202ci intake manifold ideas

[KnightEngines]

What's your goal power wise without nitrous? That will determine your intake csa more than anything. A well developed 202ci engine at 7000rpm is going to be making north of 300hp by itself, making that amongst the most powerful Holden 6's ever built

Nah, I did a group Nc 9 port last year that made 308rwhp, around 360-370 at the flywheel, just running on elf 102, no vac pump or anything exotic.
Year before I did one that made 350 odd hp with a single 4 barrel on avgas.

Got a Jzed headed one going on the dyno soon that will go around 430hp.

Drag race 9 port on meth can do 400, tho I haven't personally built one like that.

[KnightEngines]

Steve - 12 port will max out around 210-220cfm, maybe 230 with 7mm stem valves, 50 deg seats & all the tricks.

If you wanna have a bash at it I can do you 1 cylinder to copy.

[Tuner]

46 IDA Weber Triple Barrel

[Tuner]

a new side project
200ci inline 6 with 12port head and intake manifold.
Looking for feedback if this intake/plenum idea will work,carbs undecided so can adapt 2 x 2 barrel carbs or 2 x 4 barrel holleys.
The end game is around 450 hp with progressive nitrous fogger,car will be geared and converters as required wanting peak around 7000rpm
Thanks in advance.20200924_082829.jpg20200924_082739.jpg20200924_082732.jpg20200924_082712.jpg20200924_082656.jpg

You need to do some math on that runner length. I don't think it will be wanting to peak at 7000 because it is so long.

30 years ago (can't believe I'm saying that) I helped a pal play with water cooled VWs which had the intake with the long runners and plenum, such as on the Rabbit and Jetta. The long runners did not run well, in fact were unusable, with cam timing suitable for high RPM.

Long cam timing kills the mid RPM range where the intake is tuned to improve torque, and the long runners stifles the high RPM where the cam should make best power. A modified manifold with the runners cut to about 1/3 length worked good.

A another trick he made a few of was with using a stubby carb intake for a Holley/Weber progressive 2bbl off a USPO mail delivery jeep which used a Chrysler K Car engine (looked about like a 2300 Pinto intake) and mounting the CIS throttle body on the carbe flange. Either of those intake setups would run well above 8000 with the proper 270-280 @ .050 cam.

With these intakes and figuring out how to modify the CIS cold-start/warm-up regulator to control the fuel distributor properly for the large manifold vacuum fluctuations from idle to cruise we dispelled the urban lore that the CIS couldn't be used with radical cams "because the big cam makes the air flap bounce".

[F-BIRD'88]

Might Pipemax help you with dialing in the runner length?
Reminds of a Chevy sb TPI induction.

[smeg]

There's a reason Holden went to RB engines :p

But really I'd go 2x4 in a spreadbore format, even if it is just a drag car you'll appreciate the tiny primaries being able to move the car at less than full throttle. Sounds like you won't need much airflow though.

Does your class ban efi?

no class just some fun,i have a couple friends that run holden 6 cylinder stuff with nitrous and I am a SBC guy so I feel left out
My car is 1000 pounds heavier as well but I want to give the boys a run for there money and do something different, 500hp will put me in 10.9s- 11.0s area which would be fun,I want to run the holley carbs because that's what I am familiar with, I am spending money on good pistons rods etc,playing around with cast iron head and will upgrade to Australian made aluminium head if i can see some potential in induction system. The biggest challenge will be a automatic trans that will handle it,not sure if a power glide will work and the 6 cylinder trimatic could possibly fail or be a issue at least.

Steve, we are working on a new alloy head for the 202 at the moment, will be very trick, canted valve etc a real game changer. Wait a little before you go buying something.

[steve cowan]

Might Pipemax help you with dialing in the runner length?
Reminds of a Chevy sb TPI induction.

Hey bird,
I have pipemax just have not gone down the rabbit hole yet,just throwing ideas around.

[steve cowan]

a new side project
200ci inline 6 with 12port head and intake manifold.
Looking for feedback if this intake/plenum idea will work,carbs undecided so can adapt 2 x 2 barrel carbs or 2 x 4 barrel holleys.
The end game is around 450 hp with progressive nitrous fogger,car will be geared and converters as required wanting peak around 7000rpm
Thanks in advance.20200924_082829.jpg20200924_082739.jpg20200924_082732.jpg20200924_082712.jpg20200924_082656.jpg

You need to do some math on that runner length. I don't think it will be wanting to peak at 7000 because it is so long.

30 years ago (can't believe I'm saying that) I helped a pal play with water cooled VWs which had the intake with the long runners and plenum, such as on the Rabbit and Jetta. The long runners did not run well, in fact were unusable, with cam timing suitable for high RPM.

Long cam timing kills the mid RPM range where the intake is tuned to improve torque, and the long runners stifles the high RPM where the cam should make best power. A modified manifold with the runners cut to about 1/3 length worked good.

