turbobluestreak

You really need to get a N42 or a P90. I want to get a N42 to port out but I don't have that kind of money to just waist when I could put that money to a turbo. Although I did try my hand at porting on my extra P79's intake and I was pleased with it I didn't increase any volume just a lot of shaping. I would except higher flow numbers from that port if I would have it tested but after I talked to Dave at rebello I just figured that they could do a better job at porting my head for my application since they've been working on Nissans for around 20 years. Total cost for a street port and polish would be around $1760. But theres a lot that goes into that besides just porting. tbs

Guys I don't care what any of you say about doing the port work at home I'm stilling going to do it. Having said that I got my P-79 out and exsamined the intake ports to be just about a match to the p-90 if not dead on. I just bought myself a air die grinder today and with the help of my coned carbide cutter I started attacking the port. I did what I believed was best for the port from my research, I redirected the short radius to be a little more gradual drop off to the valve, I removed almost all of the valve guide boss and blended the boss to the large radius, I cut the valve guide down too, smoothed the transsion of port to valve seat, smoothed most of the castings down, also opened the sides of the port just slightly to make the transsion to the radius a little smoother. Well I was just thinking it over with my friend and had a hunney of an idea. In wind tunels if you want to see how wind flows around an object they spray small amounts of dust and watch the wind carry it. I did mostly the same thing using chalk dust and an air gun at 40psi. I noticed two small spots where the chalk build up. This test also showed how the air travels out of the port and into the chamber you can see where the most turbulance is going to be created. I just thought I would share my findings with the rest of you guys. One last thing, my port I did collected less chalk then the unpoted one. I'm not just considering the casting but the areas where there was a lot of build up. From what I can tell Nissan gave us fairly nice intake ports I just wish I could say that for the exhaust. tbs

I'm wondering why you didn't simply convert to the z31, it would have eliminated the VCM and replaced the AFM for a higher flowing MAS. Sleeper if you see this my zxt is running strong again. Also with NO EGR,AAC,FICD, AIR REGULATOR ,or other emissions, COLD start up on FIRST crank every time! OH, its about 20 degrees where I'm at. tbs[/b]

James I know your as egare to get the flow numbers back from this as anyone but I can't wait any longer in about a week I'm going to be reshaping my p-90 for increased flow and try to keep velocity up and trublance limited. Your half cuts really help man and so did talking to a few guys that run there own speed shops that really knew the ins and outs of port shaping, texturing and chamber mods. I hope you get the head back soon. tbs

I have to agree on the true 350Z remark made by Tony. tbs

the only upgrade that you can do is get the 60mm t/b off of the 240sx. tbs

Are you sure that you had it on tdc on compression stroke? also if your missing the "pointer" then how can you detrimine with any percision that that is TDC, I know it can be done to check to see if your crank pully sliped? You really need to get a haynes manual or even better a FSM. tbs

Thats very intersting but 6k sounds a little pricy I'll concider it but as it stands I'm going to exsamine the total cost of making a new head vs the cost of setting up the RB20DET. now money is one thing but finding the RB20 head to purchase is another I can't find one I tried if you can help me out in finding one I'll most likey go with the RB20 head conversion. Please keep me posted on any information that you can find. tbs

kids, arn't they a joy. I'm not looking to forward to having them some day because of things like what just happened to you. I had this problem with my 81 turbo everyone kept telling me it was timing people on the boards and off the boards. Then to get my best friend to believe me I riped it all down and showed it. My problems turned out to be that I removed 6 casting plugs from the bottom of my intake to see what was under there. Causing my z to be extreamly lean. I know it's a long shot but is the carb good? If you've checked every that is reasonable start checking the whole set up. tbs

I've searched and searched and came up with nothing on this I know how to find it but I don't have any means of pulling the data required to calculate it. Plus my z's not running at the moment. Here's a site that explains the procedure on how to calculate VE. http://www.installuniversity.com/install_university/installu_articles/volumetric_efficiency/ve_computation_9.012000.htm tbs

bump! any updates? tbs

Thanks bernardd. tbs

I have an extra 85 ecu, the fuel pump won't shut off but if you want it its yours, also I would to see the text file of the performance ignition maps for the vg30et. tbs

