Xnke Posted July 31, 2008 Share Posted July 31, 2008 I'm pretty sure you guys can, but I'm not sure if the L4's have that steel ring around the exhaust valve stem or not...the way I see it, a welded and machined head is a welded and machined head...I know you guys are up to it... Found it here: http://www.the510realm.com/phpBB3/viewtopic.php?f=2&t=9756 Posted By Baz: A few pics with recent development on L series engines. By altering the angle of the valve guides the valves are shifted away from the bore allowing more flow plus some tricky work on the exhaust ports. Apparently there are differences in down under dyno readings from the US readings. Ours are more conservative. To give some real world comparison, these heads will flow the same as an SR20 head. These heads are used for class racing where the original L series heads must be retained. Some serious HP has been achieved. Throttle bodies fit straight on the head with out the use of a manifold or adapter. Ram tubes of many sizes can be used to tune for rev range. So, what do you think they've done? Looks to me like they took the valve stems and layed them over to the manifold side, to try straightening out the ports. seems like you could really help the exhaust flow, at the expense of a LOT of work. I think it could be worth it, if they are getting the L4's to flow the same as an SR20! Quote Link to comment Share on other sites More sharing options...
Challenger Posted July 31, 2008 Share Posted July 31, 2008 I doubt its worth the money, but still very nice. BTW the tile in those photos is the same as the ones Im putting in around my mantel! Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted July 31, 2008 Share Posted July 31, 2008 Instead of leaning the valves over why not just raise the ports up? It seems much easier to mess with ports than to mess with valvetrain geometry. Quote Link to comment Share on other sites More sharing options...
Xnke Posted July 31, 2008 Author Share Posted July 31, 2008 Because the head in the photos is producing 245 N/A horsepower from an L-20b...110HP over the best "stock" rebuild I've seen for that engine... And, because you can only raise the ports so much before you run out of room. This would theoretically allow raising the ports, plus helping to alleviate the short side radius on the exhaust, PLUS straighting out the runners even more than possible by port raising. And if you are going to get the chambers welded, larger valves, and new guides, (not at all uncommon around here) it's not that much more work. Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 31, 2008 Share Posted July 31, 2008 Because the head in the photos is producing 245 N/A horsepower from an L-20b...110HP over the best "stock" rebuild I've seen for that engine... Interesting work to be sure. But just to be clear, I didn't see them actually say that an engine had produced 245 hp with that head. I read that to say that the ports now flowed enough to support 245hp. Not the same thing. I'm not saying they didn't - they just didn't specifically say that they did. At least not in that thread... Quote Link to comment Share on other sites More sharing options...
NZeder Posted July 31, 2008 Share Posted July 31, 2008 Interesting work so if you take the 245 and /2 = 122.5 then x 3 = 367.5HP for a L6 head. Well we know that can be done look at what TonyD got with the 3.0 bonny car. He stated around 100HP per 1000cc at the wheels so that would be 300HP at the wheels which would be over 360HP at the engine = 367HP at the head so very do able. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 31, 2008 Share Posted July 31, 2008 That was an L28 bored 0.040" don't know if that's quite 3.0... and that 320hp reading was blowing by like crazy because of scored walls... The 2L (1998cc) is making 205 to the rear wheels, though. All common, standard machining process that has been around on the L-Series for almost 40 years now. Nothing 'trick' or 'spectacular'...matter of fact, very standard stuff. You want predictable, not epxerimental if you're in it for the long haul. Actually, the L-4's usually make more specific HP than most L-6's because of the ability to rev higher for longer periods due to that short crankshaft. L-6's can do it but rarely do for some reason or another. Some of the items mentioned in that thread are already under development...er...'elsewhere'... Quote Link to comment Share on other sites More sharing options...
johnc Posted July 31, 2008 Share Posted July 31, 2008 In the naturally aspirated world "typical" two valve head engines can be build and tuned, with a lot of money, to make 100 to 110hp per liter. "Typical" four valve head engines can be built and tuned, with a lot more oney, to make 120 to 140hp per liter. A L20B making 245hp is beyond what's typical for a top end, high compression (over 12 to 1) build so I would be skeptical until some real, SAE certified numbers are posted. Quote Link to comment Share on other sites More sharing options...
1 fast z Posted July 31, 2008 Share Posted July 31, 2008 Im calling BS. Unless I missed it, I didnt see what angle difference, but it only looks to be a few degrees difference. The problem with L's is the cam geometry. If you start angling the valve over more, your creating ALOT of moment arm force on the valve itself, not good. I would put one of my L series P90 ports up against there angled port, and I would bet there wouldnt be if any difference. I have not seen any BEFORE and AFTER flow numbers. SR heads dont flow a whole heck of alot for being a 4v engine either. PLUS, even if both heads flow the same on a flow bench, you have valve packing area, undernieth both valves on a 4v engine. Also, the L series is still a NON cross flow head, which you loose a substantial amount there also. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted July 31, 2008 Share Posted July 31, 2008 Having met the Baz personally a couple of times, I can say that he loves what he does, and is no different than every other car enthusiast out there: Hes proud of what he accomplishes and might be guilty of over-talking the possibilities beyond the reality. I know I'm guilty just as much. Baz is a nice bloke, very willing to share his knowledge and experience. That being said, I'll believe it supports 245 when I see a dyno printout. And not one of them fang-dangle DynoJet POSs. Dave Quote Link to comment Share on other sites More sharing options...