A another trick he made a few of was with using a stubby carb intake for a Holley/Weber progressive 2bbl off a USPO mail delivery jeep which used a Chrysler K Car engine (looked about like a 2300 Pinto intake) and mounting the CIS throttle body on the carbe flange. Either of those intake setups would run well above 8000 with the proper 270-280 @ .050 cam.

With these intakes and figuring out how to modify the CIS cold-start/warm-up regulator to control the fuel distributor properly for the large manifold vacuum fluctuations from idle to cruise we dispelled the urban lore that the CIS couldn't be used with radical cams "because the big cam makes the air flap bounce".

Thanks Tuner,
Appreciate your input, you are correct about runner length, research i have done lately is total induction length of approx 11".
My initial thoughts were with intake i have shown was to try and keep carbs as far away from exhaust as possible, this engine will be drag race application only so the heat deal might not be as big of a problem.

[steve cowan]

Steve - 12 port will max out around 210-220cfm, maybe 230 with 7mm stem valves, 50 deg seats & all the tricks.

If you wanna have a bash at it I can do you 1 cylinder to copy.

I have a couple of heads and I am going to cut one up this weekend and have a look,
I have my valve grinding equipment now so I want to play with that as well, I would like to have a go at messing a couple of ports up myself before I annoy you for assistance . The open chamber on the blue head could lead me astray compared to small chambered red head.
Those engines you mentioned above are pretty impressive really, the Holden 6 cylinder engine was meant for tractors more than making good power in my opinion

[steve cowan]

There's a reason Holden went to RB engines :p

But really I'd go 2x4 in a spreadbore format, even if it is just a drag car you'll appreciate the tiny primaries being able to move the car at less than full throttle. Sounds like you won't need much airflow though.

Does your class ban efi?

no class just some fun,i have a couple friends that run holden 6 cylinder stuff with nitrous and I am a SBC guy so I feel left out
My car is 1000 pounds heavier as well but I want to give the boys a run for there money and do something different, 500hp will put me in 10.9s- 11.0s area which would be fun,I want to run the holley carbs because that's what I am familiar with, I am spending money on good pistons rods etc,playing around with cast iron head and will upgrade to Australian made aluminium head if i can see some potential in induction system. The biggest challenge will be a automatic trans that will handle it,not sure if a power glide will work and the 6 cylinder trimatic could possibly fail or be a issue at least.

Steve, we are working on a new alloy head for the 202 at the moment, will be very trick, canted valve etc a real game changer. Wait a little before you go buying something.

Subscribed and waiting in anticipation, I was considering a Irvine head later down the ways if this becomes a reasonable journey. Looking forward to your new cylinder head deal best of luck and I admire your dedication to the Australian 6 banger

[KnightEngines]

There's a reason Holden went to RB engines :p

But really I'd go 2x4 in a spreadbore format, even if it is just a drag car you'll appreciate the tiny primaries being able to move the car at less than full throttle. Sounds like you won't need much airflow though.

Does your class ban efi?

no class just some fun,i have a couple friends that run holden 6 cylinder stuff with nitrous and I am a SBC guy so I feel left out
My car is 1000 pounds heavier as well but I want to give the boys a run for there money and do something different, 500hp will put me in 10.9s- 11.0s area which would be fun,I want to run the holley carbs because that's what I am familiar with, I am spending money on good pistons rods etc,playing around with cast iron head and will upgrade to Australian made aluminium head if i can see some potential in induction system. The biggest challenge will be a automatic trans that will handle it,not sure if a power glide will work and the 6 cylinder trimatic could possibly fail or be a issue at least.

Steve, we are working on a new alloy head for the 202 at the moment, will be very trick, canted valve etc a real game changer. Wait a little before you go buying something.

Oooh! Let me know when it's done!
Sneak pics would be nice......

Would need one of them fancy billet blocks methinks, over 400hp NA & the block is nearing a consumable item.

[KnightEngines]

The black EFI head is the pick off the bunch for 12 port heads, much better short turn shape, if you try to put that turn shape in a blue head you'll be in the water jacket.

Next best is 173 blue, but get a black head if you can!

[Circlotron]

Steve, we are working on a new alloy head for the 202 at the moment, will be very trick, canted valve etc a real game changer. Wait a little before you go buying something.

You got a website that we can bookmark so we can keep an eye out for it?

[smeg]

As soon as I can get permission from the owner I will get some pics posted, I have finished the port / chamber digitizing so I am just about ready to cnc them when the castings arrive. They will be cheaper than what's currently available and you will be able to run the original 12 port headers and intakes with some modifications. That is a win not having to buy special intake manifolds etc.

[smeg]

Steve, we are working on a new alloy head for the 202 at the moment, will be very trick, canted valve etc a real game changer. Wait a little before you go buying something.

You got a website that we can bookmark so we can keep an eye out for it?

I will get the owner to put some pics on his website and let you know.