383 holden early head record reset

[KnightEngines]

This has been a long project!
She's a drag race engine & near max effort.

The existing record for an early head holden was set at 658hp by a Pete Murray built torque power headed & mechanical injected engine on methanol (killer engine, held back by throttle blade size).

We stepped that up by 10% - 65hp to 723hp.

Customer wanted a big HP holden, but didn't want to go with "VN" style later model layout heads, he wanted the original 70's port layout.

Motor is an oe "VT" block, billet 4 bolt caps, grouted, modified oiling system etc.
Scat 3.75" small journal steel crank
Callies 5.85" SJ rods
Manley pistons with 1/1.2/2.5 mm ring pack & lateral gas ports.
Custom grind crane solid roller - 278/284 on 110 centres, .454/.438" lobes.
BAM DLC roller lifters.
Crow .110" wall 5/16 pushrods.
Yella terra platinum shaft mount 1.65 ratio rockers
Isky tool room springs, Manley tool steel retainers etc.
Ferrea comp plus 2.06/1.6" valves.

Heads are 25 year old yella yerra dash 3 castings, I could not say how many hours I have in them!
50 deg seats & max effort plus a bit porting - these things are on the ragged edge.

Comp is 13.2:1

Intake is custom made for this engine, sheet metal ram by Bain racing.
Headers are also custom, 1 7/8" primary, 3.5" collectors with choke merge, made by ET race cars.

Carbs are holley 750 ultra's.

Ignition is MSD distributor, MSD crank trigger & MSD power grid.

Moroso 3 vane vac pump, CSR electric water pump.

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And the complete dyno sheet for anyone that wants to argue or insist on shenanigans.

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[HQM383]

Freakin’ awesome TK!

Refresh my memory, are the Yella Terra Dash 3’s the ones that had the raised ports and came with intake manifold China rail spacers?

[KnightEngines]

Yeah, that's the ones, raised runner but still tiny!
Flow in the 220's out the box.

[FC-Pilot]

Very impressive. So what are the header spacers for? Is it to be able to have egt’s while running customers headers, help to clear the dyno with chassis headers, or tune with different primary lengths without having to hack up the customers headers?

Paul

[KnightEngines]

Very impressive. So what are the header spacers for? Is it to be able to have egt’s while running customers headers, help to clear the dyno with chassis headers, or tune with different primary lengths without having to hack up the customers headers?

Paul

To clear the dyno & to allow the use of 8x egt's without drilling the headers.
Pretty much no commodore headers clear the plate on the dyno, they all tuck in too close.

[HQM383]

Yeah, that's the ones, raised runner but still tiny!
Flow in the 220's out the box.

Early 90’s or as you said around 25 y/o technology that were a revelation in their day for Holden v8 owners. I doubt Dave Bennett would ever have imagined they would be used for that kind of power!

Question: something I have never given much thought, what is the valve angle on Holden heads?

[KnightEngines]

Some say 5 degree, but I reckon it's 6 deg.

[steve cowan]

Yeah, that's the ones, raised runner but still tiny!
Flow in the 220's out the box.

Early 90’s or as you said around 25 y/o technology that were a revelation in their day for Holden v8 owners. I doubt Dave Bennett would ever have imagined they would be used for that kind of power!

Question: something I have never given much thought, what is the valve angle on Holden heads?

This is where the 308 head is far superior compared to 23 deg chev.
For those cubes to peak where they do I would think average CSA would need to be approx 2.50",I am not sure if those heads have enough meat (I have not done those heads).
With the shallow valve angle the port can probably handle higher air speeds,if you look back at the Holden engines Tony has done they carry power well past peak.
This engine still makes 530 ft/lbs at 7000 rpm .
General consensus says duration and LSA help carry past peak but I suspect the port is filling extremely well ABDC when piston is moving up the bore.
As always Tony has done an amazing job and I appreciate that Tony shares dyno data.
It is pulling good vacuum as well at 17" - 18".
I had the oil pan off mine twice this weekend just gone to seal it up for vacuum.

[KnightEngines]

She's sealed up real good, screwed the vac relief in a bit much & it went over 20" of vac briefly!
It's got a sbc rear seal conversion with a felpro high vac seal.

Heads are under 2.4" average csa, but I spent a lot (like a lot) of time on stability at high lift.
I actually refined the porting 4 times, last refinement was the switch to 50 deg seats, which really helped keep the ports stable out to .900" lift.

Cylinder fill ABDC is very important for high rpm power - this motor holds calculated VE% at 114% from 5800rpm through to 7300rpm & slowly tapers off to 108% at 7900rpm.
The only way to get VE% like that at high rpm on a head limited engine is fill ABDC.

[rebelrouser]

Great work. Being dumb Holden was owned by GM, but I read something about the holden engine is an AMC design? It looks kind of like an AMC engine.

[KnightEngines]

Nope, holden engine is a holden design!!

In my slightly biased opinion it's the best old school iron small block ever made.

[Chris_Hamilton]

Great work Tony. You don't get enough love on this forum. I wish you were closer so I could get you to do my Datsun head.

[Fatman]

What was your minimum port area? It carried power well up high.

[KnightEngines]

2.35" mcsa, 2.4 average.
Not big enough! - but the ports handle velocity well.

[HQM383]

2.35" mcsa, 2.4 average.
Not big enough! - but the ports handle velocity well.

Does the short side radius with a 6* valve angle play a role in maintaining port velocity and engine torque?