K-series: Portflow valve job/bowlwork
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K-series: Portflow valve job/bowlwork
This is Portflow's K-series valve job and bowl work that nets a 22cfm gain! The stock head flows 296 @ .500" but after Tom works his magic, ports untouched - the cylinder head now flows 318cfm @ .500". This is a 7% gain without even touching the ports. We hope this translates well on the dyno. Theoretically, we could see a 20-30hp gain. We'll see what happens.
-Ron
Joined: Apr 2004
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From: 909 all motor mafia,, CA, USA
Re: K-series: Portflow valve job/bowlwork (edo)
looks very nice. I like how he unshrouded the intake valves - the cuts are very clean and he didn't remove too much material which some seem to do. 
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From: land of the sheep, home of the hypocrite
Re: K-series: Portflow valve job/bowlwork (rochesterricer)
Thanks for posting up pictures of all this stuff. Was that a new head from honda? When are you planning to get on the dyno again? I think we're all looking forward to seeing your results!
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Re: K-series: Portflow valve job/bowlwork (NAturalDC2)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NAturalDC2 »</TD></TR><TR><TD CLASS="quote">does anyone know costs?</TD></TR></TABLE> something i want to know...
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Re: K-series: Portflow valve job/bowlwork
Before Valve Job (purple)
After Valve Job (purple)
Here are the dyno results, before and after a few tweaks to allow the valve job to work. The interesting and peculiar fact is that the valve job alone did not translate into any gains or losses on the dyno. The AFR was identical. We were quite bewildered, so we went looking for our restrictions.
First thing came to mind were the ITB's. We flowed both the TWM 52mm's and the LHP 54mm's and each outflowed the cylinder head. However, the TWM's have a .100" larger port than the cylinder head on both sides and the floor which causes a stepped port entry, whereas the LHP's are gasket matched. We opted to stick with the TWM's for this round of testing and looked elsewhere for the restriction, the header.
We shortened the primary lengths by two inches, they are now 21" before the collector. We also reconfigured the collector by swapping out the old
2-1/4" to 3" megaphone in favor for the new 2-3/8" to 3-1/2" megaphone.
To recap, the above results depict the gains seen with the Portflow valvejob/bowlwork and header reconfiguration tested with race cams (purple run). The milder graph (red) is shown for comparison between cam applications. Based on these findings, we suspect there may be some room for improvement if the TWM's were port matched correctly. Unfortunately, we will not be spending too much more time on this platform as the 2672cc NA and the 2140cc turbo development motors are well underway and should begin testing very soon.
The next step for the 2240cc engine is to obtain some 1/4 mile ET's in Alex's EG. After that, it will be transplanted into a DC5 chassis to be fitted with the Hayward Performance 54mm ITB's in a "street" application with full exhaust.
Lastly, here is the flowbench data comparing stock (green) vs. valvejob/bowlwork (light blue) vs. valvejob/bowlwork/porting (black):
Theoretically, we should've seen a 1:1 gain translated to the dyno, cfm:hp. It hasn't happened with this motor so far as configured. Oh well, time to move on...
-Ron
After Valve Job (purple)
Here are the dyno results, before and after a few tweaks to allow the valve job to work. The interesting and peculiar fact is that the valve job alone did not translate into any gains or losses on the dyno. The AFR was identical. We were quite bewildered, so we went looking for our restrictions.
First thing came to mind were the ITB's. We flowed both the TWM 52mm's and the LHP 54mm's and each outflowed the cylinder head. However, the TWM's have a .100" larger port than the cylinder head on both sides and the floor which causes a stepped port entry, whereas the LHP's are gasket matched. We opted to stick with the TWM's for this round of testing and looked elsewhere for the restriction, the header.
We shortened the primary lengths by two inches, they are now 21" before the collector. We also reconfigured the collector by swapping out the old
2-1/4" to 3" megaphone in favor for the new 2-3/8" to 3-1/2" megaphone.
To recap, the above results depict the gains seen with the Portflow valvejob/bowlwork and header reconfiguration tested with race cams (purple run). The milder graph (red) is shown for comparison between cam applications. Based on these findings, we suspect there may be some room for improvement if the TWM's were port matched correctly. Unfortunately, we will not be spending too much more time on this platform as the 2672cc NA and the 2140cc turbo development motors are well underway and should begin testing very soon.
The next step for the 2240cc engine is to obtain some 1/4 mile ET's in Alex's EG. After that, it will be transplanted into a DC5 chassis to be fitted with the Hayward Performance 54mm ITB's in a "street" application with full exhaust.
Lastly, here is the flowbench data comparing stock (green) vs. valvejob/bowlwork (light blue) vs. valvejob/bowlwork/porting (black):
Theoretically, we should've seen a 1:1 gain translated to the dyno, cfm:hp. It hasn't happened with this motor so far as configured. Oh well, time to move on...
-Ron
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From: The all motor Forum but my house is in, Iowa
Re: (1.6i)
First let me be honest, I dont know what to look for when i see a head thats had some work done to it. All i know is, that head my friend, Is GOOD HEAD! 
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