turbobluestreak Posted April 17, 2003 Share Posted April 17, 2003 OK does anyone know of anyone that has one or can get one I don't care squate about the car the moter is a 432 built up from an s30. Thats the head we can use with dual overhead cams with 24valves. I want to find this and see if we can get a company to mold and cast it for us. This would be the best preformance for us yet. Please can anyone help. tbs Quote Link to comment Share on other sites More sharing options...
inZane 240 Posted April 17, 2003 Share Posted April 17, 2003 The s20 engines in the skyline and 432 are completely different engines than the L series. The head will not simply "bolt up". Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted April 17, 2003 Author Share Posted April 17, 2003 Crap. tbs Quote Link to comment Share on other sites More sharing options...
HS30-H Posted April 17, 2003 Share Posted April 17, 2003 I have an S20 engine for my project car, and I can confirm it is COMPLETELY different to the L-series six. There are no interchangeable parts between the two. I know of two LY Crossflow heads currently for sale in Japan ( that's the SOHC hemi-chambered two valve Nissan head that they used on some of the Works circuit race and rally cars ) - but the price would certainly put you off. Both of them are incomplete, and even then the prices are STILL over 2,000,000 Yen each ( work THAT out at today's exchange rate ). The missing parts would take some rounding-up too........... Nice idea to get a DOHC head cast - but there's a lot more to it than just the head casting itself............. Check out old posts using the SEARCH function on the "Crossflow" and "LY" subject. Might be of interest to you. Alan T. Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted April 18, 2003 Author Share Posted April 18, 2003 Hey alan I couldn't find anything on it can you help me out and direct me to the people that see this head? I would greatly apreiate it. tbs Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 18, 2003 Share Posted April 18, 2003 If you're talking about what I think you're talking about I saw mention of this head in that one book about building race Datsuns. Y'know the black book with the yellow stripes. And they said that not only is that head only available in the land of the rising sun, and for a ton of money, but it didnt actually perform that well either. Basically you're better off with the SOHC head. Quote Link to comment Share on other sites More sharing options...
HS30-H Posted April 18, 2003 Share Posted April 18, 2003 Just to clear up any confusion that I might have caused by being unclear about it in my post - those two LY Crossflow heads 'for sale' that I mentioned are USED items. They are both at least 28 years old. As I mentioned, neither of them is complete and yet the prices the vendors want are very very high. These items are very sought after amongst serious Japanese collectors and historic racers, so you would be at the back of a very very long queue if you wanted to buy one. I've been in the queue for many years myself! Turbobluestreak - you might not be fully conversant with what was available for the L-series 6 in the area of Option and aftermarket heads. Many people confuse the S20 twin cam ( as fitted to the PGC10, KPGC10 and KPGC110 Skyline GT-R and the PS30 Fairlady Z432 and PS30-SB Fairlady Z432R ) as being related to the L-series 6 - but they are entirely unrelated and share no common parts. Here's a very quick overview. Basically, there were only two choices of head apart from the 'stock' heads: *NISSAN "LY" head ( usually nicknamed the "Crossflow" head ) which was made available to the general public via the Nissan Sports Option parts lists from roughly late 1972. This was a single overhead cam two valve per cylinder design using a hemispherical combustion chamber. To use this head effectively you had to buy the dedicated option Con Rod / Piston set and all of the special cam gear assembly. Truth be told, this was really a whole different engine configuration based on the L-series 6 block. A special transmission bellhousing and engine mounting set was also necessary, as the angle of the engine mounting was changed too. Contrary to the rather dismissive reports from people who have usually never even clapped eyes on one, these engines were absolute screamers. I have personal experience of them in both NA and Turbo form, and they are very special indeed. Putting together a running example without compromising on all of the special parts involved would be a very time-consuming and expensive job. Many of my Japanese Z enthusiast friends have been dreaming of an LY Crossflow since they were kids..... *O.S. GIKEN "TC24-B1" - This was an aftermarket head conversion made by O.S. GIKEN in the late 1970's. They also made a version for the L4. This was a double overhead cam, 4 valve per cylinder crossflow design. Again, special pistons and rods were necessary. The cams were chain driven just like the stock L6, but obviously with a much longer chain and some special chain tensioners mounted onto the front of the L6 block with some machine work. Not that many were made, and they are still very sought after in Japan. Most of these were used in NA form, but during the 1980's the Japanese tuners started using blow-through turbo and fuel injected configurations on them. I have personal experience of a rather short-lived twin turbo version of one of these, which was quite memorable to say the least. Just like the LY, the TC24-B1 has been unfairly slated by people who have little or no experience of it. Naturally, the sky-high price of these conversions was enough to give disbelievers the ammunition to damn them with. However, they were always fairly exotic and low production items intended for serious racers and ( later ) street tuners. A poor exchange rate didn't help either. Its somewhat annoying to see ( especially in the Honsowetz book ) that many of the American tuners and racers wrote them off without much personal experience of them. In the case of the NISSAN "LY" Crossflow, I'm really glad that a company like Nissan went and made something like that for their racers and were obliged to make them available to the general public too. Its now a part of Nissan's very proud race heritage. In the case of the O.S.GIKEN head, I take my hat off to them for being brave and ingenious enough to design, manufacture and market them. They were a fairly small company when they did it, and they have gone on to great things in the transmission and clutch scene in Japan. They are doing very well indeed. Its a shame that they are not in a position to re-manufacture the head conversion again, despite many years of lobbying by interested parties. Sorry to be the bearer of bad news, but there are a lot of people looking for these items in good used condition and they command high prices when they can be found. Most of them change hands without being advertised. The "normal" L6 heads perform so well ( considering that they have Inlet and Exhaust ports on the same side ) that they tend to make the aftermarket and Option heads look rather superfluous. However, in theory any crossflow or four-valve configuration is going to be superior to the stock L6 configuration. Sorry for the long-winded post, but these kind of parts are kind of my "pet" subject!.......... Alan T. Quote Link to comment Share on other sites More sharing options...
Guest livewire23 Posted April 18, 2003 Share Posted April 18, 2003 thanks for the breakdown alex, the honsowetz book was exactly where I had heard stories of the huge price and minimal gains. Quote Link to comment Share on other sites More sharing options...
Guest DaneL24 Posted April 19, 2003 Share Posted April 19, 2003 True, in theory a DOHC crossflow head would be superior to the traditonal L6 SOHC...but in the real world they are good performers. The crossflow head would help the motor develop more power at higher RPMs, but the L6 heads usually allow peak power at around 5500 RPM with the stock cam anyways, which shows that they flow pretty well. Thats another thing, its good to think about head design but don't forget about the cam. The crossflow head will help out at higher RPMs, but so will a better cam...which is much more available. I think with a decent cam, a SOHC head could perform just as well at high RPMs as a crossflow head. Don't obsess over the fact that the Z has a SOHC non-crossflow head, just make the best of what you have. In the real world it has good performance, and with the right cam grind you can go a long ways. Quote Link to comment Share on other sites More sharing options...
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