TimZ Posted July 31, 2008 Share Posted July 31, 2008 That being said, I'll believe it supports 245 when I see a dyno printout. And not one of them fang-dangle DynoJet POSs. What dyno do you require that you would accept as proof? Also, just to be clear (again), I wasn't saying that Baz was lying, but that others were taking what he said a step or two farther. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 31, 2008 Share Posted July 31, 2008 I know old tech was simply to raise the ports as mentioned. The FIA heads have ports already raised. For the standard L-4 heads, many builders would weld into the valve cover area and move the ports up so far to be almost touching the valve cover gasket...very straight shot to the back of the valve head. Truthfully my first thought was with all the work "why in the world didn't he use the barrel throttle assemblies"---45 barrels flow as much as 48mm butterflies, yet have tip-in response of much smaller carbs for better drivability when feathering the throttle to get underway... Seriously, that is exactly what I thought. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted July 31, 2008 Share Posted July 31, 2008 Nascar seems to get 120 hp per liter with old tech and 2 valve heads. Dont see why we cant get that with two valve ohc motors. Guess we need to spin them to 9000 rpm? Douglas Quote Link to comment Share on other sites More sharing options...
Xnke Posted July 31, 2008 Author Share Posted July 31, 2008 1 fast Z, How much do you think the valves would have to move in order to make it worthwhile? a 3* difference isn't much movement at the top, but could move the valves over a fair bit, I think. Really, I'm trying to find ways to increase the total flow, and without moving the valves, I think we're just about out of new(rather, new to us) ideas. Also, I'm not trying to say that this is the next big thing, But I did think it was pretty cool and that it seemed like a logical next step, especially in trying to tame the exhaust short side radius. Really, I need to get back to work on that 3xKA head casting...almost got it drawn in solidworks, still working on getting the pattern block glued up for CNC milling. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted July 31, 2008 Share Posted July 31, 2008 First i've heard of that... is this a one off casting, or planning on selling per-order at some point? Quote Link to comment Share on other sites More sharing options...
1 fast z Posted August 1, 2008 Share Posted August 1, 2008 For a permanant casting mold, it will be fairly expensive. Bolting and dowling the heads together was fairly easy to do on my project, the toughest part is the cam and timing system. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted August 1, 2008 Share Posted August 1, 2008 That's kinda what I thought you had said once before.... That's why I was confused Quote Link to comment Share on other sites More sharing options...
Xnke Posted August 1, 2008 Author Share Posted August 1, 2008 Who knows at this point...I'm just getting the molds and patterns made up as I have time, maybe sometime in the future it'll happen. Not likely, though. As for the timing system, the whole point of the head casting is to adapt the KA cam and valve system onto an L head casting. The idea is to have the head casting contain two timing chains, one from cam to cam, the other from cam to crank. This hopefully won't end up being too weak, or too hard on cam snouts, while at the same time, eliminate any extra timing cover bits, valve cover bobbles, etc. Really, it probably won't happen in the next ten years. But I'm sure there'll still be Z cars out there waiting. Quote Link to comment Share on other sites More sharing options...
woldson Posted August 1, 2008 Share Posted August 1, 2008 This question may have been dodged, 1 fast Z, How much do you think the valves would have to move in order to make it worthwhile? a 3* difference isn't much movement at the top, but could move the valves over a fair bit, I think. Really, I'm trying to find ways to increase the total flow, and without moving the valves, I think we're just about out of new(rather, new to us) ideas. Maybe I'm not paying full attention here?? Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 1, 2008 Share Posted August 1, 2008 This question may have been dodged,...Maybe I'm not paying full attention here?? Yep, the consensus is that welding the ports and raising them will give you the same effect as tilting the valve. Draw out the port configuration, and look at what you get tilting the valve 3*. Then see where you are with the valves in the stock configuration (no headaches) and raise the port and straighten it with a mikuini style manifold and not something that comes straight out the side of the head like a cannon. When the top of the port is almost touching that valve cover mounting surface, you got a pretty straight shot to the back of the valve... And remember, the L4's have nice water circulation out the bottom of the manifolds, as opposed to the L6's where you have to drill those damnable holes above the ports to get decent circulation at the back two cylinders... Quote Link to comment Share on other sites More sharing options...
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