January 6, 201511 yr comment_692717 To the Rollaclub forum... I'm a cylinder head porter. I often post examples of my work in forums around the world... why I've missed this one for so long... I have no excuse.... :oops: and now on to the topic at hand..... As I always do... my client is anonymous, unless he wants to share. This head is sold to a client in California. This is his daily driver, that gets a track beating/work out every few months or so. Retaining emissions compliance is paramount, but we can get a bit more without offending the sniffer. This is a largeport head, it is the stock thickness, having never been re-surfaced. A key for me in figuring out overall "wear" is often judged on the condition of the old valve seals. The old seals that came from this head were still "pliable" (read as didn't crumble under finger pressure) - A few intake valves did show signs of build-up, the exhaust valves were all dry. #4 exhaust port Its pretty crowded in there, but a bit of seat to bowl blending, and a re-taper of the port will allow the exhaust gasses an easier path Now that it is stripped, its off the the machine shop to get cleaned, and de-carboned. Maybe they can get rid of that horrid paint for me too More to come...... :D Report
January 7, 201511 yr comment_692730 oohh.... the ultimate black art! We are dying to watch and learn! Have you ever done a 4K head?? Do we have to send you one.... Report
January 7, 201511 yr Author comment_692761 oohh.... the ultimate black art! We are dying to watch and learn! Have you ever done a 4K head?? Do we have to send you one.... a long time ago.... friend had a 4KE, his "porter" went hog wild... and then found a cracked head :wasted: He sourced another 4KE head and I ported it as best I could.... 2008 - so early in my porting career - minimal work just to get his replacement 4KE head to fit the intake ports on the ported 4KE intake manifold Not only do I work the ports... but when bad casting flash restricts oil movement, I work those areas too MOST of my work has been on the 4AG head, although I have worked a few 6 cylinder heads, and I'm getting into SR20DE heads as well... I also have a flowbench to quantify the work performed.... As to sending me a 4K head.... I'd be happy for more work....... :wootjump: Edited January 7, 201511 yr by oldeskewltoy Report
January 8, 201511 yr Author comment_692791 Cool, home made bench? Details please? :) The flowbench is a Flow Performance 2.0 kit. I would NOT recommend this kit because the usage instructions are poor, it took me over a year to figure out its correct use. I had a friend of a friend who is studying flow dynamics go though the entire manual and re-write it for me. As to the bench itself... I built it using a Baker's Rack type cart so I could make it mobile. The Shop Vac fits on the under tray PS - attempting to fix some of the photos... hopefully back up soon Report
January 9, 201511 yr Author comment_692830 The one head I sent out for cleaning, and pressure testing has pretty significant flaws.... Chamber #3 is not quite the same depth as chamber 4... you can see this by comparing "a" and "b' in both heads. and you can see heavy machining. Chambers 2 and 3 are pretty bad, 1 is just a little bad, and 4 is "ok". All those chambers have significant flaws, and it just isn't economically feasible to fix the flaws.... so I'm after another head..... more to come...... :) Report
January 10, 201511 yr comment_692832 We sent a crank/rods/pistons etc off to be balanced last year, new pistons and a replaced rod or two after SOMEONE destroyed their 18RG doing burnouts.. turned out there was 25g difference between the rods from two motors, even though they were both 18Rs, and it wasn't feasible/economic to equalise them. We ended up swapping all 4. On the other hand, Ford found testing of random heads off the production line gave a few with better flow than the carefully ported ones from the racing workshop. Maybe its all an urban myth, but the big differences in what are meant to be identical items can have strange effects. Have you ever tried the epoxy filling of ports to reshape them? I feel uneasy about having it come loose at some point later. Report
January 10, 201511 yr Author comment_692836 We sent a crank/rods/pistons etc off to be balanced last year, new pistons and a replaced rod or two after SOMEONE destroyed their 18RG doing burnouts.. turned out there was 25g difference between the rods from two motors, even though they were both 18Rs, and it wasn't feasible/economic to equalise them. We ended up swapping all 4. On the other hand, Ford found testing of random heads off the production line gave a few with better flow than the carefully ported ones from the racing workshop. Maybe its all an urban myth, but the big differences in what are meant to be identical items can have strange effects. Have you ever tried the epoxy filling of ports to reshape them? I feel uneasy about having it come loose at some point later. I have done a bit of filling... but in correcting an intake manifold, or using