Bernardd I would like to now more about the rom, I last I knew you still had it set up and was testing it. How did that turn out? tbs

I can look into a 280ce timing chain but I'm going to stick with the KA24 valve train and the skyline manifolds for the reason that my car is turbo and I want to keep it that way, and with the skyline RB20 manifold I can do that and move my turbo away from the fire wall. All parts should be easy to get except for the manifolds, but there a few guys on these boards that don't like the stock manifolds and build headers for there cars. I've allready picked up a KA24de head out of a local junkyard and once I pull the valves out I'm going to get my measuments and cut the head up into chuncks to exsamine the the coolent and oil passages. tbs

I was wondering are we ever going to get the results from this? tbs

hey vashonz I'll look into creative casting and see about prices but I still think billet is the best way to go. Just because last time I looked into sand casting for the first run. A company would have to make a muilti layer head to get all of the internal featers for the molds. The price qoute I got from two companies was in the 12k-14k range for one head. Now if I was making like 10,000 heads that would be cost effective but this is a smaller production scale and doesn't make since to me unless someone on the boards is a experanced mold maker but me and xero have been talking about this off of the boards last night and if we get together on this I'm going to go with a billet. tbs

Guys I still think billet is the best way to go. Just because last time I looked into sand casting for the first run. A company would have to make a muilti layer head to get all of the internal featers for the molds. The price qoute I got from two companies was in the 12k-14k range for one head. Now if I was making like 10,000 heads that would be cost effective but this is a smaller production scale and doesn't make since to me unless someone on the boards is a experanced mold maker that can help. But for the cost of the aluminum I can have I have a guy that will help do the cnc machineing for me and heat treat it after he's done. tbs

RB26DETT 5K??? for the motor and shipping then a RB25 tranny, custom mounts, and custom drive shaft. it adds up real fast. also the L28et has the same boar as the Rb26 nut a longer stroke. So I would think that it would be benifitial to have a head like the RB series on the L6 Datsun motor. tbs

wow! I saw my name being mentioned on that list. Yah I'm trying to desing a DOHC 24 valve crossflow head I have to wait for the KA24DE valve get here to work on it some more but I'll be using the skyline manifolds for this head and will be a direct bolt up chain driven head. xero I would love to work on this project with you I'm a first year mechanical engering student here in OHIO. your numbers sound about right for cost of a custom head. Let me know if your in. I want one and would help with cost. sleeper240 the head you are refering to in the OS giken head that is no longer in production yes it was about 10K for one. tbs

Yes that OS G head is what has inspired me to build this head I've searched for that head with no luck. Also they made a L4 head for the Datsun 510. tbs

BRAD D I would like to look into sand casting but I don't know where to start, also I'm very lucky to have autoCAD 2004 at my disposable and intellCad 2001 at home, and thank god that they transfer back and forth. Rags your pics don't work and I would like to see what they are. Now does anyone have any reasons why I shouldn’t use the 7MGE valve train with new valve springs? This is the valve train off of the first gen non turbo supra. I need to know now so I can hit the junkyards and buy there head and basically destroy it for the parts and specs. Then, I can start designing the ports, cambers, then that will lead to the cams journals to the new chain tensioners; that I believe I'll be taking from a KA24. Also I don't know why this topic isn't as hot to all of the z drivers with the factor L6, over on http://www.starquest.com the conquest drivers are ecstatic about a guy building a head and they even send him money, and I'm not asking for money just support and ideas but it seams like no one cares. tbs

this is the big deal that you all are talking about thats only a SOHC motor and if you can even find one for sale at a decient price why bother I'm building a 24 valve DOHC head for the Datsun L6 motor. I apraitate the interst in my project but lets try and stay on topic and help pick a valve train for it so I can keep on going with the CAD drawlings. tbs

ok here is a pic of the process of the head tbs

where can I find that chain? tbs