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inlet manifold questions (Duratec)
DM - 30/11/09 at 01:41 PM

greetings all

Im looking to mate some ITB's to a Duratec and have a couple of questions regarding the inlet manifold

Does anyone* know what angle the tubes should be tilted at to to get the best flow into the engine?

Also, what effect does the length of the tubes have, anything I need to a aware of there?

many thanks,
Dan


*Flak Monkey


flak monkey - 30/11/09 at 02:15 PM

Firstly, 3GE can supply you with the manifold plate to suit in steel or ali.

I made mine straight as the ports on the head are straight (horizontal) for the first inch or so, so that gave the best match.

As for length, longer runners will give you more low down torque, shorter runners higher peak power. The leangth of the port inside the head is about 4.5" for reference.

David


hughpinder - 30/11/09 at 03:08 PM

Wot flak said.
If you go on the jenvey site it will tell you how to calculate the inlet manifold length to get the optimum for a given max power RPM.

Regards
Hugh


SJC - 30/11/09 at 07:59 PM

Hi

According to Raceline, they say 17 Deg is the optimum as that matches the inlet port.

Stu


DM - 30/11/09 at 09:52 PM

right - have finally closed the Jenvey tab of my browser after too much drooling. Never bothered looking at their site as never intended to pay their prices (tho they're worth it Im sure) but its a good read...

David - thanks, the manifold plate on 3GE's site appears to be the same as they one coming with my TB's (Scootz ones)

interesting that Raceline say 17 degress if the port starts horiztontal - I already have a big hole in my bonnet cut for a previous engine install - I think a 17 degree tilt sounds about right to put my TB's in the middle of that hole so reckon thats the one for me

Thanks all