it to fill injector ports, nothing towards reshaping a port itself. Overall, I'm not a fan of goops, or puttys. It is pretty easy to improve most castings... even if it is just a little bit... the problem is the guy who thinks he knows... then things get out of hand. Here are 2 pair of 7MG intake ports - one side to shape, the other side not yet having been touched. edit - enlarge view, drew red translucent line just along edge of port floors to better distinguish port floor remains where it was before work began You can see the transition from port to bowl, and then to the valve seat are smooth, all of the machining has been blended the short radius on the left isn't smooth, its transition is choppy and disturbed and so short radius flow is disturbed. On the right I've worked the short radius, and yet note how the port floor is in the same place in both, I managed to create a gentle curved shape without lowering the floor to do it Edited January 10, 201511 yr by oldeskewltoy Report
January 19, 201511 yr Author comment_693246 Take 2........ The old head on top, the replacement below.... chambers are far better shaped! More to come........ :D Report
January 21, 201511 yr Author comment_693298 Easiest way to begin is showing you another 2 panel of chambers 3 and 4.... the top one you've seen before... ... the bottom one is new - Cylinder 4(on left) is where we begin.... all four bowls and seats have been blended, as well as the chamber deshrouded and intake guides minimized, the seats in #4 just need their valve job. How observant are you???? What else have I done that I didn't tell you?? :wtf: The intake bowls, and seats - 4 is shaped(on left), 3 is untouched.. Bowls are now round, blended out to meet the seats, the shape is carried out to the port. The short radius transitions smoothly from port floor to the valve seats, and the guides have been minimized. Chamber... Intake.... and now exhaust A comparison between 4 (on left) and 3 and a 2 panel showing progression of #4 from half shaped, to fully shaped More to come.... :D Report
January 21, 201511 yr comment_693306 How often do you come across variations in the chamber depths? I can't say I noticed it on my spare head, but I didn't look closely either. Report
January 21, 201511 yr Author comment_693339 How often do you come across variations in the chamber depths? I can't say I noticed it on my spare head, but I didn't look closely either. The head this thread began with, that since has been replaced is the worst head I've seen. I've had to discard other heads because of flaws before*, but this is the worst head, at least in regards to correct chamber shape, that I've seen. * - http://www.hachiroku...771&postcount=7 A short annotated photo showing the areas of work, and the similar area before work - no "hogging" here As I did for the 7MG head above, I redid on this head, so the translucent redline shows us the port floor 1) The short radius - a gentle curve to the valves edge to promote cylinder filling 2 & 3 ) shaping the bowl to the seat, further promote cylinder filling 4) "Opening" the passage between the splitter and the guide, allowing the airflow easier passage past the guide - once again to aid in cylinder filling. Nothing drastic, just taking a mass produced part and making it better :2thumbs: More to come...... :D Edited January 21, 201511 yr by oldeskewltoy Report
January 22, 201511 yr Author comment_693351 From oldeskewltoy.... "from another forum the intake valve on the right got slightly more space to breath... The chambers edge around the right intake valve has changed a tiny bit' date=' so technically you are correct,[/quote'] Why did it change?? Chamber edge... this time cylinder 3. On top is the chamber edge before any work, you can see the old gasket, so that edge "sat" in the combustion chamber, the photo below shows after removing the half that is toward the exhaust valve (right) Note how significant a flaw the edge of the chamber actually is.... when measured... it is .48mm "tall", and it is .73mm "deep", or sticking into the chamber is a sharp edge. So how significant is it...??? see the little green arrow, that arrow shows where I placed the dental pick.... Edges are NOT GOOD, they promote detonation, and this one stick "in" like a sore thumb :( So... that is why the edge of chamber four around the right hand valve now has a bit more room to breath.... and it is likely that all the chambers will show this change as well More to come...... :D Report
January 22, 201511 yr Author comment_693379 Since the last post was a brief discussion about that edge... I thought a short gif of the progression of the chamber walls.... although "polished" in the last scene, it wont be finished till after I have chamber volumes, and adjust accordingly And now for exhaust port #3 More to come...... :D Report
January 27, 201511 yr Author comment_693508 exhaust port #2 mid work Chambers 4, 3, and now 2 deshrouded Intake short radii on 4, 3, and now 2.... More to come...... :D Report
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