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4" Bore DOHC Heads?


rudypoochris

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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.

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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

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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. :/

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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

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Do I have to do everything? :D

 

You're from oakland, you don't know anybody that can just "show up with them"? :lol:

 

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.

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  • 2 weeks later...

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