Guest TeamNissan Posted January 22, 2007 Share Posted January 22, 2007 Ya, I was never a fan of siamese heads. All aside though the stock does quite well with forced induction. N/a on the other hand is all down hill. I mean just compare the s20 with any L series motor. Quote Link to comment Share on other sites More sharing options...
HS30-H Posted January 22, 2007 Share Posted January 22, 2007 I mean just compare the s20 with any L series motor. Please go ahead and compare. I am interested to hear what you have to say. Quote Link to comment Share on other sites More sharing options...
gjc5500 Posted January 22, 2007 Share Posted January 22, 2007 Please go ahead and compare. I am interested to hear what you have to say. uh oh. looks like we all better go get our flame suits. haha. jkjk. Im interested in in too. Quote Link to comment Share on other sites More sharing options...
bubbleguinea Posted January 22, 2007 Share Posted January 22, 2007 the angle of that chain looks like it will snap off in high revs...or break that small gear off... Quote Link to comment Share on other sites More sharing options...
Mr.INSANE Posted January 22, 2007 Share Posted January 22, 2007 I Really Doubt theres much more power to be coaxed out of the L series. Last time i checked the OS Geiken Devil Z setup didnt get anything about 600hp. But It sure is sick to see projects like this. The old thread just made everyone crap themselves and now weve ♥♥♥♥ ourselfs yet again. But Yeah The SOHC Datsun L6 Is a beast of a motor and Garret has done what 460hp? With a completely unported head and stock cam. But Yeah Love the work 1 Fast Z What happened to turbobluestreaks setup though? Quote Link to comment Share on other sites More sharing options...
1 fast z Posted January 22, 2007 Author Share Posted January 22, 2007 Oh bubbles my son, you have so much to learn abour forces. Like I said I can teach you if you want. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 22, 2007 Share Posted January 22, 2007 the angle of that chain looks like it will snap off in high revs...or break that small gear off... I was wondering what kind of rpms that gear is going to see. Quote Link to comment Share on other sites More sharing options...
Guest TeamNissan Posted January 22, 2007 Share Posted January 22, 2007 Please go ahead and compare. I am interested to hear what you have to say. On n/a motors flow is everything and a siamese head cant compete with a crossflow head. I'm not interested in a dohc head for max hp. Because yes there are plenty of members that have got some high hp numbers out of forced induction L series motors. I just think a nice dohc head READILY available for the L series motors will make for some really nice n/a's. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted January 22, 2007 Author Share Posted January 22, 2007 Sproket is on a 3/8 inch diameter 17-4 PH stainless pin that is roset welded and has a nice fillet on the outward facing side of the pin. It is then on a high speed bearing. Crank sprocket is a 18 tooth, and if the engine sees 7k, the sproket will be a 12 tooth, so 18/12=10,500. RPM is not a issue, more of harmonics, as it is a tensioner on the SLACK side the forces are minumul. I have already added two more guides upper and lower to help with "whipping". We engineer things like this all day at our shop, I just didnt mention all the tricks of the trade . Quote Link to comment Share on other sites More sharing options...
Mr.INSANE Posted January 23, 2007 Share Posted January 23, 2007 High Speed Bearing good. I Swear i thought you where going to say bare metal So whats left todo until this baby is up and running? Quote Link to comment Share on other sites More sharing options...
bubbleguinea Posted January 23, 2007 Share Posted January 23, 2007 still....the angle of the chain at that joint looks insane....wrong wrong move an its not 12 valves you are kissing goodbye, its 24... Quote Link to comment Share on other sites More sharing options...
HS30-H Posted January 23, 2007 Share Posted January 23, 2007 On n/a motors flow is everything and a siamese head cant compete with a crossflow head. I thought you were actually going to compare an S20 with an L-series. Oh well......... Tell me though, why are you describing the normal L-series six head as a "siamese" design? I don't see that it can qualify as a 'siamese' design head, as all of the twelve ports are seperate and do not share any duties. The S20 on the other hand ( ironically, given your choice to use it for comparison ) does have what we could call a 'siamese' port design, as each port serves two valves and has a dividing wall half way down it. The heads that I believe to be a true 'siamese' design would be the ones that have common ports serving different cylinders - like the BMC 'A' series for example. Quote Link to comment Share on other sites More sharing options...
