greenmac80 Posted November 16, 2015 Report Share Posted November 16, 2015 if i'm understanding your figures correctly Quote Link to comment Share on other sites More sharing options...
batmo Posted November 16, 2015 Report Share Posted November 16, 2015 Will you be flowing the heads with an intake manifold attached too? Quote Link to comment Share on other sites More sharing options...
altezzaclub Posted November 17, 2015 Report Share Posted November 17, 2015 Like hot cams and other mods, you lose the bottom end as the air velocity is slower through a larger cross-section port. Once the air is moving faster the flow picks up more and more. What is amazing is how much faster an opening valve gains flow. At small openngs it is doubling the flow as the opening doubles, but at the top end it is not adding such a large percentage. 050=44 2X050=2X44 3X050=3X44 minus a few but 7X050=only 4X44 plus 30 8X050=4X44 plus 36 So a cam & port that gets the valve really working as it opens can add a lot of extra air. On a sort-of related topic... Why have auto engineers managed 30 years of such stunning advances in flow using swirl techiques etc, but over 100years plumbing engineers still can't design a bloody toilet that flushes properly every time! Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted November 17, 2015 Author Report Share Posted November 17, 2015 (edited) altezzaclub is close enough.... A few things to remember. The flowbench reads every 2-3 seconds, it measures airflow to the TENTH. After 18-24 readings, 6 are randomly chosen to provide a final averaged reading. Additionally in this test, the same 4 valves were used in all testing, they were simply moved from one chamber to the next. This means the low lift readings will have some discrepancies because the seat, and valve have not been mated to each other. Now for the exhaust side...... The control exhaust port is on the right, the "VE"-ized DE exhaust port on the left... just look at how much less those exhaust gasses have to bend.... :no: Our 3 test subjects are ready... And a view directly into each now to get them on the bench - calibrated for exhaust flow Exhaust numbers.... #2 control .050 - 33.1 .100 - 74.1 .150 - 110.0 .200 - 137.9 .250 - 151.7 .300 - 157.9 .350 - 161.6 .400 - 163.8 .450 - 165.9 #1 inside the lines - this is the exhaust port that stays within the original DE gasket shape .050 - 33.2 .100 - 73.4 .150 - 111.5 .200 - 139.2 .250 - 157.3 .300 - 166.5 .350 - 173.0 .400 - 176.8 .450 - 181.7 .500 - 184.0 #3 outside the lines - This is the port shaped to fit the VE gasket .050 - 36.7 (checked twice for I thought this an anomaly) .100 - 76.6 .150 - 113.2 .200 - 140.9 .250 - 161.2 .300 - 173.1 .350 - 182.9 .400 - 190.0 .450 - 195.5 .500 - 200.2 .550 - 204.0 On #2 - the control, it is quite obvious that the flow really was hampered once the cam hit .300 lift, there are additional flow rises with lift rises, but greatly hampered and basically hits a wall with the next 3 lifts points delivering less than 10 cfm change for all three of those points combined. On #1 - inside the lines, it is ported with extensive work while retaining the original outlet size and shape. At .300 lift there is nearly 8cfm more flow then the stock head @ the same lift, and where the stock head dies fast, the inside the lines port is still showing modest gains as it approaches .500 lift On #3 - outside the lines, or ported to the VE gasket, there is simply MASSIVE improvement. The improvements are electrifying. A gain of 18% while retaining the original valve size! . Edited November 17, 2015 by oldeskewltoy Quote Link to comment Share on other sites More sharing options...
altezzaclub Posted November 17, 2015 Report Share Posted November 17, 2015 Nice! Did you go and have a beer and sit there thinking how good it is? That really is a great improvement over a high-performance stock casting. Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted November 18, 2015 Author Report Share Posted November 18, 2015 I have a new client whose SR20VE I'll begin porting next week (if all goes well on delivery to me). Disassembly begins....... It doesn't look too bad..... but since I know nothing of this head prior to Saturdays's delivery..... I''ll be as observant as possible during disassembly I began on the exhaust side... the cam comes out easily enough... and I'm seeing more crud as parts are removed, below shows the underside of a cam cap, and the exhaust side oiling tube... both show a fair amount of build up Removing the intake side oiling tube shows a fair bit more crud that was under the tube... I should be saying at this point that I'm following this post for disassembly - http://www.sr20-forum.com/ve/219-how-install-cams-springs-retainers-ve.html So following the above post, I remove the 10mm Allen plug...... eeeeew.... quite a bit of sludge here..... its a good thing this head, and all the hardware are getting cleaned, the head will also get pressure checked. With the plug removed, the small bolts holding the rocker shaft removed, now the rocker shafts can be removed, freeing the rocker/VVT assembles for removal. Once the shafts are removed, and the rocker/VVT assemblies removed, valve removal can begin all the exhaust valves are now pulled, and a fair amount of crud can be seen I move to the intake side, and finish disassembly.... Now, the rocker shafts are under the head, and they are resting on the rocker/VVT assemblies in their own baggies, on the right side of the block holding the valves, are the valve keepers..... So my question to you (reader) is... what is in the small bag on the left side of the valves, and how many are there?? More to come...... :D Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted November 20, 2015 Author Report Share Posted November 20, 2015 So before I sent the head out to be clean and pressure checked, I took a pic of the chambers.... Hmmmmm, I've got work to do in those chambers.... they aren't as "clean" as the DE chambers I worked last year.... here is a closer look @ one of the VE chambers... and from last year... a pair of DE chambers So while the head is out getting cleaned and pressure checked, its time to clean the