Ken75 Posted January 23, 2022 Report Share Posted January 23, 2022 Hi, does anyone have a LY crossflow head available for reverse engineering? I’m considering to have a small series casted and machined. All options and conditions are welcome! Thanks, Ken Quote Link to comment
datzenmike Posted January 23, 2022 Report Share Posted January 23, 2022 KN20 head... https://www.roadandtrack.com/car-culture/a37360407/datsunworks-kn20-head-brings-dohc-to-the-240z/ Over $15,000 probably more than $20,000. O S Giken... https://www.thegentlemanracer.com/2013/11/os-giken-releases-l-series-head.html Over $32,000 I doubt too many of these laying around. Haven't heard of an LY head for the 240/260/280Z. got a picture? Quote Link to comment
Stoffregen Motorsports Posted January 24, 2022 Report Share Posted January 24, 2022 The LY head is a single cam crossflow head. I believe it was originally used on the 240z rallye cars. https://www.viczcar.com/forums/topic/4286-overview-of-l6-engine-heads/ Quote Link to comment
Ken75 Posted January 24, 2022 Author Report Share Posted January 24, 2022 Very much correct. In FIA historic racing, you need to stay with a SOHC and 2 valves per cylinder. The LY head was homologated for FIA group4 racing. I’m into custom valvetrain development and manufacturing, so once I’d have the head castings it’s an open road to completion... thanks, Ken 1 Quote Link to comment
datzenmike Posted January 24, 2022 Report Share Posted January 24, 2022 Never heard of them. http://blog-imgs-34.fc2.com/s/a/t/sato1511/IMGP8481.jpg Whats the power like? Quote Link to comment
Stoffregen Motorsports Posted January 24, 2022 Report Share Posted January 24, 2022 I doubt anyone has built a modern engine using this head, and lots of power has been found since then. What I mean is, if this engine (in GT trim) made 260hp back in 1974, it is probably capable of 325hp now. Or more. When BRE was building the L16 for SCCA or Trans Am, they made 175hp on a good day. When I left Rebello in 1999, we were getting 230hp from a GT4 L16. I don't remember the hp numbers from a similar GT2 L28 in the late '90s, but it was definitely over 300hp. With a production based cylinder head. Quote Link to comment
Ken75 Posted January 27, 2022 Author Report Share Posted January 27, 2022 From experience I do believe in about 125hp per liter for really good 2 valve N/A competition engines (in general), which would be 300hp on a 2.4L being a target on its own. Apart from the combustion chamber and more efficient valve angles, the crossflow design dramatically changes heat management which is a considerable challenge in endurance racing. So yes I’m willing to give it a shot to develop it. I’m into cylinder head / valtrain development and manufacturing anyway, and consider this as a personal side project. thanks, Ken Quote Link to comment
Stoffregen Motorsports Posted January 28, 2022 Report Share Posted January 28, 2022 You know who might have a lead on one of these head castings? Ralph Kenyon. I don't know his name here on Ratsun, but he doesn't come around much anymore. I know him from my racing days (we pit crewed together). He just built a beautiful KPGC10 with one of the twin cam heads on a 3.5L bottom end. He said the motor cost him about $40k. He also makes trips to Japan to source parts and his knowledge is impressive. If you like, I can PM you his personal contact info. He's also on Instagram @california_hako 1 Quote Link to comment
Ken75 Posted January 29, 2022 Author Report Share Posted January 29, 2022 That would be really nice 👍 3.5L must be a serious bore/stroke. Did he make his own twin cam conversion, or a new head? Thanks, Ken Quote Link to comment
Stoffregen Motorsports Posted January 30, 2022 Report Share Posted January 30, 2022 9 hours ago, Ken75 said: That would be really nice 👍 3.5L must be a serious bore/stroke. Did he make his own twin cam conversion, or a new head? Thanks, Ken I don't know which head it is, but I believe it is a repop of the OS Giken. The head casting alone cost him $16k. I'll pm you his private contact info. Quote Link to comment
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