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Nothing like a good head...

General engine tech -- Drag Racing to Circle Track

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lc-gtr-1969
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Nothing like a good head...

Post by lc-gtr-1969 » Mon Feb 24, 2020 8:32 pm

Hi everyone,

I thought I would share my recent build...

This is a 'holden' 202ci inline 6 from Australia. These are fairly agricultural engines, not really suited to high-performance work but we tend to love them anyway and with some R&D some pretty good performance can be had.

This setup made 1.72hp per cube on pump fuel and with a relatively moderate solid flat tappet cam. It is using an aftermarket alloy head and triple 48dco/sp webers.
IMG_4738.PNG
The head flows very well, 286cfm at .700 lift at 28 inches. It was virtually as supplied, just had a valve job done after my last engine bent every valve (long story). 12.1:1 compression. The head can support more hp than this but I didn't want to compromise its streetability or durability etc... hard to keep a 2hp per cube engine together on a 50 year old designed block...

For a few reasons, I stuck with a simple old solid flat tappet- costs were blowing out and I do a lot of extended idling in traffic etc which did worry me a little with a solid roller.

We used off the shelf Try Y pipes just fabricated to suit the aftermarket head. Standard stroke was used (3.25"") and block was half grout filled, crank girdle was added as was a crank scraper. Total seal rings (1.2mm) were used on custom Ross forged pistons.

ATI SBC balancer was used with a custom hub to suit the holden crank. We changed the rod ratio a little by using Honda rods which were 5.63 rather than 5.25.

The cam is 252/258@50 on a 106lsa, installed with 2 degrees advance. It was happy with 29 degrees on the dyno- running a locked HEI distributor.

All in all, it shows the value of a good port. These 202 engines with serious development with 9 port style cast heads can make over 320hp but usually do this with pretty big solid roller cams and race fuel (265/268@50 cams and 13.5:1 comp, custom tuned length pipes etc)..

Thanks to CamKing and Tony Knight from this forum for advice along the way.

This is an excellent street engine and is a great example (in my opinion) of the value of a good head/port. The extra cost of the head was significantly worth it as there is no way I would have a streetable, pump fuel fed 9 port with off the shelf pipes making similar hp (no matter how much porting done to the 9 port)..
IMG_4636.JPG
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Fumbling around in the shed...

Momus
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Re: Nothing like a good head...

Post by Momus » Tue Feb 25, 2020 11:58 am

Nice work lc.

There must be just about enough demand to make a heavy duty nodular iron Holden 6 block an aftermarket goer- regardless of the CAMS sanctioned circuit classes probably not being allowed to use them.

I would love to see a 9000+ rpm 450 hp red that didn't tear itself up.

BlitzA64
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Re: Nothing like a good head...

Post by BlitzA64 » Tue Feb 25, 2020 12:47 pm

That's what he said..... (sorry, couldn't help myself)

pdq67
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Re: Nothing like a good head...

Post by pdq67 » Tue Feb 25, 2020 2:53 pm

lc-gtr-1969,

You Aussies have any wild 1st Gen. SBC heads that we don't have in the States?

Like, "true hemi", "SOHC", and "DOHC"??

Just asking so I will learn something IF they might be out there in the, "Land of Oz"!!

Thanks,

pdq67

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Re: Nothing like a good head...

Post by KnightEngines » Tue Feb 25, 2020 4:55 pm

You done good, that is a damn fine street engine!

There is a mob in enzed working on billet alloy blocks that'll go 250+ cubes.

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Re: Nothing like a good head...

Post by rebelyell » Tue Feb 25, 2020 8:40 pm

KnightEngines wrote:
Tue Feb 25, 2020 4:55 pm
You done good, that is a damn fine street engine!

There is a mob in enzed working on billet alloy blocks that'll go 250+ cubes.
Is it enzed that built a 600 inch SBC motor for sprintboats?

lc-gtr-1969
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Re: Nothing like a good head...

Post by lc-gtr-1969 » Tue Feb 25, 2020 9:22 pm

KnightEngines wrote:
Tue Feb 25, 2020 4:55 pm
You done good, that is a damn fine street engine!

There is a mob in enzed working on billet alloy blocks that'll go 250+ cubes.
Cheers Tony...

Those billet blocks look outstanding... They are long over-due... I'd love a 250ci red motor with JZED and 55mm webers on e85. I think with the right R&D someone like you could get close to 500hp out of one N/A. Costly exercise but so cool...
Fumbling around in the shed...

KnightEngines
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Re: Nothing like a good head...

Post by KnightEngines » Tue Feb 25, 2020 9:49 pm

rebelyell wrote:
Tue Feb 25, 2020 8:40 pm
KnightEngines wrote:
Tue Feb 25, 2020 4:55 pm
You done good, that is a damn fine street engine!

There is a mob in enzed working on billet alloy blocks that'll go 250+ cubes.
Is it enzed that built a 600 inch SBC motor for sprintboats?
Sorry, oz slang, enzed = NZ = New Zealand.

Biteme
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Re: Nothing like a good head...

Post by Biteme » Wed Feb 26, 2020 2:59 am

KnightEngines wrote:
Tue Feb 25, 2020 9:49 pm
rebelyell wrote:
Tue Feb 25, 2020 8:40 pm
KnightEngines wrote:
Tue Feb 25, 2020 4:55 pm
You done good, that is a damn fine street engine!

There is a mob in enzed working on billet alloy blocks that'll go 250+ cubes.
Is it enzed that built a 600 inch SBC motor for sprintboats?
Sorry, oz slang, enzed = NZ = New Zealand.
If you need a contact for those blocks Tony ring Phil, Tracksport Engines, Papakura. He’s a top man. Easy to deal with.

And yes, he did build a big displacement SBC for a sprint boat. Not sure it was 600cu though. AZUDU racing.

rebelyell
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Re: Nothing like a good head...

Post by rebelyell » Wed Feb 26, 2020 8:42 am

KnightEngines wrote:
Tue Feb 25, 2020 9:49 pm
rebelyell wrote:
Tue Feb 25, 2020 8:40 pm
KnightEngines wrote:
Tue Feb 25, 2020 4:55 pm
You done good, that is a damn fine street engine!

There is a mob in enzed working on billet alloy blocks that'll go 250+ cubes.
Is it enzed that built a 600 inch SBC motor for sprintboats?
Sorry, oz slang, enzed = NZ = New Zealand.
#-o but IIRC, the 600 inch sprintboat sbc motor was built in "enzed"

Belgian1979
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Re: Nothing like a good head...

Post by Belgian1979 » Wed Feb 26, 2020 9:14 am

I almost read something else.... #-o

Old School
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Re: Nothing like a good head...

Post by Old School » Wed Feb 26, 2020 10:10 am

What is the bore, stroke, valve sizes on the engine? Thanks Billy

lc-gtr-1969
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Re: Nothing like a good head...

Post by lc-gtr-1969 » Wed Feb 26, 2020 3:07 pm

Old School wrote:
Wed Feb 26, 2020 10:10 am
What is the bore, stroke, valve sizes on the engine? Thanks Billy
3.25 bore, 3.655 stroke, intake valve is 1.9".
Fumbling around in the shed...

lc-gtr-1969
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Re: Nothing like a good head...

Post by lc-gtr-1969 » Wed Feb 26, 2020 4:41 pm

Exhaust is 1.6"
Fumbling around in the shed...

allencr267
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Re: Nothing like a good head...

Post by allencr267 » Wed Feb 26, 2020 5:16 pm

Mistake.
Sorry.

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