valves.... While cleaning the valves, I thought there was something a bit odd. So I picked out an intake and exhaust valve from the DE head and viola..... The VE valves are smaller......????? The intake isn't considerably smaller, but the exhaust is nearly a full millimeter smaller.... More to come......... :D Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted November 25, 2015 Author Report Share Posted November 25, 2015 I wasn't real happy with the head once it came back, there are some serious flaws in the chambers, VERY sharp edges!! Note the seats are "deeper" then the DE head, the resulting machining have left us with sharp edges in the chambers.... not good. Sharp anything inside the combustion chambers may lead to detonation, aka ping. This wasn't a total surprise to me, I had trolled the net, and it seems many (most?) of the VE heads have the seats deeper in the head and the residual machining left behind. Not only are they sharp, but they will cause havoc, as they disturb flow past them. So this head will see extensive chamber work. Besides the flaws in the above view, we see that the intake short radius can be improved, and the exhaust large radius has been machined from the factory. Can anyone see anything else??? So this head will see extensive chamber work. Chamber #1 as it goes through its transition It isn't obvious... but there is something missing..... anyone know whats missing? ... and no I don't mean the valves ;) more to come....... :D Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted November 29, 2015 Author Report Share Posted November 29, 2015 (edited) It isn't obvious... but there is something missing..... anyone know whats missing? ... and no I don't mean the valves ;) more to come....... :D The intake seats are missing a 3rd angle on the seats!! The red arrows are pointing to the valve to seat contact points, on the exhaust side you can see the seat has 3 angles, but the intake seats only have 2 angles. We shall fix that later when we do the valve job. #1 intake now re-worked, the short radius is smooth with no discernible edge from port floor to the edge of the valve seat, just one continuous curve Each bowl has been opened up at 2 points to allow additional filling. Finally, the seat has been opened up to 88% of the valves diameter - 30.10mm from a nominal 29mm. Each bowl has been opened up at 2 points to allow additional filling. Finally, the seat has been opened up to 88% of the valves diameter - 30.10mm from a nominal 29mm. More to come...... :D Edited November 29, 2015 by oldeskewltoy 1 Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted December 2, 2015 Author Report Share Posted December 2, 2015 So, I've looked around and I'm having a tough time finding basic info. What I'm looking for is a reliable chamber volume measurement, as well as original deck(piston above/below deck) measurement. I've scanned a few online manuals, but chamber volume and deck were not part of the information. Since I only have the head, I can at least get a chamber volume.... So I reassembled the as of yet untouched chamber 3 using the original valves from that chamber, and did a volume test on it and here is a reliable chamber volume for a stock untouched SR20VE chamber I also did a chamber test on #1 - the chamber shown above and the results..... So my chamber work adds about .5 cc to a chambers volume, that was about what I thought it would. Finally.... I measured the heads thickness.... ... although 137.02 is confirmed(5.394"), there is a tiny amount of gasket residue, along with tool tolerances, I'm gonna go out on a limb and say an uncut SR20VE head measures 137mm. More to come.... :D Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted December 4, 2015 Author Report Share Posted December 4, 2015 So work begins on the exhaust seats-bowls-ports.... opening up the seat from a measured 24.9mm, to a measured 25.9 by pushing the bowls out this far I was are able to remove the lip in the seat (seen @ the 12 o'clock position on the bowl on the right) along with the lip, by pushing the bowls we are able to actually make a round bowl to fit a round seat Can you see the infringing areas where the bowl and seat meet on the unported side?? Here is a "creatively cropped" 2 panel to show continuity from seat, through the bowl, and out the port and a final view showing a tight short radius, as well as the inner port walls Top view was yesterday... Bottom view is as finished. The finished exhaust port.... .... in comparison to #2's exhaust port, and in comparison to the VE gasket and in so doing #1 chamber, and ports are now complete, now that I'm happy with the results... when I get back to work next week, the other 3 cylinders should go quickly... so we end today with 1 down.... 3 to go More to come.... :D Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted December 8, 2015 Author Report Share Posted December 8, 2015 Half the port work now complete.... 2 down... 2 to go.... More to come...... :D Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted December 11, 2015 Author Report Share Posted December 11, 2015 new valves..... The exhaust valves are Inconel - http://en.wikipedia.org/wiki/Inconel The stem diameter of the new Inconel exhaust valves... 5.97mm With the new valves... the spec is mid tolerance.... the old valves.... a wee bit loose ;) What all of these specs, and measurements mean in the end....... No replacement valve guides needed.... Quote Link to comment Share on other sites More sharing options...
altezzaclub Posted December 11, 2015 Report Share Posted December 11, 2015 2 down... 2 to go.... A very telling photograph. Such a difference! Quote Link to comment Share on other sites More sharing options...
oldeskewltoy Posted December 14, 2015 Author Report Share Posted December 14, 2015 A very telling photograph. Such a difference! ;) this head now carries an OST serial number ;) a slightly different view.... this time from the intake side... 3 down, 1 to go...... and a more familiar view.... the exhausts, now @ 3 down.... more to come...... :D Quote Link to comment Share on other sites More sharing options...
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