[4Lowie]

Hi all, When we chose port size and manifolds for a carb engine we can't go too big on a street motor. This is because we lose air speed through the carb and ports which affects atimization..... correct? So what about direct port EFI where we don't rely on air speed to pick up fuel through the carb? Can we then go for bigger ports and a manifold that flows more??
What are your thoughts??
Thanks Dave

[mustanghelper]

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I'm not sure what you are asking, but

Vacuum, based on compression, intake, and cam duration should be a bigger factor.
I don't think that the air velocity through the carb is what you should be looking at. As far as the air flow is concerned, Heads that have the biggest port size wile maintaining the greatest air flow velocity is what you should be shooting for.
The intake should be well designed, as too feed each cylinder with the correct amount of fuel, rather than starving selected cylinders, due too poor intake deign. Direct fuel injection with wide band o2 sensors, and aftermarket putter will have the best maximum effect of monitoring the air, and fuel ratios, therefore tuning should be more effective when done through the putter. Use wide band monitoring of the air fuel charge, along with better designed fuel injectors, heads that maintain maximum velocity, and higher compression to increase vacume. A Cam should be selected to maintain, or too increase vacume through duration, and lift.


I hope this makes sense to you, because I don't even understand what I said.

[4Lowie]

Thanks, the reason for my question is that I was hoping to get the best of both worlds for my street 302. I was hoping to get a hi flow manifold / heads for top end power and the effincey of EFI to still provide plenty of power down low. As I understand it hi flow produces top end power at the sacrifice of low end, lower flow volume (greater veloctry) produces low end torque. Correct?

[mustanghelper]

oh, so your looking for a good designed package, that includes heads intake injectors and cam.

On a 302 there are a lot of good stage kits out there. stage2 should keep you were you want to be without worry of the negative effects of going to big.

Afr heads 185 is not too big on a 302, so don't go with the 165 cc.
Small Block Ford Dyno Results: Aluminum cylinder head manufacturing and flow dynamics

T flow stage 2 kit with track heat will also be a good total package.

You wont be happy with the trick flow street head, or a stage 1 kit for that matter.

stay away from Holley kits.

Canted heads are awesome for low end, and top, It is a very well designed head. Canfield Cylinder Heads Canfield Cylinder Heads

GT40 well no don't bother. intake performer rpm 2 will do nicely, or the gt 40 intake will work nicely with most head designs out there.
Fox Mustang Bolt-On Buildup - Anderson Ford Motor sport Stage 2 Kit - 5.0 Mustang & Super Fords Magazine

Of course Edlbrockmakes a nice kit too> Edelbrock.com - Power Package