[DeTomaso] intake maifold for throttle body injection

Thu Oct 14 22:11:13 EDT 2021

I just found it.  I wasn’t imagining it.  Engine Masters on Motor Trend/Hot Rod, season 1, Episode 2.

They compared a Holley 750 to Holley Terminator throttle body EFI.  It had issues on a dual plane, so they switched to a single plane, and the popping went away.

Btw, interesting on the tach sweep.  I see that on my car.  I thought it was the tach.  I didn’t realize it was the MSD 6AL.

Sent from my iPhone

> On Oct 14, 2021, at 7:49 PM, Daniel C Jones <daniel.c.jones2 at gmail.com> wrote:
> 
> 
>> 
>> I just got an email from builder stating the Ford AL dual plane
>   intake is not suited for throttle body
>   Gerry Romack has the Holley throttle body EFI on an Edelbrock Performer
>   dual plane in one of his Panteras.A  It wouldn't have been my first
>   choice for that engine but he wanted to run a bulky Chrysler 340 air
>   cleaner under a stock engine screen and needed a really low intake
>   manifold.
>   Be aware that Holley has a couple of different throttle body injection
>   options.A  One is shaped like a 4150/4160 Holley carb which allows the
>   use of a drop base air cleaner designed for those carburetors.A  If you
>   recall the 408C we did for Hugh Casey:
>   A [1]http://www.the351cforum.com/viewtopic.php?f=4&t=569
>   That engine had a Torker style intake made for Ford Motorsport A3
>   heads.A  After Hugh passed away, the Pantera was sold and I was
>   contacted by someone working on the car for its new owner.A  That
>   engine had a 740 CFM custom Holley carb yet made over 600 HP and he
>   mentioned that it was the most responsive carb he'd ever driven.A  The
>   engine was converted to Holley throttle body EFI and he said it was
>   even more responsive.A  He also mentioned that the Sniper throttle body
>   wouldn't work with the drop base air cleaner but the 4150/4160 style
>   throttle body did and all fit under the stock engine screen.A  Also, a
>   friend runs the Sniper set up on a Performer dual plane in a 302
>   powered 1968 Mustang without issue.
>> Is this true?
>   There have been some reports of builders having issues on dual plane
>   intakes that were solved by going to an open spacer, milled divider or
>   single plane intake.A  However, others have run them without issue.A  I
>   think the Engine Masters TV show has had one episode where they ran
>   into an issue running a dual plane and another issue where Steve Brule
>   mentions better results on a particular throttle body EFI engine.A  In
>   that case, they theorized the dual plane had longer runners with less
>   cylinder-to-cylinder variation that better suited to that particular
>   engine.A  Be aware the Ford aluminum dual plane has 4 good runners and
>   4 bad runners that flow considerably less (~25 CFM worse than the other
>   runners).A  The Blue Thunder is the same way but the pattern of good
>   runners is different.
>> Any experience with single plane that would fit under stock engine
>   screen
>   Below are some A/B measurements I've made on various 351C intake
>   manifolds.A  The A/B measurements represent the drop from a straight
>   edge laid across the carb pad to the closest point where the end rail
>   bends inward (each end).A  The Offenhauser 360 is the lowest of the
>   single planes and is lower than a stock Ford dual plane with EGR
>   spacer.A  That said, the Offenhauser 360 was the worst performing
>   single plane intake I've tested.A  It's just a big plenum with no
>   runner length to speak of.A  The Offenhauser Port-o-Sonic is probably
>   the lowest of the other single planes and should fit under a stock
>   engine screen.A  Also be aware that there are multiple versions of both
>   the Weiand Xcelerator and Holley Street Dominator intakes with
>   different heights.A  One casting may just clear a stock screen where
>   another might not.A  Of course, you could mill the carb pad as needed.
>   Should you need one, I think I have an Offenhauser Port-o-Sonic 4V here
>   that I would sell or lend out for a test.
>   Intake Manifold A  A  A  A  A  A  A  A  A A Height B Height
>   A  A  A  A  A  A  A  A  A  A  A  A  A  A  A  A  A (inches) (inches)
>   Edelbrock Performer LB 2V A  A  A  A  3 1/2 A  4 3/8
>   Edelbrock Performer RPM Air Gap 2V A  4 1/2 A  A  5 5/8
>   Holley Street Dominator 2V A  A  A  A 4 3/8 A  5 3/8
>   Offenhauser Dual Port 2V A  A  A  A  A 3 1/2 A  4 1/2 A
>   A Qjet/ThermoQuad Spread Bore
>   Offenhauser Port-O-Sonic 2V A  A  A  3 7/8 A  4 7/8
>   Parker Funnel Web 2V A  A  A  A  A  A  A 6 7/8 A  6 7/8
>   Parker Funnel Web 2V A  A  A  A  A  A  A 6 1/2 A  6 1/2
>   Weiand Xcelerator 2V A  A  A  A  A  A  A 4 3/16 A 5 1/8
>   Weiand Xcelerator 2V A  A  A  A  A  A  A 4 1/8 A  5 1/8
>   Weiand Xcelerator 2V A  A  A  A  A  A  A 4 1/8 A  5 1/16
>   Scott Cook (CHI 3V, 4V, A3) A  A  A  3 3/4 A  5
>   Ford 4V aluminum dual plane A  A  A  3 1/4 A  4 3/8 A  A Holley pattern
>   Boss intake
>   Bud Moore Maxi-Plenum A  A  A  A  A  A  6 5/8 A  6 5/8
>   Blue Thunder 4V A  A  A  A  A  A  A  A  A  4 3/8 A  5 3/8 A  A Canted
>   pad version
>   Coffield IR A  A  A  A  A  A  A  A  A  A  A  9 1/2 A  9 1/2
>   Offenhauser Port-O-Sonic 4V A  A  A  3 7/8 A  4 7/8
>   Edelbrock Torker 4V A  A  A  A  A  A  A  4 1/2 A  5 1/2
>   Holley Strip Dominator 4V A  A  A  A  4 1/4 A  5 1/4
>   Offenhauser 360 4V A  A  A  A  A  A  A  A 3 1/2 A  4 1/2
>   Parker Funnelweb 4V A  A  A  A  A  A  A  6 3/4 A  6 3/4
>   Weiand Tunnel Ram A  A  A  A  A  A  A  A  9 A  A  A  9 3/8
>   Edelbrock A331 (Edelbrock) A  A  A  A 4 5/16 A 5 5/16
>   Edelbrock A331 (Roush) A  A  A  A  A  A 6 3/4 A  6 3/4
>   Ford Motorsport A351 (Roush) A  A  A 6 3/4 A  6 3/4
>   Ford Motorsport B351 (Roush) A  A  A 6 3/8 A  6 3/8
>   Ford Motorsport C351 (Edelbrock) A 7 A  A  A  7
>   Dan Jones
> 
>   On Thu, Oct 14, 2021 at 10:10 AM JFByrd via DeTomaso
>   <[2]detomaso at server.detomasolist.com> wrote:
> 
>     I just got an email from builder stating the Ford AL dual plane
>     intake is not suited for throttle body
>     Is this true?
>     If so, wouldn't that rule out Blue Thunder (if I could find one)?
>     Any experience with single plane that would fit under stock engine
>     screen
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> References
> 
>   1. http://www.the351cforum.com/viewtopic.php?f=4&t=569
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>   3. mailto:DeTomaso at server.detomasolist.com
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