Another 383 Holden - pure street hyd roller

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lc-gtr-1969
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Re: Another 383 Holden - pure street hyd roller

Post by lc-gtr-1969 »

KnightEngines wrote: Wed Sep 25, 2019 6:51 pm Lol, it'd be lethal in an LC! I did a dash 3 headed 355 for an LC a couple of years ago, 530hp, it's sketchy as to drive with a manual trans.
I couldn't imagine 530hp in my car. My JZED head on my old block in the LC was sketchy, the front end was floaty and that would have been lucky to crack 340hp at the fly... they're pretty light cars.
Fumbling around in the shed...
GARY C
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Re: Another 383 Holden - pure street hyd roller

Post by GARY C »

KnightEngines wrote: Mon Sep 23, 2019 11:00 pm 6 degree valve angle.
Didn't pour the runners, min CSA is 2.5" - big suckers for a 383 cube streeter.
Throats were at 89% on a 2.08" valve with no more than a blend in.

I built it like an LS - heads were bigger than I ideally wanted so I did the "big heads & small cam" thing & it worked better than I believed it would.
Just curious if you have ever gathered data on different builds in regards to things like idle vacuum and cranking compression to see what combos bast fit power breaks and pump gas in that relation?
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Re: Another 383 Holden - pure street hyd roller

Post by KnightEngines »

Most stuff I don't care about idle vacuum - low idle vacuum is just the price you pay if you want a stomper street engine.

I never saw the value in checking cranking compression, to me it has very little to do with dynamic compression, which is what a running engine at WOT cares about!

I know the limits of static compression with various fuels & cam durations etc from experience - this one is built with a big safety margin as fuel where it lives is pretty variable.
With a known reliable source of fuel I could have pushed it out to past 12:1, but the risk was not worth the small power gain.
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Re: Another 383 Holden - pure street hyd roller

Post by bob460 »

What valve spring and spring pressure did you end up with?

Cheers, Bob
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Re: Another 383 Holden - pure street hyd roller

Post by KnightEngines »

Crane 96870 springs, set up at 165lb on the seat.
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Re: Another 383 Holden - pure street hyd roller

Post by bob460 »

KnightEngines wrote: Thu Sep 26, 2019 8:29 pm Crane 96870 springs, set up at 165lb on the seat.
Cheers Tony

One would think that a .903 lifter would be the ticket here with a little more cam and be at 620+hp......and be a reliable street car!!

Do they make a .903 lifter for holdens?
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