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What Does An Rb26 Head Need For 10000rpm?

bradsm87

By bradsm87,
in Engines & Forced Induction

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bradsm87 Proficient

bradsm87

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My mate's building up his RB26 N1 engine for streetable response and obviously as much power as possible. He already has GT2860R -5 turbos and Tomei 260 degree in and ex poncams. He's about to put a 2.7L JUN kit in it and the usual metal head gasket etc. etc. and just wondering what is required for the head to handle 10000rpm if required further down the track.

Obviously valve springs. What else?

Cheers

R31Nismoid Grand Master

R31Nismoid

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Posted
My mate's building up his RB26 N1 engine for streetable response and obviously as much power as possible. He already has GT2860R -5 turbos and Tomei 260 degree in and ex poncams. He's about to put a 2.7L JUN kit in it and the usual metal head gasket etc. etc. and just wondering what is required for the head to handle 10000rpm if required further down the track.

Obviously valve springs. What else?

Cheers

He wont EVER need 10,000rpm with those tiny turbos.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
That's why i said "if required further down the track"

It's a brand new N1 long engine. Does it still need valve guides even though the ones in it are new?

How much further?

There is little point spending mega mega $$$ on a head if its never going to be used.

Even 400rwkw CIRCUIT cars don't even use more than 8500rpm.

If its built and tuned correctly, correct turbos for the power, then you shouldn't need 10k rpm for something thats mean to be 'streetable'

Basically the whole head needs to be re-kitted for 10k rpm. Stronger everything, upgraded everything.

Your mate really needs to decide this now rather than 'if required' as its mega $$$ and effort.

350-370awkw is a very good limit really for a streetable car (and can be done with the current turbos)

Can use the stock gear in the head which is reliable and so on.

And yeah - im trying to talk ya out of it cause i think its a waste of the cashola ;)

Russco Proficient

Russco

Posted
Posted
OK I'll re-word it. How many reliable RPM will a new RB26 N1 head with tomei 260 degree poncams and tomei type A valve springs handle? The stock rev limit is about 8000 I think so it's gotta be more than that. 9000?

Tomei type A valve springs are rated to 8500rpm hence this is your safe upper limit.

Beer Baron Grand Master

Beer Baron

Posted
Posted
OK I'll re-word it. How many reliable RPM will a new RB26 N1 head with tomei 260 degree poncams and tomei type A valve springs handle? The stock rev limit is about 8000 I think so it's gotta be more than that. 9000?

if he wants it to live I'd advise sticking with 8,000rpm. stock limit is 7500 and to be honest with smallish low mounts and small cams there is no need to rev past that. for street use, sure blip it to 8,000 every now and then if you want some fun, but on the circuit, nothing will hurt your engine more than pulling big revs. look at all the reliable circuit GTRs, none of them run revs more than 8000 or 8500 tops. and many stick to around 7500. drag racing of course is another story.

giant Mentor

giant

Posted
Posted

brad, i was speaking directly to the Tomei engineer and the do not recommend reving past 8500 even with the full counter forged crank and rods! (maybe for drag only)

but for you top end (head) the n1 valves springs are uprated compared to standard, but you may need to uprate them again to ensure they close quick enough for those kind of revs and different retainers etc etc.

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