OE Iron head 355 holden street/strip - 636hp

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KnightEngines
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OE Iron head 355 holden street/strip - 636hp

Post by KnightEngines »

Dyno'd this one yesterday, it's a street/strip motor that will be street driven but not often.

It's a pretty simple combo:

Factory 304 block, 4 bolt mains conversion, short grout fill, oiling mods & good machining (4.03" bore).
COME cast 3.48" stroke crank, Scat 5.7" rods, CP pistons with regular ring pack.
Holden 'VN' factory iron head castings, manley 2.055/1.6" valves, hand ported.
Crane roller cam (268/274 on 109 centres), Crane lifters & gold stud rockers.
Basic wet sump, modified oil pump.
TP 'pro paw' intake, 4 hole tapered phenolic spacer, QF950 E85 carb, MSD ignition
12.7:1 compression.
1 7/8" primary tri-y headers (that's all that will fit in the car).
Moroso 3 van vac pump - but only running 3.5" vac - got an issue there, need to figure that one out, more HP hiding with more vac.

Holden shit just flat rocks for factory castings!

Image20180517_104148 by tony knight, on Flickr

Image20180517_192004 by tony knight, on Flickr
cjperformance
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Re: OE Iron head 355 holden street/strip - 636hp

Post by cjperformance »

Nice work Tony.
Hey the pipes mate, what part number is that. They look like the early Commodore 5.0efi comversion set but the secondary pipes are laid in with front 2 cyls on the outside, and you say 1-7/8" pri, is that a new part number?
(Thats not in my very old book!) Cheers,
Craig.
KnightEngines
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Re: OE Iron head 355 holden street/strip - 636hp

Post by KnightEngines »

Hurricane headers Craig, not on their website, 1 7/8" primary, 2.25" secondary & 3" collectors - fit in a commo engine bay.
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Re: OE Iron head 355 holden street/strip - 636hp

Post by cjperformance »

Ah ! #-o i saw blue paint and immediately thought Pacemaker! Nice.
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Re: OE Iron head 355 holden street/strip - 636hp

Post by xanadu »

Thats awesome. Just curious what size carb.
Oh and what model Commodore is it goin' in.
KnightEngines
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Re: OE Iron head 355 holden street/strip - 636hp

Post by KnightEngines »

It's a quickfuel 950 E85 carb.

Going in a VR commo.
DrillDawg
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Re: OE Iron head 355 holden street/strip - 636hp

Post by DrillDawg »

Are those Mickey Thompson's power "Y" headers from the early 70's?
BORN RIGHT THE FIRST TIME
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Re: OE Iron head 355 holden street/strip - 636hp

Post by CGT »

Thats a bad bitch! Looks like you still need to find peak. :D . Can you give some more info on the induction...lift?
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Re: OE Iron head 355 holden street/strip - 636hp

Post by Circlotron »

Makes me wish I still had my VP BT1 with something like that in it.
cjperformance
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Re: OE Iron head 355 holden street/strip - 636hp

Post by cjperformance »

Circlotron wrote: Fri May 18, 2018 1:06 am Makes me wish I still had my VP BT1 with something like that in it.
Im more ford inclined but i could certainly put up with it in an LC or HK/T 2 door
Craig.
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Re: OE Iron head 355 holden street/strip - 636hp

Post by cjperformance »

I dont mind EJ's either !
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Re: OE Iron head 355 holden street/strip - 636hp

Post by tuffxf »

Well done Tony, thats impressive!
Cheers
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Re: OE Iron head 355 holden street/strip - 636hp

Post by steve cowan »

Good stuff Tony,
Looks like hp has not peaked
Looking like big spread between peak tq and hp
Holden stuff will never die in Australia it's just got better every year with technology
I know it is at a cost but plenty of guys have the money and drive to get er done
steve c
"Pretty don't make power"
KnightEngines
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Re: OE Iron head 355 holden street/strip - 636hp

Post by KnightEngines »

Cheers guys, happy with this one!

CGT - .720/.680" lift with 1.65 rockers, crane endurance racing lobes so not lifter killers.

What I'd love to do is a motor with heads like this or a bit better (I can get more from them, but rpm had to stay reasonable) on a slightly smaller cube motor set on kill with dry sump, good crank & rods, piano wire rings, 15:1 comp, lots of vac, a race only grind cam and lightweight valve train that can turn 9000+ and run on roo16
Pretty sure I could squeeze 700 from something like that.
F*ck that'd be a fun motor.
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Re: OE Iron head 355 holden street/strip - 636hp

Post by KnightEngines »

Ps - we found peak, drops off slow after 7500, we spun it to 7800 a couple of times to find the drop off.
A 4 hole tapered spacer extended top end from 7300 to 7500rpm & was worth 14hp once tuned to suit, picked up from the hit on up.
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