quicker240 Posted March 18, 2005 Share Posted March 18, 2005 This project is quite interesting.Just a thought here.Maybe connecting the passages is not the answer.Diesel engine cyl. heads are sectioned just like this head(s) is.Provided oil comes up through the passageways in the block AND exits out the other side BACK into the block,the same applies to the water passages.The answer may be to plug up selected passages while providing a circulation route for oil and coolant.The sections could be aligned with dowel pins to facilitate camshaft alignment.This part would be the tricky one but a solution more easily found than welding nonaccessable passageways between the sections.In other words,each section recieves oil and coolant from the block.Some mapping of oil and coolant flow will be necessary but I doubt difficult.Thoughts here anyone? Quote Link to comment Share on other sites More sharing options...
Guest young frankenstein Posted March 18, 2005 Share Posted March 18, 2005 well i will tell u the fascination with keeping the L28..... parts availability! and yes this is 2 ka24de heads. so, i can get parts prettymuch anywhere 4 those 2! and with the rb motor u still have to get custom mounts custom driveshaft custom trans mounts a lot of custom stuff just 2 get it in the car let alone driving. some vailid points in this thread........ ive already got a semi workable timing cover using altima stuff and the valve cover is just the same as the heads 3 ka valve cover halves! lol lol lol i think a sleeve or an or ring like ones that they use to seal copper headgaskets will be the way to go. im thinking about using some counter sinked drilled links along with some beveled machine screws at all 4 corners to seal it up, the tighter you tighten the screws the tighter it seals the head. and that would provide rigidity 2!!! i mean if u think about it... how would an o ring fail? there is no side 2 side pressure on a head (not counting heat expansion, but that ould only seal it better!), and u have all the headbolts holding it down anyways. if i used 2 dowels per head section on the block and head, i think i would be fine. i would not sell any heads until i've put at least 3K miles on my own, unless the buyer wants to risk it. yes, im thinking somewhere around 5g's for complete heads. there is a lot of work going into this thing. plus the cams im using have 2 be gun drilled then have the lobes drilled 4 oil. i think it will be worth it in the end. also, something about keeping the original motor and i can also say there is no one out there with this set up! lol lol lol ill be the first! about casting them, sure if i could get them cast at a decent price, then i could also play with the ports and stuff 4 optimal placement and flow! i can see this head making it big in japan because the z has a god status over there and its sacreligious 2 put anything other than an Lseries motor in it. anyone got any japan contatcts 2 see if this would go over there?? ha ha ha! Quote Link to comment Share on other sites More sharing options...
RacnJsn95 Posted March 18, 2005 Share Posted March 18, 2005 Yeah, if you could get a casting made that would drop the construction price considerably also, which would make more people want to buy them. If they were affordable I'm sure people would buy them rather quickly. I would, but not for 5k. I simply can't afford it. Do the water and oil passages line up on the head and the block? Quote Link to comment Share on other sites More sharing options...
texasz Posted March 21, 2005 Share Posted March 21, 2005 Yeah, if you could get a casting made that would drop the construction price considerably also, which would make more people want to buy them. If they were affordable I'm sure people would buy them rather quickly. I would, but not for 5k. I simply can't afford it. Do the water and oil passages line up on the head and the block? I may be off base here but I would think that if you were to just weld up the three pieces then get a casting done and produce them from the casting that you would then no longer have the issue of welding the oil/water passages as the cast heads would all be one piece to begin with. Now there would be the question of how smooth those areas where the original three pieces met but I imagine that this could be taken care of relatively easily compared to trying to weld those areas like you guys are talking about now. I'm no engine builder but there are just my thoughts. Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted March 22, 2005 Share Posted March 22, 2005 Maybe I'm missing something here, but if you were going the casting route, you would only need the head to hold together. Not withstand any real loads right? So a glue or bolts could do the job until the molds are made. Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted March 22, 2005 Share Posted March 22, 2005 Yah my favorite L6 subject KA DOHC. Your head looks great I would like to talk to you about your lower timing setup that you have on that. What kind of valve to cylinder wall clearance do you see? I've been concerned with that issue since these heads operate on a 89mm bore? Now to the real issue welding the head I would get two cam blanks made up that will cause a slight interference fit, bolt them down tight. Make plates two of them to hold the sides in alignment. Next the bottom surface should be made from 1-1.5 inch thick steal plate that is ground flat and ream two head holes per chunk for locators. I you want a print of the spacing of the boltholes and bore spacing I'll send it to you. Lastly, it just wouldn't be a true DOHC L6 post if I didn't chime in. LOL Good luck and let me know if there is anything I can do you help out. tbs Quote Link to comment Share on other sites More sharing options...
