MONZTER Posted February 2, 2010 Share Posted February 2, 2010 Also, I have posted these pics before. But here is my 240 NA head with 36cc welded chambers and 280 size valves. making the chambers smaller and giving it squish is the same thing Kameari are doing. Someday I will do some real valve and port work on this thing with a 3.0 under it, that should be fun. I have seen some pics that Braap has done with welded chambers as well, nice stuff. Quote Link to comment Share on other sites More sharing options...
josh817 Posted February 2, 2010 Author Share Posted February 2, 2010 Also, I have posted these pics before. But here is my 240 NA head with 36cc welded chambers and 280 size valves. making the chambers smaller and giving it squish is the same thing Kameari are doing. Someday I will do some real valve and port work on this thing with a 3.0 under it, that should be fun. I have seen some pics that Braap has done with welded chambers as well, nice stuff. I understand making chambers smaller but giving it squish...? Is it really as straight forward as I'm thinking or is this going to be a new word to my vocabulary? How large did you go on the valves? Just stock 280 44/36 I guess? I'm hoping I can take something out a little more than that (on a P90) and my real question is, for your case, where you had the room to expand on valve size, is there anything more beneficial? As in like what if you increased the intake valve to lets just say 48mm leaving you with a 32mm exhaust (48/32), that sort of thing. Maybe that can be done so you have one giant intake valve and a smaller but still promising exhaust. I know you will be quick to say "you need more valve area for the increased capacity to let out all the exhaust you now create with a larger intake" however what if you compensated this situation by perhaps having a larger lift/duration exhaust lobe on the cam? If you're running .580"/300º intake then do a .620"/300º exhaust or something. I'm also seeing some people reserve themselves on the exhaust port to keep the velocity up, but perhaps you open that port up as much as you can to allow all that volume of gasses. Just curious! PS: This head belongs to your 200hp L24 yes? And since I see the compression being my personal limiting factor, what is yours? I'll go back to your threads and look it up if you wish to exempt the obvious. Quote Link to comment Share on other sites More sharing options...
josh817 Posted February 2, 2010 Author Share Posted February 2, 2010 Woops I saw you had a post at the bottom of the third page. His thinking sounds logical, to me, the guy who's sitting here going what the hell? Haha. It definitely looks like you'd need it because the chamber walls are like closing onto the valve... Stupid question with obvious answer, do they even seal well? If those are 46/38 seats and its overlapping I presume you wouldn't be able to use their valves. The head of the valve would encompass the entire seat usually right? Therefore the two would hit? If not then hell that looks almost promising. Even in my case where I wouldn't plan on using 46/38 valves I'd do 45/36.5 so I guess Dave's logic would come into play a little bit there too. I was reading somewhere online when I was making my ignition table, the science aspect of ignition advance and such. Obviously a smaller chamber increases the burn rate so they made the point that smaller combustion chambers and/or compressed volume motors will require less advance etc. etc. I don't really know where I'm going with this other than the thought that a smaller chamber allows for quicker burn rates which allow for higher RPM's where the dwell time of the piston is shorter (which is why you need to advance the timing) but I guess not as much for a welded head like that. That was kind of a jumbled thought. Ignore it unless if its somewhat on the right track. Quote Link to comment Share on other sites More sharing options...
Daeron Posted February 2, 2010 Share Posted February 2, 2010 I skimmed most of this thread and want to go re read it in detail, but it seems to me the overall point (and the answer to the questionin the subject line) got missed.. It's old news in Japan... As they say "expand your mind...and your rpm peak" Apparently they haven't heard of the 7500 rpm limit on strokers due to that explodo-harmonic issue. Must only happen on export-bound engines... I can't see 150hp more just because they can rev 1500-2000rpm more than the states. HP=Tq*RPM/5252. If you can make your engine make 250 lb-ft, at any given RPM, then your HP numbers are as follows at RPM: 5252 RPM=250 HP 7300 RPM=347 HP 9500 RPM=452 HP Just to illustrate scale, here are the numbers for a mythical engine holding 200 lb-ft: 5252 RPM=200 HP 7300 RPM=277 HP 9500 RPM=361 HP Holding 300 lb-ft: 5252 RPM=300 HP 7300 RPM=416 HP 9500 RPM=542 HP So, as you can see, if you can get an engine to generate 250 lb-ft by 5200 RPM, get it up to the 300 range by 7 grand, and hold it above 250 to ten grand, you can hit over 400-500+ horse usable. Now, how to achieve that is obviously a HUGE endeavour... BUT you need to look at it in this light FIRST, and then you see what you want your goals to be. Hence, expand your mind. Remember: Rev Through the harmonic as quickly as possible!!!!! Thats IT! Edit-- After re reading in greater detail, the point wasn't quite as missed as I had thought it was, but the numbers are still good to have. Quote Link to comment Share on other sites More sharing options...
josh817 Posted February 4, 2010 Author Share Posted February 4, 2010 This is from an L4 motor, I think it said an L18 motor... Obviously can't read Japanese and the translation is sketchy. Here is from rough to finish: Quote Link to comment Share on other sites More sharing options...
Daeron Posted February 4, 2010 Share Posted February 4, 2010 Go Into The Light... Quote Link to comment Share on other sites More sharing options...
josh817 Posted February 4, 2010 Author Share Posted February 4, 2010 Oh man, all my pictures aren't working. Don't know if the mods are hounding me or not but I'll link them again just to be sure. I left out a few this time so its not so terribly long and because I need sleep. I haven't slept yet... I blame you guys. You get my brain churning. Quote Link to comment Share on other sites More sharing options...
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