Mack Posted January 23, 2007 Share Posted January 23, 2007 Or the old jeep fire-ball OHC inline 6. that head has siamesed intake ports as well. now, the KA head COULD be called siamesed as the intake and exhaust are split halfway down as well. but, it still flows one HELLUVA lot better than about 99.9999% of L series heads out there. KA stock intake flows at 25" of water are about 250cfm. with a cutom intake and MILD porting one guy got 260cfm, with the intake attached. not too shabby. as far as forced induction, look at it this way, with stock cams (240* intake, 248* exhaust and about .390" of lift) there are LOTS of turbo set-ups making right around the 300rwhp mark on 12PSI from a crappy volvo junkyard turbo. and thats a 2.4L 4 cylinder. think of what a head like that will do on a 3.1L 6. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 23, 2007 Share Posted January 23, 2007 Should be 387.5rwhp based on the increase in displacement. Hopefully you guys will be using it to better advantage than that. Bigger cams, bigger turbo, more boost, etc. Quote Link to comment Share on other sites More sharing options...
Mack Posted January 23, 2007 Share Posted January 23, 2007 oh, for sure!! although to get it up and running, the cams we (or I) will be using are about the same as a stock KA cam, with a little less lift. I may contact a cam re-grinding place, as there are a few out there that specialize in KA cams, and see what a re-grind for about .040" more lift and about 256 to 264ish duration. Im shooting for a t3/tO4e hybrid with a 60 trim compressor wheel. thats not set in stone, and I may even be looking at a holset. suggestions are welcome! Im probably going to be running some 550cc injectors with megasquirt. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 23, 2007 Share Posted January 23, 2007 I don't know much about cams for DOHC heads, but that sounds like the cam is small, even the regrind. Is that lift you're quoting before the rocker ratio? What is the rocker ratio on the KA head? Quote Link to comment Share on other sites More sharing options...
Mack Posted January 23, 2007 Share Posted January 23, 2007 there is no rocker ratio. KA heads are shim-on-buckets. and the cam doesnt have to be as big because of the F-L-O-W. you really dont gain much in terms of CFM going from say, .400" to .500" lift. one guy only picked up about 5cfm jumping that last .100". here is a page with flow numbers.... KA24DE head flow #s Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 23, 2007 Share Posted January 23, 2007 You guys seem to be pretty well on top of this stuff, but I would point out that those tests are done with vacuum, but your head is going to flow differently with pressure. Any idea how the flow numbers react with boost in the intake manifold? I'm not an expert by any means, but I did read that the intake manifold is apparently the restriction on the KA. Since you will be cramming air into the cylinders you may find that there is an advantage to the increased lift since the limiting factor of the manifold won't be as big a deal. Quote Link to comment Share on other sites More sharing options...
Mack Posted January 23, 2007 Share Posted January 23, 2007 I think those tests (on the webpage) were done with no intake. when 1 fast Z and I did similar tests, we got very similar numbers (again, no intake). and I beleive the reason why the intake is the restriction on the KAs is because of the long runners and small plenum. the runners themselves are 50mm, which is the size of a stock L28E throttlebody!!! I will be going with 50MM ITBS personally and a big plenum on the end of them, very similar to the RB26DETTs. I plan to just get it up and running first, then start messing around with cams and the like. Ive got a guy that has made 100+ custom VW turbo kits (intercoolers, manifolds, everything) and he will be doing my intake welding and probably build me a simple log manifold for a big single. I may even just attach a pipe to the manifold and run it NA for a bit to see what Im dealing with, before I add boost. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 23, 2007 Share Posted January 23, 2007 I will be going with 50MM ITBS personally and a big plenum on the end of them, very similar to the RB26DETTs. This setup would make me more inclined to run a LARGE camshaft, and rev the CRAP out of it. That's what I would do anyway... Quote Link to comment Share on other sites More sharing options...
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