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tips, technology, tools and techniques related to vehicle driveline components

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TRX
Dave Williams

(2 posts)

Registered:
12/10/2009 06:46PM

Main British Car:


Rover 4.0 intake air flow?
Posted by: TRX
Date: June 01, 2019 11:14PM

Does anyone have any flow bench figures for the Rover 3.9/4.0 fuel injection intake?

To my untutored eye, it looks like it would be both restrictive and have uneven cylinder-to-cylinder air flow.


Special
ED TESTA

(7 posts)

Registered:
04/24/2019 09:58PM

Main British Car:


Re: Rover 4.0 intake air flow?
Posted by: Special
Date: June 02, 2019 09:11PM

Your talking about the air horns in the top plenum restricting since they sit so high? We always cut them down. They are tuned to the cylinder position but if i remember correctly it was for low end torque.


TRX
Dave Williams

(2 posts)

Registered:
12/10/2009 06:46PM

Main British Car:


Re: Rover 4.0 intake air flow?
Posted by: TRX
Date: June 03, 2019 10:52AM

No, I was just looking at the "basket of snakes" runner shapes in the plenum. At least the stacks are straight...


Dan Jones
Dan Jones
St. Louis, Missouri
(268 posts)

Registered:
07/21/2008 03:32PM

Main British Car:
1980 Triumph TR8 3.5L Rover V8

Re: Rover 4.0 intake air flow?
Posted by: Dan Jones
Date: June 03, 2019 02:00PM

> Does anyone have any flow bench figures for the Rover 3.9/4.0 fuel injection intake?

Not yet but I have one here and I need to make a trip down to the dyno (with flow bench) sometime soon. Tom Moss, the guy who ports all the Ford GT40/GT40P Explorer/Cobra EFI intakes lives close by so I should think about getting the lower ported and maybe dyno test it on the 4.2L Rover V8 I have going together. It would be tested against an Extrude Honed Performer Rover dual plane with throttle body injection.

Woody Cooper's son (on here with the username thewedgeshop) recently purchased a modified Rover EFI set up from England for his turbo 3.5L. As I understand it, it's had the works done (shortened and larger diameter stacks, large throttle plate, etc.).

Dan Jones


minorv8
Jukka Harkola

(165 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Rover 4.0 intake air flow?
Posted by: minorv8
Date: June 10, 2019 01:16AM

"To my untutored eye, it looks like it would be both restrictive and have uneven cylinder-to-cylinder air flow."

To mine as well. I ported my EFi manifold years ago and some runners are pretty difficult to get nice looking, e.g. cylinder #1. I was actually thinking about welding some material outside to get the short side turns at manifold flange smoother. There are places where the turn is quite abrupt. I also shortened the trumpets and they are about 1 3/4" in diameter.

I donīt know how this works from cylinder to cylinder but the 4.6 engine made over 310 hp at flywheel.


Ruiskun imusarja.jpg


BeemerNut
Carl Winterbauer

(9 posts)

Registered:
09/07/2019 04:07PM

Main British Car:


Re: Rover 4.0 intake air flow?
Posted by: BeemerNut
Date: September 07, 2019 09:29PM

Mark,
that extrude hone flow bench vs a completely stock trumpet base first then with trumpet base with intake as well heads would be great posting the result numbers. Always excited when extrude hone is mentioned. Friend's "Shovel Head" was honed with great results keepinhg old iron alive.
Owning a big lump 95 D1 5 spd, 4.6 engine, Rp4 cam (too small of cam was talked into it), Tornado chip, Borla Cat back exhaust it woke up a little. Cold ram air another boost.
Installing a set of 4 hole Bosh injectors plus a 1 1/2" thick intake spacer between manifold and trumpet base was the best low rpm around town improvement yet. It will keep pulling past 5,200 but why beat a dead horse pulling a heavy D1?
Also milled out a 1/4" thick aluminum ring raising the plenum cover allowing straighter airflow feeding the end trumpets. No higher as plenum top is now touching the under hood padding.
Sorry not a track car or engine squeezing out the maximum Hp at high track rpm's but looking for a useful broad Tq range engine.
I need a bigger cam plus opened up intake including larger trumpets but not shortening them being it's a street vehicle plus must pass Kalifornia smog tests......~~=o&o>......


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