rudypoochris Posted February 6, 2008 Share Posted February 6, 2008 So I was reading up on the L31DETT thread which ultimately got me to dreaming, just dreaming, about DOHC heads that could be spliced to work similarly well on our old SBF's. I know the Porsche 944/968 DOHC motors use a 104mm bore which is close, but those are expensive heads to find/source. The Subaru 2.5L boxer also has ~4" bore, but that is a less than ideal setup, especially since they are not known to flow. So what do you guys think/know of that might be the right direction? It seems very hard to find large bore DOHC setups for some reason. Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted February 6, 2008 Share Posted February 6, 2008 biggest problem i can think of would be.... Aren't SBF's pushrod engines? i don't think there's any way in hell you could get a dual overhead cam setup on an SBF if they're pushrod engines. I know that there are those modular V8's that are SOHC and DOHC, but as for the older 4in bore engines (302 right?) you're kinda sol Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 6, 2008 Author Share Posted February 6, 2008 Well it wouldn't be plug and play. It would require modifications to the cam drive inevitably. Quote Link to comment Share on other sites More sharing options...
MrWOT Posted February 6, 2008 Share Posted February 6, 2008 http://www.araoengineering.com/Ford/frdsmb.htm A set already exists, though probably pretty expensive. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 6, 2008 Author Share Posted February 6, 2008 http://www.araoengineering.com/Ford/frdsmb.htm I know about those, they aren't DOHC. Thanks though! Quote Link to comment Share on other sites More sharing options...
MrWOT Posted February 6, 2008 Share Posted February 6, 2008 Ah wanting for the cam adj, my mistake. edit: They make 32V heads for sbc and lsx as well for you GM fans Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted February 6, 2008 Share Posted February 6, 2008 Arao heads are also sickeningly expensive. their 16v heads for Type1 vw's START at $4400 a set Quote Link to comment Share on other sites More sharing options...
blueovalz Posted February 6, 2008 Share Posted February 6, 2008 I used to ponder this as well. My thoughts were to search for a head that had the Ford bore spacing rather than the bore diameter, but those offer even fewer options from what I saw. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 6, 2008 Author Share Posted February 6, 2008 I used to ponder this as well. My thoughts were to search for a head that had the Ford bore spacing rather than the bore diameter, but those offer even fewer options from what I saw. The Porsche head might really be the best bet... just kind of sucks - hard to find. I can't find the bore centerline either. Ducati 999 uses a 100mm bore... But you would need 4 bikes worth of heads and they are each separate cylinders. :/ Quote Link to comment Share on other sites More sharing options...
Gollum Posted February 6, 2008 Share Posted February 6, 2008 when was the last time I told you that you are insane? Just dreaming huh? Just wait until we're searching the junkyards for some head. I'll see what I can dig up. Quote Link to comment Share on other sites More sharing options...
Careless Posted February 6, 2008 Share Posted February 6, 2008 the ford head has the cam gear in the middle of the cam though, doesn't it? at least my friend's 968 w/ variocam does =/ Quote Link to comment Share on other sites More sharing options...
Gollum Posted February 6, 2008 Share Posted February 6, 2008 Ok, best I've found so far is the NEW boss platform, that's going to have a 102mm bore. http://en.wikipedia.org/wiki/Ford_Boss_engine EDIT: Nissan VK56 is 98mm. way off, but honestly that's closer than pretty much all the other motors i've seen thus far. http://en.wikipedia.org/wiki/Nissan_VK_engine Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 6, 2008 Author Share Posted February 6, 2008 I know about the VK, but what is the bore spacing? The new Boss motor is spaced at 4.53" or so IIRC which isn't close enough or even available yet. Quote Link to comment Share on other sites More sharing options...
Gollum Posted February 6, 2008 Share Posted February 6, 2008 Taken from nico forums Thanks for the info. It looks like VH and VK all had 112mm bore spacing' date=' so at least that shouldn't be the stopping issue. I think the biggest hurdle is getting the right sleeves, because I am pretty sure just boring out the stock ones is risky. I don't have experience in this, but it just seems like boring out a sleeve that much rather than making a new one from more rigid material is asking for trouble.[/quote'] So 112mm would put you at 4.40945 bore spacing. I don't know what the 5.0 is though. I'm assuming you do though. Oh, and here's the link for the thread. http://forums.nicoclub.com/zerothread/301342 Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 6, 2008 Author Share Posted February 6, 2008 4.38" - Interesting. So 5.6L Titan heads might be close... Now where do you get Titan Heads? Quote Link to comment Share on other sites More sharing options...
Gollum Posted February 6, 2008 Share Posted February 6, 2008 Do I have to do everything? You're from oakland, you don't know anybody that can just "show up with them"? Well, I can ask a local nissan dealer what they'd charge, odds are it's insane, but it's worth asking. We can then also ask some nissan wreakers if they ever get VK56 engines in. I know the cranks are sought after so I'd bet that enough of them get parted out that buying just heads shouldn't be a problem. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 9, 2008 Author Share Posted February 9, 2008 Nissan Patrol TB48DE... 99.5mm bore = 3.92" It makes 241hp @ 4800 and 294lbft @ 3600. Not sure if that is really much better than stock... might be a camshaft swap away though from big power. Quote Link to comment Share on other sites More sharing options...
Careless Posted February 10, 2008 Share Posted February 10, 2008 the ford head has the cam gear in the middle of the cam though, doesn't it? at least my friend's 968 w/ variocam does =/ i meant to say, my friends 944 head has the cam gears in the middle. Quote Link to comment Share on other sites More sharing options...
IdfMF Posted February 25, 2008 Share Posted February 25, 2008 For the cost of developing the cam drive and all the machine work, you could go this route: It can be yours for $6395.95 turnkey from Kar Kraft: http://www.karkraft.com/new_page_9.htm Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 25, 2008 Author Share Posted February 25, 2008 Yes, I could. I don't want to though. Thanks for the suggestion, that is a nice engine. Quote Link to comment Share on other sites More sharing options...
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