then the remaining Vaseline is removed from the intake runner via carb cleaner and compressed air after crank is rotated so intake valves are closed in one cylinder head bank which effectively seals the valve in that runner port with the Vasoline to further aid in good sealing with no water leakage whatever. Then water is poured in via a calibrated/indexed Pyrex beaker. Then a clear Plexiglass template with a "fill-spout" hole is laid over that intake runner with vaseline to seal it to the intake gasket flange and water is added again via indexed beaker to a certain point. After that water is added one drop at a time and when full that number of drops is added to the beaker numbers for total CC's. Once largest volume runner is known all other intake runners are ported as little as possible then measured til they hold EXACTLY the same amount of water within 1 drop volume. This can take up to 12-20 attempts per runner to nail it dead-on. When finished this will have taken 18-24 hours to do a 6 cylinder car. I started last night at 6pm and worked till 11pm and again this morning from 9am to just now (3pm) and am ready now to move to the opposite bank 3 cylinders. They key is to keep EVERY intake runner ID as small as possible yet still have the greatest flow and identical shape then have them all hold IDENTICAL water volume across-the-board. Not an easy or fun-filled task I assure you!!
Above pic was taken last night after finishing the right-most runner in pic to establish my "standard" for all other runners. The other runners in that cylinder bank now are a virtual carbon copy of the right-most runner in pic. I'll post finish pics before reassembly.
Back-breaking stuff this because of having to be stooped over the engine while doing it and NO WAY to pull up a stool and work from the sitting position.
I'll probably stretch this out until Sunday before cleaning everything up under the IM and putting it all back together.
08-29-2008, 04:18 PM
#4
AudiWorld Super User
Thread Starter
Mine are the real-deal RCE (Lucas) balanced/blueprinted injectors as opposed to re-worked Bosch's...
<center><img src="http://pictureposter.audiworld.com/711/properaf.jpg"></center><p>
mine are even under-sized compared to stock but because they have a better spray pattern and MUCH finer fuel atomization I'm able to get by with a less-than-stock flow-rate injector via a slight increase in fuel pressure over stock which improves fuel atomization further, creates more power with less fuel and cleaner burning with less tailpipe emissions and black, puffy/sooty deposits.
Even with my new engine I only plan to move back up to stock-size injectors due to the efficiency of these over Bosch.
Pic shows my tailpipe tips after an entire day on-track at WOT. This demonstrates an as ideal/perfect A/F ratio as is possible to attain on the 12V engine!!
mine are even under-sized compared to stock but because they have a better spray pattern and MUCH finer fuel atomization I'm able to get by with a less-than-stock flow-rate injector via a slight increase in fuel pressure over stock which improves fuel atomization further, creates more power with less fuel and cleaner burning with less tailpipe emissions and black, puffy/sooty deposits.
Even with my new engine I only plan to move back up to stock-size injectors due to the efficiency of these over Bosch.
Pic shows my tailpipe tips after an entire day on-track at WOT. This demonstrates an as ideal/perfect A/F ratio as is possible to attain on the 12V engine!!
08-29-2008, 06:44 PM
#7
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wow! i know i need O2's but that is amazing...hmm are injectors on the "bed" next...
also i got the mounts, as usual you are a god amongst men when it comes to business
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08-31-2008, 05:06 AM
#8
Mance, any chance you could post a pic or two of the above ports from another...
angle? I'm curious to see how you blended the fuel injector spray area into the port when you gasket-matched it. The existing pic doesn't quite give me enough info. Thanks!