Guest young frankenstein Posted March 23, 2005 Share Posted March 23, 2005 well ive been talking this over with my boss and a few others in the shop and ive come 2 the conclusion that bolting them together will work the best in the long run and 4 right now. im gonna drill for some press fit pins inbetween the cylinder head halves so that will keep them aligned properly then im gonna run a sheet of ptfe gasket material inbetween the cylinder head halves. the bolts come in and go thru pockets milled into the intake ports, then get covered up with epoxy so u'll never know they are there also a bolt goes thru on the exhaust side, but i found a place where i can run the bolt, just above the exhaust port without cutting into the port. plus, this way if the gasket does ever fail (doubtful, its temp range is -40 to +500, extremely resistant to steam, water, chemicals, pressure) all u have to do is clear out the epoxy and undo the bolts, replace the gasket and u'r set to go. so, tbs U'R the other guy doing this, eh? how is urs coming along? oh, and i plan on putting this on either a full 3.1L storker or maybe a 88mm bore motor and just notch the tops of the bores for valve clearance. not really a big deal, especially if i go 4 the 3.1L. i should have pics as soon as this weekend! Quote Link to comment Share on other sites More sharing options...
Phyxius Posted March 23, 2005 Share Posted March 23, 2005 back when i was thinking about this, i thought it would be a good idea to weld flanges external to the head and bolt them together that way. Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted March 23, 2005 Share Posted March 23, 2005 franky, if you do a search on here for the DOHC under my name. You'll find that the suggestions of epoxy and welding. But one way was to mill extra off each piece and then lay up a .040-inch bead of weld on each side that butts and then mill it back into spec. Next build a jig to hold it and send it out to be laser welded it's about 40 bucks a seam. I wish I would have decided to do this but it's to late for that now. This way its perfectly sealed and then just stress relief the welds and your head will be solid. tbs Quote Link to comment Share on other sites More sharing options...
Guest young frankenstein Posted March 23, 2005 Share Posted March 23, 2005 do u have the name of any companies that will laser weld for private usage, i could only find places that would do it 4 industrial uses.... also i looked into electron beam welding and they said that it wouldnt work so good on the trash that cylinder heads are made out of. can laser welding penetrate to seal up the water passages as well? or is that what laying the extra bead down is for? i was thinking of milling an extra 1mm off inbetween the head chunks and then tracing over the outline (to build back up that extra mm of material)with tig aluminum welding and getting pure aluminum on each half, milling it back to spec, then sending it off 2 be e-beamed, but this is a lot of work and in the long run will more than likely warp the head almost 2 the unusable end of the spectrum. the bolt approach is quick, precise, and repairable. what happens when u have it laser welded and it leaks or one of the welds cracks under stress or head or the head goes banana when u put it on the block and run it 4 the first time? some diesel heads use this approach and they work just fine, plus its a prototype! if i see beneficial gains from this head(i see no way that i wouldn't! lol), the next one might be e-beamed or laser welded. i just wanna get this one running and see what happens. Quote Link to comment Share on other sites More sharing options...
Toysport Posted March 23, 2005 Share Posted March 23, 2005 First of all, I don't have the skills and knowledge you guys have. I have to give you a lot of respect and credit for your project but...i think that there's too much work involve. I think dropping a 2JZ-GTE or a 7M-GTE will simplify -cost and labor- the whole concept of DOHC. What do you guys think? Quote Link to comment Share on other sites More sharing options...
Guest young frankenstein Posted March 23, 2005 Share Posted March 23, 2005 well, this is not costing me tooo much since i have access 2 a machine shop, but this is costing me an absolute assload of time. 2 reproduce this head would cost a fair bit. i estimate machine shop time and stuff and parts with all the modifications would come 2 about $5k. the whole point here is 2 do something no one else has done 4 a long time. 2 have a running dohc head that will bolt on 2 the l series blocks. the toyo motors would simplify labor on the engine end, but this head will allow u to use stock mounts, drivetrain, everything except manifolds basically. it will still retain the stock L28 dist. or you can put in the turbo dizzy if u want. (leaning towards MSnS) plus, this will keep it all nissan, lol im kind of a purist. this will also be the final word in the war over whether the head or the block is the limiting factor in ultimate power production 4 the Lseries motors. plus 7mgte = headgasket PITA and 2jz's are still spendy ive seen flow numbers on 7m heads and i was not impressed. the ka24de intake flows 250cfm@ .500 and 25in of water STOCK. Quote Link to comment Share on other sites More sharing options...
Toysport Posted March 23, 2005 Share Posted March 23, 2005 That'll make you the first ever to accomplish this project. Good luck! Quote Link to comment Share on other sites More sharing options...
Jolane Posted March 23, 2005 Share Posted March 23, 2005 First, I think your project is great. I feel that I can appreciate the work involved with this. I also think that bolting the head together is a good idea for a prototype. I would not put epoxy over the bolt heads though for a number of reasons, the biggest being that it shouldn't be necessary. Another avenue you may want to consider is soldering/brazing, similar to what they do with radiator cores. You could probably bolt it together with a fixture, and bake the whole assembly in a furnace to braze the pieces together. If it was my project, I would be inclined to call a custom radiator shop (Ron Davis to start, then BeCool) and ask about the process. I don't know if they make their own cores or not, but maybe they could give you a contact for a core shop. Please keep the updates coming! Joshua Quote Link to comment Share on other sites More sharing options...
tay-fu300zxtt Posted March 23, 2005 Share Posted March 23, 2005 Wow Quote Link to comment Share on other sites More sharing options...
RacnJsn95 Posted March 24, 2005 Share Posted March 24, 2005 Clearing out epoxy is easier said that done. But if the gasket never fails then it would be a nice easy fix. Quote Link to comment Share on other sites More sharing options...
qwik240z Posted March 27, 2005 Share Posted March 27, 2005 Don't know if this has been covered here yet but I remembered this thread and thought someone here might be interested in this. I saw it on eBay. Seems to be a related topic. Check it out: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=35935&item=6521117133&rd=1 Quote Link to comment Share on other sites More sharing options...
Guest anlasak Posted April 23, 2005 Share Posted April 23, 2005 Out of curiousity what cams are you using? Custom grinds,salvaged cams from a twin-six,or 2 sets of KA cams welded together? Also you mentioned using altima timing components,which ones? Altima upper timing cover/Z lower timing cover,or am I wrong? Quote Link to comment Share on other sites More sharing options...
510six Posted April 25, 2005 Share Posted April 25, 2005 Some links to a similar project .A fabricated and welded together 488 CID V12 from two Buick 215 CID heads and block. http://www.the510realm.com/modules.php?set_albumName=album150&op=modload&name=gallery&file=index&include=view_album.php A PDF file to the specs for the twincam LY head. http://www.osgiken.co.jp/tc16/tc16.pdf Thanks Rob. Quote Link to comment Share on other sites More sharing options...
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